. 6
( 21)


duced achromatic lenses for telescopes and micro- delay, but in 1947 he was given the gold medal and
scopes. the diploma.
Doppler, Christian Johann (1803“53) Austrian
Dolland was for many years a silk-weaver; he was
the son of a French Huguenot refugee. In 1752, physicist: discovered the Doppler effect.
Douglass, Andrew Ellicott

Doppler was educated at the Vienna Polytechnic continuous dendrochronological time scale for
and, despite his ability, for some time could only timber building materials back to the first century
gain rather junior posts in tutoring or schoolteach- (later workers, using the Californian bristlecone
ing. At 32 he decided to emigrate to America, but on pine, extended this to about 5000 bc). Although the
the point of departure was offered a senior teach- technique of radiocarbon dating has to a large
ing post in a school in Prague. After 6 years he extent superseded it, dendrochronology has proved
became professor of mathematics at the State vital in calibrating the radiocarbon time scale.
Draper, John William (1811“82) British“US chemi-
Technical Academy there, and in 1850 professor of
experimental physics at Vienna. cal physicist: a pioneer of scientific photography.
His claim to fame rests on a single important dis- Draper™s life and his scientific interests were both
covery, the Doppler effect (1842). This proposed oddly disperse. His father was an itinerant
that the frequency of waves from a source moving Methodist preacher whose possession of a telescope
towards an observer will be increased above that attracted the boy to science. He began premedical
from a stationary source; and waves from a source studies in London in 1829 but emigrated to Virginia
moving away from an observer will be decreased in in 1832. Helped by his sister Dorothy™s earnings as a
frequency. In 1845 a test was made at Utrecht in teacher, he qualified in medicine by 1836 and then
which an open railway carriage carrying a group of taught chemistry in New York. When Daguerre™s
trumpeters was taken at speed past a group of musi- process for fixing photographs was published in
cians with perfect pitch. It was one of the extraor- 1839, Draper took it up and in 1840 he made what
dinary occasions that made the 19th-c approach to is probably the oldest surviving photographic por-
physics entertaining and, while unsubtle, it trait; it shows his sister Dorothy (exposure, 65 s). In
demonstrated the correctness of Doppler™s idea. the same year his photograph of the Moon began
Doppler recognized that the effect applies not astronomical photography and in 1850 he made
only to sound but also to light, and Fizeau (1848) the first microphotographs, to illustrate his book
pointed out that the spectral lines of stars should on physiology. In 1841 he proposed the principle
be shifted towards the red end of the spectrum that only absorbed radiation can produce chemical
according to the speed at which they are receding change (Draper™s Law; this principle was also
from us (the Doppler shift). Huggins observed this known to T C J D Grotthus (1785“1822) in 1817). He
for the star Sirius (1868) and Hubble later used the made early photographs in the infrared and ultra-
redshift to infer the speed of recession of other violet regions; and he showed that all solids become
galaxies from us: the ˜expanding universe™ of incandescent at the same temperature and, when
cosmology. heated sufficiently, give a continuous spectrum. His
The Doppler effect has also been used to measure later work was on the history of ideas.
Dubois, Marie Eugène Francois Thomas
the speed of the Sun™s rotation and Saturn™s rings,
and the rotation of double stars. It forms the basis [dübwah] (1858“1940) Dutch anatomist and
of police radar speed traps for vehicles; and palaeoanthropologist: discovered Java Man.
˜Doppler satellites™, emitting a fixed radio fre- After graduating in medicine from the University
quency and whose position is known, are used by of Amsterdam in 1884, Dubois was appointed lec-
ships and aircraft to locate their position and by turer in anatomy, but resigned in 1887 after some
mapmakers and surveyors to give precise locations disagreements with his professor. His great interest
using the global positioning system (GPS). Doppler in the ˜missing link™ between apes and man
reflection is also used in echocardiography. The fre- prompted him to join the Dutch East Indian Army
quency of a beam of transmitted ultrasound is com- as a surgeon, this being a convenient way of getting
pared with the frequency of the beam reflected to Java, where he believed that the remains of such
from the moving blood cells in the blood vessel a hominid might be found (on the grounds that it is
under examination. This allows the velocity of the the only place in which the orang-utan and gibbon
blood flow (around 1 m s “1) to be measured and is are found). In 1891, having obtained support from
of great value in locating valve and other heart the army in the form of a gang of convict labour, he
defects, especially in children. eventually succeeded in finding the skullcap, femur
Douglass, Andrew Ellicott (1867“1962) US and two teeth of Java Man (Homo erectus), a hominid
astronomer and dendrochronologist: devised a who lived approximately 0.5“1.5 million years ago.
tree-ring dating technique (dendrochronology). Dubois™s belief that Java Man represented the miss-
Douglass worked at the Lowell Observatory in ing link was at first widely ridiculed but was ulti-
Arizona. His interest in the Sun led to an interest in mately accepted after the announcement in 1926 of
climate. While trying to construct a historical the discovery of Peking Man (also Homo erectus).
record of sunspot activity, Douglass recalled that Irritated by the lack of support for his theory,
climatic conditions affected the width of the Dubois refused to allow study of his specimens until
annual growth rings of trees, and that these dis- 1923, by which time he had convinced himself that
tinctive patterns could often be recognized and they were merely the bones of a giant gibbon.
du Bois-Reymond, Emil see Bois-Reymond
seen to overlap in timber buildings. (Fortunately in
Dufay, Charles [düfay] (1698“1739) French chemist:
the dry climate of Arizona ancient wood is well pre-
served.) He developed this idea into an important discovered positive and negative charges of static
dating technique and succeeded in constructing a electricity.
Duve, Christian de

Dufay came from an influential family, which other organic compounds. In some cases he showed
secured an army career for him; he left as a captain that the reaction had replaced hydrogen by chlo-
to become a chemist at the Acad©mie des Sciences rine on an atom-for-atom basis and yet gave a prod-
when he was 25. He had no training in science, but uct of essentially the same type (eg acetic acid,
he began to study electricity in 1733. He showed CH3CO2H, gives a series of three chlorine-substi-
that there are two kinds of electricity (and only two) tuted acids CH2ClCO2H, CHCl2CO2H, CCl3CO2H,
generated by friction; he called them vitreous and which are not greatly unlike their parent in their
resinous because they were obtained by rubbing chemistry). This was in direct conflict with
glass (or rock crystal, hair or wool) or resin (or Berzelius™s dualism theory, which did not allow for
amber, silk or paper) respectively; they are the pos- atoms of opposite electrical type replacing one
itive and negative charges of today. Dufay showed another in this manner. Dumas pressed his theory
that like types repelled and unlike kinds attracted of substitution and his theory that organic com-
one another. The ˜two-fluid™ theory of electricity pounds exist as ˜types™ (eg the alcohols) and argued
was linked with these results in opposition to that a type may contain a series of compounds
Franklin™s later one-fluid theory. Dufay™s experi- whose formulae differ by a constant unit (eg CH2).
ments included suspending a boy by silk cords, Somewhat similar views were developed by others
electrifying him by friction and drawing sparks (notably Laurent, Gerhardt and Wurtz in France,
from him. Gray in London had done similar exper- Liebig and Hofmann in Germany and Williamson
iments, and had also distinguished conductors in England). During the period of debate many new
from insulators (eg silk from metal wire). and useful organic compounds were made and
Dulong, Pierre Louis [dülµ] (1785“1838) French theory was advanced, apparently with rejection of
chemist: co-discoverer of law of constant atomic Berzelius™s views. However, after 1930, it was seen
heat. that the Berzelius approach to organic reactions (in
Originally a physician, Dulong moved to chem- a much modified form) had an important part in
istry as assistant to Berthollet. In 1811 he discov- understanding why organic reactions occur, while
ered NCl3, which cost him an eye and two fingers. his opponents had also been right in their criti-
He was an early supporter of the hydrogen theory of cisms. Dumas, ambitious and energetic, followed a
acids. From 1815 he worked with A T Petit (1791“ pattern more familiar in France than elsewhere by
1820) on thermometry; and in 1819 they published moving from science to politics, holding various
Dulong and Petit™s Law. This stated that the specific ministerial posts after 1848.
Dutrochet, Henri [dütrohshay] (1776“1847) French
heat capacity of a solid element, when multiplied
by its atomic weight, gives a constant which they plant physiologist: discovered some basic features
called the atomic heat. The law is only approxi- of plant physiology.
mately observed and is best followed at or above Born into a wealthy family, Dutrochet™s early life
room temperature (eg C, B and Si only have specific was blighted by a club foot, ultimately fully cor-
heat capacities in accord with it at high tempera- rected by a local healer (also the hangman) after
ture). It had some use, however, for easily giving medical men had failed. After the Revolution he
rough atomic weights for new metals, at a time became an army medical officer but had to retire
when this was valuable. In modern parlance we can after catching typhoid in the Peninsular War.
express the law as: After his resignation from the army in 1809 he
relative atomic mass (ie atomic weight) seems to have spent his time researching in animal
— specific heat capacity ≈ 25 J K “1 mol “1 = 3R and especially plant physiology. He held the view
where R is the gas constant. that life processes are explicable in chemical and
Dumas, Jean Baptiste Andr© [dümah] (1800“84) physical terms and that cellular respiration is
French organic chemist; classified organic com- essentially similar in plants and animals. In 1832
pounds into types. he found the small openings (stomata) on the sur-
Originally an apprentice apothecary, Dumas face of leaves, later found to be the entry points for
improved his knowledge of chemistry in Geneva gas exchange in plants. Ingenhousz had shown
and also attracted the notice of some eminent sci- that plants absorb carbon dioxide and emit oxygen,
entists, with the result that he was encouraged to and Dutrochet found that only those parts of plants
go to Paris. There he got a post as assistant at the containing the green pigment chlorophyll can do
École Polytechnique, and by 1835 a senior post this. He was the first to study successfully the pro-
there. He initially worked on atomic weights but duction of heat during plant growth. Although
his main distinction is that he was a leader in the osmosis had been observed previously, it was he
group of mainly French chemists who partly who first studied it fully and proposed that it was
rejected the authoritative views of Berzelius and the cause of sap movement in plants.
Duve, Christian (Ren©) de [düv] (1917“ ) Belgian
offered new views on the relations between organic
compounds, setting the stage for the major biochemist: discovered lysosomes.
advances made later by Kekul©. Dumas™s work in Born in England and educated in medicine in
this began with his study of the choking fumes Louvain, de Duve worked in Sweden and the USA
from candles used in the Tuileries. He found that before returning to Louvain in 1947 and later hold-
these had been bleached with chlorine and from ing a dual post also at Rockefeller University, New
this clue examined the reaction of chlorine with York.
Du Vigneaud, Vincent

From 1949, de Duve obtained ingenious experi- complete (and rather complex) structure of biotin
mental evidence that some at least of a cell™s diges- in 1942. He next studied two pituitary hormones,
tive enzymes must be enclosed in small organelles oxytocin and vasopressin, the first of which
within the cell. By 1955 these were positively iden- induces labour and milk flow. Both structures were
tified with the aid of electron microscopy and determined, and in 1953 he synthesized oxytocin “
named lysosomes. These serve both to isolate the the first synthesis of an active polypeptide hor-
enzymes from attack on their own animal or plant mone (it contains eight amino acids). For this work
cells and to concentrate their attack when the lyso- in particular he was awarded a Nobel Prize for
some fuses with a food vacuole. After digesting the chemistry in 1955.
Dyson, Freeman John (1923“ ) British“US theor-
macromolecules present in the food, the resulting
small molecules of sugar or amino acid pass etical physicist: unified the independent versions
through the lysosome wall into the cell. Another of quantum electrodynamics.
function of lysosomes is to destroy worn-out cell Dyson, the son of a distinguished English musi-
organelles, or even cells. Some hereditary meta- cian, graduated from Cambridge and spent the
bolic diseases (eg cystinosis) are due to absence of a Second World War at the headquarters of Bomber
lysosomal enzyme. De Duve shared a Nobel Prize in Command. In 1947 he did research at Cornell and
1974. joined the staff at Princeton in 1953.
Du Vigneaud, Vincent [doo veenyoh] (1901“78) US Shortly after the war several people began to
biochemist: researcher on sulphur-containing vita- apply quantum mechanics to systems in which par-
mins and hormones. ticles (particularly electrons) interact with electro-
Originally a student of chemistry at Illinois, Du magnetic radiation (photons). In 1946 Willis Lamb
Vigneaud™s postgraduate work in the USA and in (1913“ ) observed a shift (the Lamb shift) in the
the UK became increasingly biochemical; from lowest energy levels of the hydrogen atom, away
1938 he was head of biochemistry in Cornell from the previously predicted levels. Schwinger,
Medical School and his research became ˜a trail of Tomonaga and Feynman rapidly developed inde-
sulphur research™. This began with studies on the pendent theories correctly describing how elec-
hormone insulin in the 1920s. In the 1930s he trons behave when interacting with photons, and
worked on the sulphur-containing amino acid accounted for the Lamb shift. Dyson then showed
methionine and showed that its function is partic- how the formulations related to each other and
ularly to transfer methyl (-CH3) groups in biochem- produced a single general theory of quantum
ical reactions. In 1941 he isolated vitamin H from electrodynamics (˜QED™, dealing with the interac-
liver and showed that it was identical with the tions of subatomic particles with photons).
growth factor biotin, which had been isolated in Subsequently Dyson was involved in many areas
1936 by F Kögl (1897“1960) (1 mg from 250 kg of of physics, in cosmology and even speculations on
dried duck egg yolk). Du Vigneaud deduced the space travel.

Eddington, Sir Arthur (Stanley) (1882“1944) protein chains (˜light™ and ˜heavy™) linked by sul-
British astrophysicist: pioneered the study of phur bridges. He went on to study the sequence of
stellar structure; and discovered mass“luminosity amino acids in the chains of the immunoglobulin
relationship. IgG and by 1969 had achieved this; the 1330 amino
Eddington was the son of the head of a school in acids form a Y-shaped structure, in which the
Cumbria where, a century earlier, Dalton had amino acids in the tips are very variable but the
taught. He was an outstanding student at main part of the structure is constant. This result
Manchester and then at Cambridge, where he later could be linked with R R Porter™s biochemical and
became Director of the Observatory. The internal immunological study of IgG to give a more detailed
structure of stars is an area of study pioneered by picture of this molecule, which is likely to be typi-
Eddington. In 1926 he demonstrated that, in order cal of antibodies (see Porter™s entry for diagram).
to remain in equilibrium, the inward gravitational His later work was on neural networks and the
pressure of a star must balance the outward radia- computerized simulation of brain function. Edel-
tion and gas pressure. He realized that there was man and Porter shared the Nobel Prize for 1972.
consequently an upper limit on the mass of a star Since then Edelman has worked on embryonic
(of about 50 solar masses), because above this the development and has identified the adhesive mole-
balance between gravitation and radiation pres- cules that have a central place in morphogenesis.
sure could not be achieved. (Some stars, verging on Always attracted by large problems in rather unex-
instability, pulsate; these are the Cepheid vari- plored fields, he has since attacked the difficult
ables.) He discovered the mass“luminosity relation- problem of the nature and origin of consciousness.
ship, which shows that the more massive a star the He visualized brain development as a process in
greater its luminosity and which allows the mass of which random neurone connections are progres-
a star to be determined from its intrinsic bright- sively refined by a process akin to Darwinian selec-
ness. Eddington provided some of the most power- tion, to give a brain in which effective activities are
ful evidence for the theory of relativity by observing retained and useless ones discarded. Neuro-
that light from stars near to the Sun™s rim during scientists are divided in their response to this idea,
the total solar eclipse of 1919 was slightly deflected some seeing it as of little worth while others foresee
by the Sun™s gravitational field in accordance with it as the start of a fruitful revolution in their field.
Edison, Thomas (Alva) (1847“1931) US physicist
Einstein™s predictions.
Edelman, Gerald (Maurice) (1929“ ) [aydlman] and prolific inventor.
US biochemist: pioneer in study of molecular struc- Edison received virtually no formal education,
ture of antibodies. having been expelled from school as retarded, and
Edelman originally planned a career as a concert
violinist, but came to realize that he lacked the
extroversion needed for success as a performer. He
had also been attracted to science and, believing
rather ingenuously that medical school was a suit-
able start (his father was a physician in New York),
he entered the University of Pennsylvania. After
qualifying he worked as a US Army physician in
Paris, where his interest in proteins, physical chem-
istry and immunology began, and he returned to
New York to work at Rockefeller University in this
During his doctorate studies at Rockefeller
University Edelman investigated the immuno-
globulins and after he joined the staff there he con-
tinued his interest in these compounds. They are
formed on the surface of B-lymphocytes and when
released into the body fluids are known as antibod-
ies. They form a class of closely related proteins, T A Edison, aged 14. Already an entrepreneur, he was
each specific in its ability to bind with a particular working a 14-hr day as a newsboy and food-vendor on the
antigen; the system forms a major part of the verte- railway, making $20 weekly profit. He soon set up a spare
brate animal™s defence against infection. Edelman freight car as a laboratory and printery for his Grand
found that human immunoglobulin, a large pro- Trunk Herald, most of it written by him; at 16 he became a
tein molecule, is a combination of two kinds of telegraphist and began his career as an inventor.
Edwards, Robert

was educated by his mother. During the American in the Portuguese Parliament until 1917 when he
Civil War he worked as a telegraph operator, was appointed Ambassador to Spain, and later that
during which time he invented and patented an year he became Minister for Foreign Affairs and he
electric vote recorder. Some 3 years later, in 1869, was President of his Delegation at the Paris Peace
he invented the paper tape ˜ticker™, used for com- Conference of 1918.
municating stock exchange prices across the coun- In 1920 he devised cerebral arteriography: injec-
try, sold it for $30 000 and opened an industrial tion into the brain of a non-toxic iodine compound
research laboratory. He was thereafter to apply (which acts as a contrast agent for X-rays; the heavy
himself full-time to inventing, filing a total of 1069 iodine atom absorbs them strongly) enabled some
patents before his death. His more notable inven- tumours, and deformities of the blood vessels, to be
tions include the carbon granule microphone, to located.
improve A G Bell™s telephone, the phonograph (a In 1936 he introduced a surgical treatment (later
device for recording sound on a drum covered in called lobotomy) for schizophrenia: previously
tin foil, invented in 1877) and the electric light there was no effective treatment, and simple
bulb. The latter required an extraordinary amount restraint or sedatives were used. Following up some
of trial and error testing, using over 6000 sub- surgical work done on chimpanzees which made
stances until he found a carbonized bamboo fibre them less aggressive, Moniz injected ethanol into
that remained lit for over 1000 hours in a vacuum. the white matter of the frontal lobes (which extend
This led in turn to improved electricity generators from above the eyes to beyond the crown of the
(he increased their efficiency from 40% to over head) in patients with acute schizophrenia which
90%), power cables, the electricity meter and the deactivated and sclerosed the cells. He went on in
revolutionizing of domestic lighting and public 1937 to surgically sever a number of connections
electricity supply. During his work on light bulbs between the prefrontal region and other parts of
he also discovered the Edison effect, that electricity the brain in another group of patients, finding that
flows from a heated filament to a nearby electrode the procedure was simple, safe and effective in
but not in the reverse direction, which was later to some cases. The method came to be widely used in
form the basis of the thermionic diode. Edison™s the 1940s, in part because of the absence of alter-
impact on 20th-c life was immense and his reputa- natives (and in part also because of Moniz™s high
tion as a prolific inventive genius remains unrivalled. reputation, perhaps). However, it cured few and left
Edwards, Robert (Geoffrey) (1925“ ) British many apathetic and with degenerated personality.
physiologist: pioneer of human IVF. It is now little used, although more selective psy-
After qualifying in medicine at Edinburgh and chosurgery has a limited use. Also in 1937 Ugo
research on mammalian reproduction in the UK Cerletti (1877“ ) and Lucio Bini (1908“ ) began to
and USA, Edwards became professor of human use electroconvulsive therapy (ECT) for acute
reproduction at Cambridge (1985“89), with special depression, and this has retained a valued place in
interests in fertility and infertility and the process psychiatry. In 1952 the first modern antidepres-
of conception. Attempts to fertilize mammalian sant, chlorpromazine, came into use and has been
eggs outside the body (in vitro fertilization, IVF) followed by other drugs with similar effects, which
were made in 1878; but it was not until 1978 that have led to reduced use of the earlier methods.
the first IVF baby, Louise Brown, was born. Success Moniz shared a Nobel Prize in 1949 with the physi-
was due to work by Edwards in collaboration, from ologist W R Hess (1881“1973) who worked on blood
1968, with the gynaecologist P C Steptoe (1913“88) flow and the regulation of respiration, and notably
whose expertise with the laparoscope allowed eggs on the effects resulting from the insertion of fine
to be removed from the womb. Edwards systemati- electrodes into the brains of cats; stimulation of
cally studied the factors needed to preserve and groups of cells in this way leads to reversible effects
ripen the immature eggs, which were then fertil- (flight, agression, sleep etc). This work has led to
ized with sperm; the resulting embryo was detailed mapping of the interbrain and hypothala-
matured in ˜a magic culture fluid™ before being mus by research groups worldwide since Hess
implanted in the uterus. Much work was needed to began such studies in the 1920s.
Ehrlich, Paul [ayrlikh] (1854“1915) German medical
define this optimum culture medium and condi-
tions for success, and to show that the artificially scientist: pioneer of chemotherapy, haematology
fertilized embryos would not result in abnormal and immunology.
offspring. The IVF method has proved very success- Ehrlich was born in eastern Germany, the son of
ful in dealing with some types of infertility. an eccentric Jewish innkeeper and his talented
Egas Moniz, Antonio (C De A F) (1874“1955) wife. Undistinguished at school (where he hated
Portuguese neurologist who introduced cerebral examinations) he did well enough to enter uni-
angiography, and prefrontal lobotomy (which versity to study medicine, and qualified at Leipzig
proved controversial). in 1878. With difficulty, partly because he was
Egas Moniz studied medicine at Coimbra, Jewish, he got a hospital post in Berlin. He spent his
Bordeaux and Paris, and spent his career from 1911 career there and in Frankfurt (from 1897), except
as professor of neurology at Lisbon. Remarkably, he for a year in Egypt using its dry air as a cure for his
maintained an active business and political career tuberculosis; at the time it was probably the best
as well as a medical one. From 1903 he was a Deputy treatment.
Einstein, Albert

While Ehrlich was a student the aniline dyes had kitchen. Then a change occurred and the birds
recently been discovered and his mother™s cousin recovered. Eijkman discovered that a new cook
Carl Weigert (1845“1904) had used them for micro- refused to give ˜military rice™ to civilian birds and
scopic staining. Ehrlich worked with him and was had changed to less refined rice. Eijkman went on
impressed by the way in which some dyes would to show that the disease could be cured by adding
stain selectively. The study of this linked his inter- rice husks to the diet and could be caused by feed-
est in chemistry with his medical work and was to ing polished rice. He did not interpret his results
form the basis of all his later research. He found correctly (he thought the bran contained a sub-
how to stain and classify white blood cells, discov- stance which protected against a poison) but his
ered the mast cells later found to be important in work was a valuable step towards the full recogni-
allergy and worked with Behring and Kitasato on tion of vitamin deficiency diseases by F G Hopkins
antitoxins. His work on antibodies largely began after 1900. Isolation and synthesis of vitamin B1
modern immunology. It led him to think that, (thiamin) was achieved by R R Williams (1886“1965)
although the search for vaccines against malaria in the 1930s; deficiency of it in the diet causes
and syphilis had failed, it might be possible to beriberi. Eijkman and Hopkins shared a Nobel Prize
attack the parasites causing these diseases in in 1929.
Einstein, Albert [iynshtiyn] (1879“1955) German“
another way, since they could be selectively
stained. He also knew that when an animal died Swiss“US theoretical physicist: conceived the theory
from lead poisoning the lead was found concen- of relativity.
trated in certain tissues. He hoped that he could Einstein™s father was an electrical engineer
find a synthetic chemical which would bind on to whose business difficulties caused the family to
and injure the parasites. He was encouraged by his move rather frequently; Einstein was born while
discovery that the dye Trypan Red was fairly effec- they were in Ulm. Despite a delay due to his poor
tive against trypanosomes (the pathogens causing mathematics he entered the Swiss Federal Institute
trypanosomiasis) in mice, although he also discov- of Technology in Zürich at the age of 17, and on
ered that drug resistance soon developed. Both dis- graduating became a Swiss citizen and sought a
coveries were important. post in a university, or even in a school. However,
From 1905 he and his assistants began trials using he had great difficulty in finding any job and set-
compounds with molecules not unlike dyes but tled for serving in the Swiss Patent Office in Bern. It
containing arsenic, as a part of his programme to worked out well; he was a good patent examiner
find a ˜magic bullet™ that could locate and destroy and the job gave him enough leisure for his
the invading pathogenic cells. Their organoarseni- research. In 1903 he married a fellow physicist,
cal compound No. 606 (which had failed against Mileva Maric; their illegitimate daughter, born in
trypanosomes) was eventually found by them in 1902, was adopted; two sons followed. This mar-
1909 to be effective against Treponema pallidum, the riage ended in divorce in 1919 and he then married
bacterium that causes syphilis, and it was soon his cousin Elsa, who had two daughters by a previ-
used in patients as ˜Salvarsan™. The principles used ous marriage. It was while at the Patent Office that
by Ehrlich came to guide this new approach he produced the three papers published in 1905,
(chemotherapy) to disease, in which a compound is each of which represented an enormous achieve-
sought that will seek out and destroy the disease ment, covering Brownian motion, the photoelec-
organisms with only minor damage to the patient. tric effect and special relativity.
In the event, it was over 20 years later before Einstein™s first university post was secured in
Domagk achieved the next major success. 1909, when he obtained a junior professorship at
Ehrlich inspired loyalty in some of his co-workers the University of Zürich, and a full professorship at
and high exasperation in others. He was dictatorial Prague (1910) and Zürich (1912) followed. In 1913
and impatient and appeared to live largely on he was made Director of the Institute of Physics at
cigars and mineral water. He shared a Nobel Prize the Kaiser Wilhelm Institute in Berlin. The general
in 1908 for his work on immunity, which is only a theory of relativity was completed during the First
part of his contribution to medical science. World War and following its publication (1915)
Eijkman, Christiaan [aykman] (1858“1930) Dutch Einstein was awarded the 1921 Nobel Prize for
physician: discovered cure for beriberi. physics for his work of 1905.
Eijkman served as an army medical officer in the He began to undertake many lecture-tours
Dutch East Indies in the early 1880s and was sent abroad and was in California when Hitler came to
back there in 1886 to study beriberi, then an epi- power in 1933. He never returned to Germany,
demic disease in south Asia. This paralysing and resigning his position and taking up a post at the
often fatal disease is in reality a deficiency disease, Institute of Advanced Study, Princeton. Einstein
whose rise was linked with increased use of pol- put much effort into trying to unify gravitational,
ished (white) rice as the major diet in some ˜closed™ electromagnetic and nuclear forces into one set of
communities. When Eijkman began his work in field equations, but without success. He had some
Java, it was assumed to be an infection, but he involvement in politics, in that he helped initiate
noticed that some laboratory birds showed similar the Allied efforts to make an atomic bomb (the
symptoms to beriberi victims, and they had been Manhattan project) by warning Roosevelt, the
fed on left-over rice from a military hospital American president, of the possibility that
Einstein, Albert

AA Michelson, Albert Einstein and R A Millikan (wearing bow tie) in 1931.

Germany would do so, in a letter in 1939. In 1952 Einstein correctly proposed that the speed of
Einstein was offered, and sensibly declined, the light is the same in all frames of reference moving
presidency of Israel. He was also active in promot- relative to one another and, unknown to him, this
ing nuclear disarmament after the Second World had been established by the Michelson“Morley
War. He led a simple life, with sailing and music as experiment (1881, 1887). He put forward the prin-
his main relaxations. ciple of relativity, that all physical laws are the
The first of his papers of 1905 considered the same in all frames of reference in uniform motion
random movement of small suspended particles with respect to one another. When applied it natu-
(Brownian motion, discovered in 1828). The bom- rally gives rise to the Lorentz“FitzGerald transfor-
bardment by surrounding molecules will make a mation, with classical mechanics obeying this
tiny particle in a fluid dart around in an erratic rather than simple addition of velocity between
movement, and Einstein™s calculations provided moving frames (the Galilean transformation). A
the most direct evidence for the existence of mole- further consequence derived by him was that if the
cules when confirmed experimentally by Perrin energy of a body changes by an amount E then its
mass must change by E/c2 where c is the velocity of
The next paper by Einstein tackled the photoelec- light.
tric effect by considering the nature of electromag- From 1907 Einstein sought to extend relativity
netic radiation, usually thought of as waves theory to frames of reference which are being accel-
obeying Maxwell™s equations. Einstein assumed erated with respect to one another. His guiding
that light energy could only be transferred in principle (the principle of equivalence) stated that
packets, the quanta used by Planck to derive the gravitational acceleration and that due to motion
black body radiation spectrum. Einstein then was viewed in an accelerating frame are completely
able to explain fully the observations of Lenard equivalent. From this he predicted that light rays
(1902), in which the energy of electrons ejected should be bent by gravitational attraction. In 1911
from a metallic surface depended on the wave- he reached a specific prediction: that starlight just
length of light falling on it but not on the intensity. grazing the Sun should be deflected by 1.7” of arc.
The result became a foundation for quantum During a total eclipse of the Sun in 1919 Eddington
theory and clothed Planck™s quanta with a physical measured this in observations made at Princip© in
interpretation. West Africa, finding 1.61” of arc. This dramatic con-
Finally, Einstein set out the special theory of rela- firmation immediately made Einstein famous
tivity (restricted to bodies moving with uniform world-wide and made it clear that he had moved
velocity with respect to one another) in his third the foundation of physics.
paper. Maxwell™s electromagnetic wave theory of In 1915 he had published the general theory of rel-
light indicated that the velocity of a light wave did ativity in complete form, using Riemannian geome-
not depend on the speed of the source or observer try and other mathematical ideas due to H
and so contradicted classical mechanics. Lorentz, Minkowski (1864“1909) (in 1907), Riemann (1854)
FitzGerald and Poincar© had found a transforma- and C Ricci (1853“1925) (in 1887). Mass was taken to
tion of Maxwell™s equations for a region in uniform distort the ˜flatness™ of space-time and so to give rise
motion which left the speed of light unchanged to bodies in space moving along curved paths about
and not altered by the relative velocity of the space one another. While the resulting ˜gravitational™
and observer (the Lorentz transformation). attraction is very close to that predicted by Newton™s
Panel: The history of nuclear and particle physics

THE HISTORY OF NUCLEAR AND radioactive elements: alpha rays, which carried posi-
PARTICLE PHYSICS tive electric charge and were not very penetrating;
and beta rays, which carried negative electric charge
One of the continuing themes of science is to discover and were more penetrating. In 1900 Paul Villard
and understand the constituents of matter. Nuclear (1860“1934) found a third component, called
physics is one aspect of this endeavour and deals gamma rays, which carried no electric charge and
with the nucleus at the centre of atoms. It grew natu- were not easily stopped or detected. More work,
rally from attempts at the end of the 19th-c to under- principally by Rutherford, showed that alpha rays
stand the structure and composition of atoms and were in fact helium ions, that beta rays were elec-
has had profound effects on the development of trons, and that radioactive emissions caused the
science as a whole and on society in general. transmutation of one element into another. (Gamma
Although the existence of a nucleus in atoms was rays are ultra-high-energy X-rays.)
established only in 1911, the phenomenon of The fact that atoms contained very light nega-
radioactivity, which is essentially a nuclear process, tively charged particles called electrons had been
had been discovered earlier by BECQUEREL in Paris in shown by J J THOMSON in 1897 at the Cavendish
1896. He had been investigating the mysterious X- Laboratory in Cambridge. In 1907 Thomson put
rays discovered by R–NTGEN in Germany in 1895. forward what he called the ˜plum pudding™ model of
Becquerel left some uranium salts for several days on the atom, in which he postulated that the electrons
top of a wrapped photographic plate intended for his were dispersed in a uniform distribution of positive
X-ray experiments, which had been held up by damp charge in an atom, like plums in a pudding. This
conditions. On developing the plate, he found that it model was refuted by a famous series of experiments
had been fogged in the region where the uranium carried out in 1911 at Manchester University by
had been resting on it. He concluded that there was GEIGER and Ernest Marsden (1889“1970), working
some kind of radiation emanating from the uranium under the supervision of Rutherford. In these experi-
which could penetrate the paper around the photo- ments a beam of alpha particles was directed at thin
graphic plate. This phenomenon came to be called foils of gold or platinum, and the number of alpha
radioactivity, and its discovery caused a great stir in particles scattered through various angles was
the scientific community. One prominent investigator recorded. It was found that a few alpha particles
of radioactivity was MARIE CURIE, a Polish scientist were scattered through large angles. Rutherford real-
working in Paris with her French husband, PIERRE ized that the very strong electrical forces needed to
CURIE. In 1898, as the main subject of her doctoral do this could only be produced if, in contradiction to
thesis, and after painstaking work in finding ways of Thomson™s model, all the positive charge of the atom
chemically isolating other radioactive substances in was concentrated in a tiny ˜nucleus™ at the centre of
uranium ore by detecting their radioactivity (using the atom. Thus, the nuclear model of the atom was
electrometers devised by Pierre Curie), she discov- born. If an atom is imagined as a large concert hall,
ered two very radioactive new elements to which she the nucleus would be the size of a pea at its centre.
gave the names polonium and radium. Most of the volume of an atom is empty space, with a
The discovery of radium and its means of isolation number of electrons moving around a tiny but heavy
made available a far more powerful source of radia- central nucleus. This suggests that electrons orbit the
tion for experiments than had been available before. central nucleus, just as planets orbit the Sun.
Several of the early workers with radioactive materi- The next major step was taken by Danish physicist
als, including Becquerel and the Curies, noticed that NIELS BOHR. He realized that the basic force holding
it could cause red patches and burns to appear on the electrons in an atom was the electric attraction
skin. It is likely that Pierre Curie was suffering from exerted by the positively charged nucleus, but that a
radiation sickness during his last years before his radically new approach was needed to understand
untimely death in a road accident in Paris in 1906, what determined the size of electron orbits and what
and that radiation damage was a factor in Marie stopped them from collapsing, given that the elec-
Curie™s death from aplastic anaemia in 1933. Its use trons should continuously radiate energy away.
as a luminous material on watches led to cases of The key step which he took was to postulate that
cancer among the workers who painted the dials. angular momentum was quantized, ie only able to
Nevertheless, radium was found to be effective in take on integer multiples of some constant value. The
treating some cancers, and its controlled use in this idea of quantization had been introduced, but only
way has continued. for the energy of electromagnetic radiation, in 1900
The systematic study of the nature of radioactivity by PLANCK. In 1913, Bohr produced a convincing
began in 1898, when RUTHERFORD showed that there theory of the hydrogen atom, and explained the
were at least two types of radiation emitted by origin of its spectral lines as due to what we today

Panel: The history of nuclear and particle physics

call ˜quantum jumps™, in which the energy of an atom produced in the fission of one uranium nucleus could
suddenly changes, resulting in the emission of a cause the fission of other uranium nuclei. One of the
quantum of energy now called a photon. The ˜Bohr physicists involved was Fermi, by then working in the
atom™ was a great step forward in both physics and USA. He and others realized that it might be possible
chemistry, and led to the new subject of quantum both to construct a power plant and also a very pow-
mechanics, established between 1920 and 1930, erful explosive (a million times more powerful than
which eventually gave a rather different but far more TNT) based on nuclear fission. These developments
satisfactory theoretical understanding of atoms. The occurred at the start of the Second World War, and a
key people in the development of quantum mechan- major secret programme (the Manhattan project,
ics were SCHR–DINGER and HEISENBERG. directed by OPPENHEIMER) was started in the USA to
In the process of beta radioactivity electrons produce what became known as the atom bomb. As
emerge from the nucleus, so it was natural to assume part of this project, Fermi constructed the world™s
that nuclei contain electrons whose negative charge first nuclear reactor in Chicago in 1942 as a source of
cancelled out some of the positive charge of the plutonium for bombs and also to provide experimen-
protons (the name given to the nucleus of hydrogen). tal information on fission chain reactions. The project
However, in 1932 CHADWICK discovered a neutral par- led to the testing of the first atom bomb in 1945, and
ticle, the neutron, of about the same mass as a the dropping of a uranium bomb on Hiroshima and a
proton. From then on, it was realized that nuclei were plutonium bomb on Nagasaki in August 1945, so
built up from neutrons and protons, and that they did ending the Second World War.
not contain electrons. The problem of where the elec- After the war, the production of even more power-
trons came from in beta radioactivity was solved in ful nuclear bombs based on nuclear fusion reactions
1934 by FERMI, working in Rome. His theory used was pursued. In nuclear fusion, light nuclei such as
quantum mechanics, and also involved the neutrino, hydrogen and tritium fuse together to produce
a new neutral particle postulated by PAULI in 1929. heavier nuclei, while in fission heavy nuclei such as
Fermi proposed that an electron and a neutrino are uranium and plutonium split into two. Both these
created in a nucleus at the instant of beta decay by a processes release large amounts of energy. One chief
new force called weak interaction. scientist working on the so-called hydrogen bomb
Very soon after the discovery of the nucleus, it was based on fusion was EDWARD TELLER. The purely scien-
realized that there must be a new strong attractive tific study of nuclear physics also continued after the
force operating in the nucleus to overcome the elec- war, with the main emphasis on nuclear structure. In
trical repulsive force between the protons. This new 1948, MARIA GOEPPERT MAYER put forward the shell
force would have to have a very short range, as its model of nuclei, which explains many features of
effects were not observed outside the nucleus. The nuclei in terms very similar in principle to the
first theoretical understanding of how a strong short- analogous atomic shell model: this formed the basis
range force could be produced was provided in 1934 for most subsequent work.
by YUKAWA. His meson exchange theory of nuclear Particle physics may be regarded as the study of the
forces provided a spring-board for the development most fundamental constituents of matter and the
of theoretical nuclear and particle physics. The new forces which act between them. As a subject in its own
particle, named the pi meson (pion), predicted by right, it diverged from nuclear physics in the early
Yukawa, was not discovered until 1947 by POWELL. 1930s. Until then, the study of the atomic nucleus was
Nuclear fission, the process by which a nucleus regarded as the most fundamental part of physics, and
splits into two, was discovered in Berlin in 1938 by in fact the term particle physics came into use only in
HAHN and Fritz Strassman (1902“80). They had found the 1960s. As noted above, in 1932 Chadwick discov-
traces of light elements such as barium in the prod- ered the neutron, a particle similar to the proton but
ucts of the bombardment of uranium by neutrons. without electric charge. This similarity prompted
The interpretation of this as the splitting of the Heisenberg to describe the proton and neutron as dif-
uranium nucleus into two roughly equal parts was ferent states of a particle called the nucleon, with spin
mainly due to LISE MEITNER and her nephew, OTTO up and spin down. So began an investigation of a new
FRISCH. Meitner had been a colleague of Hahn in layer of nature, more fundamental even than the realm
Berlin, but had fled to Sweden to escape the Nazis. of neutrons and protons. It was also the start of a
Many physicists soon confirmed these important mathematical approach based on symmetries, which
results, and within a few months in 1939 it was proved to be very fruitful in the 1960s.
established that a large amount of energy was By the early 1930s the existence of the neutrino
released in fission and that a number of free neutrons came to be taken seriously, and the idea of anti-
were also produced. This meant that it was likely that particles was introduced by DIRAC as a necessary
a chain reaction was possible in which the neutrons consequence of his relativistic theory of quantum

Einstein, Albert

mechanics. In particular, Dirac predicted in 1931 that quark model by GELL-MANN and, independently, by
an anti-electron should exist. This particle was dis- George Zweig (1937“ ), which explained the large
covered by CARL ANDERSON at the California Institute number of hadrons in terms of combinations of just a
of Technology in 1932, although he was not aware of few elementary particles called quarks, which had
Dirac™s prediction at the time. Soon this positive elec- fractional electric charge.
tron was identified with Dirac™s prediction by A new large electron linear accelerator (SLAC) at
BLACKETT and was named the positron. Thus, fairly Stanford, CA, enabled experiments to be done that
quickly in the early 1930s, the number of supposedly were analogous to Rutherford™s scattering of nuclei.
elementary particles increased from two (the electron These experiments scattered electrons from protons
and proton) to at least four. inelastically, and showed that the proton could
In 1938, studies of cosmic radiation (which is indeed be regarded as a composite of much smaller
a flux of high-energy particles from outer space) entities as envisaged in the quark model. The key
revealed the tracks of a particle whose mass was experiments were carried out by a team led by
intermediate between that of the electron and the Richard Taylor (1929“ ), Henry Kendall (1926“ )
proton. This was subsequently called the mu-meson and Jerome Friedman (1930“ ). The interpretation
(muon). It is now known to be one of the class of of these experimental results was largely the work of
fundamental particles called leptons. At first it was FEYNMAN. His other important contributions to
thought to be the particle, predicted by Yukawa, theoretical particle physics included the renormali-
whose exchange causes nuclear forces, but the fact zation technique for quantum electrodynamics and
that it appeared not to undergo nuclear interactions the theory of weak interactions.
argued against that interpretation. It was not until A milestone in particle physics was the unification
1947 that Yukawa™s predicted particle, the pi-meson, of the theories of electromagnetic and weak inter-
was discovered in cosmic rays by Powell. Between actions in the early 1970s, principally by WEINBERG,
1947“53 several other new particles were discovered SALAM and GLASHOW. A consequence of their work
in cosmic rays. The discovery techniques used cloud was the prediction of new, very heavy particles called
chambers and photographic emulsions, and were the W and Z bosons. These were discovered in a large
mostly carried out on mountain tops in the Alps, scale experiment at CERN in 1983 involving colliding
where the flux of cosmic rays is higher. Prominent in beams of protons and anti-protons. The team
this work were Clifford Butler (1922“ ) and George which made the discovery was led by Carlo Rubbia
Rochester (1908“ ) who, in 1947, discovered the (1934“ ), later the director-general of CERN.
so-called strange particles, later known as K and A. Since then, most advances in particle physics have
Two important developments in experimental come about through the work of large experimental
methods were made in the 1950s and early 1960s teams, and a biographical account is no longer
which changed dramatically the scale of experiments appropriate. The present situation is that there is now
and the rate of progress. These were the invention of a ˜standard model™ of particle physics expressed in
a particle detector called the bubble chamber by terms of six quarks, six leptons (which are the con-
GLASER (and its large scale implementation by LUIS stituents of all matter) and a small number of so-
ALVAREZ), and the development of large-particle called gauge bosons (which are responsible for
accelerators, notably the proton synchrotron. Most of fundamental forces). This model has been subjected
this work was carried out in the USA, but from 1959 to (and has survived) precision tests by a series of
the European Organization for Nuclear Research large experiments carried out principally on the elec-
(CERN) became a major contributor. As a result of tron-positron colliding beam machine, LEP, at CERN.
these developments in experimental methods, many The scope of particle physics has much increased
new particles (collectively called hadrons) were dis- since the early 1980s and it is now indispensable for
covered during the 1960s and 1970s. It became hard an understanding of astrophysics and cosmology,
to believe that they were all fundamental and several and particularly of the ˜Big Bang™ model of the early
physicists searched for theoretical explanations of stages of the universe.
them in terms of more elementary constituents. A
Dr Gareth Jones, Imperial College, London
breakthrough came with the development of the

law, there are small corrections. Einstein and M predictions, such as that light passing from one
Grossmann (1878“1936) estimated that the ellipse part of a gravitational field to another would be
traced out by Mercury around the Sun should rotate shifted in wavelength (the Einstein redshift). This
by 43” of arc per century more than that given by was observed astronomically in 1925 and terres-
Newtonian theory. The observed value is indeed 43” tially, with a 23 m tower on Earth using the
of arc larger and Einstein reported: ˜I was beside Mossbauer effect, by R Pound and G Rebka in 1959.
myself with ecstasy for days™. Gamma rays moving from the bottom to top of the
General relativity produced many other startling tower were found to have a longer wavelength.
Einthoven, Willem

Cosmological models of the universe were also Lewis (1881“1945) in London) related the ECG trac-
completely changed by general relativity and ings to clinical data for this and other heart diseases.
Friedmann (1922) put forward a model that repre- This became an important diagnostic method, and
sented an expanding universe obeying Einstein™s Einthoven won the Nobel Prize for 1924.
Ekman, Vagn Walfrid (1874“1954) Swedish ocean-
During the 1920s and 1930s Einstein engaged in ographer: explained the variation in direction of
debate over quantum theory, rejecting Born™s intro- ocean currents with depth.
duction of probability (˜God may be subtle, but He is After graduation, Ekman worked at the Interna-
not malicious™). He also sought to find a unified tional Laboratory for Oceanographic Research in
theory of electromagnetic and gravitational fields, Oslo for several years before returning to Sweden in
without success. By 1921 he had been prepared to 1908. He was appointed professor of mathematical
say ˜Discovery in the grand manner is for young physics at Lund in 1910. In the 1890s the Norwegian
people¦ and hence for me a thing of the past™. Arctic explorer Nansen had noted that the path of
Einthoven, Willem [aynthohven] (1860“1927) drifting sea ice did not follow the prevailing wind
Dutch physiologist: introduced clinical electrocar- direction, but deviated about 45° to the right. In
diography. 1905 Ekman was able to explain this as an effect of
Einthoven™s father was a physician in Java, where the Coriolis force caused by the Earth™s rotation. He
the family lived until he was 10, afterwards settling went on to describe the general motion of near-sur-
in Utrecht. He studied medicine there and was face water as the result of the interaction between
appointed professor of physiology at Leiden in surface wind force, the Coriolis force and frictional
1886. The next year A D Waller (1856“1922) in effects between different water layers. Ekman flow
England showed that a current was generated by thus accounts for situations in which near-surface
the heart, but his recording device was cumber- water moves in the opposite direction to that at the
some and insensitive. Einthoven was interested in surface, with the net water transport at right
physics, and he devised a sensitive string gal- angles to the wind direction. The resulting varia-
vanometer. It used a fine wire stretched between tion of water velocity with depth is known as the
the poles of a magnet. When a current passed Ekman spiral. An analogous situation exists in
through the wire it was deflected and an optical atmospheric flow.
Elion, Gertrude (Belle) (1918“99) US pharmaco-
system magnified this for recording. Einthoven
made electrocardiograms (ECGs) from the chest logical chemist.
wall and from contacts on the arms and legs, and Elion studied biochemistry at Hunter College,
described his results from 1903. Soon afterwards, New York and after graduating in 1937 worked in
cardiologists gave full accounts of coronary artery industry and as a high-school science teacher for 7
disease and Einthoven and others (especially Sir T years. At the same time she was a part-time
research student at New York University, obtaining
her master™s degree in 1941. She began to work for
a doctorate, but could not continue because full-
time study was required for this. She gained three
honorary doctorates later in life.
She joined the Burroughs Wellcome laboratory in
1944 and the next year began working with
Hitchings. At that time the usual path to new
drugs was to synthesize variations on natural plant
drugs and then to look for useful therapeutic
effects when they were given to test animals. Elion
and Hitchings used a different approach. They
looked for differences between the biochemistry of
normal human cells and the cells of bacteria and
other infective agents, or of cancer cells, and then
used the differences to deduce chemical structures
that would damage the infective or cancerous cells
only. This rational programme of drug design gave
important successes for the team led by Hitchings
and Elion for over 20 years, including drugs for
treatment of leukaemia, malaria, gout and autoim-
mune disorders. They shared with James Black the
Nobel Prize for physiology or medicine in 1988.
After 1967 Elion led the Wellcome group, and in
1974 she announced another major therapeutic
and commercial success, the antiviral drug acy-
A demonstration to the Royal Society in 1887 by A D
clovir “ evidence of her position in research, recog-
Waller, taking an electrocardiograph from a dog. A popu-
nized by the award of the US National Medal of
lar protest that this was cruel (untrue) was not easily
Science in 1991.
Enders, John Franklin

romethyl (CF3-) derivatives of metals and non-
Emiliani, Cesare [emeelyahnee] (1922“ ) Italian“
US geologist: demonstrated the cyclic nature of ice
ages and established the climatic history of the
Quaternary period.
Emiliani emigrated to the USA in 1948, graduat-
ing from the University of Chicago in 1950, where
he remained until moving to the University of
Miami in 1956. Following the suggestion of Urey
that the isotopic ratio of oxygen (18O/16O) in sea
water depends upon the prevailing temperature
(due to isotopic fractionation), Emiliani pioneered
a technique for determining the past temperature
of the oceans by measuring the 18O/16O ratio in the
carbonate remains of microorganisms in ocean sed-
iments. By selecting for study only pelagic species
(ie those that live near the ocean surface) he was
able to establish, in 1955, that there had been seven
glacial cycles during the Quaternary period, almost
double the number of ice ages that were formerly
thought to have occurred. Oxygen isotope methods
are now an established technique in palaeoclimatic
Walter Elsasser in the 1960s.
Empedocles (of Acragas) [empedokleez] (c.490“
Elsasser, Walter Maurice (1904“91) German“US c.430 bc) Greek philosopher: proposed early view on
theoretical physicist: developed theory of Earth™s nature of matter.
magnetic field. Active in politics, poetry, medicine and mysti-
Elsasser was born and educated in Germany; he cism, Empedocles is credited with the suggestion
left that country in 1933 and spent 3 years in Paris, that all substances are derived from four ˜roots™ or
where he worked on the theory of atomic nuclei. In elemental principles: fire, air, water and earth.
1936 he settled in the USA and began to specialize These are joined or separated by two forces, attrac-
in geophysics. During the 1940s he developed the tion and repulsion (or love and strife). This view,
dynamo model of the Earth™s magnetic field, which especially as developed later by Aristotle, was
attributes the field to the action of electric currents influential for 2000 years, until Boyle™s work.
flowing in the Earth™s fluid metallic outer core. Empedocles is said to have ended his life by jump-
These currents are amplified through mechanical ing into the volcanic crater on Mount Etna, possibly
motions in the same way that currents are main- in an attempt to prove his divinity.
Enders, John Franklin (1897“1985) US virologist:
tained in power station generators. The analysis of
past magnetic fields, frozen in rocks, has since developed improved method for culturing viruses.
turned out a very powerful tool for the study of geo- Enders had several early career changes. He left
logical processes. Yale in 1917 to become a flying instructor in the
Elsasser™s theory of the origin of Earth™s magnetic First World War; began a career as an estate agent
field was confirmed in 2000 by groups in Germany, and left it to study languages at Harvard, and then
who used liquid sodium metal flowing at 15 m s“1 changed to microbiology, thereafter staying at the
in a 25cm-wide pipe: a propeller recirculated the Harvard Medical School through a long career.
molten metal and also twisted its flow. A small Before his work, few laboratory cultures of viruses
electric field was used as a ˜seed™, and after its were available and these were inconvenient (eg
removal the system maintained the induced cultures in a living chick embryo). Enders argued
magnetic field. that living cells should be adequate, without the
Emel©us, Harry Julius (1903“93) British inorganic whole animal, if bacterial growth was prevented
chemist: revitalizer of experimental inorganic by adding penicillin. In 1948 together with F C
chemistry. Robbins (1916“ ) and T H Weller (1915“ ) he cul-
A student at London, Karlsruhe and Princeton, tured the mumps virus using a homogenate of
Emel©us was professor of inorganic chemistry at chick embryo cells and ox serum with added peni-
Cambridge from 1945“70. He worked on a wide cillin. The next year a similar method was used for
variety of topics and his experimental work did the polio virus and in the 1950s for the measles
much to dispel the pre-1945 view that rather virus. For measles they were able to develop a vac-
little of interest remained to be done in inorganic cine by 1951 that came into widespread use in 1963.
chemistry. His early work was on phosphorescent The trio shared a Nobel Prize in 1954 and their
flames and on photochemistry. In the 1940s he methods of culturing viruses allowed virology to
made novel silicon compounds and after 1950 advance with successes such as the Salk and the
many new halogen compounds, especially trifluo- Sabin polio vaccines.

Eratosthenes (of Cyrene) [eratostheneez] (c.270“ Dorothea Erxleben™s father was a doctor in the
c.190 bc) Greek astronomer and polymath: gave first small town of Quedlinburg, in Germany. He
accurate measurement of the Earth™s circumference. grieved at the waste of talented women being con-
Eratosthenes was educated in Athens and became fined to household duties and taught his daughter
chief librarian of the Alexandrian museum. He alongside his son, teaching them Latin, basic sci-
devised an ingeniously simple way of measuring ence and medicine, preparing them both for a med-
the circumference of the Earth. Eratosthenes knew ical career. Dorothea petitioned King Frederick II
that on a certain day the Sun at its highest point for consent to accompany her brother to Halle to
(midday), at Cyrene (now Aswan), was exactly over- study for a medical degree in 1740; this was
head (it was known to shine down a deep well). He granted. However, the prospect of a woman study-
determined that on the same day at Alexandria, ing medicine caused outrage; it was pointed out
when the Sun was at its highest point, it was at an that, as women were forbidden by law to hold
angle corresponding to 1/50th of a circle south of public office, they could not practise medicine and
its zenith. Knowing the distance between the two they did not need a medical degree.
places he therefore calculated that the Earth™s cir- War with Austria broke out and Dorothea™s
cumference was 50 times that length. His result brother left for military service. Alarmed at the
was probably fairly accurate, perhaps within 50 prospect of going to university on her own, she
miles of the correct value. married a widower with five children and contin-
Among his other discoveries Eratosthenes sug- ued to study. Her father died 6 years later leaving
gested a method of separating primes from compos- debts and her husband became ill; financial respon-
ite numbers (known as the sieve of Eratosthenes); he sibility for the family fell to her. Her attempts to
obtained an improved value for the obliquity of the practise medicine once more fell foul of the
ecliptic (the tilt of the Earth™s axis), and he produced licensed doctors of Quedlinburg, who demanded
the first map of the world based on meridians of lon- that she must sit an examination. The rector of the
gitude and parallels of latitude. In later life he University of Halle decided that on the matter of
became blind and, no longer able to read, commit- women™s entry to university “ ˜one designates the
ted suicide. sex to which the degree most often applies, but by
Erdös, Paul [air-dosh] (1913“96) Hungarian mathe- affirming the one sex the other is not excluded™; he
matician: a prolific and talented eccentric. also ruled that the profession of medicine was not
Erdös was a pure mathematician in both senses of the same as holding public office, so that Dorothea
the phrase. His interest was number theory, and he Erxleben was free to take her examination. She sat
thought of nothing else. His brilliance was such her final examinations without delay and was
that his 1500 papers represent the greatest contri- granted her degree on 12 June 1754.
Esaki, Leo (1925“ ) Japanese physicist: discovered
bution to this area during the last century (only
Euler, in other fields, has produced more papers). the tunnel (Esaki) diode.
He was one of three children born in Budapest to While working for his doctorate on semicon-
two Jewish mathematics teachers. His two sisters ductors at the University of Tokyo (1959), Esaki was
were considered even brighter, but both died also leading a small research group at the Sony
young of scarlet fever. After studying at Budapest Corporation. He chose, in 1957, to investigate con-
and Manchester, and unable to return home, he duction by quantum mechanical ˜tunnelling™ of
moved to the USA in 1939. Before he was 20 he electrons through the potential energy barrier of a
showed that between any two numbers N and 2N, germanium p-n diode. Such conduction is in the
there lies at least one prime number. His greatest reverse direction to the normal electron drift and,
achievement was in 1949, when with Atle Selberg using narrow junctions (only 100 … wide) with
he gave the first elegant and ˜elementary™ proof of heavy impurity doping of the p-n junction, Esaki
the Prime Number Theorem, which describes their observed the effect. He realized that with narrower
pattern of distribution. (Specifically, this 18th-c junctions the effect would become so strong that
theorem shows that the approximate number of the total current would actually fall with increas-
primes less than X is X/loge X.) In the McCarthy era ing bias (negative resistance) and succeeded in
Erdös was banned from the US for being reluctant making such devices (tunnel or Esaki diodes) in
to denigrate Marx. Absent-minded and over-gener- 1960. These devices have very fast speeds of opera-
ous with money, he had no wife, family or perma- tion, small size, low noise and low power consump-
nent residence, and stayed with friends or at tion; they have widespread electronic applications
conferences, living on lecture fees, prizes and the in computers and microwave devices. In 1960 Esaki
hospitality of collaborators (he had hundreds of co- joined IBM™s Thomas J Watson Research Centre and
authors, the largest number in mathematical his- in 1973 was awarded the Nobel Prize with Josephson
tory). His mother™s death in 1971 caused him to and I Giaever (1929“ ) for work on tunnelling
work longer hours, sustained by coffee and ben- effects.
Eskola, Pentti Elias (1883“1964) Finnish geologist.
zedrine. He died at a conference in Warsaw, still
working. Eskola graduated in chemistry in Helsinki in 1906
Erxleben, Dorothea Christiana Leporin [erks- but then turned to petrology, especially the mineral
laybn (1715“62) German physician: the first woman facies of rocks. The term facies refers to the appear-
to gain a full medical degree in Germany. ance of a rock and the total of its characteristics.
Euler, Leonhard

Eskola was professor of geology at Helsinki from limits of his time (with its inadequate concepts of
1928“53. He concluded in 1914 that in metamor- infinity, little algebra and no convenient arith-
phic rocks the mineral composition when equilib- metic) his attempt at an unflawed, logical treat-
rium is reached at a particular temperature and ment of geometry is remarkable.
Euler, Leonhard [oyler] (1707“83) Swiss math-
pressure is controlled only by the chemical compo-
sition. Later work has confirmed this view. For ematician: the most prolific mathematician in
example, a zeolite results when the appropriate history.
chemical components are equilibrated in a region Euler was the son of a Calvinist pastor who gave
where temperature is 100“220°C and pressure him much of his early education, including mathe-
150“400 kbar. matics. Later he studied at the University of Basle,
Euclid [yooklid] (lived c.300 bc) Greek mathema- where he became close friends with members of
tician: recorded, collated and extended mathemat- the Bernoulli family, and Daniel Bernoulli in par-
ics of the ancient world. ticular. Because he was still rather young (he grad-
Euclid offers strange contrasts: although his uated at 16), Euler could not obtain a post at the
work dominated mathematics for over 2000 years, university. However, Daniel persuaded Euler to
almost nothing is known of his life and personality. join him at Catherine I™s Academy of Science at St
One alleged remark survives, his reply to Ptolemy Petersburg in 1727. The Empress died the day Euler
Soter, King of Egypt, who hoped for an easy course arrived in Russia and the future of the academy
of tuition: ˜in geometry there is no straight path for became uncertain. After an unhappy period work-
kings™. Working in Alexandria, then a new city but ing in the Naval College and medical section of the
a centre of learning, Euclid brought together previ- Academy he became professor of physics in 1730.
ous work in mathematics and his own results and When Bernoulli returned to Switzerland in 1733
recorded the whole in a systematic way in 13 Euler succeeded him as professor of mathematics.
˜books™ (chapters), entitled Elements of Geometry. The repressive reign of a boy Tsar led Euler, now
Others are lost. married, to retreat into reclusive mathematical
The system attempted to be fully rigorous in prov- work, and this solitariness increased during the
ing each theorem on the basis of its predecessors, reign of Anna Ivanovna (1730“40) which was one of
back to a set of self-evident axioms. It does not the bloodiest in Russian history. During this time
entirely succeed, but it was a noble attempt, and Euler lost the sight of his right eye, perhaps due to
even the study of its deficiencies proved profitable looking at the Sun accidentally during his astro-
for mathematicians. His work was translated into nomical studies. Although conditions eased in
Arabic, then into Latin and from there into all Russia after Anna™s death, Euler departed to join
European languages. Its style became a model for Frederick the Great™s Berlin Academy of Science in
mathematicians and even for other fields of study. 1741. Despite great authority in mathematics Euler
Six of the chapters deal with plane geometry, four frequently engaged ineptly in philosophical discus-
with the theory of numbers (including a proof that sions and Frederick sought a replacement. In 1766
the number of primes is infinite) and three with Euler took up Catherine the Great™s offer of the
solid geometry, including the five Platonic solids directorship of the St Petersburg Academy, accom-
(the tetrahedron, octahedron, cube, icosahedron panied by his family and servants (18 people in all).
and dodecahedron “ Euclid finally notes that no He became totally blind soon after his arrival, but
other regular polyhedrons are possible). due to his remarkable ability to calculate in his
Only in the 19th-c was it realized that other kinds head his productivity did not diminish and he suc-
of geometry exist. This arose from the fact that, cessfully carried out his work for another 15 years.
while most of the Euclidean postulates are indeed He remained in Russia for the rest of his life.
self-evident (eg ˜the whole is greater than the part™), Euler was the most prolific mathematician in his-
the fifth postulate (˜axiom XI™) is certainly not so. It tory and contributed to all areas of pure and
states that ˜if a point lies outside a straight line, applied mathematics. In analysis he lacked Gauss™s
then one (and only one) straight line can be drawn or Cauchy™s rigour but he had a gift for deducing
in their plane which passes through the point and important results by intuition or by new ways of
which never meets the line™. Then in the 19th-c it calculating quantities. He systematized much of
was accepted that this certainly cannot be deduced analysis, cast calculus and trigonometry in its
from the other axioms, and Lobachevsky and modern form and showed the important role of e
others explored geometries in which this ˜parallel (Euler™s number, 2.718 28¦). Euler developed the
axiom™ is false. In the 20th-c, Einstein found that use of series solutions, paying due regard to con-
his relativity theory required that the space of the vergence; he solved linear differential equations
universe be considered as a non-Euclidean space; it and developed partial differential calculus. He
needed the type of geometry devised by Riemann. applied these analytical tools to great effect in
For all everyday purposes, Euclidean space serves us problems in mechanics and celestial mechanics
well and the practical differences are too small to and introduced the principle of virtual work. The
be significant. formidable three-body problem of the Earth, Sun
Euclid™s achievement was immense. He was less and Moon system was solved approximately by him
talented than Archimedes but for long-lived (1753, 1772), leading to an award of £300 by the
authority and influence he has no peer. Within the British Government for the resulting improvement
Euler, Ulf Svante von

in navigational tables. In the course of this he devel- German army as an artillery officer, but then
oped much of classical perturbation theory. became commander of a bomber squadron in the
He worked on number theory, fluid flow, geomet- air force for half of each year, with his university
ry and acoustics. A large number of theorems are work in Stockholm compressed into the remaining
named after this extraordinarily creative and pro- half-year. On this odd basis began a research career
ductive man. One of the best-known is Euler™s rule, dominated by his study of enzymes and to a lesser
which shows that for a polyhedron with v vertices, extent their relatives the vitamins. His prolific
f faces and e edges, then v + f “ e = 2. output included work on saccharase, zymase,
He was active in mathematics to the moment of his urease and the pepsidases and on the co-enzymes
death, on a day spent partly in calculating the laws NAD and NADP. For his work on enzymology he
of ascent of the recently invented hot-air balloons. shared the Nobel Prize for chemistry in 1929 with
Euler, Ulf Svante von [oyler] (1905“83) Swedish Harden; his son Ulf von Euler shared the Prize for
physiologist. physiology or medicine in 1970 for isolating the
Son of a physiologist who won a Nobel Prize in neurotransmitter of the sympathetic nervous
chemistry, von Euler was a student and later a pro- system, and showing it to be noradrenalin; Ulf had
fessor at the Royal Caroline Institute in also discovered the first of the prostaglandins, in
Stockholm. In 1903 T R Elliott (1877“1961) of 1935.
Ewing, William Maurice (1906“74) US marine
Cambridge made the novel suggestion, based on
experiments, that nerve transmission is at least geologist: made first measurements of the thick-
partly chemical. For a time this idea was largely ness of the oceanic crust and discovered the global
ignored but it led to later successes by Dale and by extent of mid-ocean ridges.
O Loewi (1873“1961) and in 1946 von Euler isolated Ewing joined the Lamont“Doherty Geological
a neurotransmitter of the sympathetic nervous Observatory, New York, in 1944 and was instru-
system and showed it to be noradrenalin, and not mental in making it one of the world™s leading geo-
adrenalin as had been believed. Already, in 1935, he physical research institutes. Using marine seismic
had initiated work in another area by showing that techniques he discovered that the oceanic crust is
human semen contained a potent chemical, which much thinner (5“8 km thick) than the continental
lowered blood pressure and contracted muscle, crust (c.40 km thick). He also demonstrated the
which he named prostaglandin. (Bergstrom later global extent of mid-ocean ridges and in 1957 dis-
isolated two prostaglandins; more are now known covered the presence of a deep central rift in them.
and they form an important biochemical group.) His studies of the ocean sediment showed that its
Von Euler shared a Nobel Prize in 1970 with Julius thickness increases with distance from the mid-
Axelrod (1912“ ), US neuropharmacologist, and ocean ridge, which added support for the sea-floor
(Sir) Bernard Katz (1911“ ), German“British bio- spreading hypothesis proposed by H H Hess in
physicist, both of whom worked on neurotransmit- 1962.
Eyring, Henry (1901“81) US physical chemist: devel-
ters, and especially on the way these chemicals are
stored, released and deactivated in the nervous oped the theory of reaction rates.
system. Trained as a mining engineer, Eyring changed to
Euler-Chelpin, Hans K A S von (1873“1964) chemistry for his PhD and worked thereafter on
German“Swedish biochemist. chemical kinetics and the theory of liquids; his
Born in Germany, Euler-Chelpin began higher career was spent in Princeton and Utah.
education as an art student, but his interest in In a chemical reaction, some chemical bonds are
colour led him into science, which he studied in broken and new bonds are formed. Eyring devel-
Berlin, Göttingen and Paris, with teachers including oped methods based on quantum mechanics for
Planck, Nernst, Emil Fischer and van ™t Hoff. calculating the energies involved from which the
He became a lecturer in physical chemistry at rate of the chemical reaction can be calculated (in
Stockholm in 1900, and took Swedish nationality in selected cases) and also the effect of temperature
1902. When the First World War began he joined the on the rate.

Fabre, Jean Henri [fabruh] (1823“1915) French
Always poor, Fabre spent his working life as a
science teacher and was aged 50 before he could
spend all his time as a field entomologist. In 1878
he bought a small plot of land in Serignan,
Provence, to make an open-air laboratory. There he
observed and wrote about the insect world in a way
which revitalized interest in it by others and which
made him the best known of all entomologists. His
early research was on parasitic wasps but his close
studies of a variety of groups led him to write a 10-
volume survey of insects, which remains a classic.
Fabricius, David [fabreesyus] (1564“1617) German
astronomer: discovered first variable star.
A clergyman and an amateur astronomer,
Fabricius discovered that the brightness of the star
ο Ceti regularly varied from magnitude 9 to magni-
tude 3 over a period of about 11 months. This was
the first variable star to be found, causing him to
J H Fabre
name it Mira (the marvellous). In fact, Mira™s

change in luminosity is the result of a true change
in surface temperature, rather than the eclipsing
effect of a binary companion (eg Algol).
Fabrizio, Girolamo (Ital), Fabricius ab Aquapen-
dente (Lat) [fabritsioh] (c.1533“1619) Italian anato-
mist: pioneer of scientific embryology.
Fabrizio is often named in Latin, coupled with the
Tuscan village of Aquapendente where he was
born. He was a student in Padua and later taught
there for 50 years. He first studied the classics and
then medicine; his teacher of anatomy and surgery
was Fallopius, whom he succeeded as professor in
1565. He researched and wrote on the larynx, the
eye, muscular action and respiration. He super-
vised the building of the anatomy theatre in Padua,
which was the first of its kind and which still exists.
It was there that he demonstrated the valves in the
veins to his students, including Harvey, who
became interested in the problem of blood circula-
tion; Fabrizio did not understand the function of
the valves, which were to be a key in Harvey™s work.
Fabrizio™s most original research was in embryol-
ogy. In 1600 he wrote a comparative study of the
late fetus in various animals and in 1604 he
described the formation of the chick in the hen™s
egg from the sixth day. His well-illustrated descrip-
tions mark the beginning of embryology as a new
branch of biology.
After he officially retired in 1613 he continued as
an active researcher until his death, aged about 86.
Fahrenheit, Gabriel Daniel [fahrenhiyt] (1686“
1736) German physicist: developed the mercury
Louse and a human hair: Hooke's drawing from the com-
thermometer and the Fahrenheit temperature
pound microscope he invented, in his Micrographia of
Panel: Pheromones

PHEROMONES females in the ubiquitous aroma. Mating disruption is
remarkably effective in controlling the pink bollworm
Chemical communication is a new branch of chem- (Pectinophora gossypiella) in cotton. The advantage
istry. Pheromones are the best-known examples of and disadvantage of pheromone traps is that they are
that subject. A pheromone is a substance (or mixture effective for only one species. The use of pheromones
of substances) used for communication between in agriculture and horticulture is still limited com-
individuals of the same species. There are other terms pared to insecticides (perhaps a few million US
for chemical communication between species (eg dollars per annum, compared with billions of US
between plants and insects, prey and predators, dollars spent on insecticides), but is nevertheless of
hosts and parasites). These chemical messages growing importance in the control of pest insects.
belong to the greater subject of semiochemistry This kind of chemical communication is not con-
(semio = signalling). The word ˜pheromone™ was fined to insects. Pheromones have been recognized in
coined by analogy to ˜hormone™, a chemical messen- a wide range of species from bacteria, moulds, fungi,
ger within the individual (pherein = (Greek) I carry, marine and terrestrial invertebrates, fish and
horman = excite). mammals, right up to elephants. Today pheromones
The subject of pheromones can be traced to the of hundreds of species have been purified and identi-
work of FABRE, who discovered the attraction of male fied. Chemical communication probably reaches its
night-flying moths by females of their species, but it highest development in the social insects (ants,
was only in the 1930s that it began to emerge that termites, some bees and some wasps). A whole
this attraction was chemical. The first pheromone iso- language of chemicals has evolved to mark sexual
lated and identified was bombykol (see structure), attraction, alarm and attack, guidance to food
the substance produced by females of the silkworm sources, dominance in the colony, to distinguish
moth (Bombyx mori) to attract males for copulation. between colony members and aliens, and many other
This work was completed by BUTENANDT and co- functions. Knowledge of some of these is already
workers in 1959 after years of investigation. It was being used in commercial bee-keeping. Looking to all
followed by that of the gypsy moth (Lymantria dispar) species, the commonest uses of pheromones are
in the USA and the isolation of the aggregation sexual attraction, conveying an alarm or flight
pheromone of species of bark beetle that attack and message, and territorial marking. Many unusual
destroy trees, including the vector of Dutch elm actions in animals (eg the spraying of urine upwards
disease. and backwards by tigers and cats, the chinning on
The sexual attractant pheromones of some grass stalks by rabbits, the rubbing of facial glands on
hundreds of species of moths and butterflies twigs by deer) are now recognised as applying terri-
(Lepidoptera) that are agricultural pests have been torial marking pheromones. The cat brushing its
identified. The pheromone compounds can be syn- cheek against one's leg is really marking the recipient
thesized in the laboratory and incorporated into with chemicals from its cheek glands. Individual
slow-release lures made of rubber or plastic, and recognition pheromones are common among
these lures placed in traps with a sticky surface to mammals, but their structures are complex and
catch adult males. Pheromone traps are used in three largely unknown.
ways. In some cases sufficient males can be caught in Pheromone substances may be synthesized from
the traps to prevent many females being inseminated simple starting materials in the organism, or they
and so the production of the next generation can be may be modifications of substances ingested (eg
blocked, achieving complete control of the pest. In alkaloids or terpenes from plants). Their chemical
many more cases, in spite of massive capture of structures tend to fall into four groups: those derived
males, sufficient females are inseminated to produce from fatty acids (bombykol is an example); small
a new generation. The traps can still be used for mon- molecules of volatile substances, such as 2,5-
itoring the state of development of the adult insects dimethylpyrazine, a component of the mouse urinary
and spraying with insecticide can be limited to the pheromone that delays onset of female puberty,
time of build-up of the adults. This reduces the use which together with trimethylpyrazine (see structure)
(and cost) of insecticides and the amount of insecti- is also a component of some ant trail pheromones.
cide on the harvested crop. Thirdly, the traps can be Other pheromones are derivatives of amino-acids
used to assess the extent of infestation and decide from dipeptides to large proteins; and steroids, par-
whether insecticide spraying is necessary or economi- ticularly in vertebrates, where sexual hormones and
cal. Another technique is mating disruption. Small derivatives also function as mating pheromones “ eg,
sandwich-like pieces of plastic with the pheromone 17,20-dihydroxypregnenone, used by the female
impregnated into the central portion are scattered goldfish, Carassius auratus, to attract males at egg-
through the crop. The males are unable to locate the laying and stimulate them to produce milt.

Faltings, Gerd

Pheromones are usually produced in special pheromones in humans is very unclear, it is now
exocrine glands (those secreting to the external known that babies recognize their mother™s odour
surface) but may also be present in saliva, urine or from birth.
Professor E D Morgan
Infant animals can recognize their own mothers
Chemical Ecology Group
(as commonly observed in sheep) through
University of Keele
pheromones, from birth. While the evidence for

Fahrenheit worked as a glassblower in Holland, anions. Both rules follow from simple electrostatic
specializing in the construction of meteorological energy requirements; and they lead to the ˜diag-
instruments. He succeeded in improving the relia- onal similarities™ shown by elements in adjacent
bility and accuracy of the alcohol thermometers of periodic groups (eg Li and Mg; Be and Al; B and Si).
Fallopius (Lat), Gabriello Falloppio (Ital) (1523“62)
the day and in 1714 constructed the first successful
mercury thermometer, following Amontons™s Italian anatomist.
work on the thermal expansion of the metal. Using Fallopius first studied to become a priest, but
these instruments he discovered that different changed to medicine and was taught anatomy by
liquids each have their own characteristic boiling Vesalius. From 1551 he taught in Padua, and 10
point, which varies with atmospheric pressure. He years later his textbook extended and corrected
also discovered the phenomenon of supercooling of Vesalius™s work. His discoveries included structures
water, whereby water may be chilled a few degrees in the human ear and skull and in the female geni-
below its freezing point without solidification. talia. He first described the tubes from the ovary to
He is best remembered, however, for devising the the uterus; he did not know their function. It was
Fahrenheit scale of temperature, which used as its almost 300 years later that the ovum was discov-
reference points the melting temperature of a mix- ered; ova are formed in the ovary and pass down
ture of ice and salt (the lowest temperature he these Fallopian tubes to the uterus; if they are fer-
could obtain), and the temperature of the human tilized on their way, the embryo develops in the
body. This range was subdivided into 96 equal uterus. Fallopius is claimed to have invented con-
parts, with the freezing point of water falling at doms. Made of linen, they were intended to prevent
32°F and the boiling point at 212°F. syphilis rather than conception.
Fajans, Kasimir [fahyans] (1887“1975) Polish“US Faltings, Gerd (1954“ ) German mathematician.
physical chemist: devised rules for chemical Faltings graduated from university in Münster,
bonding. before taking positions at Harvard, Münster,
Born in Warsaw, Fajans studied in Germany and Wuppertal, Princeton and the Max Planck Institute
in England, and worked in Munich from 1917“35, in Bonn. He became interested in a conjecture put
when he emigrated to Chicago. His early research forward by Louis Mardell in 1922, and his proof of
was in radiochemistry, where he had ideas on iso- this led to the award of the 1986 Fields Medal (see
topes, and the displacement law, simultaneously Atiyah, p. 15). Mardell had suggested that a set of
with others. Although he worked in several areas of rational equations with rational coefficients that
physical chemistry, he is best known for Fajans™s defines an algebraic curve of genus greater than or
rules on bonding between atoms. The first rule is equal to two has a finite number of rational solu-
tions. An example of this is that xn + yn = zn in
that as highly charged ions are difficult or impossi-
ble to form, so covalent bonds are more likely to Fermat™s last theorem could have only a finite
result as the number of electrons to be removed or number of integer solutions for n > 2, which is a
donated increases; the second rule is that ionic first step in proving (see Wiles) that in fact there
bonding is favoured by large cations and small are no such solutions.
Faraday, Michael

Faraday, Michael (1791“1867) British chemist and special permission; it was a strange education, but
physicist: discovered benzene and the laws of elec- it gave him an awareness of most of the physical
trolysis; invented an electric motor, dynamo and and chemical science of the time and he became a
transformer; creator of classical field theory. skilful chemical analyst. The main omission was
Faraday had an intuitive grasp of the way physical mathematics, a shortcoming which he never
nature may work, combined with a genius for repaired. His first solo research, made when he was
experiment and great energy. Einstein had the 29, was the synthesis of the first known chlorocar-
view that physical science has two couples of equal bons (C2Cl6 and C2Cl4) and until 1830 he was mainly
magnitude; Galileo and Newton, and Faraday and a chemist. In 1825 he discovered benzene, which
Maxwell: an interesting equation. was later to be so important in both theoretical and
Faraday™s talents ripened late (he was at his best technical chemistry. He worked on alloy steels and
in his 40s; many scientists have their major ideas he liquefied chlorine and a range of other gases by
behind them at 30), but he began his education late. pressure and cooling. He was established at the
His father was an ailing blacksmith and the boy Royal Institution, became an excellent lecturer and
became a bookseller™s errand boy at 13. He learned never left until retirement; he could have become
bookbinding, read some of the books and was cap- rich from consultant work, but he belonged to a fer-
tivated by an article on electricity in an encyclope- vent religious group and he declined both wealth
dia he had to rebind and by Jane Marcet™s and public honours.
Conversations on Chemistry. These books were to From about 1830 he increasingly studied electric-
shape his life, and he soon joined a club of young ity. An early venture was the study of electrolysis,
men who met weekly to learn elementary science. and in 1832 and 1833 he reported the fundamental
He was given tickets to attend Davy™s last course of laws of electrolysis: (1) the mass of a substance pro-
lectures at the Royal Institution and he wrote ele- duced by a cathode or anode reaction in electrolysis
gant notes of these and bound them. These notes he is directly proportional to the quantity of electric-
sent to Davy, and applied for a job with him. Davy ity passed through the cell, and (2) the masses of
firmly recommended him to stay with bookbind- different substances produced by the same quan-
ing, but he had injured an eye (making NCl3) and tity of electricity are proportional to the equivalent
took Faraday as a temporary helper. After a few masses of the substances (by equivalent mass is
weeks he gave him a permanent job as assistant; meant the relative atomic mass divided by the
Faraday was later to become his co-worker, then his valence). Faraday had an excellent set of new words
successor at the Royal Institution and in time his devised for him by Whewell for work in this area:
superior as a scientist. Faraday learned quickly and electrolysis, electrolyte, electrode, anode, cathode,
he was lucky, because Davy decided to make a ion. It follows from the laws of electrolysis that an
grand European tour, taking Faraday with him as important quantity of electricity is that which will
helper and valet. The young man was to meet most liberate one mole of singly charged ions. This
of the leading scientists during a one-and-a-half amount, the Faraday constant, F, is defined by
year tour, made despite the Anglo-French war by F = NAe where NA is the Avogadro constant and e is

Michael Faraday (right) and J F Daniell (left, hand on head)
Fehling, Hermann Christian von

the charge on an electron. F can be measured accu- Farman worked briefly in the aerospace industry
rately (eg by electrolysis of a silver solution) and has before embarking on a career with the British
the value 9.648 — 104 C mol “1. Also named for Fara- Antarctic Survey in 1956.
day is the unit of capacitance, the farad (F). It is the In 1984 Farman and his colleagues discovered an
capacitance of a capacitor (condenser) having a ˜ozone hole™ in the stratosphere above the
charge of one coulomb (C) when the potential dif- Antarctic. This finding, made using ground-based
ference across the plates is one volt. This is a large instruments, was confirmed by American satellite
unit and the more practical unit is the microfarad, observations and a review of past satellite data
equal to 10 “6 F. revealed that winter ozone levels had been declin-
Faraday™s work on electricity in the 1830s largely ing for the past 10 years and by the mid-80s were
developed the subject. Oersted had shown that a down to about 50% of the 1957 level. This had not
current could produce a magnetic field; Faraday been noticed earlier because the computers that
argued that a magnetic field should produce a cur- processed the satellite measurements had been
rent. He found this to be so, provided that ˜a con- programmed to ignore such low values as ˜impossi-
ductor cut the lines of magnetic force™. He had ble™, although ozone loss was foreseen by P
discovered electromagnetic induction (indepen- Crutzen, M Molina and S Rowland in the 1970s,
dently discovered by J Henry) and to do it he used who won a Nobel Prize for this in 1995.
his idea of lines and fields of force producing a The stratospheric ozone layer plays a vital role in
strain in materials, an idea which was to be highly protecting the Earth™s life from the more harmful
productive. With it he was able to devise primitive effects of the Sun™s ultraviolet rays. Increased levels
motors, a transformer and a dynamo; he cast off the of UV light have been shown to cause skin cancers
old idea of electricity as a fluid (or two fluids) and and eye cataracts, to kill phytoplankton and there-
moved to solve some basic problems. For example, fore disrupt the marine food chain, and to decrease
he showed that current from an electrostatic crop yields. Long-term depletion of the ozone layer
machine, a voltaic cell and a dynamo is the same, could have very serious effects for life on Earth.
and devised methods to measure its quantity. He For the first few years after Farman™s discovery it
examined capacitors and the properties of di- was hoped that the depletion of the ozone layer,
electrics, and he discovered diamagnetism. In the which undergoes natural seasonal variations, was a
early 1840s he was unwell for 5 years with ˜ill natural and transient phenomenon. However, the
health connected with my head™. It may have been depletion has both continued and increased in
mercury poisoning. severity, and has also been observed in the ozone
Back at work in 1845, he worked on his idea that layer of the more heavily populated northern hemi-
the forces of electricity, magnetism, light and grav- sphere, which is losing its ozone at a rate of about
ity are connected and was able to show that polar- 5% per decade.
ized light is affected by a magnetic field. He failed It is now widely accepted that the depletion is due
to get a similar result with an electric field (Kerr to the effects of man-made chemicals, notably chlo-
succeeded in 1875) and the general theme of the rofluorocarbons (CFCs), released into the atmos-
˜unity of natural forces™ has been pursued to the phere over the past 20“30 years. CFCs have been
present day. In 1846 Wheatstone was due to speak widely used in refrigeration and insulation materi-
at the Royal Institution, but at the last moment als, but also have the unforeseen property of
panicked and Faraday had to improvise a lecture. catalysing the breakdown of ozone (O3). Although
He included his ˜Thoughts on Ray Vibrations™, governments are now taking measures to reduce
which Maxwell claimed were the basis of the elec- the release of CFCs into the atmosphere, it is esti-
tromagnetic theory of light that Maxwell, with new mated that even if CFC production were completely
data and more mathematical skill, devised 18 years halted immediately, it would take another 70 years
later. before this had a significant effect on restoring the
Faraday had a very strange mind, but it well fitted ozone layer.
the needs of physics at the time. His personality Farman™s discovery has been of the utmost impor-
offers curious contrasts; he had much personal tance in highlighting the fact that man™s polluting
charm, but no social life after 1830. He had great activities are now of such a scale as to jeopardize
influence on later physicists, but no students, and the whole future of life on Earth. Within 3 years of
worked with his own hands helped only by a long- his discovery the Montreal Protocol took the first
suffering ex-soldier, Sergeant Anderson. He had steps to limit worldwide CFC production. Farman
highly abstract ideas in science, but he was a most has remained extremely active in lobbying govern-
effective popularizer; his Christmas lectures for ments and other bodies on the consequences of
young people, begun in 1826, are still continued ozone depletion and in campaigning for increased
and are now televised. In quality and in quantity, restrictions on the manufacture of CFCs.
Fehling, Hermann Christian von [fayling] (1812“
he remains the supreme experimentalist in
physics. 85) German organic chemist.
Farman, Joseph C (1930“ ) British atmospheric A pupil of Liebig, Fehling taught in Stuttgart. He
scientist: found the Antarctic ozone hole. is best known for the test reagent Fehling™s solu-
After graduating from the University of Cam- tion, which contains a deep blue copper(II) complex
bridge in mathematics and natural sciences, in aqueous alkaline solution. If the organic test
Fermat, Pierre de

sample on boiling with this removes the blue
colour and reduces the copper to brick-red copper(I)
oxide, it is likely to be an organic aldehyde or reduc- glass
air air
ing sugar. However, formates, lactates, haloforms
and some esters and phenols also give a positive
Fermat, Pierre de [fairmah] (1601“65) French
mathematician: ˜the prince of amateurs™.
As a senior Government law officer it is remark-
able that Fermat found time to maintain his skills
as a linguist, amateur poet and, most notably, as an B
amateur mathematician. After 1652, when he
nearly died of plague, he did give most of his time
to mathematics, but he still did not publish his
work in the usual sense, and his results are known Fermat™s principle “ the dotted line shows the shortest
through his letters to friends, notes in book mar- path between A and B. A light beam follows the solid line,
consistent with the laws of refraction, because the veloc-
gins and challenges to other mathematicians to
ity of light in the glass is less than in air. The solid line is
find proofs for theorems he had devised.
the path of least time.
His successes included work on probability, in
which he corresponded with Pascal and reached
agreement with him on some of its basic ideas; on discovered a truly marvellous demonstration¦
analytical geometry, where again he achieved par- which this margin is too narrow to contain™. For
allel results with another talented researcher, over three and a half centuries after he wrote this
Descartes, and went further in extending the in about 1637, generations of mathematicians
method from two dimensions to three; and on the failed to re-create his proof, and some thought that
maxima and minima of curves and tangents to it might be inherently unprovable. However, in
them, where his work was seen by Newton as a 1993 the British mathematician A J Wiles
starting point for the calculus. In optics he devised announced a proof. His work has had a great
Fermat™s principle and used it to deduce the laws of impact on mathematics, as the Last Theorem was
reflection and refraction and to show that light also demonstrated to be linked with elliptic equa-
passes more slowly through a dense medium. He tions and modular forms, two topics of wide appli-
worked on the theory of equations and especially cation in modern mathematics.
Fermi, Enrico [fairmee] (1901“54) Italian“US
on the theory of numbers. Here he was highly
inventive and some of his results are well known nuclear physicist: built first atomic reactor.
but, as he usually did not give proofs, they teased Enrico Fermi was the greatest Italian scientist of
other mathematicians in seeking proofs for a modern times and was highly creative both as a the-
long time, with much advantage to the subject. oretical and experimental physicist. The son of a
Proofs were eventually found, recently in one railway official, he showed ability from an early age
case. Fermat™s last theorem, noted in one of and earned his PhD at Pisa, researching on X-rays.
his library books, states that the equation Fermi then worked with Born at Göttingen and
xn + yn = zn where n is an integer greater than 2, can with P Ehrenfest (1880“1933) at Leiden, before
have no solutions for x, y and z, and records ˜I have returning to a professorship at Rome in 1927. He
had already published over 30 papers, including
some on quantum statistics (Fermi“Dirac statistics)
followed by work on spin- particles (now called
fermions) such as the electron.
Fermi worked hard to build up Italian physics,
but the circle of talent around him was dispersed
by the growth of Fascism, and Fermi and his wife,
who was Jewish, left for Columbia University, New
York in 1938. While in Rome, Fermi worked on the
Raman effect, hyperfine structure, cosmic rays and
virtual quanta. In 1933 he produced the theory of
radioactive beta-decay, whereby a neutron emits an
electron (beta-particle) and an anti-neutrino and
becomes a proton. The following year he showed
that, rather as the Joliot“Curies had used helium
nuclei (alpha-particles) to induce nuclear transmu-
tations, neutrons were even more effective. This led
to his rapid discovery of over 40 new radioactive iso-
topes. He then, by chance, discovered that paraffin
wax could be used to slow down the neutrons and
make them more effective, by a factor of hundreds,
Pierre de Fermat
Panel: The history of mathematics

THE HISTORY OF MATHEMATICS influence. His Arithmetic introduced the Indian
decimal-place-value numerals, and his Algebra has
The earliest mathematical writer whose name we given the subject its name (his own name still being
know was the Egyptian scribe Ahmes, who in c.1650 remembered in the word algorithm). By the late
BC copied an earlier text on handling fractions and 12th-c much mathematical knowledge had been
solving arithmetical problems. But for at least 1000 developed and held in the Islamic culture around the
years before that, scribes in the great river civiliza- southern shores of the Mediterranean, and it was
tions of Egypt and Mesopotamia were developing beginning to percolate into Christian Europe through
ways of representing numbers and solving problems trading posts in such places as Sicily and Spain.
that are recognizably precursors of today™s mathe- In particular, the Islamic world was using for its
matical activity. numerals a decimal-place-value system. An Italian
A significant change was introduced by Greek- with trading links to Sicily, FIBONACCI, noticed that the
speaking people around the E Mediterranean during Arabs were using much more efficient numerals “
500“200 BC: the development of the notion of which one could calculate with as well as record
proving results as a fundamental characteristic of number values “ and wrote his book Liber abaci
mathematical activity. A research tradition in geo- (1202, Book of the Abacus) to publicize this.
metry grew up, whose basic results were codified by This period is one of rich mathematical activity in
EUCLID in Elements of Geometry (c.300 BC), and many parts of the world. China at this time was home
culminated in the work of ARCHIMEDES and APOLLONIUS. to mathematicians of the calibre of Yang Hui, who
Later, the idea that the cosmos is intrinsically math- had explored the binomial pattern several centuries
ematical, an influential idea found in the work of before ˜Pascal™s triangle™ became known in the West;
Plato, was retrospectively attributed to the semi- and Chu Shih Chieh, who took the Chinese arithmeti-
mythical figure of PYTHAGORAS. The Greek math- cal-algebraic computational style to new heights. In
ematical tradition lasted for several further centuries, India, Bhaskara (12th-c) wrote valuable works on
notably in Alexandria, and ranged from the astro- arithmetic, algebra and trigonometry; and Madhava
nomical and geographical work, exemplified by (c.1340“1425) headed a research tradition in Kerala
PTOLEMY, to the arithmetical investigations of whose work in infinite series and trigonometrical
DIOPHANTUS, who raised the solving of number- functions, anticipating later European work in math-
problems to a new height. It was in Alexandria, too, ematical analysis, is only now beginning to be dis-
that the first well-attested woman mathematician, covered. In Iran, Omar Khayyam (c.1048“c.1122)
HYPATIA, lived and where she was murdered in 415, worked to develop arithmetic, algebra and geometry,
probably by a mob of zealous early Christians. as well as astronomy and philosophy.
Meanwhile, mathematical activity had been During the late Renaissance, European math-
vigorously pursued in the civilizations of China and ematics had begun to absorb ancient Greek
India. It is not easy to reconstruct Chinese math- mathematical works, made available by the efforts of
ematics before the Emperor Shih Huang Ti™s great such scholars as Regiomontanus (1436“76),
book-burning of 212 BC. Nonetheless, during the Maurolico (1494“1575), and Commandino (1509“
following centuries scholars such as Lui Hui (c.260) 75). An important development was the solution of
worked to reconstruct and comment on earlier math- cubic and quartic equations in Italy, notably in the
ematical works, besides developing both geometry Ars magna (1545, Great Art) of CARDANO, and the
and a characteristically Chinese arithmetical- further development of algebraic analysis by VIETE.`
algebraic computational style, which they brought During the 17th-c, Europe saw not only a spec-
to bear on such areas as computing bounds for π and tacular flourishing of mathematical creativity “ with
solving determinate and indeterminate problems. such mathematicians as NAPIER, DESCARTES, FERMAT,
India, too, has a long mathematical tradition, HUYGENS, NEWTON and LEIBNITZ “ but also the growth
initially in a religious context of astronomy and altar- of institutions for promoting scientific activity and
construction, first recorded by Baudhayana c.800“ journals to communicate and broadcast the results.
600 BC. The later mathematician-astronomer During the next century, mathematization of many
Aryabhata (late 5th-c) and Brahmagupta (early 7th-c) diverse fields of human interest became fashionable
wrote important works involving arithmetic, algebra, in the wake of the enormous success of Newton™s
and trigonometry, whose influence spread to the Principia (1687). Mathematicians of the calibre of the
West in succeeding centuries. BERNOULLI family, EULER and LAGRANGE consolidated
Baghdad in the 9th-c was an important centre for the methods of calculus, applied them to mechanics
the pivotal Islamic contributions to mathematics. and developed new mathematical areas and
There AL-KHWARIZMI wrote a number of books, approaches “ notably, an increasing movement
drawing together Babylonian, Greek and Indian from geometry to algebra as the natural language of

Fernel, Jean Fran§ois

mathematics. It was in the 18th-c too that some real numbers, helped consolidate the process of arith-
women began to play a part in disseminating and metizing analysis, as did the work of WEIERSTRASS. One
researching into mathematics, notably AGNESI, of Weierstrass™s pupils who benefited from the slowly
CH‚TELET-LOMONT and GERMAIN. opening higher educational opportunities for women
One consequence of the French Revolution was was SONYA KOVALEVSKY.
the promotion of mathematics in education. About During the 20th-c much new mathematics
this time text-books were increasingly used, along developed, partly through exploring structures
with tests and examinations, to create mathematics common to a range of theories, thus counteracting
syllabuses and new educational practices. the tendency to split into more and more distinct
Mathematical activity in France (MONGE, LAPLACE, specialized areas. Topology has, under the consider-
CAUCHY) and subsequently in Germany (GAUSS, able influence of POINCARÉ, reached new heights of
JACOBI, DIRICHLET, RIEMANN) was strongly developed geometrical generality and unifying power, while
and professionalized, in both research and teaching algebra too has become even more general in its


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