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http://www.archive.org/details/cu31924031226370 



BRITAIN'S HERITAGE OF SCIENCE 




Sir Isaac Newton 



From an engraving 



BRITAIN'S HERITAGE 
OF SCIENCE 

BY 

ARTHUR SCHUSTER, F.R.S. 

AND 

ARTHUR E. SHIPLEY, F.R.S. 
ILLUSTRATED 



LONDON 

CONSTABLE & CO. LTD. 

1917 



ERRATA. 

Page 70, line 5 from bottom : 

for " Robert " read " Charles." 

Page 286, liae 10 from bottom : 

for " Sir William Herschel " read " Sir William 
James Herschel, eldest son of Sir John 
Herschel." 

for " Foulds " read " Faulds." 

Page 291 , line 11 from top : 

for " Thompson " read " Thomson." 



LIST OP PORTRAITS 



Sib Isaac Newton - - Frontispiece 

From an engraving of a painting by Kneller, in the posses- 
sion of Lord Portsmouth. 

John Dalton - Facing p. 16 

From, a painting by R. B. Faulkner, in the possession of the 
Royal Society. 

Michael Faraday - Facing p. 32 

From, a painting by A. Blaheley, in the possession of the 
Royal Society. 

The Hon. Robert Boyle - Facing p. 72 

From a painting by F. Kerseboom, in the possession of the 
Royal Society. 

John Clerk Maxwell - Facing p. 86 

From an engraving in " Nature " by O. J. Stodart of a photo- 
graph by Fergu,s, of Olasgow. 

SiE Humphry Davy - Facing p. 112 

From a painting by Sir Thomas Lawrence, in the possession 
of the Royal Society. 

Sm George Gabriel Stokes Facing p. 124 

From a photograph by Fradelle <fc Young. 



VI 



List of Portraits 



James Pbescott Jottxe . . - 

From a photograph by Lady Roscoe. 

William Thomson, Loed Kelvin 

from a photograph by Messrs. Dickinsons. 

Thomas Young ... 

From a portrait by Sir Thomas Lawrence. 

John Ray - 

After a portrait in the British Museum. 

Stephen Hales - - - - 

After u, portrait by Thomas Hudson. 

Charles Daewin 

After a photograph by Messrs. MauU <& Fox. 

William Haevey 

After a painting by Gorneliva Janssen, now at 
Physicians. 

Charles Lyell - - - 

After a daguerreotype by J. E. Mayal. 



Facing p. 160 

- Faxjing p. 190 

- Facing p. 212 
Facing p. 232 

- Facing p. 236 

- Facing p. 268 

- Facing p. 294 
the OoUege of 

- Facing p. 310 



SYNOPSIS OF CONTENTS 



Chapter Pages 

I. The Ten Landmarks of Physical Science 1-45 

Roger Bacon — Gilbert, the founder of terrestrial mag- 
netism, his electrical researches — Napier's discovery of 
logarithms — Continuity of scientific progress in Great 
Britain from the seventeenth century onwards — ^New- 
ton's laws of motion and discovery of gravitation — 
Importance of Newton's work — Foundation of modern 
chemistry by Dalton — Foundation of undulatory theory 
of light by Young — Faraday's electrical discoveries — 
Conservation of energy established by Joule and Thom- 
son — Clerk Maxwell's electro -magnetic theory of hght 
— His work on kinetic theory of gases — Biographical 
notes on Newton, Dalton, Young, Faraday, Joule, 
Thomson, and Clerk Maxwell. 

II. Physical Science — ^The Heritage oe the 
Universities during the Seventeenth and 
Eighteenth Centuries 46-71 

Activity in the Universities during the seventeenth cen- 
tury — Foundation and early history of Gresham College 
— Briggs, tables of logarithms and decimal fractions — 
Edward Wright and Meroator's projection — ^Wallis — 
Lord Brouncker's use of infinite series — ^Wren's mathe- 
matical and astronomical work — The Gregory family, 
first suggestion of reflecting telescopes — Newton's op- 
tical discoveries — Robert Hooke, " Miorographia " — 
Flamsteed, first Astronomer Royal — HaUey's mag- 
netical and astronomical work — Bradley's discovery of 
aberration and nutation — Bliss — Maskelyne, founder 
of the " Nautical Almanac " — Density of earth — The 
Scottish Universities — ^William Cullen, founder of the 
Scottish school of Chemistry — Black's chemical dis- 
coveries — Latent heat — ^Use of hydrogen for filling 
balloons — Rutherford's isolation of nitrogen — Robison 
— Playfair — Desaguliers — Robert Smith. 



viii Contents 

Chapter Pages 

III. Physical Science— The Non-Academic Herit- 
age DUEING THE SEVENTEENTH AND EIGHTEENTH 

Centuries - - - 72-105 

Distinction between amateurs tind professional men 
of science — Robert Boyle's life and work — Boyle's law 
— Optical and chemical experiments— Taylor's theorem 
—Early history of the Royal Society — First record 
of electric spark by Hauksbee— Isolation of argon 
forestalled — Joseph Priestley, chemical production 
of oxygen — Composition of water — Direct proof of 
gravitational attraction by Cavendish — Michell's tor- 
sion balance — Horrocks, first observation of transit 
of Venus — Molyneux— William Hersohel, discovery 
of Uranus and other astronomical work — Discovery of 
infra-red radiations — Importance of construction of 
scientific instruments — Oughtred's slide-rule — Gas- 
ooigne's eyepiece-micrometer — Hadley's sextant — Tem- 
perature compensation of pendulum by Graham and 
Harrison — Divided circles — Ramsden's eyepiece — 
Achromatism : More Hall and DoUond — Early history 
of steam engine : Somerset, Savery, Papin, Newoomen 
— Improvements by James Watt— Invention of con- 
denser — ^First locomotive constructed by Trevithick — 
First compound engine by Hornblower — Murdock and 
illuminating gas — Bramoh's hydraulic press. 

IV. Physical Science — The Heritage of the 

Nineteenth Century - - - - 106-142 

Nicholson's electrolytic decomposition of water — Cor- 
relation of physical forces — Count Rumford's generation 
of heat by mechanical power^Humphry Davy — Dis- 
covery of laughing gas — Isolation of metallic potassivim 
and sodium— Safety lamp — Revival of scientific re- 
search at Cambridge — Woodhouse, Peacock, Whewell — 
Physical optics advanced by Airy and Baden Powell — 
The golden age of mathematical physios at Cambridge 
— Green — Stokes' researches on light and hydrodynamics 
— Fluorescence — Discovery of Neptune by Adams — 
Sylvester, Cayley, Routh — Miller's work on crystallo- 
graphy — Physical science in the Scottish Universities — 
Maximum density of water discovered by Hope — 
Leslie's investigations on radiant heat — Brewster's 
researches on light — Important work of Forbes — Tait, 
Chrystal, Kelland — Rankine and conservation of energy 
— James Thomson — Hamilton, discovery of conical 
refraction — Physical science in Ireland — Trinity College 



Cont^its ix 

Chaptbb Pages 

— Lloyd, MoOullagh, Jellett, Salmon, Haughton — Fitz- 
gerald, Johnstone Stoney — Andrews on ozone and 
liquefaction of gases — Science at Oxford : Henry Smith, 
Odling, Vernon Harcourt, Pritchard. 

V. Physical Science — The Heritage of the 

Ndtetebnth Centuky — (continued)- - 143-186 

Fomidation of University of London — ^University Col- 
lege and Bang's College — De Morgan — Graham's re- 
searches on gases^Discovery of palladium and rhodium 
by Wollaston — Chemical work of Williamson — ^Electrical 
researches of Wheatstone — Owens College and Man- 
chester University — Chemical school of Frankland and 
Koscoe — Osborne Reynolds and scientific engineering — 
Balfour Stewart on radiation and absorption — ^History 
of spectrimi analysis — Discovery of thallium by Crookes 
- — Riicker's researches on thin films, his magnetic sur- 
veys — Poynting and energy paths — Radiation pressure 
— Distinguished work of amateurs : Baily, Gassiot, 
Grove, Spottiswoode, Schunck, Sorby — ^Waterston's 
neglected investigations on theory of gases — Progress in 
astronomy : Jolm Herschel, Gill, Rosse, LasseU, Nas- 
myth — ^Application of photography to astronomy : de 
la Rue, Common, Roberts — Application of spectrum 
analysis to astronomy : Lockyer, Huggins — NewaU's 
large telescope — Early history of photography : Wol- 
laston, Wedgwood, Herschel, Fox Talbot— Dry plates 
and gelatine emulsions — Abney's work on theory of 
photography — Colour photography : Rayleigh, Joly — 
Geophysical work of Kater, Sabine, Clarke — Meteoro- 
logical work of Wells, Howard, Apjohn, Glaisher, 
Archibald, Buchan, Aitken — George Darwin and oos- 
mical evolution— Foundation of seismology by Milne — 
Recent advances in physics — Rayleigh's discovery of 
argon — Researches of Ramsay — Discovery of helium — - 
Crookes' radiometer — His improvement of air pumps — 
J. J. Thomson and electric discharge through gases — 
Electric constitution of matter — Larmor — Discovery of 
radio-activity — ^Rutherford's discovery of emanation — 
Theory of radio-activity — Moseley's brilliant researches 
and early death. 

VI. Physical Science — Some Industrial Appli- 

cations 187-202 

Manufacture of steel — ^The electric telegraph : Ronalds, 
Cooke, Wheatstone — Submarine cables : Kelvin, Newall, 
Hancock — ^Vulcanization of rubber — The microphone 



X Contents 

Chapter Paoes 

of Hughes — Sturgeon's electromagnet — Development of 
electrical industry — ^Wilde — Hopkinson, Ewing, Ayrton 
The alkali industry : Gamble, Leblano, Muspratt, — 
Gossage, Solvay, Mond, Deacon, Weldon — Royal Col- 
lege of Chemistry — Discovery of coal-tar dyes — Perkin, 
Nicholson — Early promise and subsequent neglect of 
industry — ^Meldola — Explosives : Abel, Dewar — Play- 
fair and encouragement of science. 

VII. Physical Science — Scientific Institutions 203-215 

Early history of Royal Society — Privileges as regards 
patents — Their action in promoting food production, 
inoculation, the prevention of jail fever, and protection 
against lightning — Repository of natural rarities — Pro- 
motion of scientific expeditions, surveys — Comparison 
of standards — Connexion with Greenwich Observatory 
and Meteorological Office — Foundation of National 
Physical Laboratory — Friendly relations with foreign 
academies — Royal Society of Dublin — Royal Society 
of Edinburgh — Royal Society of Arts and other scientific 
societies — Constitution of Royal Society compared with 
that of foreign academies — Royal Institution — Dewar's 
work on liquefaction of gases — ^The British Association. 

Vlll. Biological Science in the Middle Ages- 216-228 

Physiologus — Bartholomew's " Liber de Proprietatibus 
Rerum " — Roger Bacon — Vesalius, the founder of 
modern anatomy and physiology — Moffett — Biological 
science in Elizabethan and Stewart times — Francis 
Bacon — Lord Herbert — Evelyn — Pepys — King Charles' 
interest in science. 

IX. Botany 229-255 

Early herbalists — Turner, Gerard, Johnson — New era 
inaugurated by Ray — Morison — Grew, one of the 
first students of vegetable anatomy — Hales, the 
founder of the physiology of plants — Knight and cir- 
culation of sap — Foundation of Linneean Society by 
Smith — Scientific explorers : Sloane, Banks — Great 
Britain leads the way in introducing scientific classifica- 
tion — Robert Brown — Discovery of nucleus of cells — 
Brownian movement — Lindley, a great taxonomist — 
The elder Hooker, Bentham — Joseph Hooker ; early 
expeditions, friendship with Darwin, Himalayan 
travels — ^Flora Indica — Huxley's influence on teaching 
of botany — Berkeley and cryptogamio botany — Botany 



Contents xi 

Chapter Pages 

at Oxford : Sherard, Sibthorp, Daubeny — Botany at 
Cambridge : Martyn, Henslow, Marshall Ward — Botany 
in Scotland : Sutherland, Greville, Balfour — Botany in 
Ireland : Threlkeld, Allman — Historical summary of 
British Botany. 

X. Zoology - - - - 266-293 

Early history — Turner, Wotton, Caius, Topsell — 
Influence of falconry — ^WiUughby and Ray — The Tra- 
descants — Zoology in eighteenth century : Pennant, 
WiUiam Hunter — John Hunter, his zoological collections 
— Revival in nineteenth century — Owen — His efforts 
to reorganize the natural history department of British 
Museum — Charles Darwin — ^His ancestry, Erasmus Dar- 
win — Studies at Edinbvu-gh and Cambridge — ^Voyage 
of the "Beagle" — Appreciation of Darwin's work by 
Wallace — ^History of evolution and natural selection — 
Heredity — ^Early supporters of Darwin : Huxley, Lyell, 
Hooker — The work of Wallace — ^Allman — ^Huxley, 
morphologist, teacher, and organizer — F. M. Balfour's 
work on embryology and early death — ^Romanes, Sedg- 
wick — Biometrics : Weldon, Galton — Ray Lankester, 
his work on morphology and other branches of zoology 
— ^Maritime zoology — ^Edward Forbes, Gosse — ^Voyage 
of " Challenger " — Scientific results of cable lajring — 
Progress in scientific classification dvuing nineteenth 
century — Exploration of Central America by Godman 
and Salvin — Marine stations and laboratories. 

XI. Physiology - .... 294-307 

Harvey, the circulation of blood — ^Mayow's researches 
on respiration and the oxidizing of venous blood, 
muscular heat — ^Medical science and physiology — Syden- 
ham, Glisson, Lower and the transfusion of blood — 
Willis and brain anatomy — Havers' " Osteologia Nova " 
— Important researches of Hales, blood pressure, secre- 
tions—Joseph Black's contributions to physiology — 
Hewson, discovery of lymphatic and lacteal vessels — 
Coagulation — ^Young, founder of physiological optics 
— Addison — Bowman — Cambridge School of Physio- 
logy — ^Michael Foster — Gaskell, studies on nerves and 
. heart action — Action of chloroform on heart — Sharpey 
— SpeciaUzation of biological science— Wooldridge — 
Contributions to the practice of medicine — ^Discovery 
of chloroform by Simpson — Jenner, preventive inocu- 
lation — Bell — Lister's antiseptic surgery — Roy. 



xii Contents 

Chapter Pages 

XII. Geology - - - - 308-319 

Great Britain, a geological microcosm — ^WUliam Smith, 
rock strata — ^Beds of rocks characterized by fossils— 
CShronological sequence — Hutton and the Huttonian 
theory — Lyell and Unifonnitarianisin — ^Allport, D. 
Forbes — Sorby, crystal structure — Influence of local 
surroundings — ^The district of St. David's, oldest rocks 
in Great Britain — Aymestry limestone — ^The Silurian 
system — Sedgwick, Cambritm rocks — Miller, old red 
sandstone — Delabeche, importance of mapping — The 
Government geological svu-vey — PhiUips — ^New red sand- 
stone — Fitton and ManteU- — Prestwich, E. Forbes — 
Palseontological work by Davidson and others — James 
Geikie — Archibald Geikie — Buckland, diluvial deposits 
— Economic geology. 

Index - - - . 321 



PREFACE 

npHIS book does not pretend to estabKsh any thesis. 
-*- Incidentally it may point a moral which different 
readers will interpret in different ways. Our main 
purpose was to give a plain account of Britain's great 
heritage of science ; an heritage that — handed down 
through several centuries of distinguished achieve- 
ments — ^will, if the signs speak true, be passed on to 
the coming age with untarnished briUiancy. 

A hmit had to be set to the extent to which 
contemporary science should be included, and some 
difficulty was felt in fixing that Hmit. It seemed 
desirable — ^for obvious reasons — to avoid discussing the 
work of hving men ; but no fixed rule could be enforced 
because that work is often too much interwoven with 
that of others who are no longer with us to be com- 
pletely ignored. Sometimes, also, researches undertaken 
by our present leaders have led to results that are 
firmly established, and to have omitted them would 
have conveyed a false idea of the part which Great 
Britain has played in the recent progress of science. 
In such cases we had to use our discretion in breaking 
through a rule which — as a principle — we have tried to 
adhere to. 



Preface xv 

Part of the History of Biological Science has been 
taken, by kind permission of the Editors and of the 
authorities of the Cambridge University Press, from 
the "Cambridge History of EngHsh Literature." In 
that portion of the chapter on Zoology which deals 
with Charles Darwin considerable extracts have also 
been made from the Presidential Address to the Zoo- 
logical Section of the Winnipeg Meeting of the British 
Association. 

Our thanks are due to the Council of the Royal 
Society for permission to reproduce a number of por- 
traits, and to the Editor of " Nature " for allowing 
the reproduction of the excellent engraving of Clerk 
Maxwell. The portraits which accompany the last five 
chapters were prepared from photographs kindly taken 
by the Rev. Alfred Rose, of Emanuel CoUege, Cam- 
bridge, from various well-known prints. The excellent 
likeness of Joule, taken about 1875 by Lady Roscoe, 
now appears for the first time. 

A. S. 
A. E. S. 
August 1917. 



BRITAIN'S HERITAGE OF SCIENCE 

CHAPTER I 

The Ten Landmarks of Physical Science 

(Roger Bacon, Gilbert, Napier, Newton, Dalton, Young, 
Faraday, Joule, William Thomson, Clerk Maxwell) 

THE history of British Science begins with Roger Bacon, 
the Franciscan friar, who, cutting himself adrift 
from the scholastic philosophy of his time, rejected the 
traditional appeal to recognized authority, and urged with 
a powerful voice that a knowledge of Nature can only be 
attained through experimental research and by logical 
reasoning. Intellectually he stood high above the level of 
his contemporaries;^ by his writings he set the true 
standard of scientific enquiry, and planted the first of the 
great landmarks along the path of British science. 

" There are two methods," he writes, " in which 
we acquire knowledge, argument and experiment. Argu- 
ment allows us to draw conclusions, and may cause us 
to admit the conclusion ; but it gives no proof, nor does 
it remove doubt, and cause the mind to rest in the 
conscious possession of truth, unless the truth is dis- 
covered by way of experience, e.g., if any man who had 
never seen fire were to prove by satisfactory argument 
that fire bums and destroys things, the hearer's mind 
would. not rest satisfied, nor would he avoid fire; imtil 
by putting his hand or some combustible thing into 
it, he proved by actual experiment what the argument 
laid down; but after the experiment had been made, 
his mind receives certainty and rests in the possession 
of truth, which could not be given by argument but 

* An interesting account of the general character of scientific 
speculations before Bacon's time has been given by Charles L. Bamee 
(" Manch. Lit. and PhU. Soc," Vol X. 1896). 



2 Britain's Heritage of Science 

only by experience. And this is the case even in mathe- 
matics, where there is the strongest demonstration. 
For let anyone have the clearest demonstration about an 
equilateral triangle without experience of it, his mind will 
never lay hold of the problem until he has actually before 
him the intersecting circles and the lines drawn from the 
point of section to the extremities of a straight Une."' 
In a more detailed discussion of experimental science, 
he points to three " prerogatives " which it has over other 
sciences. It tests the conclusions of these other sciences 
by experience, it attains to a knowledge of truth which could 
not be reached by the special sciences, and "it has no 
respect for these, but investigates on its own behalf the 
secrets of Nature, which consist in a knowledge of the future, 
the past and the present, and the inventing of instruments 
and machines of wonderful power." 

We further note Bacon's repeated plea for the study of 
mathematics, which he judges to be " the key and door to 
the special sciences." 

Roger Bacon was bom about 1214, in the county of 
Dorset, of wealthy parents. Having completed his studies 
at Oxford, he seems very soon to have gained a reputation 
by lecturing, both at Oxford and Paris, where he went 
about 1236. He entered the Franciscan Order, and, though 
in bad health, continued his studies, devoting part of his 
time to optical experiments. 

" During the twenty years," he writes in 1267, " in 

which I have laboured specially in the study of wisdom, 

aiter abandoning the usual methods, I have spent more 

than £2,000 on secret books and various experiments and 

languages and instruments and mathematical tables, etc." 

Bacon found a friend in Pope Clement IV., an enlightened 

Frenchman, who, having been a lawyw and judge, took orders 

after his wife's death and rapidly rose in the Church. In 

1263 Clement was appointed papal legate in England, and 

it was probably then that he came to hear at Bacon's 

writings. When elected Pope, two years later, he asked 

'The translation (with a slight modification) is that given by 
Prof. R. Adamson {see '• Conmiemprat;iop Essays on Boger Bacon," 
edited by A. G. Settle, p. 18). 



Roger Baoon 3 

for fair copies of Bacon's works, who, thinking that nothing 
he had yet written was good enough, set out on a more 
ambitious undertaking, of which the " Opus Majus " was the 
first instalment. In this work he displayed such indepen- 
dence of thought, and attacked the prevailing ideas so 
forcibly, that his opponents were converted into bitter 
enemies. They saw their opportunity — and used it — when 
Clement died. Accusations of heresy were raised, and 
Roger Bacon was condemned to prison by the General of the 
Franciscan Order in 1277. He remained in captivity till 
shortly before his death, which took place in 1292. 

With Roger Bacon England took the lead in laying the 
foundation of modem science. While the scholastic tradi- 
tion held the whole of Europe in bond he stood alone, 
fearlessly holding up the torch of enhghtenment ; but its 
rays fell on eyes that could or would not see. More than 
three barren centuries separated Bacon from the next great 
scientific figures, William Gilbert and John Napier. 

Gilbert (1540-1603) has been called the father of electric 
and magnetic science. He belonged to an old Suffolk family, 
was bom at Colchester, and after a distinguished career 
at Cambridge, spent three years in Italy and other parts 
of Europe. On his return he settled down in London as a 
medical practitioner, and soon gained a reputation which 
secured him many honours, and among them the appoint- 
ment as physician to Queen Elizabeth. His chief work is 
described in a volume pubUshed in 1600 under the title of 
" De magnete, magnetisque corporibus et de magno magnete 
tellure." 

It was known to the Greek philosophers that a certain 
miners,! originally found in Magnesia had th^ power of 
attracting small pieces of iron. In the twelfth century the 
knowledge of the compass was brought to Europe. The 
Chinese, who had been familiar with it in very early times, 
already, knew that the direction in which the needle points 
was a little to one side of North, and Columbus discovered 
that this deviation differed in different localities. Nearly 
a century later, Robert Norman, a British sailor, had 
observed that the force which acted on the needle was not, 
as had generally been assumed, directed upwards towards 

A 2 



4 Britain's Heritage of Science 

the pole star, but downwards, and in 1576 he measured 
the angle between the horizontal and the direction of the 
magnetic needle, which we now call the magnetic dip, and 
found it to be nearly 72° in London. Such was the know- 
ledge at Gilbert's disposal when he began his celebrated 
researches. The word " loadstone " for the magnetic mineral, 
derived from lead-stone, indicates how the main interest in 
magnetic properties had been concentrated in their use for 
purposes of navigation. Gilbert's object, on the other 
hand, was chiefly scientific. The high position which he 
occupies in the history of science is not merely due to his 
discoveries, but to a great extent on his being the first man 
of science who gave effect to Roger Bacon's teaching, 
possessing the power and will to draw logical conclusions 
from his experiments, and to verify by new experiments 
the wider views suggested by these conclusions. 

Mapping out the directions in which a freely suspended 
magnetic needle sets at different points on the earth's 
surface, it appears to us a simple matter to infer that the 
earth as a whole behaves like a huge magnet. A diagram 
seems to be all that is required to complete the deduction. 
But the world at the time was not accustomed to logical 
reasoning of this kind. It was necessary, therefore, to 
enforce conviction by corroborative evidence, which Gilbert 
supplied, showing that the earth, so far as could be tested, 
possessed all the properties of a magnet. He pointed out 
that rods of iron lying about become magnetic under its 
influence, just as when placed near magnetized iron, and 
he noted that the effect is the stronger the more nearly 
-the direction of the rods coincides with the direction in 
which a suspended needle comes to rest. Gilbert further 
constructed a magnetic sphere, and suspending small 
magnets by thin fibres, he Examined how these set in 
different directions at different points on the sphere. He 
could thus, on a small scale, reproduce a model of the 
earth as a magnet, and, observing that the magnetic forces 
extend beyond the surface of his " terellum," was led to 
speculate on the possible action of terrestrial magnetism on 
the moon, and the mutual magnetic effects of planets on 
each other. We readily forgive him if in these cosmic 



William Gilbert 5 

speculations he travelled beyond the justifiable limits of his 
experimental facts. 

In his electrical researches Gilbert had the same wide 
outlook. Amber, when excited by friction, was known to 
attract Ught bodies ; why— he asked himself— should special 
properties be confined in one case to iron and in another to 
amber? He tried but failed to find a magnetic action on 
water and other bodies, but discovered that the property 
of amber was shared by a large number of substances, 
such as glass, sulphur, and the precious stones. He was 
the first to note that electric effects persist longer in dry 
air than in wet weather, that an electrified body loses its 
power when moistened with water or spirit, or when glowing 
coal is brought near to it. We also owe to him the word 
" electricity " (derived from " ^XcKrpov ", the Greek word for 
amber) ; though only in the form of the adjective. " Vim 
illam," he writes, " electricam nobis placet appellare, 
quse ab humore provenit." In a posthumous work he 
declares himself to be an adherent of the Copernican 
doctrine, and shows a clear scientific perception, as when 
he explains that there is no intrinsic property of " levity," 
but that when light bodies are seen to ascend they do so 
under the influence of the pressure of the surrounding 
heavier bodies. 

Galileo,' almost the only man of science born in the 
sixteenth century who stands on an intellectual level with 
Gilbert, appreciated his work. In the third of the famous 
" Dialogues " he gives an account of it, and Salviati, the 
imaginary person who is made to express Galileo's own 
views, mentions Gilbert's book, " which might not have 
come into my hands if a peripatetic philosopher had not 
presented it to me, for the reason, I believe, that he did 
not wish to contaminate his own library with it." After 
referring to some of Gilbert's experiments, Salviati further 
says : 

" I highly praise, admire, and envy this author for 

having formed such a stupendous conception on a 

' The name is given in its usual form, but it sounds rather like 
calling a man Thomas whose full name is Thomas Thomasson. Galileo's 
father was Vincenzio Galilei; his own full name Galileo Galilei. 



6 Britain's Heritage of Science 

matter which has been treated by many sublime 
intellects, but solved by none; he appears to me also 
to deserve the highest praise for his many and true 
observations, putting to shame the lying and vain 
authors who write not only of what they know, but 
also of what they hear from the silly crowd, without 
satisfying themselves by experiment of what is true — 
perhaps, because they do not wish to shorten their 
books. What I should have desired in Gilbert is that 
he would have been a little more of a mathematician, 
and especially well schooled in geometry, the practice 
of which would have made him less incUned to accept, 
as conclusive proofs, what are only arguments in favour 
of the deductions he draws from his observations. . . 
. . . I do not doubt that in the course of time this 
new science will be perfected by new observations, and 
by true and cogent demonstrations. But the glory 
of the first inventor will not be diminished thereby; 
I do not esteem less, but, on the contrary, admire, the 
first inventor of the lyre (though probably his instru- 
ment was roughly constructed and more roughly played), 
much more than the hundred other players who, in the 
succeeding centuries, have brought his art to exquisite 
perfection." 

Coming from Galileo this wa.s high praise, indeed. 
The next landmark was planted by a man of equal 
power but different type of intellect. 

John Napier, of Merchiston, descended from a distin- 
guished Scotch family, which, in the fifteenth century, 
included three Provosts of Edinburgh among its members. 
His father. Sir Archibald Napier, was Justice Deputy under 
the Earl of Argyll, and Master of the Mint. John was 
born at Merchiston Castle in 1550; after a short period 
of study at the University of St. Andrews, he probably 
spent some time in foreign travel, but returned to Scotland 
at the age of twenty-two. Though involved in the political 
and religious controversies of his age, he devoted his spare 
time to the study of mathematics, and, what to him seemed 
of greater importance, the writing of a book on the Apoca- 
lypse. This mathematical work culminated in the discovery 



John Napier 7 

of logarithms, and gave to the world a method by means 
of which multiphcation is converted into addition, division 
into subtraction, and the extraction of square or cube root 
into a division by two or three respectively. The scientific 
merit of introducing logarithmic functions into the domain 
of mathematics is surpassed by the incalculable importance 
of assisting the complicated numerical calculations which 
were vital to the progress of astronomy and of other branches 
of science. Without explaining the objects which Napier 
primarily had in view, or the steps by which he arrived at 
his final results, we may justify the prominent position 
here given to him in the history of science by quoting a 
few passages from an article contributed by Dr. J. W. L. 
Glaisher to the " Napier Tercentenary Memorial Volume " : 
" The process of multiphcation is so fundamental 
and direct that, from an arithmetical point of view, 
it might well be thought to be incapable of simpUfica- 
tion or transformation into an easier process, so that 
there would seem to be no hope of help except from 
an apparatus. But Napier, not contented with such 
aids, discovered by a most remarkable and memorable 
effort of genius that such a transformation of multipli- 
cation was possible, and he not only showed how the 
necessary table could be calculated, but he actually 
constructed it himself. That Napier at a time when 
algebra scarcely existed should have done this is most 
wonderful; he gave us the principle, the method of 
calculation, and the finished table. 

" The ' Canon Mirificus ' is the first British contribution 
to the mathematical sciences, and next to Newton's ' Prin- 
cipia ' it is the most important work in the history of the 
exact sciences that has been published in Great Britain, 
at all events until within the memory of hving persons. 

" In whatever country the ' Canon Mirificus ' had 
been produced, it would have occupied the same com- 
manding position, for it announced one of the greatest 
scientific discoveries ever made." 
Independently of his work on logarithms, Napier's con- 
tributions to spherical trigonometry would alone have 
secured him a high position among mathematicians. 



8 Britain's Heritage of Science 

The interval between the death of Gilbert in 1603 and 
that of Napier in 1617 marks the period of Galileo's astro- 
nomical discoveries and of Kepler's fundamental work on 
planetary orbits. The world was now waiting for a great 
generalization, but Kepler passed away and Galileo died an 
old and broken man before one was bom who surpassed 
both in genius and power as much as they had excelled those 
who went before them. 

From the seventeenth century onwards, British science 
has continuously advanced, sometimes rushing ahead with 
torrential energy, sometimes in a smooth and almost imper- 
ceptible flow ; at one period chiefly concentrated in the uni- 
versities; at others almost entirely kept alive by private 
enthusiasts ; but taken as a whole never losing contaot with 
past achievements or ceasing to foreshadow future conquests. 
To appreciate correctly the different stages of the advance, 
we must distinguish between the slow work of accumulating 
facts or proving and disproving theories and the generation 
of new ideas which suddenly alter the whole trend of 
scientific thought. Such creations form the seven land- 
marks which bring us to nearly the end of the nineteenth 
century: Newton's estabUshment of the law of gravitation, 
Dalton's atomic theory, Faraday's electric discoveries, 
Young's contribution to the wave-theory of light, Joule's 
foundation of the conservation of energy, Kelvin's demon- 
stration of the dissipation of energy; finally. Maxwell's 
formulation of the electro-magnetic theory of Ught. 

Roger Bacon made an acute remark to the effect that 
while in mathematics we can proceed from the simple to 
the more complicated, it is impossible to do so in other 
branches of science, because Nature does not, as a rule, 
present us with the simple phenomenon. The whole history 
of science shows how it is always struggUng in search of the 
simple startiag point with respect to which we are constantly 
driven to modify or even reverse our ideas. Thales believed 
water to be the elementary substance from which everything 
else could be derived, Anaximenes thought it was air, and 
Heraclitus substituted fre, while, accorcSng to Pythagoras, 
it was the relations between integer numbers which formed 
the foundation of all science. 



Sir Isaac Newton 9 

Take the case of " rest " and " motion." At first sight 
it seems obvious that the former is the simpler phenomenon ; 
but our trouble begins when we try to define " rest." Dis- 
regarding this difficulty, let ua ask " What is the simplest 
kind of motion ? " Every schoolboy now could give the 
answer : "A uniform motion in a straight line " ; but he 
would be sorely puzzled if he were required to give an example 
of a body moving with uniform motion in a straight line, for 
such a thing does not exist. The Greek philosophers kept 
more in touch with reahties when they considered motion 
in a circle to be the simplest of its kind, because they had 
observed that the stars describe circles in the sky, and they 
could artificially produce circular motion by tying a weight 
to a string and whirUng it round. As astronomy advanced, 
and the motion of the planets were further investigated, 
it became more and more difficult to reduce everything to 
circular motion. All efforts to persevere in such attempts 
finally broke down when the laws regulating the fall of 
bodies from a height were discovered. The straight line 
motion — although never directly brought within the range of 
observation — then took its place as the simpler basic idea. 

Sir Isaac Newton (1643-1727) formulated the laws of 
motion; they have formed ever since the foundation of 
physical science, and a few words must be said as to their 
significance. Our first idea of " force " is derived from 
muscular sensation. We push a body, and see it change its 
place, and are conscious that we can ourselves be made to 
move by an apphcation of muscular force from outside. 
From this it is natural, though perhaps not altogether logical, 
to conclude that every change of motion which we observe 
in a body is due to some push or pull on that body. This 
imaginary push or pull we call a force. The first law, 
originally due to Galileo, asserts that absence of force does 
not necessarily imply that a body is at rest ; it may be moving, 
but, if so, it continues to move in a straight line with unaltered 
velocity. The second law allows us to measure a force, and 
may be said to have been first appUed by Huygens. The 
third law asserts that whenever we observe a change of 
motion in a body there must be an equal and opposite 
change of motion in another body or system of bodies. This 



10 Britain's Heritage of Science 

is the law of " action and reaction," which has played so 
important a part in the history of science. 

Having accurately defined what is meant by change of 
motion, Newton in his " Principia " establishes a number 
of propositions relating to the motion of a body acted on 
by a force directed to a fixed centre. The Copemican 
hypothesis that the earth and planets are in motion round 
the sun, replacing the older view which believed the earth 
to be the centre of the universe, was at that time generally 
accepted by scientific men, and Kepler had formulated three 
laws defining the orbits of the planets. Newton's pro- 
positions, applied to Kepler's laws, proved that the movements 
of the planets may be accoxmted for by imagining attracting 
forces to act between the sun and the planets diminishing 
in proportion to the squares of the distances. If this attrac- 
tion be accepted, it is natural to identify it with the force 
that keeps the moon in its orbit round the earth, and finally 
with that which we observe directly when a body falls down 
from a height. But it had to be proved that the intensity 
of gravitation at the surface of the earth and that acting 
on the moon were related to each other according to the 
law deduced from the planetary motions; in other words, 
as the distance between the centres of the earth and moon 
is 60 times the earth's radius it had to be shown that 
the gravitational force at the surface of the earth is 3,600 
times as great as that which keeps the moon in its orbit. 
The calculation is easily made if we know the length of the 
earth's diameter, and this having been ascertained with 
sufficient accuracy by Picard in Stance shortly before the 
publication of the " Principia," Newton had the satisfaction 
of finding an almost perfect agreement. His theory was 
confirmed, and it was definitely proved that the motion of 
the planetary system, as well as the behaviour of heavy 
bodies on the surface of the earth, could all be deduced from 
the general proposition that every particle of matter attracts 
every other particle with a force which varies in the inverse 
ratio of the square of the distance. 

Commentators on Newton's work frequently draw atten- 
tion to the delay in publishing for ten years or more the 
results of his calculations, because when they were first 



Sir Isaac Newton 11 

completed there seemed to be a discrepancy of about 11 per 
cent, between the value of gravity at the surface of the earth 
as deduced from the moon's orbit, and that which can be 
observed directly. It has even been said that, for a time, 
he rejected the theory altogether, but there is reason for 
believing that the delay was due to one uncertain step in the 
argument which might have caused an error and accounted 
for the disagreement. Newton consequently deferred pubU- 
cation until he could satisfy himself with regard to this 
doubtful point. The attraction of the earth as a whole is 
made up of the attraction of its separate parts. When the 
attracted body is at a distance, no great error can be committed 
by assuming the earth's mass to be concentrated at its centre, 
but it might be otherwise, if it is near the surface. Ulti- 
mately, Newton proved that, when the law of attraction 
is that of the inverse square, we may indeed take the 
attraction of a sphere at aU distances to be the same as that 
of an equal mass placed at its centre. The real cause of the 
disagreement was then found to be the inaccurate value 
originally adopted for the circumference of the earth. When 
the measurements of Picard became known the agreement 
was found to be complete. 

The importance of Newton's discovery extended far 
beyond its immediate results; its wider and far-reaching 
effect lay in the demonstration it supplied that by means 
of a rigorous mathematical analysis the facts of Nature can 
be represented not only in the vague speculative manner 
which then was considered sufficient by the majority of 
philosophers, but definitely and quantitatively, allowing 
a numerical test to be appUed. Apart from the philosophic 
value of a rigorous treatment, the human mind is always 
strongly (on occasions too strongly) impressed by numerical 
coincidences. Newton's investigation which enabled him to 
calculate the force of gravity at the earth's surface from the 
time of revolution of the moon therefore carried conviction, 
and was accepted by the majority of his countrymen ; but 
it took some time before the continent of Europe gave its 
fuU assent, and the criticisms which were raised illustrate 
the danger of taking up too definite an attitude with regard 
to the ultimate starting point representing the simple 



12 Britain's Heritage of Science 

phenomenon from which everything else should be derived. 
In France, at any rate, the influence of Descartes' philosophy 
was paramount, and Descartes had truly started from the 
beginning : " I think, therefore I exist," was to him the 
only justifiable d priori assertion to make ; everything else 
was to be deduced from that proposition. With a most 
powerful and original intellect, he had developed an ingenious 
and in many ways logical and consistent system, in which 
there was no room for the motion of any body except that 
which was brought about by the impulse of another body 
which itself was in motion. If the planets revolve round 
the sun, it was to him, therefore, clear that they must be 
carried along by an invisible medium whirhng round the 
sun. Hence his hypothesis of gigantic vortices fiUing all 
space. This is not the place to explain how all phenomena 
in Nature were supposed to be accounted for by such means, 
but it is clear that the hypothesis was elastic, and could be 
varied, added to, and infinitely extended, whenever some 
difficulty arose. What concerns us here is that it seemed 
to go to the foundation of things — the origin of motion — 
and to those trained up in the doctrine of vortices, the mere 
postulate of a universal attraction to account for one set 
of natural phenomena, disregarding all the rest, seemed to 
be a retrograde step. Hence very naturally arose consider- 
able opposition, and it was mainly those who disagreed with 
Descartes and believed in the possibility of action at a 
distance, who incUned towards Newton. But this was 
really beside the point, because Newton expressly guards 
himself against the implication that his theory necessarily 
involved action at a distance, the origin of gravitational 
force being in no way prejudged by the afSrmation of its 
existence. We have here an example of the often re- 
curring struggle between a general but indefinite hypothesis 
which suggests many things, but cannot be submitted to a 
numerical test, and what is characteristic of the Cambridge 
school of investigation. This school, which had its period 
of triumph in the nineteenth century, clearly defines a 
problem, confining it to such limits, wide or narrow, as will 
convert it into a precise problem which can be formulated 
and submitted to mathematical analysis. There must 



Sir Isaac Newton 13 

always be a definite answer to a definite question, and, 
unless the mathematical difficulties are insuperable, the 
consequences of any assumption may be obtained in a form 
in which they can be tested, not only as to their general 
nature but also as to their numerical values. The result 
may not be far-reaching, but within its Umited field it is 
definite. We may not have penetrated to the foundation 
of the building, but we shall have mapped out one of its 
apartments and perhaps reached a fresh starting point. 

Two centuries and a quarter have now passed since the 
publication of Newton's " Principia," and during that time 
our astronomical measurements have become more and 
more accurate. Though the mathematical analysis has 
sometimes found it difficult to keep pace with the improved 
methods of observation, Newton's simple law of the inverse 
square has hitherto always been found sufficient to explain 
apparent irregularities in the motion of the celestial bodies, 
with perhaps the solitary exception of an irregularity in 
the motion of Mercury, which may ultimately be cleared up 
without calling in some other agency or perhaps is destined 
to open out an entirely new aspect of gravitation. 

The most precious heritage bequeathed to us by Newton 
is this : He has given us the confidence that, complicated 
as the problems of Nature may be, they are soluble if we 
confine ourselves to a limited and definite range, and follow 
up by irrefragable logical or mathematical reasoning the 
consequences of clearly-defined premises. 

By his laws of motion Newton laid the foundation of 
modem dynamics. The next great advance relates to 
the constitution of " matter." Common experience shows 
that each piece of matter may change in shape or volume; 
it even seemingly vanishes, as when water evaporates, or 
is freshly formed, as when dew is deposited on a blade of 
grass. If this be kept in mind, we are forced to concede, 
in opposition to the school which professes to reject all 
theories, that an introspective philosophy entirely detached 
from observation may lead to a truth hidden from the pure 
experimentalist. To perceive that matter in spite of all 
appearances is indestructible goes beyond the limits of 
our direct observation, and a science without imagination 



14 Britain's Heritage of Science 

confining itself to that which it can see would have grown 
very slowly indeed. We owe that much to the Greek 
philosophers, that they took a wider view, and at any rate 
tried to evolve a system which would satisfy our sense 
of harmony in the perception and interpretation of Nature. 
Their imagination frequently led them astray, but as often 
prepared the way for the evolution of the correct view. The 
idea that all matter is composed of separate small particles 
which cannot further be subdivided appears very early 
among the Greek philosophers. Anaxagoras, in the fifth 
century before Christ, assumed the existence of indestructible 
and immutable elements of which all bodies are composed, 
and called them " seeds." Half a century later, Democritus 
first used the word " atom," but differed from Anaxagoras 
by ascribing the different properties of bodies not to a differ- 
ence in kind, but merely to one in shape and arrangement. 
Aristotle rejected this hypothesis completely, and his 
unhappy doctrine, apparently borrowed from Indian sources, 
which treats matter as an embodiment of mixtures in different 
proportions of the imaginary elements, fire, earth, water, 
and air, had a most paralysing influence on the history of 
science. The atomic theory consequently remained through 
centuries the subject of metaphysical speculations and the 
plaything of philosophers ; as the foundation of chemical 
science, it takes its place only in modem times. But 
one great obstacle had to be removed. The chemistry 
of the eighteenth century was entirely under the influence 
of an erroneous theory of combustion, according to which 
inflammable bodies contained an invisible substance-— 
" phlogiston " — showing itself as a flame on being expelled, 
and no progress was possible until the true nature of com- 
bustion bad been demonstrated by the eminent French 
chemist Lavoisier. His explanations were so simple and 
convincing that it is difficult to understand why the atti- 
tude taken up by English chemists with regaid to them 
was entirely hostile. Cavendish, like Black and Priestley, 
adhered to the phlogiston theory, even when the latter, by 
his discoveiy of oxygen, had supplied the chief weapon by 
which it ultimately fell. 

Robert Boyle (1627-1691) had clearly shown how a 



John Dalton 15 

sharp distinction between elementary and compound bodies 
could be drawn, and even explained the difference between 
mixtures and chemical compounds. But it was only when 
phlogiston had been finally abandoned that the way was 
prepared for our present conception of the constitution of 
matter. This is indeUbly connected with the name of John 
Dalton (1766-1844), who taught us that the material uni- 
verse contains a certain number of elementary substances, 
each possessing, as its ultimate constituent, a distinctive 
atom which cannot be spUt up farther by chemical or 
phjrsical means. There are, therefore, as many different 
kinds of atoms as there are elementary substances. The 
atoms of each element are aUke in every respect, and have 
the same weight. When atoms of different elements enter 
into close union with each other, they form what Dalton 
called " compound atoms," or, according to our present 
nomenclature, " molecules " ; these are the ultimate con- 
stituents of compound bodies. 

Dalton's first scientific interests, which he preserved 
through life, were connected with meteorology. He was 
led to his chemical investigations through attempting to 
find a reason for the uniformity in the mixture of gases 
at different levels of the atmosphere, being much puzzled 
to know why the oxygen, nitrogen, and aqueous vapour 
did not arrange themselves in laj'ers according to their 
density, as when oil rises to the top if mixed with water. 
His diflSculty was mainly due to the peculiar ideas he had 
formed of the nature of a gas. For a time he seems to 
have adopted the correct view that all gases at the same 
temperature and pressure have the same number of ultimate 
particles in unit volume, but he abandoned it because it 
did not seem to him to lead to the observed intermingling 
of gases imsipective of their density. He then invented 
a rather fanciful hypothesis which drew a distinction between 
the density of an atom and its weight, and he tried to 
find some connexion between the two. This led hiT P 
to investigate atomic weights. Dalton's temperament and 
methods of procedure were different from those of the 
other leaders of science whose work is imder review. He 
is rightly coBsjdered to be the originator of the principle 



16 Britain's Heritage of Science 

of multiple proportions, but he did not base his results 
so much on accurate measurements, as on the logical 
coherence of the system he advocated. In its simplest 
form, this principle means that if one atom of an element 
can combine with one, two, or more atoms of another, the 
weight of the compound molecules formed must increase 
by equal steps. But in the " New System of Chemical 
Philosophy " (first pubUshed in 1810), though examples 
are given in illustration, no systematic attempt is made to 
reach an accuracy sufficient to estabhsh a proof. To Dalton 
the principle was obvious, and he was mainly interested in 
determining the relative atomic weights and showing, for 
a number of simple substances, how many atoms of each 
element are combined to form the compound molecule. 
The most important portion of the work deals with sub- 
stances in which one or all of the combined elements are 
gaseous, and he depends a good deal on the measurement 
of volumes before and after combination. As the methods 
of drying and otherwise purifjring gases were imperfectly 
understood at the time, the figures which he obtained were, 
according to our standard, very inaccurate; nevertheless, 
the power and success with which he treated the subject 
very soon convinced other chemists that the foundations 
of his system were correct. 

Dalton's evidence was cumulative rather than indi- 
vidually decisive, and it may be said that he convinced 
the scientific world more by the strength of his own con- 
victions than by the experimental proofs he supplied. 

The total number of elements known in Dalton's time 
was twenty-three, but others were soon added, until, towards 
the middle of last century, over sixty elementary sub- 
stances were recognized. At present we have reason to 
believe that the number is strictly limited.' Whatever 
opposition there was to Dalton's views it died out quickly, 
though some philosophers found much that was distasteful 
in the immediate result of his teaching. There is, indeed, 
at first sight, something repellent in the idea that there 
should be one niunber, whether it be sixty-three or ninety- 
two, raised in importance so far above all others that it 

• See the result of Moaeley's researches, page 185. 




John Dalton 



From a painting hy R. R.Fatilkner 
in the possession of the Royal Society 



John Dalton 17 

fixes the limits of creation, as regards the possible diversity 
of matter. But all such scruples must be set aside, for 
the atom of Dalton is only a stepping-stone to a higher 
level of knowledge. The chemist knows what he means 
by an atom, and when he is building up his compounds 
with them, he is not concerned with the question of their 
ultimate constitution; just as the builder who constructs a 
house with bricks need not trouble to enquire whether the 
substance of the bricks is continuous or made of up of mole- 
cules. The merit of Dalton's atomic theory, Uke that of the 
law of gravitation, is that it sets certain boundaries beyond 
which our imagination need not wander for the moment ; 
it defines a hmited problem and for the time solves it. 

Speculations on the nature of light could not fail to 
attract the attention of the old philosophers; but, for our 
present purpose, we need not go farther back than to the 
rival theories of Newton and Huygens. The former — led, 
no doubt, by his predilection for an accurately definable 
starting point from which he could proceed to develop the 
consequence of a theory with mathematical precision — 
adopted the view (to be found already in the writings of 
Democritus), that fight consists of small corpuscles emitted 
by the luminous body. The rectilinear propagation of fight, 
and its bending as it passes from one transparent body 
to another, could easily be explained on this theory, and 
though it was incapable of deafing with the more complex 
properties of fight, it received general support until the 
middle of last century. 

It was apparently Hooke who first suggested that light 
was an undulatory motion in an all-pervading medium, but 
Huygens has the merit of showing how this h3rpothesis could 
explain luminous phenomena with a precision at least equal 
to that of the corpuscular theory. There being at that 
time no crucial test to decide between the rival theories, 
the cleavage of scientific opinion took place along the fine 
of separation between metaphysical tendencies. Those who 
disfiked the idea of a vacuum and action at a distance 
incUned towards Huygens, others towards Newton. Com- 
promises have never been favoured by men of science, and 
as the theory of gravitation starts from an assumption 

B 



18 Britain's Heritage of Science 

implying action at a distance, those who were guided by 
Newton considered it to be almost a sacrilege to go further 
than the master. To them action at a distance became 
an universal dogma, and the undulatory theory had no chance 
until it could produce a conspicuous success by explaining 
experimental facts, which were not amenable to treatment 
by the more favoured hypothesis. 

The analogy of light to sound attracted the attention 
of Thomas Young (1773-1829), and was emphasized by 
him in a paper published in the Philosophical Transactions 
of the Royal Society in 1800. Here, again, it was the 
detailed examination of one special aspect of the problem 
which led to the decisive advance. Some of the charac- 
teristic features of a wave motion may be illustrated by 
an examination of the waves passing over a sheet of water. 
Everyone is famiUar with the circles spreading out from 
a centre when a stone is thrown into water; each point 
of the surface as the wave passes over it rising and falling 
alternately. If two stones are thrown, and enter the water 
at points near each other, each will start its own system 
of circles. These will overlap, and the question arises : 
how does the motion at any point of the surface of the 
water depend on the motion due to each wave separately? 
The question is so simple, and the answer seems so easy, 
that many must have passed it by as hardly worth 
recording; but Young saw that it was the key to the 
position : each wave produces its own effect without inter- 
ference from the other. If, under the influence of one set 
of waves, a point were raised one inch above the undisturbed 
level, and the other set caused by itself alone an elevation 
of two inches, then the combined effect would be a rise of 
three inches. If the effect of the second wave at any time 
were a depression of two inches, the effect of the first being 
the same as before, the depression of two inches would 
overbalance the rise of one inch, and leave a depression 
amounting to one inch. If the rise due to one set of 
waves equals exactly the fall due to the other, there will 
be neither a rise nor a fall, but the point will remain 
at rest. This, in a few words, is the principle of " super- 
position of motions," which applies only approximately to 



Thomas Young 19 

water waves, but generally to all small displacements such 
as those we suppose to occur in the propagation of light. 
The important point to notice is, that two rays of light 
falling on the same point can neutralize each other's effect, 
so that there is darkness, where each ray separately produced 
illumination. 

The colours of thin plates could not be explained on 
Newton's theory, unless the corpuscles of hght were endowed 
with some peculiar attributes, and it occurred to Young 
that a more natural explanation presented itself by con- 
sidering the overlapping of waves which occurs whenever 
two rays of light meet at a point. This led him to design 
new experiments in which two sets of hght waves could 
be made to overlap in such a manner that the crest of 
one set falls exactly over the hoUow of the other, so that 
the two waves neutraUze each other. By measuring the 
distances of the dark regions from each other, he showed 
how the lengths of waves could be determined. All seemed 
simple and straightforward, when a formidable difiBculty 
arose, through the discovery of a new property of hght, 
now called polarization. This seems to have baffled Young 
to such an extent that he began to be doubtful of his 
theory. It was only when the French engineer, Presnel 
(who rediscovered the cause of the " interference " of hght 
and corrected Young's explanation of " diffraction "), had, 
in conjunction with Arago, formulated more precisely the 
experimental conditions under which polarized hght may 
interfere, that the clue to the solution was found. In a 
letter to Arago, dated 12th of January 1817, Young 
suggested that the pecuharity of waves which gave rise 
to polarization might be due to the direction in which the 
motion takes place. In a wave of sound, each particle 
of air moves backward and forward in the direction in 
which the sound is propagated, so that if the sound 
spreads out from one point, the motion is directed every- 
where to or from the centre. In a wa- er wave propagated 
over a horizontal sheet of water, on the other hand, the 
direction is mainly up and down. It occurred to Young 
that if a wave of hght resembled that spreading over a sheet 
of water, two disturbances propagated in the same direction 

B 2 



20 Britain's Heritage of Science 

might still show different effects, for if the wave comes 
straight towards us the direction of motion might be hori- 
zontal or vertical. 

If the originality of a discovery can be gauged by the 
opposition it rouses, Young's work takes a high rank. In 
referring to his explanation of the interference of light — 
{Edinburgh Review, Vol. I., p. 450) — Lord Brougham 
expresses the opinion that it " contains nothing which 
deserves the name either of experiment or discovery," 
and concludes by " entreating the attention of the Royal 
Society, which has admitted of late so many hasty and 
unsubstantial papers into its Transactions." 

As regards the suggestion of transverse vibrations, one 
might have imagined that the analogy of water waves 
would have secured its being more readily accepted, but 
the passage from two to three dimensions is by no means 
obvious, and its diflSculties presented themselves with 
special force to mathematicians. When Fresnel had inde- 
pendently recognized that the experimental facts could 
not be explained except by accepting this transverse 
motion, he placed the wave theory of light on a new 
and firm basis ; but he lost the collaboration and sympathy 
of his colleague Arago, who, up to the time of his death 
in 1853, would not recognize the possibility of a spherical 
wave in which the motion was not entirely radial. Even 
Laplace and Poisson were strongly antagonistic to the idea 
of spherical waves with transverse displacements ; their 
difficulty was a very substantial one, solved only at a later 
date by the investigations of Stokes. 

Of all men who have spent their lives in the search for 
experimental discoveries, no one has ever approached 
Michael Faraday (1791-1867) in the number, the variety, 
or the importance of the new facts disclosed by his labours. 
If we wish to select from among these discoveries one or 
two which have had a predominant influence in directing 
scientific efforts into new channels, we must give the first 
place to his researches on electro-magnetic induction. 
Starting from the discovery that an electric current suddenly 
generated or suddenly stopped caused an instantaneous 
current in a wire placed in its neighbourhood, he proceeded 



Michael Faraday 21 

to show that a current passing through a wire which is 
made to move in the neighbourhood of another circuit 
induces similarly a current in the latter; and finally he 
extended these facts to the effects of moving magnets in place 
of electric currents. Faraday thus not only prepared the way 
for a consistent theory of electro-magnetic action, but proved 
that it was possible to convert electric energy into mecha- 
nical power, or, reciprocally, obtain electric energy by an 
expenditure of mechanical work. In other words, the whole 
of the present electric industry is based on his discoveries. 

As a second example of Faraday's experimental genius, 
vre may take his work on the chemical decomposition of a 
liquid when an electric current is sent through it. Though 
this process of electrolysis had been used with great success 
by Sir Himiphry Davy, its laws were not fuUy understood. 
Faraday proved that the total quantity of the substance 
decomposed depends only on the total quantity of electricity 
which has passed, independently of whether it be a strong 
current acting for a short time, or a weak current actin g 
for a correspondingly longer time. He also discovered a 
most importent relation between the amount decomposed 
and the chemical constitution. In his own words : " If 
we adopt the atomic theory and phraseology, then the 
atoms of bodies which are equivalents to each other in 
their ordinary chemical action, have equal quantities of 
electricity naturally associated with them." How pregnant 
these words are as forerunners of the most recent researches 
in electricity will appear in due course. 

During a long life Faraday piled his discoveries one 
upon another in almost continuous succession, yet they 
are united by a common thread of thought applied both 
consistently and persistently. New facts were brought 
to light, not through an omnivorous desire to penetrate 
into detached bits of unexplored regions, but by. the wish 
to find a common link binding together all the forces which 
in each branch of Physics — gravity, electricity, magnetism 
and chemistry — ^had been treated aa peculiar to that branch. 
His manner of looking at things was so different from that 
of other scientific men of his time, and in some waj^ so 
prophetic, that a few words must be said with regard to 



22 Britain's Heritage of Science 

it, more especially as it was much more thorough-going 
than is generally represented. 

Matter is only known to us through the forces which 
it exerts, and we cannot, therefore, reason about matter 
at all, but only about forces. This truth was so strongly 
impressed on Faraday's mind, that he warned scientific 
men against the use of the word " atom," because it fixed 
their attention on what he considered to be unessential. He 
could only conceive centres of force and lines of force 
emanating from these centres. Though all visible effects 
are perceived at the termination of the lines, his whole 
attention was fixed on the space which was filled by them. 
He objected to all materialistic conceptions and looked upon 
an all-pervading medium which had been invented to explain 
the phenomena of Ught as an unnecessary and objectionable 
imagination. He insisted that the Unes of force which 
spread out from a centre cannot be conceived to be made of 
(Afferent stuff from the centres themselves, and that, therefore, 
the aether, if it exist at all, must itself be made up of lines of 
force emanating from separate centres. We may, perhaps, 
regard this view as a dim foreshadowing of the most recent and 
not yet firmly established views which have emerged from 
the so-called principle of relativity. The vibration of Ught 
Faraday tentatively suggested to be due to a vibration of 
the Une of force emanating from a centre, and therefore 
forming an essential part of it. Each particle of matter 
in his mind sends out tentacles through space, and when 
two bits of matter seem to act on each other at a distance 
they only appear to do so because their tentacles are in- 
visible to us. During the closing days of his fertile life 
he planned experiments — no doubt in connexion with his 
speculations on the nature of light — to test whether magnetic 
force requires time for its propagation. 

Our belief in the conservation of energy now forms the 
foundation of our conception of nature, and we hold to it 
more firmly than to anything else that science has taught 
us. All the changes we witness in the material world are 
merely transformations of one form of energy into another, 
and these different forms can all be measured in the same 
units. The principle of conservation asserts that energy 



John Prescott Joule 23 

is never lost or gained in any of these transformations, 
the total quantity in the universe remaining the same. 
The simplest kind of energy is that of a body in motion, 
and is measured by half the product of the mass and the 
square of the velocity. If a heavy body be allowed to drop 
from a height, it increases its velocity as it falls, and strikes 
the ground with a certain amount of energy. If that energy 
has not been created, it must have existed already when 
the body was placed at the height from which it feU. Hence 
we must recognize some form of energy which depends on 
the gravitational attraction between the earth and the 
body. This potential energy, as we call it, is being trans- 
formed into the energy of motion (kinetic energy) as the 
body falls. These are the two great subdivisions of energy. 
If heat be not a substance, as was generally beUeved tiU 
the middle of last century, but a form of energy, a definite 
quantity of heat should be equivalent to a definite amount 
of energy ; so that whatever the means by which we trans- 
form mechanical work into heat, we ought always to get 
the same amount. That this conclusion is correct was esta- 
blished by Joule's researches. It forms our first law of 
thermodynamics . 

John Prescott Joule^ (1818-1889) began his scientific 
career at the age of nineteen, and already six years later 
he had established his position as one of the greatest 
benefactors of the community. The characteristic quality 
of mind which enabled him without aid and without en- 
couragement to accomplish so much was his ability to fix 
on the essential factors of a problem, and to verify his 
ideas by accurate measurements. Inspiration came to him 
from his own experiments; his first ideas were hesitating 
and sometimes wrong, but correcting them step by step, he 
was led almost automatically to the final great discovery. 
His cautious and strictly scientific procedure showed itself 
at an age when an abundance of energy and oiiginaJity so 
often lead to ambitious speculations which are beyond the 
powers of inexperienced youth. Joule published his first 

' A valuable account of Joule's life and work, by Osborne Reynolds, 
vrUl be found in the Joule volume of the Manchester Literary and 
Philosophical Society. 



24 Britain's Heritage of Science 

results in a series of letters addressed to Sturgeon's 
" Annals of Electricity," and in the fourth of them he 
gives us the guiding motive of his research. 

" I can hardly doubt," he writes, " that electro- 
magnetism will ultimately be substituted for steam to 
propel machinery. If the power of the engine is in 
proportion to the attractive force of its magnets, and 
if this attraction is as the square of the electric force, 
the economy will be in the direct ratio of the quantity 
of electricity, and the cost of working the engine may 
be reduced ad infinitum. It is, however, yet to be deter- 
mined how far the effects of magnetic electricity may 
disappoint these expectations." 

Sturgeon's electro-magnetic engine which Joule tried to 
improve was a very primitive machine. His first attempt 
to render it more effective was not successful, as he admits ; 
but what is remarkable is the strictly scientific manner in 
which he measured the power by the weight the engine 
could raise per minute. Joule next turned his attention 
to the measurement of the electric power absorbed. He 
designed and constructed a galvanometer for the purpose, 
and as a first result discovered an important law (subse- 
quently shown to be only approximately true), which appeared 
to him to justify hia belief in the future of the electro-magnetic 
engine. The passage — quoted above — ^in which he expresses 
this belief shows, however, that consideration of the con- 
servation of energy had not crossed his mind at that time, 
and that he considered it possible to have an effective machine 
the cost of working wWch may be reduced ad infinitum. 
He had, nevertheless, some scruples about the effects of 
" magnetic electricity," which may disappoint his expecta- 
tions. He therefore directed his attention to these effects. 
Referring to the impossibility of understanding experiments 
made by different investigators, " which is partly due to 
the arbitrary and vague numbers which are made to 
characterize the electric current," he adopted a system of 
units which can be reproduced anywhere, using the amount 
of water decomposed per hour as the standard of current, 
and the quantity of electricity delivered in one hour by the 
unit current as the unit quantity. 



John Prescott Joule 25 

In a paper " On the Production of Heat by Voltaic 
Electricity," he announced the most important law, that 
heat generated in a circuit is proportional to the time, the 
resistance and the square of the current. 

In the early stages of his investigations, Joule tacitly 
adopted the then accepted view that heat is a substance, 
which could not be generated or destroyed, but he soon 
altered his opinion. In 1843 he expressed himself as 
follows : — 

" The magnetic electrical machine enables us to 

convert mechanical power into heat by means of the 

electric currents which are induced by it. And I have 

Uttle doubt that, by interposing an electro-magnetic 

engine in the circuit of a battery, a diminution of the 

heat evolved per equivalent of chemical change -would 

be the consequence, and this in proportion to the 

mechanical power obtained." 

It seems that Joule wa-s not then aware of the previous 

experiments by Count Rumford, in which heat had been 

generated by means of mechanical work (see page 108). 

He assumed a more decisive attitude in a subsequent 
paper, which is introduced with the words : — 

" It is pretty generally, I believe, taken for granted 
that the electric forces which are put into play by the 
magneto-electrical machine possess, throughout the whole 
circuit, the same calorific properties as currents ajising 
from other sources. And indeed when we consider heat 
not as a stibstance, but as a state of mbration, there appears 
to be no reason why it should not be induced by an action 
of a simply mechanical character, such, for instance, as 
is presented in the revolution of a coil of wire before 
the poles of a permanent magnet. At the same time, it 
must be admitted that hitherto no experiments have 
been made decisive of this very interesting question ; for 
all of them refer to a particular part of the circuit only, 
leaving it a matter of doubt whether the heat observed 
was generated or merely transferred from the coils in which 
the magneto-electricity was induced, the coils themselves 
becoming cold. The latter view did not appear untenable 
without further experiments. . . ." 



26 Britain's Heritage of Science 

The crucial experiment was performed by Joule with the 
result — again in his own words — " that we have therefore in 
magneto-electricity an agent capable by simple mechanical 
means of destroying or generating heat." The second part 
of the same paper, entitled " On the Mechanical Value of 
Heat," begins as follows : — 

" Having proved that heat is generated by the magneto- 
electrical machine, and that by means of the inductive 
power of magnetism we can diminish or increase at 
pleasure the heat due to chemical changes, it became an 
object of great interest to enquire whether a constant 
ratio existed between it and the mechanical power gained 
or lost. For this purpose it was only necessary to repeat 
some of the previous experiments and to ascertain, at the 
same time, the mechanical force necessary in order to 
turn the apparatus." 
He thus finds that — 

" The quantity of heat capable of increasing the 
temperature of a pound of water by one degree of Fahren- 
heit's scale is equal to, and may be converted into, a 
mechanical force capable of raising 838 lbs. to the 
perpendicular height of one foot." 
The particular method adopted to determine what we 
now call the mechanical equivalent of heat was beset with 
many experimental difficulties, and it is not therefore sur- 
prising that his first result was nearly 9 per cent, in error. 
Osborne Reynolds observed that the paragraph quoted really 
overstates the conclusions Joule was entitled to draw, because 
he has only shown that work could be converted into heat, 
but not the inverse process, and that, at that time, he had 
no clear ideas as to the conditions under which heat may be 
converted into work. In fact he had dealt only with the 
first law of thermodynamics, and it took some years before 
the second law could be formulated with precision. It must 
be remembered, however, that Joule was only twenty-five 
years old at the time of his great discovery, and that he 
was working alone, unsupported, and opposed by all the 
prejudices of the recognized authorities, 

It is not necessary to refer here in detail to the skill with 
which Joule extended his investigations in many directions, 



John Prescott Joule 27 

generating heat by mechanical force in different manners, 
but always finding the same equivalent, until no vestige of 
doubt was left that all different forms of energy could be 
expressed in the same imits. His measurements became 
more and more accurate, and such imcertainties as remained 
in the numerical value of the equivalent were, in great part, 
due to the difficulty of measuring the temperature with a 
glass thermometer; the accuracy obtained was indeed to 
some extent the result of the accidental excellence of his 
thermometers. A few years later the composition of glass 
became much less suitable for scientific use. 

It has already been noted that while the conversion 
of mechanical work into heat was completely and satis- 
factorily dealt with by Joule, the converse transformation 
of heat into work involves further important considerations, 
into which it was necessary to enter. Sadi Carnot had, in 
1824, pubhshed a work entitled " Reflexions sur la puis- 
sance motrice du feu, et sur les machines propres k developper 
cette puissance," in which the subject was treated with 
masterly perspicuity, but his reasoning was expressed in 
the language of the material theory of heat. He was, however, 
the first to point out that the mechanical production of 
an effect by a heat engine is always accompanied by a 
transference of heat from one body to another at a lower 
temperature. Reljdng on the axiom that a perpetual motion 
involving a continuous performance of work is impossible, 
he laid down the conditions for a thermodynamic engine 
which, with a given transference of heat, would do the 
maximum amount of work. The pecuharity of such an 
engine is, that whatever amount of work can be derived 
from a certain transference of heat, an equal reverse thermal 
effect will be produced if the same amount of work be spent 
in working it backwards. Further, the work done by a 
perfect heat-engine must be the same for the same trans- 
ference of heat, whatever be the nature of the material 
used. If heat be a form of energy, and not a substance, 
it is clear that the amount which enters the cooler body 
of an engine must be less than that which leaves the 
hotter one, and that the difference is equivalent to the 
mechanical work done in the passage. The position of 



28 Britain's Heritage of Science 

Joule was, therefore, necessarily antagonistic to Camot's 
assumption. 

William Thomson (1824r-1907), known to the present 
generation as Lord Kelvin, while studying in Regnault's 
laboratory in Paris, had become acquainted with the 
important conclusions that may be drawn from Camot's 
thermodynamic cycle, and with the efforts which were being 
made in France to verify the relations between the thermal 
properties of substances which can be derived from it. 
Though at first reluctant to abandon so fertile a principle, 
and hesitating to give full assent to Joule's views, he. soon 
discovered that Camot's reasoning may be modified so as to 
bring it into harmony with the principle of the conservation 
of energy. The same solution had occurred to Clausius, who, 
anticipating Kelvin, was thus the first to give the correct 
theory of the heat engine; but we are here concerned only 
with the account of Kelvin's share in advancing the 
subject; and a very magnificent share it was. His great 
paper " On the Dynamical Theory of Heat," communicated 
to the Royal Society of Edinburgh in 1851, places the whole 
matter on a firm scientific basis, and establishes relations 
between the physical properties of substances which have 
all been veriSed experimentaUy. Full credit is given in 
the paper to those who have contributed to, and, in part, 
initiated, the ideas which led up to the final recognition 
of the conservation of energy as the most fundamental 
law of nature. What is called the second law of thermo- 
d3mamics is really the adaptation to thermodynamics 
of the axiom expressing the impossibility of obtaining 
a perpetual motion by a heat-engine. As formulated 
by Lord Kelvin, it runs as follows : " It is impossible, 
by means of inanimate material agency, to derive 
mechanical effect from any portion of matter by cooUng 
it below the temperature of the coldest surrounding 
objects." 

Considerations leading up to a complementary principle 
as important as that of the conservation of energy seem to 
have been in Kelvin's mind at an early stage. If we imagine 
a hot and a cold body, say, the boiler and condenser of a 
steam engine, we may, by transferring the heat from the 



WiUiam Thomson 29 

first to the second, transform part of the thermal energy 
into work, but only a certain definite portion, exactly 
calculable in accordance with the second law and Camot's 
principle. But if wo bring the hot and cold bodies into 
actual contact with each other, and allow the heat to pass 
directly from one to the other, without doing mechanical 
work, their temperature will be equahzed, and we shall have 
lost for ever the possibiUty of utilizing the thermal energy 
which has been transferred. There is, therefore, a funda- 
mental difEerence between the transformation of mechanical 
work into heat and the inverse transformation. In the 
former case we may convert the whole mechanical energy 
into heat, as when we rub two bodies together and raise 
their temperature through friction, while, in the reverse 
operation, when heat is transformed into work, only part 
of that which leaves the source of heat is utilized. We must 
therefore distinguish in the energy of a body a part which 
is available for the performance of useful work, and another 
part which is unavailable, the thermal energy of a body 
containing only a definite proportion belonging to the first 
category. Moreover, it is only the ideally perfect engine 
that can utihze the whole of the available energy; in 
machines such as those we can construct there is always a 
further loss due to their imperfection. We must conclude 
that in the constantly occurring processes in which heat is 
allowed to pass from one piece of matter to another without 
doing useful work, the quantity of available energy stored 
in the universe is diminished. This leetds us to the counter- 
part of the principle of conservation, which is that of the 
dissipation of energy. Among the wealth of achievements 
contained in the intellectual heritage left us by Kelvin, 
the discovery of this truth is pre-eminently the one which 
stands out as a landmark to future generations. It was 
first annoimced in 1852, and we may quote the main 
conclusions as then formulated. 

1. There is at present in the material world a universal 
tendency to the (issipation of mechanical energy. 

2. Any restoration of mechanical energy, without more 
than an eqviivalent dissipation, is impossible in inanimate 
material processes, and is probably never effected by means 



30 Britain's Heritage of Science 

of organized matter, either endowed with vegetable life, or 
subject to the will of an animated creature. 

3. Within a finite period of time past, the Earth must 
have been, and within a finite period to come the Earth must 
again be, unfit for the habitation of man as at present 
constituted, unless operations have been, or are to be, 
performed, which are impossible under the laws to which 
the known operations going on at present in the material 
world are subject. 

The third of these statements must necessarily apply 
not only to this earth but to the whole universe, and there 
is therefore no escape from the conclusion that the material 
universe, as we know it, is Hke a clockwork which is slowly 
but steadily running down. 

It was reserved to Clerk Maxwell to perceive the reason 
of our inability to check the gradual degradation of energy. 
Heat is essentially a disorderly motion, the particles of 
matter in a body which is apparently at rest moving 
irregularly in all directions. We are unable to convert this 
irregular into a regular motion, and it is this Umitation of 
our powers which prevents our making fuU use of molecular 
energy as a source of mechanical work. Speaking of the 
second law of thermodynamics, Maxwell says : . . . . 
"it is undoubtedly true, as long as we can deal with- bodies 
only in mass, and have no power of perceiving or handUng 
the separate molecules of which they are made up. But 
if we conceive a being whose faculties are so sharpened that 
he can follow every molecule in its course, such a being, 
whose attributes are still as essentially finite as our own, 
would be able to do what is at present impossible to us. 
For we have seen that the moleciiles in a vessel full of air 
at uniform temperature are moving with velocities by no 
means uniform, though the mean velocity of any great 
number of them, arbitrarily selected, is almost exactly 
uniform. Now let us suppose that such a vessel is divided 
into two portions, A and B, by a division in which there is 
a small hole, and that a being, who can see the individual 
molecules, opens and closes this hole so as to allow only 
the swifter molecules to pass from A to B, and only the 
•lower ones to pass from B \.o A. He will thus, without 



Clerk MaxweU 31 

expenditure of work, raise the temperature of B and lower 
that of ^, in contradiction to the second law of thermo- 
dynamics." 

In the history of electrical science Maxwell (1831-1879) 
stands in very much the same relative position to Faraday 
as Lord Kelvin occupied towards Joule in the domain of 
heat. They both brought pre-eminently mathematical minds 
to bear on the results of experimental discoveries, and saw 
more clearly than the original discoverers the important 
consequences which flowed from their researches. Neither 
Faraday nor Joule were experimentaUsts pure and simple, 
they were indeed guided mainly by theoretical considera- 
tions; but it lay beyond their object or powers to enter 
fully into the wider generalizations, though Faraday showed 
in the passages we have quoted that his imagination went 
far beyond his immediate experimental results. 

The theory of electrostatics which deals with electric 
charges at rest, their distribution on conductors, and their 
mutual attractions or repulsions, is explained in the simplest 
manner by assuming the existence of two kinds of electricity, 
for which it is convenient to retain the old names, positive 
and negative electricity. The mechanical effects of the 
charges may be dealt with mathematically very much as 
we do in the case of gravitational attractions. There is 
also a formal analogy between magnetic and electric actions, 
so that independent magnetic fluids were sometimes intro- 
duced to facilitate the treatment of magnetic problems. 

Faraday saw that, if we wish to grasp the relationship 
between the action of electric charges at rest and the electro- 
dynamic effects produced by electricity in motion, and 
more especially, if we wish to include in the same field of 
enquiry the electric effects produced by moving magnets, 
we must take a more comprehensive view. We must cease 
to look at the centres or origin of the forces, and fix our 
attention on the medium between them. This, as has already 
been explained, was Faraday's outlook. Further, if the 
effects of Ught and electricity are both transmitted through 
a medium, our natural distaste to add unnecessarily to 
the number of hypotheses inclines us to the belief that the 
same medium serves both purposes. But here a formidable 



32 Britain's Heritage of Science 

difficulty presented itself. The phenomena of Ught seemed 
to be explained in a satisfactory manner by giving to the 
aether the properties of ordinary incompressible elastic 
bodies, though certain circumstances might have roused the 
suspicion that we had not got hold of the whole truth. Yet 
the essential points seemed so well accounted for by the 
investigations of Green and Stokes, that there was every 
reason to beUeve that outstanding difficulties would be 
satisfactorily solved, without abandoning the substance of 
the theory. It was quite clear, nevertheless, that the medium 
invented to explain the properties of Ught, could not account 
for the electrical effects. 

It is here that Maxwell's genius saw the solution : the 
problem had to be inverted. It was not the question of 
whether a medium adapted to account for the comparatively 
simple phenomena of Ught could explain electrical action, 
but whether a medium constructed so as to explain electrical 
action could also explain the phenomena of Ught. In 
formulating the essential properties of the medium which 
could produce the electrical effects, MaxweU had to fit a 
mathematical mantle on the somewhat crude skeleton of 
Faraday's creation. The task was formidable, and the 
manner in which it was carried through stands unequalled 
by any achievement in the whole range of scientific history, 
both as regards its inteUectual effort and its final results. 
Only one of its successes need here be recorded. A quantity 
of electricity may be measured either by its electrostatic, 
when it is at rest, or by its electrodynamio effect, when it 
is in motion. Looking separately at the two manifestations 
of electricity, we are led to two different units in which it 
can be measured, the so-caUed electrostatic and electro- 
magnetic units. The time of propagation of an electro- 
dynamic effect through space was proved by MaxweU to be 
equal to the ratio of these two units. It could be calculated, 
therefore, from purely electric measurements, and it turned 
out to be exactly equal to the velocity of Ught. Hence 
luminous and electrodynamio disturbances are propagated 
with the same velocity, and we must conclude that their 
nature is identical. There was, after the pubUcation of 
MaxweU's work, reaUy nothing more to be said for the older 




Michael Faraday 



From a painting by A. Blakeley, in 
the possession of the Royal Society- 



Clerk Maxwell 33 

view which gave to the aether the properties of elastic 
solids. 

Brought up in a school of physicists which based the 
explanation of natural phenomena on perfectly defined 
conceptions, and required, therefore, always a mechanical 
model to represent properties of matter and force. Maxwell 
in his first efforts tried to outhne the mechanical construction 
of the aether necessary to explain the electrical effects. He 
conceived this aether, the ultimate elements of which retained 
the properties of the cruder forms of matter, to be composed 
of cells, each of which enclosed a gyrostatic nucleus. 
Gradually, however, he abandoned these attempts at finding 
a mechanical model for the aether, and was satisfied to rely 
mainly on the mathematical formulae which expressed its 
properties in the simplest way. In this he followed, or, to 
be strictly accurate, helped to initiate, the modem tendency 
of refusing to go beyond the immediate results of observa- 
tion, relegating tacitly all questions of interpretation to the 
domain of metaphysics; which means disregarding them 
altogether. Maxwell's electrical work has revolutionized the 
whole aspect of science ; and though undertaken in the purest 
spirit of philosophic enquiry, it has led directly to the great 
practical results which we see in the present apphcations of 
wireless telegraphy. 

It is seldom that it is given to one man to open out new 
paths of thought in more than one direction. Newton's 
theory of gravitation and his optical work is an example 
of such a rare success, and there is perhaps no other equally 
marked except that supplied by Maxwell. Though his 
work on the constitution of gases may not have been as 
far-reaching in its results as the monumental researches we 
have already noted, it has introduced a new and original 
idea into the treatment of the properties of matter. 

Towards the middle of last century, Herapath had 
revived the theory originally proposed by Daniel Bernoulli, 
according to which the pressure of a gas is due to the impact 
of its molecules against the sides of the vessel which contains 
it, and Joule, adopting this view, had calculated the velocity of 
the molecules of a gas from its known density and pressure. 
Such calculations can only give us the measure of an 



34 Britain's Heritage of Science 

average. Through mutual colUsions or otherwise, each 
particle constantly changes its velocity both in magnitude 
and direction, and it becomes important to determine the 
law regulating the distribution of velocities. Maxwell's 
classical investigation of this difficult problem has since 
been modified in detail and extended, but the manner in 
which he attacked it introduced an entirely novel method of 
applying mathematical reasoning to physical phenomena. 
Its results were decisive, and led to the discovery of new 
experimental facts connected with the internal friction of 
gases. When a metal disc is suspended from a wire passing 
through its centre so that the plane of the disc is horizontal, 
a twist imposed on the wire will cause the disc to perform 
oscillations in its own plane, which diminish in magnitude 
and gradually disappear owing to the internal friction of 
the gas surrounding it. Maxwell's calculations led to the 
unexpected result that this retarding effect should be the 
same whatever the pressure of the gas, so that air at a 
pressure of a few millimetres should diminish the motion of 
the disc as rapidly as when it is at atmospheric pressure. 
This surprising result was tested experimentally and found 
to be correct. 

We are naturally interested in the personal history of 
those who have initiated new departures in science, and it 
is more especially instructive to record the character of their 
early education and the conditions under which they accom- 
plished their work. Without entering into biographical 
details, we may briefly state, so far as they have not already 
been given, the essential facts in the hves of the great men 
whose achievements have formed the subject of this chapter. 

Isaac Newton, the posthumous son of a small freehold 
farmer in Lincolnshire, is reported to have been — like Kepler — 
a seven months' child. While attending school at Grantham, 
he showed Uttle disposition towards book learning, but 
great aptitude for mechanical contrivances, and he amused 
himself with the construction of windmills, water clocks, and 
kites. Not being considered fit to be a farmer, he was 
sent to the Uuiversity of Cambridge in 1661, on the recom- 
mendation ol an uncle who was a graduate of Trinity College. 
He does not seem to have received much inspiration from 



Clerk Maxwell, Isaac Newton 35 

his teachers, but pursued his reading according to his own 
choice, and it was Descartes' " Geometry " that inspired 
his love for mathematics. In 1665, at the age of twenty-five, 
he left Cambridge on account of the Plague, and it seems 
that in this year the method of " fluxions," which contains 
the germ of the differential calculus, first occurred to him. 
Returning to Cambridge, he began his optical and chemical 
experiments, and continued his mathematical researches at 
the same time. In the year 1669, he was elected Lucasian 
Professor of Mathematics, and chose Optics as the subject 
of his first series of lectures. He continued his studies at 
Cambridge, the " Principia " being published in 1687. As 
a sign of national gratitude, Montague (afterwards Earl of 
Halifax), then Chancellor of the Exchequer and at the same 
time President of the Royal Society (1695-1698), offered 
Newton the post of Warden of the Mint in 1695, and this 
was followed five years later by his appointment to the 
Mastership, which was then worth between £1,200 and 
£1,500 per annum. Newton continued, however, to dis- 
charge his professorial duties at Cambridge until 1701. 
Prom 1703 onwards until his death, twenty -five years later, 
he held the Presidency of the Royal Society. 

One is tempted to look upon the quiet fife of the old 
Universities as being specially conducive to study and 
research, but the times of active progress in the Universities 
coincided rather with the periods when poiitical disturbances 
were sufficiently intense to penetrate these havens of rest. 
Such a time was the end of the seventeenth century, when 
the interference of James II. into University affairs was a 
source of trouble both at Oxford and Cambridge. Newton 
himself took an active part in defending the prerogatives 
of the University. On a previous occasion he had taken the 
side of the Senate against the Heads of Colleges in a dispute 
about the Public Oratorship, and when in 1687 the King 
issued a mandate that a certain Benedictine monk should 
be admitted a Master of Arts without taking the oaths of 
allegiance and supremacy, Newton was one of the deputies 
appointed by the Senate to make representations to the 
High Commissioners' Court at Westminster. 

In recognition of the services rendered to the University, 

C2 



36 Britain's Heritage of Science 

he was elected on two occasions as their representative in 
Parliament. The interest which Newton displayed in 
University pohtios illustrates his intellectual vigour, and 
is inseparable from those quaUties to which he owes his 
commanding position in the history of science. While it is, 
therefore, useless to speculate whether he was wise to allow 
his attention to be diverted from his more serious work, 
it is much to be regretted that his mind should have been 
disturbed by discussions about priority which affected his 
nervous system and damaged his health. These discussions 
were forced upon him, and he would gladly have avoided 
the bitter controversies with Hooke and, in later years, 
with Leibnitz. 

No two men could differ more in temperament or outlook 
than Newton and John Dalton. To Newton the accurate 
numerical agreement between the results of observation 
and those of theory was of paramount importance, while 
in Dalton's experiments, numerical results were mainly used 
as illustrations of a theory which to him did not admit of 
any doubt. John Dalton was the second son of a weaver 
in poor circumstances living in Cumberland. In 1778, 
when only twelve years old, he started teaching at the 
Quaker School in Eaglesfield, where he himself had obtained 
his first instruction. In this he was not successful, and 
after a brief attempt at earning his living as a farmer, he 
left his native village in 1781, in order to assist a cousin who 
kept a school at Kendal. In 1793 he moved to Manchester, 
where he spent the remainder of his Mfe as a teacher of 
mathematics and natural philosophy, first in " New College " 
(which ultimately was transferred to Oxford as " Manchester 
College "), and later privately. As early as 1787 he began 
to keep a meteorological diary, which he continued to the 
time of his death fifty-seven years later. He led the quiet 
life of a student, interrupted by occasional visits to the 
Lake District. In 1822 Dalton paid a short visit to Paris; 
of London he remarked that it was " the most disagreeable 
place on earth, for one of a contemplative turn, to reside in 
constantly " In addition to the work which gained him 
immortahty, he foreshadowed several subsequent discoveries, 
and enunciated the correct law of expansion of gases some 



John Dalton, Thomas Young 37 

months before Gay Lussac, without, however, ever giving 
the numerical measurements required to prove the law. 
He was affected by colour-blindness, and first examined that 
defect scientifically. Dalton died in 1844, being then 
seventy-eight years old. 

Thomas Young was probably, next to Leonardo da 
Vinci, the most versatUe genius in history. He was 
descended from a Quaker family of MUverton, Somerset, and 
at the age of fourteen was acquainted with Latin, Greek, 
French, Itahan, Hebrew, Persian and Arabic. He studied 
medicine in London, Edinburgh and Gottingen, and subse- 
quently entered Emmanuel College, Cambridge. In 1799, 
at the age of twenty-six, he estabSshed himself as a physi- 
cian in London. Subsequently he held for two years ihe 
Professorship of Physics at the Eoyal Institution, but 
resigned, fearing that his duties might interfere with his 
medical practice ; during the tenure of his Professorship he 
delivered many lectures, which were subsequently pubhshed, 
and contain numerous anticipations of later theories. In 
1804 he was elected Foreign Secretary of the Royal Society, 
and held that position for twenty-six years. In 1811 
he became physician to St. George's Hospital, and Super- 
intendent of the Nautical Almanac. His efforts to decipher 
Egyptian hieroglyphic inscriptions were among the first that 
were attended with success. His share in estabhshing the 
undulatory theory of Ught has already been described, and his 
claims as the founder of physiological optics will be discussed 
in another chapter (p. 299). Thomas Young was a man 
of private means, and not dependent on his medical practice 
for a hving. He died in London in the year 1829. To 
quote Helinholtz : 

" He was one of the most clear-sighted of men who 

ever lived, but he had the misfortune to be too greatly 

superior in sagacity to his contemporaries. They gazed 

at him in astonishment, but could not always follow the 

bold flights of his intellect." 

Michael Faraday, the son of a working blacksmith, was 

brought up in humble circumstances, and had but a 

scanty school education. In 1804, at the age of thirteen, 

he became an errand boy to a bookseller and stationer in 



38 Britain's Heritage of Science 

London, part of his duties being to carry round the news- 
papers in the morning. After a year of probation he was 
formally apprenticed to learn the art of bookbinding. It 
was by reading some of the books that passed through his 
hands that his mind was first attracted to science. Noticing 
an advertisement in the streets announcing evening lectures 
in Natural Philosophy with an admission fee of one shilling, 
he obtained his master's permission to attend the lectures. 
The account of his first connexion with the Royal Institution 
may be given in his own words : 

" When I was a bookseller's apprentice I was very 
fond of experiment and very averse to trade. It 
happened that a gentleman, a member of the Royal 
Institution, took me to hear some of Sir H. Davy's 
lectures in Albemarle Street. I took notes, and afterwards 
wrote them out more fairly in a quarto volume. 

" My desire to escape from Trade, which I thought 
vicious and selfish, and to enter into the service of Science, 
which I imagined made its pursuers amiable and liberal, 
induced me at last to take the bold and simple step of writing 
to Sir H. Davy, expressing my wishes, and a hope that, 
if an opportunity came in his way, he would favour 
my views ; at the same time, I sent the notes I had taken 
of his lectures. . . . This took place at the end of 
the year 1812, and early in 1813 he requested to see me, 
and told me of the situation of assistant in the laboratory 
of the' Royal Institution, just then vacant. 

" At the same time that he thus gratified my desires 
as to scientific emplojmient, he still advised me not to 
give up the prospects I had before me, telling me that 
Science was a harsh mistress; and in a pecuniary point 
of view but poorly rewarding those who devoted them- 
selves to her service. He smiled at my notion of the 
superior moral feeUngs of philosophic men, and said he 
would leave me to the experience of a few years to set 
me light on that matter. 

" Finally, through his good efforts, I went to the 
Royal Institution early in March of 1813 as assistant 
in the laboratory ; and in October of the same year went 
with him abroad as his assistant in experiments and 



Michael Faraday 39 

writing. I returned with him in April 1815, resumed 

my studies in the Royal Institution, and have, as you 

know, ever since remained there." 
The journey abroad was a great event in Faraday's 
life, as he became acquainted with many famous men of 
science. Unfortunately his position was an unpleasant 
one. At the last moment, Sir Humphry Davy's valet had 
refused to leave the country, and Faraday had undertaken 
to replace him until he could engage a substitute at Paris ; 
but no suitable person being found there, Faraday had to 
continue in the menial work which did not form part of 
the duties for which he was engaged. " I should have 
Uttle to complain of," wrote Faraday, in connexion with 
this matter, " were I travelling with Sir Humphry alone, 
or were Lady Davy like him." An interesting incident 
took place during their stay at Geneva in the summer of 
1814. During a shooting expedition, Faraday accompanied 
the party in order to load Davy's gun, and De La Rive, 
their host, accidentally entering into conversation with 
him, found that the boy who had been dining with his 
domestics was an intelHgent man of science; accordingly 
he invited Faraday to dine at his table. To this Lady 
Davy strongly objected, and matters had to be compro- 
mised by dinner being served for Faraday in a separate 
room. 

On his return home, after an absence of eighteen months, 
Faraday was again engaged as an assistant at the Royal 
Institution, and obtained some practice in lecturing at the 
" City Philosophical Society." His independent scientific 
work began in 1816, and was continued without interruption 
until 1860. In 1827 Mr. Brande, who had succeeded Davy 
as Professor of Chemistry at the Royal Institution, resigned 
his position and Faraday was elected in his place, having 
already, since 1825, occupied the position of Director of the 
Laboratory. Faraday's emoluments were insufficient even 
for his modest requirements, so that he had to supplement 
them by undertaking private practice in chemical analysis 
and expert work in the law courts; but though the income 
which he thus secured was very substantial, he soon gave 
it up, as he found it interfered with his scientific work. 



40 Britain's Heritage of Science 

In its place he accepted a lectureship at the Royal Academy 
of Woolwich with a salary of £200. Subsequently, he was 
made scientij&c adviser to Trinity House. At a later period 
he was granted a Civil List pension of £300. Unselfish, 
high-minded, and modest, Faraday enjoyed the confidence 
of his friends, and decHned aU official honours. His out- 
standing quahty was his irrepressible enthusiasm for experi- 
mental research. Foreign visitors to the laboratory relate 
how, after a demonstration of one or other of his 
discoveries, " his eyes Ut up with fire," or how, when in 
their turn, they showed him a striking experiment, he 
danced around, and wished he could always five " under 
the arches of hght he had witnessed." Though interested 
in all practical apphcations of science, he preferred to leave 
their development to others. 

" I have rather," he is reported to have said, " been 
desirous of discovering new facts and new relations 
dependent on magnetoelectric induction than of exalting 
the force of those already obtained; being assured that 
the latter would find their full development hereafter." 
The importance of the electrical industries to-day prove 
how brilliantly this assurance has been justified. 

Joule's name appears to be derived from " Youlgrave," 
a village in Derbyshire where his family originally resided; 
but his grandfather migrated to Salford and acquired wealth 
as a brewer. When Joule was ten years old, his father 
sent him, together with his elder brother, to study chemistry 
under Dalton, who, however, during two years confined 
his instruction entirely to elementary mathematics, and 
before they could proceed to chemistry, Dalton was struck by 
paralysis, and had to give up work. It has already been 
explained how Joule was led to his final discoveries, starting 
from the desire to utilize the power of electrodynamic 
machines, which were then not more than interesting toys. 
Towards the end of 1840, when Joule was only twenty-two 
years of age, he forwarded a paper to the Royal Society 
in which he announced the correct law indicating how the heat 
developed in a wire through which a current of electricity 
passes depends on the intensity of the current. That paper 
was published in abstract in the Proceedings of the Royal 



John Prescott Joule 41 

Society, but full publication in the Transactions was 
declined. A worse fate befell a later paper : "On the 
Changes of Temperature produced by the Rarefaction and 
Condensation of Air," read on June 20th, 1844, but not 
printed by the Society even in abstract. Joule must 
have felt severely disappointed at the time, but his dis- 
position was so amiable and indulgent to human failings 
that, at any rate in his later years, he did not show any 
resentment. "I can quite understand," he once remarked, 
" how it came about that the authorities of the Royal 
Society refused my papers. They hved in London ; I Uved 
in Manchester ; and they naturally said : What good can 
come out of a town where they dine in the middle of the 
day 1 " 

Joule had not, however, to wait long for recognition; 
he was elected a Fellow of the Royal Society in 1850, a year 
before the same honour fell to Lord Kelvin and Stokes. 
The turning poiut in his life came with the meeting of the 
British Association at Oxford iu June 1847, where he 
described his experiments. According to Joule's account 
that communication would have passed without comment 
if a young man had not risen, and by his intelligent observa- 
tions created a hvely interest in the new theory of heat. 
That man was WiUiam Thomson, afterwards Lord Kelvin, 
whose recollection of the meeting differs, however, from that 
of Joule. 

" I heard," he writes some years later, " his paper 
read at the sections, and felt strongly impelled to rise 

and say that it must be wrong but as 

I listened on and on, I saw that Joule has certainly a 

great truth and a great discovery and a most important 

measurement to bring forward. So, instead of rising 

with my objection to the meeting, I waited tUl it was 

over, and said my say to Joule himself at the end of 

the meeting." 

Whichever version of the incident be the correct one, 

it led to a lifelong friendship, and marks the date at which 

opposition to Joule's views began to break down. Faraday 

was also present at the meeting, and was impressed by 

Joule's work. 



42 Britain's Heritage of Science 

On the whole, Joule's life ran a smooth course. The 
independent means of his father allowed him to devote 
his whole time to scientific researches. He never took an 
active share in the management of the brewery, but the 
record of his observations of the pressure and temperature 
of the air are often entered on the blank pages of the books 
in which the stocks of barrels were kept. After his father's 
death, unfortunate investments materially diminished his 
income, and he was unable to undertake the heavy 
erpenditure involved in the prosecution of his researches 
without some assistance from scientific societies with 
funds available for research purposes. The grant of a 
pension of £200 from the CSvil List released him in 1878 
from further anxieties. In private Ufe Joule often 
expressed his opinions strongly, but the kindness of his 
character impressed all who came into contact with him, 
and the modesty of the man who, as much as any one, 
has placed experimental science in this country in the 
commanding position it occupies, is typically illustrated 
by the remark he made about himself two years before 
his death : "I beheve I have done two or three little things, 
but nothing to make a fuss about." 

William Thomson, born in 1824, was the second son of 
James Thomson, who, at the time of his marriage, was 
Professor of Mathematics in the " Academical Institution," 
Belfast. He was eight years old when his father took over 
the Professorship in the same subject at the University of 
Glasgow, and matriculated at that University at the early 
age of ten. He entered as an undergraduate at Cambridge 
in October, 1841, his first paper " On Fourier's Expansions 
of Functions in Trigonometrical Series " having already been 
published in the Cambridge Mathematical Journal in May 
of the same year. The paper was apparently written during 
a journey to Germany in the previous summer. No less 
than thirteen additional papers were published by him in 
the same journal during his imdergraduate career, which 
ended in 1845 with his graduation as second wrangler. In 
the following year he was appointed Professor of Natural 
Philosophy at Glasgow, a position which he held during 
fifty -four years. From an early period he waa recognized 



John Prescott Joule, Lord Kelvin 43 

as one of the greatest scientific intellects of his time, sur- 
passed in power by none, ip originaUty perhaps only by 
MaxweU. Well merited honours came to him in rapid 
succession. He was created a knight in 1866, Gteneral 
Commander of the Victorian Order in 1896, and a Peer of 
Great Britain as Lord Kelvin in 1892. The Royal Society 
awarded to« him the Copley Medal — their highest distinc- 
tion — ^Ln 1883, and he occupied their Presidential Chair 
between 1890 and 1895. He was one of the original members 
of the Order of Merit, which was founded in 1902, and in 
the same year was made a Privy Councillor. He was buried 
in Westminster Abbey by the side of Newton. 

Lord Kelvin's powers of work were prodigious and his 
memory unequalled. He claimed to be able to take up at 
any time the thread of an investigation which he had left 
unfinished ten years previously. His brain was uninterruptedly 
active ; his notebook handy on every railway journey, and 
he could work till the late hours of an evening without 
risking a sleepless night. 

Everyone interested in the history of science must often 
have asked himself the question how far its progress would 
have been retarded if a particular brain had never been 
called into existence. With few exceptions the answer 
arrived at would be that, though discoveries might have 
been delayed and reached by different roads, and the work 
of one man divided between two and three, the effect in the 
long run would have been small and perhaps insignificant ; 
but it is difficult to beUeve that science would stand where 
it does to-day if Maxwell had never lived. Faraday's way 
of looking at things was perhaps equally distinctive, but 
Faraday's originaUty lay in the manner in which he was 
led to perform the experiments which brought new facts 
to hght, and the same experiments might have suggested 
themselves to others in a different manner. Maxwell's 
originaUty of thought, on the other hand, was the essential 
factor in the investigation, and it is almost impossible to see 
how his results could have been arrived at by a different 
road from that which he took. He also possessed another 
power not always given to great intellects. A mind that 
excels in origiaaUty is frequently unable or, at any rate, 



44 Britain's Heritage of Science 

unwilling to follow other men's lines of reasoning, and 
thereby loses much of its power of fructifying contemporary 
thought. But in Maxwell it was not only his originahty, 
but also his receptivity that was exceptional. No one was 
less imitative, either in the manner of expression or in the 
direction of his thoughts ; but he always knew how his own 
way of looking at things was related to that of others. 

We possess a good accoimt of Maxwell's life,^ rendered 
specially valuable by the number of his letters which are 
reproduced; these allow us to get a ghmpse of the 
attractive quaintness .with which he could illuminate every 
subject, but the barest outline of his career must here 
suffice. 

His powers of observation showed themselves at a very 
early age. In a letter, written when he was not yet three 
years old, his mother relates that " Show me how it does " 
was never out of his mouth, and that he investigated the 
hidden courses of streams and bell wires. At school, he did 
not at first take a very high place, and his schoolfellows 
so much misunderstood the character of the reserved, 
dreamy boy, that they gave him the nickname of " Dafty." 
He soon, however, grew interested in his work, and all his 
letters home breathe a healthy playful spirit. When fourteen 
years old he was taken by his father to attend some of the 
meetings of the Royal Society of Edinburgh, and a year 
later wrote a paper " On the Description of Oval Curves," 
which, on the recommendation of Professors Kelland and 
Forbes, was pubUshed by that Society. At that time he 
was already repeating for his own instruction experiments 
on light and magnetism. He entered the University of Edin- 
burgh in 1847 at the age of sixteen, and after remaining three 
years entered Peterhouse at Cambridge, from which college, 
however, he soon migrated to Trinity, graduating as second 
wrangler in 1854. While still an undergraduate he pub- 
lished a number of papers in the Cambridge and Dublin 
Mathematical Journal ; from that time onwards his scientific 
activity never ceased and gradually spread over a wider 
and wider range of subjects. 

1 " Life of James Clerk Maxwell," by Lewis Campbell and William 
Garnett (Maomillan, 1882), 



Clerk Maxwell 45 

In November 1856 Maxwell was appointed Professor of 
Natural Philosophy at Marischal College, Aberdeen, a chair 
which was abolished in 1860 in consequence of the fusion 
of the two colleges in tha' town. Among many characteristic 
remarks which occur in his letters of that period we may 
quote the following : "I found it useful at Aberdeen to tell 
the students what parts of the subject they were not to 
remember, but to get up and forget at once as being rudi- 
mentary notions necessary to development, but requiring 
to be sloughed off before maturity." Between 1860 and 
1865 Clerk Maxwell taught Physics at King's College, 
London. His duties there were exacting and he suffered 
from two serious iUnesses. He may have reahzed that his 
powers of teaching did not lie in the direction of making 
matters easy to students, many of whom were not over 
anxious to learn, but it was probably mainly for reasons 
of health that he resigned his chair and settled down at 
Glenlair, the house built by his father on the family estate 
in Dumfriesshire. A few years later he was, however, 
persuaded with some difficulty to take over the newly- 
estabUshed Professorship of Experimental Physics at Cam- 
bridge. The Cavendish Laboratory was built in that 
University by the Vllth Duke of Devonshire for the pro- 
secution of experimental research in Physics ; it was opened 
in 1870, and there probably never has been a benefaction 
more fruitful in its results. The laboratory has, indeed, had 
a brilliant history ; its immediate result was to allow Clerk 
Maxwell to spend the closing years of his hfe among old 
friends and new pupils. He died after a short but painful 
illness in November 1879, at the age of forty-eight. Those 
who knew him will hold his memory in affectionate remem- 
brance, and to all who turn to his writings for a knowledge 
of his work he wiU always remain a source of inspiration. 



46 Britain's Heritage of Science 



CHAPTER II 

(Physical Science) 

The Heeitaoe of the Univebsities 
during the Seventeenth and Eighteenth Centuries 

ri^^HE range of activity covered by University teaching 
J- in the sixteenth century is indicated by the subjects 
assigned to the five Regius Professorships founded in 1546 
at Oxford and Cambridge by King Henry VIII. These 
were Divinity, Hebrew, Greek, Civil Law, and Medicine, 
the latter subject forming the only point of contact with 
science. The practical demands of navigation were, how- 
ever, beginning to stimulate the study of mathematics and 
astronomy, and when Gresham College was founded in 1575, 
separate professorships in these subjects were provided for. 
A few years later (1583), Edinburgh appointed professors 
of mathematics and natural philosophy, and Oxford followed 
with the endowment of the Sedleian Professorship of Natural 
Philosophy (1621), the Savilian Professorship of Geo- 
metry (1619), the Savilian Professorship of Astronomy 
(1621), and a Professorship of Botany (1669). During the 
seventeenth century, Cambridge could only claim the 
Lucasian Chair of Mathematics (1663), but it was the first 
University with a Chair of Chemistry, endowed in 1702. 
Its two Professorships of Astronomy were founded in 1704 
and 1749 respectively. Chemistry and Botany being mainly 
introduced as adjuncts to medicine, it appears that science 
at the Universities may be said to have been confined to 
the application of mathematics first to Astronomy, and 
subsequently to other subjects, which, as they became more 
definite began to supply material for the exercise of mathe- 
matical skUl. Experimental science for its own sake began 
to be taught at the Universities only in comparatively recent 



Gresham College 47 

times. On the other hand, it is well to dispose at once of 
the erroneous impression that the British Universities were 
bodies which confined themselves to the academic discussion 
of abstruse subjects unrelated to the ordinary interests of the 
community. The Universities trained the medical men, 
who kept the flag of science flying in the eighteenth century, 
and the study of astronomy was pursued in great part for 
the sake of its value in finding the position of ships at sea, 
and in the measurement of time. The problems dealt with 
by mathematicians were, at first, generally suggested by 
practical requirements, and only gradually became detached 
from them. In fact, science began to be taught as a means 
towards a practical end. 

If Gresham College had developed — as it ought to have 
done — ^into a University of London, it might have affected 
the higher education of England at a critical time in a 
manner which it is difficult now to estimate. Its founder, 
Sir Thomas Gresham, had studied at Cambridge, and was 
a man of exceptional abilities. He was admitted to the 
Mercers' Company at the age of twenty -four, and soon 
afterwards went to the Netherlands, where his father, a 
leading London merchant, had business interests. By his 
management of affairs in Amsterdam he helped King 
Edward VI. over his private financial difficulties, and 
received valuable grants of land as a reward. Under Queen 
Elizabeth he continued to act as financial agent of the 
Crown, and was knighted previous to his departure on a 
mission to the Count of Parma. Having reahzed the utihty 
of the " Bourse " of Amsterdam during his residence in 
Holland, he offered to build at his own expense what after- 
wards became the Royal Exchange in London, if a suitable 
plot of land were placed at his disposal. This was done, 
and, in the upper part of the building erected, shops were 
estabhshed, the rental for which was handed over to 
Gresham. He then conceived the idea of converting his 
own mansion in Bishopsgate into a seat of learning, and 
endowing it with the revenues arising from the Royal 
Exchange. Some correspondence about this scheme took 
place in 1575, and after his death in 1579 it was found that 
— subject to the Ufe interest of his wife — he had provided 



48 Britain's Heritage of Science 

in his will for the foundation of a college. The first lectures 
were given in 1597, each professor receiving the stipend 
of £50, a sum somewhat larger than the revenue of the 
Regius Professors at Oxford and Cambridge, which was 
£40. The building contained residential quarters for the 
professors, an observatory, a reading hall, and some aims- 
houses. It ultimately proved to be too expensive to be 
maintained with the available funds, and in 1768 was 
handed over to the Crown; the lectures were then held 
in the Royal Exchange until 1843, when the present building 
was erected. 

The appointment of the professors was, by Gresham's 
will, vested in the Mayor and Corporation of London, who 
in their first selection consulted the Universities of Oxford 
and Cambridge, requesting them to nominate two candi- 
dates for each of the seven professorships ; the final selection 
included three graduates of Oxford, three of Cambridge, 
and one who was a graduate of both Universities. The 
first Professor of Geometry at Gresham College was Henry 
Briggs (1561-1631), who, after the discovery of logarithms 
by Napier, calculated complete tables, and thus made 
their general use possible He also introduced the present 
notation of decimal fractions, one of the most important 
advances in the history of arithmetic. The last twelve 
years of his life were spent at Oxford, where he held the 
newly-founded Savihan Professorship of Greometry. 

Edward Wright (1560-1615), a mathematician closely 
associated with Napier and Briggs, translated into English 
the Latin original of the work which contains the first 
account of logarithms, but his name deserves chiefly to be 
remembered in connexion with navigation, to which science 
he rendered conspicuous service by laying the scientific 
foundation of the method of constructing maps known as 
" Mercator's Projection." Wright studied at Cambridge, 
was elected to a fellowship of Caius College, and became a 
teacher of mathematics in the service of the East India 
Company. 

Among those who, during the seventeenth century, held 
professorships at Gresham College, we note John Greaves, 
Isaac Barrow, Robert Hooke, Edward Gunter, Henry Gilli- 



H. Briggs, E. Wright, J. Greaves, J. Barrow 49 

brand, and Christopher Wren. Their work now calls for 
consideration. 

John Greaves (1602-1652), who held also for a time 
the Savilian Professorship of Astronomy at Oxford, from 
which position he was dismissed on poUtical grounds in 
1646, must be considered to be the earliest scientific metro- 
logist. He determined with fair accuracy the relation 
between the Roman and Enghsh foot, and also carried out 
some investigations on Roman weights. One of his suc- 
cessors at Oxford, Edward Bernard (1638-1697), followed 
up this work, and published a treatise on ancient weights 
and measures.^ 

The mathematics of the time, as has already been noted, 
was under the influence of Descartes, who had invented the 
method of analytical geometry, in which the position of a 
point is defined by its distance from two fines at right angles 
to each other, and which represents a curve in the form of an 
equation as an algebraic relationship between these distances. 
When this is done, many problems suggest themselves, 
such as that of forming the equation to its tangent at any 
point, or calculating the area bounded by the curve. 
The solution of such problems led naturaUy to the concep- 
tions from which the differential calculus emerged. Isaac 
Barrow (1630-1677), working along the lines indicated by 
Fermat and Pascal, succeeded in finding the correct expres- 
sion for the tangents of a number of curves. A successful 
lecturer and writer of books, rather than an independent 
discoverer, he was, nevertheless, an interesting figure in 
the history of science. The son of a finendraper in London, 
educated at Charterhouse, he proceeded to study medical 
subjects as well as Uterature and astronomy at Cambridge, 
where he took his degree and obtained a Fellowship at 
Trinity College. Having been driven out of the University 
by the persecution of the Independents, he travelled in 
France and Italy, proceeding thence to Smyrna and Con- 
stantinople. After spending a year in Turkey, he returned 
home through Grermany and Holland in 1659. In the 
following year, he was appointed to the Chair of Greek at 

1 See " Report of the Smithsonian Institution, 1890," " The Art 
of Weighing and Measuring," by William Harknes8. 

D 



50 Britain's Heritage of Science 

Cambridge, and subsequently was elected Professor of 
Astronomy at Gresham College. He returned to his Alma 
Mater in 1663 to take up the newly-founded Lucasian 
Professorship of Mathematics. Perhaps he performed his 
most noteworthy scientific act when he resigned his chair 
in favour of his pupil Newton. 

John WalHs (1616-1703) is another example of a Univer- 
sity Professor who took an active share in the national life. 
After passing through Cambridge, where — ^like Barrow — he 
studied medicine, he took Holy Orders in 1641, but became 
involved in pohtics; he attained considerable facihty in 
deciphering intercepted despatches of the Royahsts, and 
thereby rendered considerable service to the Puritan party. 
After holding several livings in succession, he was appointed 
SaviUan Professor of Geometry in 1649, in spite of the 
opposition of the Independents, who resented his having 
signed the protest against the execution of Charles I. John 
WaUis was one of the foremost mathematicians of his time. 
His work dealt chiefly with appUcations of Descartes' 
analytical geometry; but he also pubUshed a book on 
algebra. He seems to have been the first to conceive the idea 
of representing geometrically the square root of a negative 
quantity, and is the originator of the sign oo for infinity. 
Other writings of his dealt with the tides. His efforts to 
teach deaf mutes to speak, which are said to have been 
successful, were the first attempts in that direction. Wallis 
was also interested in investigations on sound, and in a paper 
published in the Philosophical Transactions he communicated 
some interesting experiments made by WiUiam Noble, 
fellow of Merton College, and Thomas Kgot, Fellow of 
Wadham, which contain important investigations on the 
phenomenon of resonance in sound. Light bodies were 
placed as riders to investigate the vibrations of stretched 
wires, and it was shown that when these wires responded 
to a higher harmonic, the riders were not set in motion if 
placed at what we now caU the nodal points. 

Associated with the group of mathematicians who were 
contemporaries of Newton, Lord Brouncker (1620-1684) 
takes an intermediate place between the professional and 
non-academic class. The title descended to him from his 



John Wallis, Christopher Wren 51 

father, who had been elevated to the peerage by Charles I. 
Brouncker, after obtaining the degree of Doctor of Physio 
in the University of Oxford, devoted himself to the study 
of mathematics, and acquired a great reputation at home 
and abroad by his investigations, which take a high rank 
in the history of the subject. He made extensive use of 
approximation by infinite series, and though he is not the 
originator of continued fractions, he first used them 
effectively. He was one of the original promoters of the 
Royal Society, and was named as its President in the Charter. 
He occupied that position for fifteen years, during which 
he assiduously devoted himself to its duties. The first years 
of the Society were necessarily critical ones, and much 
credit for the judicious and successful direction of its affairs 
is due to his distinguished services. 

Christopher Wren (1632-1723), though known to fame 
mainly as a great architect, distinguished himself at Oxford 
as a mathematician. He had, independently of Newton, 
suggested the existence of a universal attraction as the 
cause which retained planets in their orbits, and is highly 
spoken of in the " Principia." He also was the first to 
calculate the length of the curve called the cycloid. 

In 1657 he became Professor of Astronomy at Gresham 
College, and three years later took over the Savihan Profes- 
sorship at Oxford. Wren's contributions to science were 
substantial. When the Royal Society expressed a wish 
that mathematicians should iuvestigate the laws of impact, 
Huygens, Wallis and Wren sent in independent investiga- 
tions. All these contained a correct appreciation of the 
principle of conservation of momentum. The great archi- 
tect's solution was correct so far as perfectly elastic bodies 
were concerned. Wallis began with the consideration of 
inelastic bodies, but ultimately treated the problem in the 
most general manner, including both perfect and imperfect 
elasticity. 

A most striking instance of a family, who in many 
successive generations reached distinction in the academic 
world, may here be recorded. James Gregory (1638-1675), 
educated at Aberdeen, published, at the age of twenty- 
five, a treatise on optics, containing the invention of the 



52 Britain's Heritage of Science 

reflecting telescope which goes by his name, but he had no 
opportunity of actually constructing an instrument. He 
was also the first to show how the distance of the sun 
could be deduced by observations of the passage of Venus 
across the disc of the sun. After a period of study at Padua 
he became Professor of Mathematics at St. Andrews and 
subsequently at Edinburgh. His elder brother, David Gregory 
(1627-1720), was privately engaged in scientific pursuits, 
and having used a barometer to predict the weather, paid 
the penalty of his success by being accused of witchcraft. 
David had three sons, the eldest of whom (1661-1708) 
successively held the Chair of Mathematics at Edinburgh 
and the Savihan Professorship of Astronomy at Oxford ; 
the second son succeeded his elder brother in the Chair of 
Mathematics at Edinburgh, and the third (Charles) was 
Professor of Mathematics at St. Andrews. The eldest son 
of David, the Savihan Professor, was Dean of Christ Church 
and Professor of Modem History at Oxford. 

Among the descendants of James Gregory we find in 
three generations four distinguished medical men, all of 
whom held professorships in the subject, and in the fourth 
generation, two brothers, the elder of whom, William (1803- 
1858), became Professor of Chemistry at the Andersonian 
University in Glasgow, at King's College in Aberdeen, and 
finally at Edinburgh University. His younger brother, 
Duncan Farquharson Gregory, entered Trinity College, 
Cambridge, assisted for a time the Professor of Chemistry, 
but ultimately devoted his attention to mathematics, and 
founded the Cambridge Mathematical Journal. 

The scientific activity of the Universities in the second 
half of the seventeenth century was naturally dominated 
by the influence of Newton's work. His dynamical investi- 
gations, leading up to the explanation of the observed motions 
in the solar system, have already been described, and it 
is interesting to trace the historical connexion between 
those discoveries and others which remain to be mentioned. 
Fortunately his own words describing the succession of 
ideas as they occurred to him have been preserved : 

" In the beginning of the year 1665 I found the 

method of approximating series and the rule for deducing 



David Gregory, Isaac Newton 53 

any dignity of any binomial into such a series. The 
same year, in May, I found the method of tangents of 
Gregory and Slusius, and in November had the direct 
method of fluxions, and the next year, in January, had 
the theory of colours, and in May following I had entrance 
into the inverse method of fluxions. And the same year 
I began to think of gravity extending to the orb of the 
moon, and having found out how to estimate the force 
with which a globe revolving within a sphere presses 
the surface of the sphere, from Kepler's rule of the 
periodical times of the planets being in a sesquialterate 
proportion of their distances from the centres of their 
orbs, I deduced that the forces which keep the planets 
in their orbs must be reciprocally as the squares of their 
distances from the centres about which they revolve ; 
and thereby compared the force requisite to keep the 
moon in her orb with the force of gravity at the surface _ 
of the earth, and found them answer pretty nearly. 
All this was in the two Plague years of 1665 and 1666, 
for in those days I was in the prime of my age for inven- 
tion, and minded mathematics and philosophy more than 
at any time since."' 
In explanation of this passage it may be noted that the 
" method of fluxions " was the foundation of the differential 
calculus, and the " inverse method of fluxions " that of the 
integral calculus. 

Newton's attention was probably drawn to the study of 
optics by Barrow. The change of direction of a ray of 
hght on entering a transparent body obliquely had been a 
favourite subject of investigation in many countries, and 
the law regulating it was first correctly formulated by Snell 
(1591-1626), Professor of Mathematics at the University of 
Leiden. It was reserved to Newton to show that ordinary 
white hght, such as sunhght, consisted of a mixture of 
different rays. When transmitted through a prism it 
spreads out into a band of coloured light caUed the spectrum, 
because the different rays are deviated to a different degree. 
With the same transparent material, the measure of the 

' From a MS. among the Portsmouth Papers, quoted in the 
preface to the " Catalogue of the Portsmouth Papers." 



54 Britain's Heritage of Science 

deviation, or the refrangibility, as we should now call it, 
is perfectly definite for each ray, and is intimately connected 
with its colour. Having once separated a ray of definite 
colour, no further refraction will alter that colour, and it 
will continue to retain the same properties. As one of 
the results of this discovery it became apparent that a lens 
cannot form a perfect image of an object, because different 
colours are not brought together at the same focus. This 
appeared to Newton to be such a serious and irremediable 
defect of telescopes with glass objectives, that he set himself 
to construct an instrument in which the principal lens is 
replaced by a mirror. At the request of the Royal Society, 
who had heard of his telescope, Newton forwarded the 
instrument to its secretary in December, 1671, with the 
result that in January of the succeeding year he was elected 
a PeUow of the Society. The idea of reflecting telescopes 
had, as already mentioned, previously occurred to Gregory, 
whose proposal differed, however, essentially from that of 
Newton in the manner in which the rays were ultimately 
brought to the observer's eye. 

Newton's name is attached to the coloured rings seen 
when two slightly curved surfaces of glass are brought 
together, so that there is a thin circular wedge of air formed 
near the point of contact. The explanation of these rings 
presented considerable difficulties, especially with the theory 
of hght adopted by Newton. Though cognisant of the wave- 
theory of hght, which, as shown by Huygens, could explain 
its propagation and refraction, Newton had good grounefc for 
not accepting it. He saw that the analogy of sound which 
had been invoked in its favour broke down when appUed 
to the formation of shadows. Sound after passing through 
an opening spreads in all directions, while hght apparently 
follows a straight course. In other words, sound can turn 
a comer, while Hght seems unable to do so. More than a 
century later, Fresnel gave the correct explanation of the 
apparent discrepancy, showing that when the experimental 
conditions were made to correspond, the analogy was main- 
tained. It is necessary for the purpose that the relation 
between the size of the aperture and the length of the wave 
should be the same, and as the waves of light are very short. 



Isaac Newton, Robert Hooka 55 

either the aperture through which the light is made to enter 
has to be very small, or the opening allowing the sound to 
be transmitted must be large. In the latter case we get 
" sound shadows," in the former the Ught spreads out just 
as the sound does. But such refined considerations only 
matured in the nineteenth century. In the meantime, the 
ordinary laws of refraction and reflexion of hght could be 
satisfactorily explained by the corpuscular theory, which 
seemed better able to cope with the formation of shadows, 
and Newton therefore preferred the simpler theory. It is 
tmfortunate that an error of judgment, arising really from 
superior knowledge, paralysed the progress of optics for 
the time being, but this is the price which had to be paid 
for the many benefits which accrued to science through the 
confidence which Newton's work had inspired, and which 
in aU other cases proved to be justified. 

Newton's work on light brought him into controversy 
with Robert Hooke (1635-1703), a man of great genius but 
unpleasant temperament, who, for a time, held the Chair 
of Geometry at Gresham College. Hooke graduated at 
Oxford and there came into contact with John WUkins, 
Thomas WiUdns and Robert Boyle. With an extraordinarily 
prolific mind he touched on many subjects, insisting on 
his priority in almost every new idea that was brought 
forward by others. 

In his " Micrographia " Hooke described important 
observations on the nature of combustion and of flames. 
Almost identical experiments were conducted by John 
Mayow (1640-1679), a feUow of AU Souls CoUege, Oxford, 
and it is impossible now to ascertain to whom they were 
originally due. Mayow, who was also a distinguished 
physiologist (see p. 296, Chapter XI.), interpreted these ex- 
periments with remarkable foresight. He truly recognized 
that there must be a common element in air and in such 
bodies as nitre, which readily give up their oxygen, and 
showed that the air contains some constituent which is 
consumed in combustion; he thus came very near anti- 
cipating by more than a century Lavoisier's great discovery. 

Hooke was the first who conceived the idea of regulating 
watches by the balance wheel and spiral spring, and this 



56 Britain's Heritage of Science 

alone would give him a high place among discoverers. He 
first constructed a spirit level, but others had anticipated 
him in the use of the Vernier. He was the first to use fight 
powders to study the vibration of sounding bodies, and 
invented an instrument to measure the depth of the sea. His 
more theoretical speculations always showed acuteness, 
and might have led to great things if he had been more 
persevering. In 1674 he published views on a universal 
gravitation which was to explain the planetary motions ; 
with the exception of the law of the inverse square, these 
contained the main principles of the theory which Newton 
had then already worked out, though not pubfished. In 
optics, Hooke favoured the undulatory theory, and even 
expressed the idea that the motion of the particles of the 
medium which transmitted light was transverse to the direc- 
tion of propagation, differing in this respect from the waves 
of sound. Newton, who disliked controversies, is said to 
have delayed the publication of his book on optics until after 
Hooke's death for fear of rousing an acrimonious discussion. 

The second edition of Newton's " Principia " was pub- 
fished in 1713 by Cotes (1682-1716), a distinguished and 
promising mathematician, who died at the early age of thirty- 
four, having held during the last ten years of his fife the 
newly -founded Plumian Professorship at Cambridge. 

Among the professional representatives of mathematics 
diiring the eighteenth century, it must suffice to name 
Maclaurin (1698-1746), Professor of Mathematics at Aberdeen ; 
Matthew Stewart (1717-1785), who succeeded him in the 
Professorship, and Thomas Simpson, the son of a grocer, 
who ultimately became Professor of Mathematics at the 
Royal Woolwich Academy. 

After Newton had placed astronomy on a sound 
dynamical foundation, a vast field was opened out to further 
research. It had stiU to be proved that the law of gravita- 
tion was sufficient to account for every detail of the motions 
of celestial bodies, and was not only a first approximation 
to be supplemented by other effects. Hence it became 
necessary to increase the accuracy of astronomical observa- 
tions, and to extend the theoretical investigations, based 
on the laws of gravity, so as to include the mutual action 



Isaac Newton, John Flamsteed 57 

of planets on each other. We have now to consider the work 
of some of the great men occupied in this task. 

Flamsteed (1646-1720) does not strictly belong to the 
academic circle, but as he was the first official representative 
of astronomy in this country it is convenient to speak of his 
work at this stage. Flamsteed began at an early age to take 
an interest in astronomical observations. He entered Jesus 
College, Cambridge, apparently with the object of taking 
holy orders, but after obtaining his degree, influential friends 
procured him an appointment as " King's astronomer." 
About the same time, a Frenchman, called Le Sieur de S. 
Pierre, visited England with proposals for improved methods 
of determining longitudes at sea, and Flamsteed in a report 
expressed the opinion that the project was impracticable, 
because the position of the stars were not known with 
sufficient accuracy. According to some manuscripts kept 
at the Greenwich Observatory, when this came to the ears 
of King Charles II, " he was startled at the assertion of the 
fixed stars places being false in the catalogue, and said, 
with some vehemence, he must have them anew observed, 
examined and corrected, for the use of his seamen." This 
incident was the immediate cause of the foundation of Green- 
wich Observatory, the warrant for its building being issued 
on June 12th, 1675. When it was completed, Flamsteed 
set to work to form an improved star catalogue. Up to 
that time, only observations with the naked eye had been 
used to determine the positions of the stars, though 
the cross wire and measuring micrometer had already been 
invented by Gascoigne. Flamsteed realized the advantages 
of applying the telescope in combination with a clock. But 
he had to struggle against great disadvantages ; his salary 
was £100 a year, and he was provided by the Gfovemment 
with neither assistants nor instruments. The latter had 
to be provided by friends, or made at his own expense. In 
spite of these difficulties he produced as a result of his labour 
a star catalogue three times as extensive as, and six times 
more accurate than, that of Tycho Brahe, which up till then 
had been in use. Altogether he recorded the positions of 
3,000^tars. 

Flamsteed was succeeded at Greenwich by Edmund 



58 Britain's Heritage of Science 

Halley (1656-1742), who plays an important and interesting 
part in the history of science. The son of a soap-boiler, 
and educated at St. Paul's School and Queen's College, 
Oxford, Halley, at the early age of nineteen, invented an 
improved method for determining the elements of planetary 
orbits. Finding that more accurate measuremente of the 
positions of fixed stars were necessary to the progress of 
astronomy, and that this task was being satisfactorily 
carried out at Greenwich for the northern heavens, he planned 
a journey to catalogue some of the southern stars. Through 
the good offices of the East India Company he obtained a 
passage to St. Helena, but disappointed with the weather 
conditions, he returned to England after having registered the 
positions of about 300 stars. He was an ardent supporter 
of Newton, and it was in great part due to HaUey's efforts 
that the " Principia " were pubUshed. 

Halley was the first to take a comprehensive view of the 
subject of Terrestrial Magnetism. Some advances had been 
made in that subject since Gilbert's time, notably by Edward 
Gunter (1581-1621), one of the early professors of astronomy 
at Gresham College, who had taken regular observations of the 
angle between the direction in which the magnetic needle 
sets and the geographical north, and found a progressive change 
in its amount. When the first observation was taken in 
England, the needle pointed to the east of north; in 1657 
it pointed due north, and the declination then gradually 
increased towards the west. Henry GeUibrand (1597-1637) 
continued and extended these observations. 

In order to explain these slow changes called " the 
secular variation of terrestrial magnetism," Halley formed 
the theory that the earth is divided into an outer crust 
and an inner nucleus, each part possessing its own inde- 
pendent magnetic poles. A fluid layer was supposed to 
separate the shell and the core, and HaUey imagined the 
latter to revolve with a shghtly smaller velocity than the 
former about a common axis. It is easy to see that if 
we accept the premises, a suitable adjustment of the mag- 
netic axes of the inner and outer parts of the earth would 
lead to a slow revolution of the resulting magnetic axis. 
This theory was recently renewed and extended by Henry 



Edmund Halley 59 

Wilde, and, though not generally accepted, it shows that 
Halley recognized that the study of terrestrial magnetism 
could yield important information on the constitution of 
the earth and that he looked upon the subject from a 
wider point of view than that of its mere application to the 
purposes of navigation. The observations he took in two 
journeys specially undertaken for the purpose of determining 
the magnetic declination in different parts of the world, are 
invaluable to us as historical records. 

Halley's most important discoveries in astronomy were 
the secular acceleration of the moon's mean motion, the 
proper motion of the stars, and the periodicity of comets. 
Comparing the dates at which certain total eclipses of the 
sun had occurred, Halley could fix the times of the new 
moon with sufficient accuracy to ascertain that the length 
of the month was diminishing by about one-thirtieth of a 
second per century. This imphed that the moon's orbital 
velocity is increasing and may be explained in accordance 
with Newton's principles, partly as a result of an indirect 
effect on the earth's orbit round the sun due to the attrac- 
tion of planets, and partly by friction between the tides and 
the sohd parts of the earth, which increases the length of 
the day, and indirectly reacts on the moon. 

In all three of the discoveries mentioned, HaUey made 
extensive use of old records ; it was by comparing the 
observed distances of weU-known stars from the ecliptic 
with the observations of the Greek astronomers, that he 
discovered their independent motions, and, similarly by 
calculating the orbits of comets observed in previous 
centuries, he found that some of them pursued nearly 
identical paths. He concluded that though these were regis- 
tered each time as new intruders into the solar systems, 
they might only be reappearances of the same body. As an 
example, he took the comet which had been observed at 
intervals of about seventy-six years, and had last been seen 
in 1682. He predicted that it would be seen again in 1758. 
Halley did not Kve to see his prophecy come true : the 
comet was actually observed on Christmas Day of that 
year, and is now recognized as a permanent member of the 
Solar System. 



60 Britain's Heritage of Science 

Halley succeeded Waller as Professor of Geometry at 
Oxford in 1678, and Flamsteed as Astronomer Royal in 
1720. When he arrived at Greenwich, he found most of 
the instruments removed, being the private property of his 
predecessor. He procured some new ones, and began the series 
of observations of the moon, the continuance and improve- 
ment of which has always been the special care of the Royal 
Observatory. But the age at which he took over his duties 
prevented his making much progress. 

Halley 's activity covered a large range of subjects, and 
proved lum to be a man of extensive knowledge and great 
versatility. He investigated, independently of Mariotte, 
the diminution of the pressure of air as we rise above the 
surface of the earth, and gave the correct formula for 
calculating differences in altitude from the barometric 
records ; he observed the aurora boreahs, and connected 
it with terrestrial magnetism by noting that the highest 
point of the arch lies in the magnetic meridian. He gave 
the generally accepted explanation of* the cause of the 
trade winds, but was less successful in his attempts to 
improve the construction of thermometers ; he was the 
first to give the formula which connects the position of 
objects and images formed by lenses ; he formed an esti- 
mate of the quantity of water vapour which enters the 
atmosphere by the action of solar heat on the oceans; he 
wrote on the effect of the refraction of air on astronomical 
observations, worked out the method of deducing the 
distance of the sun from observations on the transit of 
Venus, and made valuable contributions to the method of 
calculating logarithms. He improved the construction of 
diving bells, and was the originator of " life statistics." 
There are few men who can show a finer record of scientific 
activity. 

Halley was succeeded at Greenwich by Bradley (1692- 
1762), to whom, according to the astronomer Delambre, 
we owe the accuracy of modem astronomy. Bradley was 
a nephew of John Pond (1669-1724), a clergyman who had 
erected an astronomical observatory at his rectory of Wan- 
stead in Essex, and done some meritorious work on the 
satellites of Saturn and Jupiter. After graduating at Oxford, 



Edmund Halley, James Bradley 61 

Bradley went to reside with his uncle, and became interested 
in astronomical work. His observational skill soon secured 
results of sufficient importance to justify his election to the 
fellowship of the Royal Society in 1718, and the appointment 
to the SaAdhan Chair of Astronomy in 1721. He, however, 
continued to live in Wanstead even after the death of his 
uncle, visiting Oxford only for the delivery of his lectures. 

It was known to Robert Hooke that the distance of the 
stars might be ascertained by noting their change of position 
at different times of the year, for as the earth revolves round 
the sun, we look upon each star from a slightly different 
point of view according to the position of the earth in its 
orbit. The more remote the stars, the smaller will be the 
displacement, and no one could tell beforehand whether 
any of them were sufficiently near to show a measurable 
effect. Hooke himself, with his accustomed impetuosity, had 
tried the method, and using a star which for particidar 
reasons was specially fitted for the purpose, beUeved that he 
had observed a comparatively large displacement. Samuel 
Molyneux {see page 90) had erected a suitable telescope 
at his house in Kew Green, for the purpose of verifying 
Hooke's observations, and observed the same star on a 
series of evenings during the early part of December, 1725, 
but no material change of position was noted. At this 
stage Bradley, a friend of Molyneux, began to take part 
in the investigation. On visiting the Observatory at Kew 
on December 17th, curiosity tempted him to take an observa- 
tion, and he noted that the star had shghtly increased in 
declination. To his surprise, however, the displacement was 
found to be in a direction opposite to that to be expected 
if it were due to the proximity of the star. The apparent 
movement was then continuously watched, and the star 
was found to describe a closed curve, returning at the end of 
a year's observation very nearly to its original position. 
Bradley, much puzzled by the result, at first thought that 
the displacement might be due to a periodic change in the 
inclination of the earth's axis. In order to test this idea, 
it was necessary to observe stars in different parts of the 
sky, and Bradley set up a new instrument at his home in 
Wanstead for the purpose. He found, indeed, that evesy 



62 Britain's Heritage of Science 

star examined described an elliptic curve similar to that 
observed with Molyneux's telescope, but the difierences 
ia size and shape did not agree with the hjrpothesis he had 
formed. At last the true expland,tion occurred to him. 

Owing to the fact that hght is not transmitted instanta- 
neously, a star is not actually seen in the direction in which 
it would appear if hght took no time in its passage to the 
earth. The cause of this curious effect may be illustrated by 
a familiar analogy. A person driving in a carriage during a 
shower of rain on a windless day, though the drops fall 
down vertically will feel them striking against his face, as if 
he were meeting the wind. Hence, holding up an umbrella 
to shield himself, he would have to tilt it forwards and it 
he were unaware of his own motion, he would believe that the 
drops fall at an angle sUghtly inclined to the vertical. Sub- 
stituting Newton's corpuscles of light for the drops of rain, 
it becomes clear that the velocity of the earth affects the 
angle at which the Ught coming from a star seems to reach 
us. This effect is called the " aberration of Ught." As the 
earth's velocity changes in direction while it revolves roimd 
the sun, a star, though stationary, wiU appear to describe 
a closed curve. From the known velocity of the earth, and 
the extent of a star's apparent motion, the velocity of Ught 
may be calculated, and Bradley found it to agree closely 
with that which had been calculated by Roemer from the 
echpses of Jupiter's sateUites. The accuracy of Bradley's 
observations may be appreciated by noting that if the star's 
position in the sky be such that it appears, owing to the 
aberration of Ught, to describe a circle, the angular diameter 
of the circle is about that of a halfpenny piece placed at a 
distance of 420 feet; the dimensions of the curve described 
by the star were measured by Bradley with an accuracy of 
about two per cent. 

After Bradley had estabUshed himself at Greenwich 
Observatory, he continued his observations, and found that 
the stars after a year's interval did not return to the same 
position, as they ought to do if the aberration of Ught were 
the only cause of their apparent displacement. Returning 
to his original idea of a small change in the incUnation of 
the earth's axis, he then found it to account satisfactorily 



James Bradley, Nevile Maskelyne 63 

for this residual effect. He thus discovered the " nutation " 
of the earth's axis, which is caused by an attractive effect 
of the sun on the equatorial protuberance of the earth, 
which is not an exact sphere, but a spheroid with a larger 
equatorial than polar diameter. 

When it is considered that every measurement of a star's 
position has to be corrected so as to eUminate the effects of 
aberration and nutation before its true position is ascer- 
tained, Delambre's judgment that the accuracy of astro- 
nomical observations owes everything to Bradley cannot 
be gainsaid, and we shall also probably agree with the same 
author^ that " ce double service assure k son auteur la place 
la plus distinguee aprfes celle de Hipparque et de Kepler, et 
au-dessus des plus grands astronomes de tousles ages et de 
tous les pays." 

After Bradley's death, Nathaniel BUss, SaviUan Professor 
of Geometry at Oxford, was appointed Astronomer Royal, 
but he oiUy held the position for two years. Nevile 
Maskelyne (1732-1811), a man of much greater ability, 
next had charge of Greenwich Observatory. He graduated 
as seventh wrangler at Cambridge in 1754, and twelve years 
later was appointed to the post of Astronomer Royal, the 
duties of which he discharged successfully during forty- 
six years. His mind was first turned to astronomy as 
a boy of sixteen by watching a solar ecUpse. During a 
voyage undertaken to observe the Transit of Venus, in 
1761, he became interested in a process for determining 
longitudes by measuring the distances of selected stars 
from the moon, and he ultimately succeeded in introducing 
this method as a regular practice in navigation. The im- 
portance of the procedure consisted in its being independent 
of timekeepers, and it consequently retained its place until 
recently, when the construction of chronometers improved 
so much that it lost its practical value. 

In order to make the tabulations of the position of the 
moon and of the selected stars readily accessible to navi- 
gators, Maskelyne persuaded the Government to issue an 
annual pubUcation. This was the origin of the Nautical 

1 Delambre, " Histoire de I'Astronomie au dix huiti^me sifeole." 



64 Britain's Heritage of Science 

Almanac, which has proved to be of immeasurable value 
to all seamen. Maskelyne remained its editor imtil his 
death. He also re-organized in many ways the work and 
instrumental equipment of the Greenwich Observatory, and 
instituted an important research which led to the first 
determination of the density of the earth. To appreciate 
the importance of this experiment, we must remember 
that by noting the rate of faU of a body we can measure the 
force with which the earth attracts it, but not knowing the 
total mass of the earth, we cannot tell how much one povmd 
of matter would attract another poimd at a given distance. 
That can only be ascertained by measuring the attraction 
between masses both of which are known. From the result 
of such a measurement the mass of the earth may be calcu- 
lated, and as its dimensions are known, we can deduce its 
mean density. The problem of finding the density of the 
earth is, therefore, identical with that of finding the gravita- 
tional attraction between known masses, and herein hes 
its chief value. Maskelyne 's method consisted in deter- 
mining the deflexion of a plumb fine in the neighbourhood 
of a mountain. As this deflexion cannot be observed directly, 
we must have recourse to an indirect method; but tins 
presents no difficulties. If the latitudes of two places, one 
to the north and the other to the south of a mountain, 
be determined astronomically, and their distances directly 
measured, the discrepancy between the observed and 
measured differences of latitude gives us the data we want 
for calculating the gravitational effect of the mountain. 
The method cannot give very accurate results, as the density 
of the material composing the mountain must be taken into 
account, and this requires a geological survey and complicated 
calculations. Maskelyne was assisted in his measurements, 
which were conducted in the neighbourhood of the mountain 
SchehaUien in Perthshire, by Charles Button (1737-1823), 
Professor of Mathematics at the Mihtary Academy, Wool- 
wich; the figures they obtained showed that bulk for bulk 
the material of the earth is on the average between 4*48 and 
5 "38 times heavier than water. 

While learning at Oxford and Cambridge rapidly declined 
after the first impulse of Newton's discoveries had died away. 



William CuUen, Joseph Black 65 

the reputation of academic science in the eighteenth century 
is retrieved by the splendid record of the Scotch Univer- 
sities, and notably of Edinburgh. It was indeed a brilliant 
period in which Black originated quantitative chemistry, 
Hutton founded the science of geology, Robert Simpson 
taught mathematics, and John Robison, natural philosophy, 
while Watt worked out his inventions, and in other branches 
of knowledge Adam Smith and David Hume added to the 
fame of their Universities. 

William Cullen (1710-1790), who may be said to be the 
founder of the Scotch school of chemists, studied at the 
University of Glasgow, and at the age of nineteen obtained, 
through the influence of friends, a post as surgeon on a 
merchant ship saihng to the West Indies. On his return 
home he became a medical practitioner in his native town, 
Hamilton, but a small legacy enabled him to spend two 
years at Edinburgh, in order to pass through a regular 
course of study. After a period of activity in Glasgow, 
during which he occupied the Chair of Medicine, and assisted 
in founding the medical school in that xiniversity, he returned 
to Edinburgh as Professor of Chemistry. Cullen was the 
discoverer of the lowering of temperature which takes place 
when a liquid evaporates, or a sohd dissolves in a hquid. 
He also experimented on the heat generated in chemical 
transformations . 

It was no doubt these researches on heat which directed 
Joseph Black's attention to that subject. Black (1728- 
1799) was the son of a Scotch wine merchant hving at 
Bordeaux. He was educated at Belfast, Glasgow and Edin- 
burgh, studied medicine at the latter University, and 
presented to it at the age of twenty-six an inaugural disser- 
tation containing discoveries of fundamental importance to 
chemistry. Limestone, which forms so important a portion 
of the earth's sxu^ace layers, was at that time considered 
to be an elementary substance. It was known, of course, 
that at a high temperature its properties are changed; it 
becomes quicklime, which gives off a great amount of heat 
when brought into contact with water. This was explained 
at the time by supposing that the hmestone absorbed, when 
heated, an imaginary thermal or caustic substance which 



66 Britain's Heritage of Science 

it gave out again when brought into contact with water. 
The corresponding compound of magnesia behaved similarly, 
and was not clearly distinguished from the calcium salt. 
Magnesia had then already some importance as a drug, 
and the title of Black's dissertation " De humoro acido a 
cibis orto et magnesia alba " indicates that it was the medi- 
cal aspect that led him to the research. Black proved that 
the current explanation was wrong, and that, instead of 
absorbing anything, limestone, on heating, lost in weight, 
and gave out a gas, which he collected and identified with 
Helmont's " gas sylvestre." He definitely proved that this 
gas, now known as, carbonic acid, differed from air, because 
it could combine with caustic soda and potash, which air 
could not; he also showed that atmospheric air always 
contained small quantities of it. Black further established 
the essential differences between the behaviour of calcium 
and magnesium compounds. His use of the balance in 
these researches justifies the claim that has been made on 
his behalf of being the father of quantitative chemistry. 

In his researches on heat, Black showed an equal power 
of selecting the fundamentally important questions, and of 
treating them with experimental sMll and scientific precision. 
His results were explained in his lectures, but many of them 
remained unpublished imtil after his death It is, therefore, 
not always easy to fix the dates at which his discoveries 
were communicated to his students, so as to compare them 
with similar results arrived at in other coimtries, notably 
by WUcke at Stockholm, and Deluc, who, bom in 1727 at 
Geneva, left his native towa at the age of forty-three and 
after various travels settled down in England, and died at 
Windsor in 1817. There is no doubt, however, that Black 
was the discoverer of latent heat. Deluc had noted the slow 
melting of ice, and made the observation that when a mixture 
of ice and water is heated, the temperature of the water 
remains constant until all the ice is melted, but Black went 
a good deal further, and not only measured the heat required 
to melt the ice, but showed it to be the same in amount as 
that which was set free in freezing the water. He appUed 
the term " latent heat," which is still in use, and his 
measurements were correct to two per cent. The corre- 



Joseph Black 67 

spending phenomenon was observed when water was 
converted into steam, but, owing to the greater experimental 
difficulties, the numerical value obtained was not so accurate. 
Black also had clear ideas on the differences in the amounts 
of heat required to raise different substances through the 
same range of temperature; but handed over this part of 
the subject to his pupil Irvine. 

An interesting paper by Black on " The supposed effect 
of boiling on water in disposing it to freeze more readily, 
ascertained by experiments " (Phil. Trans. 1775) is worth 
reading as an example of clear thinking, lucid description, 
and good experimenting. It is still to-day the common 
behef of plumbers, and those who derive their knowledge 
of science from plumbers, that hot-water pipes freeze more 
readily in winter than cold ones. This belief seems to have 
had its origin in the report, made on good authority, that 
when water is exposed at night in the dry atmosphere of 
the Indian winter, in order to convert it into ice through 
the loss of heat by radiation, it is essential to boil it 
previously. In order to find the reason for this, Black exposed 
two similar cups, one fiUed with boiled and the other with 
unboiled water, to a temperature below the freezing point, 
and saw, indeed, ice crystals appearing on the surface of 
the former, whUe the latter remained clear. But on intro- 
ducing thermometers, he discovered that the temperature 
of the unboiled water had fallen below the freezing point, 
without being converted into ice, which, however, formed 
as soon as the water was stirred. Black was aware of 
Fahrenheit's observation that water, when kept perfectly 
quiescent, could be cooled considerably below the normal 
temperature of freezing. The question that remained to 
be solved was, therefore, this : why should the unboiled 
water be more easily undercooled than that which had been 
boiled? The only effect that boihng can have on the water 
is to expel the absorbed air, and one might be tempted to 
reason from the above experiment that the absorbed air 
favours the undercooling. But this explanation is negatived 
by the circumstance that Fahrenheit's experiments were 
conducted in a vessel from which the air had been removed 
by the air pump. Black, realizing, therefore, that water 

E 2 



68 Britain's Heritage of Science 

deprived of its air could be undercooled as well as ordinary- 
water, concluded that the cause of the difference lay in the 
act of re-absorbiag the air. He suggested that the absorp- 
tion caused (possibly through minute differences of tempera- 
ture or density) sufficient circulation, or, as he expressed it, 
" agitation " to prevent the undercooling. It is remarkable 
that the subject has never been examined further, but 
Black's explanation finds some support in the experiments 
made by Thomas Graham, who showed that the admission 
of air into a previously boiled and undercooled solution of 
Glauber salt, set the crystalMzation going, and this was 
traced to a slight diminution of the solubility of the salt 
in water which contains air. 

To Black must also be given a place in the history of 
aeronautics, as he was the first to make the attempt to fill 
a baUoon with hydrogen; this was as early as 1767, two 
years before Montgolfier made his first baUoon ascent. 

Black practised as a medical man ; he held for a time the 
Chair of Anatomy and Chemistry at Glasgow, but distrustful 
of his quahfications as a chemist, exchanged it for that of 
Medicine. In 1766 he succeeded Cullen in the Professorship 
of Medicine and Chemistry at Edinburgh. In private life 
he was fond of painting; the weakness of his health is 
probably responsible for a certain lack of energy which 
sometimes led him to abandon his work when half finished, 
and to leave many of his researches unpubhshed. " No man 
had less nonsense in his head," said Adam Smith, " than 
Black." 

One further contribution of the Scotch Universities to 
chemistry remains to be noticed. Rutherford (1749-1819), 
a medical man who occupied the Chair of Botany at Edin- 
burgh, was the first to isolate the gas nitrogen in 1772, by 
burning substances in an enclosed volume of air, and 
absorbing the carbonic acid formed in the combustion. 

Black's lectures were edited after his death by John 
Robison (1739-1805), a man of great intellectual powers, 
who, Uke so many other men of science of the time, led an 
eventful life. After a brief period of study at Glasgow, he 
became tutor to the son of Admiral Knowles, who as a 
midshipman was about to accompany General Wolfe to 



Joseph Black, John Robison 69 

Quebec. Robison took part in the war, and after his return 
home was charged by the Board of Longitude to under- 
take a journey to the West Indies for the purpose of 
testing a chronometer constructed by John Harrison. A 
few years later Robison accompanied, as private secretary. 
Admiral Knowles to Petrograd, on his appointment as 
President of the Russian Board of Admiralty. For a time 
he also held the mathematical professorship attached to the 
cadet corps of nobles at Petrograd. Before he went to Russia 
Robison had occupied during four years the Chair of 
Chemistry at Glasgow, and after his return home in 1773 he 
became Professor of Natural Philosophy at Edinburgh. 
When the Royal Society of Edinburgh received its charter 
in 1783 he was elected secretary, and held this position until 
within a few years of his death, which took place in 1805. 

Robison enjoyed a high reputation among his contem- 
poraries, but we cannot assign any great advance in science 
to him. He was a man of great learning and pubUshed 
researches, which only just fell short of marking a distinct 
step. He deserves to be remembered even if it were only 
for his connexion with . James Watt, who owed him much 
assistance and encouragement. Robison was always inter- 
ested in steam, and had, before Watt's improvement of the 
steam engine, conceived the idea of applying the power 
of steam to the propulsion of vehicles. 

■David Brewster collated some of the manuscripts left by 
Robison, and pubhshed them in a work of four volumes : 
" Elements of Mechanical Philosophy." 

It appears from this " work that Robison undertook 
several researches, which he omitted to pubUsh. Among 
them was an experimental investigation on the law of action 
of electrical forces. This, he states, was communicated to 
a " pubhc society " in 1769, some years before Cavendish 
and Coulomb discovered the law of the inverse square. The 
experiments which are described in the pubUshed work, 
lead unmistakably to that law, but it is not stated whether 
they were the original ones or were repeated and improved 
upon later. Robison makes no claim in this respect, but 
refers to Cavendish as having " with singular sagacity and 
address, employed his mathematical knowledge in a way 



70 Britain's Heritage of Science 

that opened the road to a much ftirther and more scientific 
prosecution of the discovery, if it can be called by that 
name," and finally adopts Coulomb's measurements as con- 
clusive. It seems, however, to have escaped notice hitherto 
that Robison in his experiments used what must be con- 
sidered to be the first absolute electrometer, the electric 
force being balanced by the action of gravity, and there- 
fore reducible to its value in terms of dynamical units. 

Bobison was a strong adherent of BoscoAdch, the Itahan 
philosopher, who tried to dispose of the difiBculties ioherent 
in the definition of matter by considering atoms to be merely 
centres of forces without extension. Boscovich had applied 
his theory to the effects of ponderable matter on the trans- 
mission of Ught, and Robison took up this subject and treated 
it in a paper (Ed. Phil. Trans., Vol. II., 1790), which in 
many ways is remarkable. Its title, " On the motion of fight 
as affected by refracting and reflecting substances which are in 
motion," shows that it deals with one of the most puzzling and 
difScult problems of physics. It was the phenomenon of aberra- 
tion of light discovered by Bradley which gave practical im- 
portance to the subject, and, without entering into details, it 
deserves to be recorded that Robison had the idea of apply- 
ing telescopes filled with water to clear up experimentaUy 
some of the obscure points, which up to our own times have 
puzzled mathematicians. This idea was revived and success- 
fully applied later by Airy, but Robison failed on account 
of the difficulty of obtaining water that was sufficiently 
transparent. Although his ideas are now superseded, the 
paper gives us some idea of the powers of the man of whom 
Watt wrote : "He was a man of the clearest head and the 
most science of anybody I have ever known." 

Robison's successor, both in the Chair of Physics and 
as Secretary of the Royal Society of Edinburgh, was John 
Playfair (1748-1819), previously Professor of Mathematics, 
who had taken part in the geological survey connected 
with the Schehalfien experiment of Maskelyne and Robert 
Hutton. His first work was a book on " Button's Theory 
of the Earth," which had considerable influence in making 
James Button's geological theories known and appreciated. 
His mathematical contribution to science is mainly con- 



Robison, Desaguliers, Robert Smith 71 

fined to a publication " On the Arithmetic of Impossible 
Quantities." 

Though but httle work of importance was produced at 
Oxford and Cambridge in the eighteenth century, science 
was kept alive. John Theophilus Desaguhers (1683-1744), 
the son of a French Protestant clergyman, who left his 
country on the revocation of the Edict of Nantes, was 
brought to England while an infant. He studied at Oxford 
and acted as Professor of Physics in that University. He 
settled in London in 1712, and ultimately became Chaplain 
to the Prince of Wales. After leaving Oxford, he became 
a voluminous writer on many subjects. In his first paper 
he describes a new method of building chimneys so as to 
prevent their smoking. He invented a machine for measur- 
ing the depth of the sea and other mechanical contrivances. 
He is best remembered by his electrical work in which he 
clearly defined the nature of a conductor as distinguished 
from bodies which could be electrified by friction with- 
out being attached to insulating handles. He enjoyed a 
great reputation, being consulted by men of science, and 
notably by James Watt in connexion with steam engines, 
having himself introduced some improvements in their 
construction. 

At Cambridge, Robert Smith (1689-1768), as Plumian 
Professor, made some valuable contributions to acoustics, 
published in a separate volume — " Harmonics." His great 
treatise on light contains a wealth of information, and still 
possesses considerable historical interest. It had a great 
influence at the time, stimulating the study of optics, more 
especially with regard to its practical applications in the 
construction of optical instruments. 



72 Britain's Heritage of Science 



CHAPTER III 
(Physical Science) 

The Non-Academic Hbeitagb 
during the Seventeenth and Eighteenth Centuries 

THE scientific investigator should be endowed -with 
knowledge, critical judgment, and inventive power. 
For the first two attributes we must look mainly to pro- 
fessional men, who have gone through a recognized training 
and are engaged in teaching or research. Such men, brought 
up under the compelling infiuence of accepted currents of 
thought, though well prepared to advance their subject 
and even to make new discoveries along the paths opened 
out by their predecessors, are heavily handicapped when 
the time has come for a revolution of fundamental ideas. 
Often they have risen to the occasion, and thrown anti- 
quated doctrines overboard, but sometimes the academic 
tradition is strong enough to prevail. The advantage, then, 
Mes with those who are not burdened by the weight of 
inherited opinions, and great opportvmities are offered to 
the inexperienced youth or the enthusiastic amateur. What 
constitutes an amateur ? All efforts to define the term 
must fail, because we cannot defime what is not definite. 
The word in its literal sense denotes a man who pursues 
a subject for the love of it, but it carries a suggestion of weak- 
ness, or rather a suspicion, associated more particularly 
with amateurs in art, that they have not completely mastered 
their craft. So far as the actual work of research is con- 
cerned the difference between the amateur and professional 
man is not always pronounced, and is frequently obliterated ; 
some University professors have retained through life the 
characteristic attributes of free lances of science, and 




The Hon. Robert Bovle 



From a painting by F. Kerseboom, in 
the possession of the Royal Society 



Robert Boyle 73 

amateurs have occasionally rivalled professional scholars in 
proftmdity of knowledge and academic conservatism. 

The essential distinction — and it is an important one — 
lies in the wider range of subjects which the professional 
man of science has to cover. He may have to lecture or 
advise students on matters which are outside his own 
researches, or he may have to direct an institution burdened 
with a quantity of routine work which cannot be neglected. 
He both gains and loses by the exigencies of his duties ; while 
his compulsory reading may supply him with analogies which 
are frequently fertile in valuable suggestions, he is often drawn 
away to side issues, and is tempted to adopt a dogmatic 
attitude on those portions of his subject which he teaches 
or directs, but is not much interested in. 

The non-academic class of workers are free from any 
routine which they do not impose on themselves and, as 
might be expected, present less imiformity in their aims and 
modes of working. What greater contrast could, indeed, 
be found than that between the three men whose work 
forms the main subject of this chapter : Robert Boyle, 
the indefatigable experimenter and voluminous writer, who, 
though refusing a peerage and the Presidency of the Royal 
Society, found his chief pleasure in intercourse with other 
men of science : Henry Cavendish, the taciturn recluse, who 
disUked contact with the ordinary affairs of life, and was 
remiss even in pubhshing his revolutionizing researches; 
William Herschel, the poor Hanoverian oboist, who had to 
earn his hving as a teacher of music, and fight his way 
up untU, with telescopes constructed by his own hands, he 
attained unrivalled pre-eminence as an astronomer. 

Robert Boyle (1627-1691) belonged to an old Hereford- 
shire family, whose name is mentioned in Domesday Book 
as BiuviUe. His father, Richard, described by Thomas Birch 
as one of the greatest men of his age, passed through a 
course of study at Cambridge, and having spent some time 
in London as a student of the Middle Temple, went to 
Ireland to make his fortime, married a rich wife, and ulti- 
mately became Baron of YoughaU, Viscoimt of Dungarvan 
and Earl of Cork. He was married twice and had fifteen 
children. Robert, the last but one of them, received his 



74 Britain's Heritage of Science 

education partly at Eton, and then privately at his father's 
newly-purchased property near Stalbridge in Dorsetshire. 
At the age of eleven he was sent on a lengthy journey to 
the continent, accompanied by an elder brother and a 
French tutor, Marcombes; they reached Geneva, where 
they stayed nearly two years before proceeding to Italy. 
At Florence, Boyle became acquainted with the works of 
Galileo, and one can imagine the impression the death of 
that great man, which occurred during his stay, must have 
made on his youthful mind. The party proceeded to Rome, 
and ultimately set out on their return journey, but found 
themselves at Marseilles without means, as a remittance 
from Boyle's father had been stolen by the messenger. 
Almost penniless, they made their way back to Geneva, 
M. Marcombes' native place, and ultimately the two 
brothers reached England in the summer of 1644. They 
found their father dead, and the country in such confusion 
that it was nearly four months before Robert Boyle, who 
inherited the manor at Stalbridge, could make his way 
thither.* In London, Robert Boyle made the acquaintance 
of John Wallis, Christopher Wren, and other distinguished 
men, whose weekly meetings were destined to lead to the 
foundation of the Royal Society. Though his scientific 
studies were interrupted by an enforced visit to his dis- 
ordered Irish estates, which extended over two years, he 
settled down in 1654 at Oxford, where, during the following 
fourteen years, he devoted himself entirely to scientific 
researcL He spent the remainder of his hfe in London, 
taking an active part in the affairs of the Royal Society 
until two years before his death. Boyle had strong reUgious 
views; but he refused to take orders on the groimd that 
he felt no inner call, and thereby lost the appointment as 
Provost of Eton. He so strictly interpreted the command 
of the New Testament not to swear " neither by heaven, 
nor by earth, nor by any other oath," that he refused the 
Presidency of the Royal Society, because the Charter pre- 
scribed the taking of an oath on his accession to office. By 
his will he founded the " Boyle Lectures " for the defence 

' " Dictionary of National Biography." 



Robert Boyle 75 

of Christianity. He was never strong in health; weak 
eyesight troubled him throughout life, and a painful disease 
caused him much suffering in later years. 

His scientific work is distinguished by great experi- 
mental skUl, and a determination to remain free from the 
bias of preconceived notions. In his travels he had 
become proficient in several languages, and he continued 
to keep himself informed of what was being done on the 
continent of Europe. Having read an account of Guericke's 
air-pump (or, as Boyle calls it, " wind-pump "), he set 
to work to construct one, and with the help of Robert 
Hooke, who appears to have acted as his assistant at that 
period, succeeded in effecting considerable improvements. 
With this pump a large number of experiments were per- 
formed, all devised to prove some definite point, such as 
comparing the weight of air with that of water, or inves- 
tigating what he calls the spring of air. He showed that 
flames are extinguished and hot coal ceases to glow in a 
partial vacuum. He proved that magnetic and electric 
actions persist in his exhausted receiver, and that warm 
water begins to boU under reduced pressure. The action 
of the pump in removing air from a vessel suggested the 
inverse process of increasing the pressure, and this led to 
the construction of the compression pump. In his measure- 
ments he attained considerable accuracy; the specific 
gravity of mercury was correctly determined to one half 
per cent., that of air to about 20 per cent. 

Boyle's name is associated with the important law 
connecting the density of air with its pressure. The proof 
of the law is contained in a long paper entitled " Defence 
of the doctrine touching the spring and weight of air," 
pabUshed in 1662. The range of pressures covered by the 
experiments extended from four atmospheres (involving 
the use of glass tubes ten feet long) down to I J inches of 
mercury; the agreement between observed pressures and 
those calculated from the changes of volume, assuming that 
density and pressiu-e are proportional, was quite sufficient 
to prove the correctness of the law. The often repeated 
assertion that it was Townley who first drew Boyle's 
attention to the significance of these observations and for- 



76 Britain's Heritage of Science 

mtdated the law is not justified, and is founded apparently 
on some misconception of a passage in Boyle's account of 
his experiments. 

We owe to Boyle the use of the term " barometer," 
and he constructed an instrument in which the mercury 
is replaced by a short column of water with sufficient air 
above to counter-balance the atmospheric pressure. When 
no temperature changes interfere, such an instrument 
would be considerably more sensitive than an ordinary 
barometer. With it Boyle could observe the difference of 
pressvire between the roof and floor of Westminster Abbey, 
thus confirming Pascal's experiment without having to 
ascend a mountain. 

In his optical experiments Boyle showed that colours 
are produced by a modification of the light which takes place 
at the surface of the coloured body. The connexion between 
radiant heat and light was illustrated by covering half of a tile 
with black and the other half with white paint, when he 
found that in sunlight the black paint becomes hot while 
the white remains cold. He also first drew attention to the 
colours of thin films such as soap bubbles. He investigated 
freezing mixtures and discovered that when salt is added to 
snow or ice the observed cooling is connected with the hque- 
faction of the salt. Boyle invented the hydrometer and 
showed how to determine by means of it specific gravities not 
only of liquids but also of solids. He made extensive chemi- 
cal experiments, and correctly explained a chemical reaction 
as being due to the substitution of an atom of one kind for 
an atom of another kind in the original compoimd. 

Boyle's completed works occupy six folio volumes; 
he is somewhat prolix in his discussions, but his descrip- 
tions are always clear and interesting. By the manner 
in which he allows himself to be led from one experiment 
to another he almost reminds one of Faraday, though his 
indiscriminate mixing of what is important with what is 
of minor value partakes a Uttle of the weakness of the 
dilettante. He was highly esteemed by his contemporaries, 
and Newton, as well as many other eminent men of science, 
showed, in their correspondence, that they attached great 
value to his opinions. 



Robert Boyle, Brooke Taylor 77 

It is comparatively rare to find an eminent mathema- 
tician among amatem-s, but a noteworthy example is 
furnished by Brooke Taylor (1685-1731), a wealthy man 
who, having completed his studies, soon acquired a reputa- 
tion by his researches, and was elected into the Royal 
Society in 1712; two years later, he became one of the 
secretaries of that body. Taylor's theorem is known to 
every student of mathematics; in the subject of mathe- 
matical physics we owe to him the formula which connects 
the period of vibration of a stretched string with its length, 
cross-section and tension. 

The meetings of the Royal Society in the early days 
of its activity were only partly occupied by the reading 
of papers. Experiments were shown and discussed, and 
new subjects were proposed for investigation; particular 
questions were occasionally assigned to individual Fellows 
for enquiry and report. In this manner scientific research 
was organized more successfully than has ever since been 
possible. To assist the Society's work, a curator was 
appointed, whose special duties consisted in preparing the 
experiments for the meetings. A wide range of subjects 
was therefore brought to the notice of the meetings in an 
attractive form, and we find that many Fellows extended 
their researches in consequence of the stimulus received 
at the meetings. The inducement to do so was more 
especially strong with those who acted as curators, and this 
may be one of the reasons why Robert Hooke, the first 
who occupied that position, touched upon such a variety 
of subjects in widely different fields of enquiry. Among 
those who were employed at the beginning of the eighteenth 
century to prepare experiments, though he does not seem 
to have received the title of curator, was Francis Hauksbee, 
to whom we owe many interesting observations. Passing 
a strong current of air over the reservoir of a barometer, 
he found that the height of the column of merciu:y dimi- 
nished by two inches, thus proving the reduction of pressure 
accompanying the increase of kinetic energy in fluid 
motion. He connected this observation with the fall of 
the barometer during a gale of wind. He was the first 
who investigated the transmission of sound through water, 



78 Britain's Heritage of Science 

and made some interesting experiments on the intensity of 
sound transmitted through air of different densities. 

Hauksbee deserves, perhaps, most to be remembered 
by his researches in electricity. Frequent references occur 
in the pubUcations of the time to the curious luminosity 
in the partial vacuum above the barometer column which 
occasionally appears when the mercury is made to oscillate 
in the dark. Hauksbee had the idea that the luminosity 
was connected with some electrical action. To test this, 
he mounted a spherical glass vessel so that it could be made 
to rotate round a central axis. The vessel was exhausted, 
and, being set in motion, became highly electrified by 
friction when the hand was placed against it. At the same 
time the remnant of air in the vessel became luminous, 
and Hauksbee rightly concluded that the luminosity was of 
the same nature as that observed in the barometer; in 
the latter case, of course, the friction is produced internally 
between the moving mercury and the glass. Incidentally 
it may be mentioned that the first record of an electric 
spark occurs in Hauksbee's writing; it was produced by 
approachiag the finger towards the electrified glass vessel, 
and is said to have been an inch long. 

Very Mttle is known about the life of Hauksbee, or of 
that of Stephen Gray and Granville Wheler, two other 
important contributors to our knowledge of electricity. 
Gray, elected a Fellow of the Royal Society in 1732, was 
the first to point out the effects of conductivity in electrical 
experiments, classifying bodies as conductors or insulators. 
He had been led to this fundamental distinction by 
experimenting with a glass tube which was closed at one 
end by a cork, and noting that, when the glass was excited 
by friction, the cork attracted Hght bodies, thus showing 
that it had become electrified. When a rod several feet 
in length carrying an ivory sphere at its further end was 
inserted in the cork, the sphere also became electrified. 
When other experiments did not give the expected result. 
Gray seems to have consulted another Fellow of the Royal 
Society, Granville Wheler, a clerg3Tnan, who suggested to 
him that the cause of the failure was hkely to be due to the 
difficulty of supporting the bodies experimented upon in 



Francis Hauksbee, Robert Symmer 79 

such a manner that the electricity could not escape to 
earth. He advised the use of silk threads, as owing to 
their thinness they were likely not to conduct so well. 
This proved to be successful, not for the reason given 
but because silk is an excellent non-conductor. Besides 
sUk, other substances like glass and resins were recognized as 
insulators, and the range of experimentation was thereby 
much enlarged. 

There was at the time considerable confusion owing to 
the capricious manner in which electrical forces showed 
themselves, sometimes by attraction and sometimes by 
repulsion. No progress could be made in this respect until 
Dufay, a Captain in the French army, showed in the year 
1733 that these apparently contradictory effects could be 
explained by assuming the existence of two kinds of elec- 
tricity, which he called vitreous and resinous, terms which 
in our own time Lord Kelvin used in preference to the more 
common nomenclature of positive and negative electricity. 
Dufay's experiments attracted httle attention, and lYanklin, 
two years later, formed independently a theory, which 
admitted only one kind, but distinguished between an excess 
and defect of that kind. Bodies were called positively and 
negatively electrified according as they contained an excess 
or deficiency. 

Another FeUow of the Royal Society, Robert Symmer, 
also apparently unaware of Dufay's work, revived in 1759 
the theory of two separate kinds of electricity with opposite 
properties, and he was for some time supposed to be its first 
originator. He did much to promote clear and definite 
notions on electrical matters and the merit of his investigations 
cannot be called in question. Though the controversies 
between the followers of Franklin and those of Dufay and 
Symmer lasted imtil quite recent times, they could not lead 
to any substantial result because there is no fundamental 
difference between the two views. Both emphasize the 
distinction between two opposite electrical states, and our 
preference for one or other alternative depends mainly on 
the ideas which we imconsciously attach to forms of expression 
which suggest more than they are intended to do. As a 
matter of convenience, we may think of positive and negative 



80 Britain's Heritage of Science 

electricity without committing ourselves to any definite 
theory as to their ultimate nature. 

When the primary phenomena of static electricity had 
been established, the. further progress took its natural and 
regular course. Experimental appliances had to be improved, 
and instruments constructed suitable for quantitative measure- 
ments. In this work John Canton (1718-1772), a private 
schoolmaster, took an active and successful part. He 
increased the efficiency of electrical machines by coating 
the friction cushion, which was pressed against the glass 
cyUnder, with an amalgam of mercury. For the coarser 
indicators of electricity, such as that which Gray had used, 
Canton substituted two small spheres of pith or cork, 
suspended from threads, which diverged when the spheres 
became electrified. 

Canton was also successful in other fields of science; we 
owe to him the first experimental demonstration that water 
is compressible, and the discovery of a new phosphorescent 
body which he prepared by the action of stdphur on oyster 
shells. WiUiam Henley, a linen-draper residing in London, 
who reached sufficient distinction to be admitted to the 
fellowship of the Royal Society, also constructed an electro- 
scope intended for quantitative measurements. He was 
chiefly interested in thunderstorms and atmospheric elec- 
tricity generally, and noted the positive electrification of 
the air in a dry fog. Greater importance is to be attached 
to Abraham Bennett (1756-1799), a clergyman residing in 
the Midland counties, who introduced the gold-leaf electro- 
scope, the most sensitive instrument invented up to that 
time for the detection of small quantities of electricity. 
Simultaneously with Volta, he showed how the electric 
condensers could be used in conjunction with electrometers 
so as to increase their effectiveness. This led him to invent 
an instrument called a duplicator which in principle is 
identical with Lord Kelvin's replem'sher ; but as it contained 
conductors covered with shellac for purposes of insulation, 
irregularities in its action interfered with the experiments. 
In spite of these defects it was the embryo of our modem 
" influence " machine. William Nicholson (1753-1815), to 
whom further reference will be made (p. 107), cured most of 



John Canton, Henry Cavendish 81 

the defects of Bennett's doubler and converted it into an in- 
strument which ought to have come into more extensive use. 

WilUam Watson (1715-1787), who started life as an 
apothecary, but reached sufficient distinction as a medical 
man to obtain the honour of knighthood, improved the 
Leyden jar by substitutiag tin-foil for the liquid which till 
then had formed the ioner coatiag. In his experiments with 
these jars he was much assisted by Dr. John Bevis (1695- 
1771), another medical man, who was, however, mainly 
interested in astronomical work, and also deserves to be men- 
tioned as being the first to make a glass containing borax, 
and to note that its refractive power was thereby increased. 
Dr. Ingenhouse, a Dutch doctor settled in England, conducted 
many electrical experiments, and claimed to have been the 
first to replace the glass cyKnder used in electrical machines 
by a disc. The same claim is, however, made by others both 
in France and Gtermany, and, among Englishmen, by Jesse 
Ramsden, the optician and instrument maker, of whom more 
will have to be said presently, and who certainly first brought 
glass-plate machines into general use. 

On a higher plane stand the researches of Henry Cavendish 
which now demand our consideration. A paper pubhshed 
in the " Philosophical Transactions " contains the foundation 
of the mathematical theory of electrostatics. There were 
probably but few mathematicians at the time interested in the 
subject, and the experimental part of the enquiry, which 
might have directed more general attention to the importance 
of the work, was not pubhshed until a century later. The 
mathematical investigation showed that i£ the whole of the 
electricity communicated to a body collects at its surface, 
none entering the interior, it necessarily follows that the 
repulsion between two quantities of electricity must diminish 
with increasitig distance according to the same law as that 
of gravitation. No other law would lead to the same result. 
Robison appreciated the importance of this investigation 
(«,ee p. 69), but, hke others, he was ignorant of the unpublished 
experiments which Cavendish had actually made on the 
subject. These verified with a sixfficient degree of accuracy 
that the charge of a body in electrostatic equihbrium resides 
at the surface, and that if any part of it penetrates into the 



82 Britain's Heritage of Science 

interior, it can only be a small fraction. Fortunately the 
manuscripts of Cavendish's electrical experiments have been 
preserved, and were placed in the hands of Clerk Maxwell 
when he took over the Professorship of Experimental Physics 
at Cambridge. Their subsequent publication throws quite 
a new hght on Cavendish's importance as a physicist, giving 
evidence of a wonderfully balanced combination of theoretical 
power and experimental skill. Adverting to the many 
instances in which Cavendish neglected to pubhsh results of 
importance. Maxwell^ remarks : 

" Cavendish cared more for investigation than for 

publication. He would undertake the most laborious 

researches in order to clear up a difficulty which no one 

but himself could appreciate, or was even aware of, and 

we cannot doubt that the result of his enquiries, when 

successful, gave him a certain degree of satisfaction. 

But it did not excite in him that desire to communicate 

the discovery to others which, in the case of ordinary men 

of science, generally ensures the pubUcation of their 

results. How completely these researches of Cavendish 

remained unknown to other men of science is shown by 

the external history of electricity." 

This is not the place to enter into the details of the various 

researches which were edited by Maxwell in 1879. Suffice 

it to say that Cavendish measured experimentally the 

electrostatic capacity of bodies, anticipating Faraday in the 

discovery of the difference of the inductive capacities of 

various substances, and Ohm in showing that the electric 

current is proportional to the electromotive force. He also 

compared the electric resistance of iron with that of rain 

water and of different salt solutions. All this was done 

by means of a rough electroscope and without a galvanometer. 

He converted, in fact, his nervous system into a galvanometer, 

by comparing the electric shocks received when Leyden jars 

were discharged through various conductors, altering the 

length of the conductors until the shocks were estimated 

to be equal. He obtained astonishingly accurate results 

with such simple and almost primitive means. 

' " The Electrical Researches of the Hon. Henry Cavendish," 
Introduction, p. zlv. 



Henry Cavendish 83 

The second of the two electrical papers which Cavendish 
communicated to the Royal Society attracted considerable 
attention, and though it does not deal with any matter which 
we should now consider of fundamental importance, it shows 
how far Cavendish was in advance of his time in appreciating 
electrical matters correctly. The shocks which certain fishes, 
such as the torpedo,* are capable of giving to those who touch 
them had been known for some time, and John Walsh, a 
Member of ParUament and Fellow of the Royal Society, had 
described some experiments showing the conditions under 
which the shocks were received. He suggested that they 
were of an electrical character. The idea was not generally 
accepted, and was even laughed at on the ground that a 
fish immersed in sea water, which conducts electricity, could 
not be electrically charged. In answer to this objection. 
Cavendish actually constructed an imitation torpedo and 
demonstrated to an assembly of scientific friends the possi- 
bility of obtaining shocks even when it was immersed in salt 
water. 

Maxwell remarks that this is the only recorded occasion 
on which Cavendish admitted visitors to his laboratory. 

Henry Cavendish was born in 1731 ; he entered Peterhouse, 
Cambridge, in 1749, and left that University four years later 
without taking his degree. He was elected a Fellow of the 
Royal Society in 1760 and died in 1810. His father, Lord 
Charles Cavendish, third son of William, second Duke of 
Devonshire, was interested lq scientific' subjects and pubhshed 
a paper on the capillary depression of mercury in glass tubes, 
which was highly spoken of by Franklin; he was also the 
first to construct maximum and minimum thermometers, 
and received the Copley medal of the Royal Society for the 
invention of these useful instruments. We may infer 
that the mind of Henry Cavendish was first directed towards 
science by his father's example. He hved on an allowance 
of £500 until he was about forty years of age, when through 
the death of an uncle he acquired a fortune which made him 

* The word " torpedo " comes from the Italian, and is derived 
from "torpor;" the name was given to the fish on accoimt of the 
numbness caused by the electric shock felt on touching it. The 
torpedo is not now generally associated with torpor. 

F 2 



84 Britain's Heritage of Science 

one of the richest men of his time, without altering the simple 
mode of life to which he had become accustomed. It has 
been said of him that his chief object in life was to avoid 
the attention of his fellows ; "his diimer was ordered daily 
by a note placed on the hall-table, and his women servants 
were instructed to keep out of his sight on pain of dismissal."' 

There is some evidence, however, that in his intercourse 
with scientific men he was not equally reticent. He attended 
the meetings of the Royal Society regularly, dined nearly every 
Thursday with the Philosophical Club, composed of some 
of the Fellows, and in 1772 was an energetic member of a 
committee formed to consider the best means of securing a 
powder magazine against the danger of lightning. 

Some of Cavendish's most remarkable results were de- 
rived from experiments on gases. Such investigations then 
tested the skill of an experimenter to a degree which is not 
easily realized at present. To the diflSculties of isolating, 
purif3Tng, and examining the chemical properties of these 
invisible substances was added the mystifying belief in the 
imaginary body, phlogiston, which was supposed to be 
expelled in every act of combustion, and to account for 
flame and fire. 

From the purely experimental point of view a great 
advance was made when gases were collected over mercury 
instead of over water, which had been the usual practice. 
The credit of this is due to Joseph Priestley (1733-1804), a 
Nonconformist minister, who, having renounced his early 
Calvinism and become a Unitarian, was then in charge of 
Mill Hill Chapel, Leeds ; subsequently he moved to Birming- 
ham. Priestley held strong pohtical views, which he expressed 
freely, and these, together with his unorthodox opinions, 
frequently got him into trouble. He wrote against England's 
attitude towards the American colonies, and sympathized with 
the French revolutionists. When he attended a dinner 
arranged to celebrate the anniversary of the taking of the 
Bastille, the mob burned his chapel and sacked his house. 
He then went to live in London for a few years, but ultimately 
emigrated to America. We owe to Priestley the discovery of 

I " Encyclopeedia Britaimica," 



Henry Cavendish, Joseph Priestley 85 

a number of gases, and he first prepared oxygen by heating 
oxide of jneroury with a burning glass. He obtained hydro- 
chloric acid by heating spirits of salt, sulphur di-oxide 
by the action of sulphuric acid on mercury, and ammonia 
by heating spirits of hartshorn. Cavendish's attention was 
attracted by an observation of Waltire, who worked with 
Priestley, that when a mixture of hydrogen and common 
air was fired, dew appeared on the walls of the glass 
tubes. This was explained as being a condensation of 
water which had been present as vapour in the original 
gases. But Cavendish was able to prove that the water 
formed was really the result of the combustion of oxygen 
and hydrogen. In order to interpret correctly the lan- 
guage in which chemists expressed their results at the 
time we must remember that oxygen was referred to as 
" dephlogisticated air," nitrogen as " phlogisticated air," 
and hyiogen as " phlogiston." Cavendish therefore ex- 
presses his result by saying " that water consisted of 
dephlogisticated air united with phlogiston." The conclusion 
embodies the discovery of the composition of water, which 
tm then was unknown. 

Similar experiments seem to have been made by James 
Watt, who subsequently claimed priority, but we need not 
here enter into the discussions to which the dispute gave 
rise, and which passed without interfering with the subse- 
quent friendly intercourse between Cavendish and Watt. 

A remarkable research originated in the interest which 
Cavendish took in the composition of the terrestrial atmo- 
sphere. By burning various bodies in measured volumes 
of air, he satisfied himself that the amount of oxygen 
present was the same in all the samples experimented upon. 
He noticed, however, that in one of the experiments in 
which a mixture of hydrogen and oxygen was fired by an 
electric spark, the resulting water contained nitric acid. 
This, Cavendish attributed to a remnant of atmospheric 
nitrogen in the oxygen used, and, following up the matter, 
showed that nitrogen and oxygen actually did combine 
under the influence of an electric spark. Absorbing the 
nitric acid formed, he could observe a shrinkage of volume 
when sparks were passed through mixtiires of nitrogen and 



86 Britain's Heritage of Science 

oxygen. He then put himself the question, " whether 
there are not in reality many different substances com- 
pounded together by us under the name of phlogisticated 
air ? " and to satisfy himself on that point, he investigated 
whether the whole of the air could be transformed into 
nitric acid by combination with oxygen. He found that 
there was, indeed, a small portion, estimated by him as 
y|^ of the whole, which resisted the change. This remnant 
undoubtedly consisted of argon, a separate gas, identified as a 
new element only in our own times. The amount of argon 
actually present in the air agrees remarkably well with 
Cavendish's estimate of his residual gas. 

There are many investigations on heat, unpublished at 
the time, by which Cavendish anticipated Black in the 
discovery of latent heat; he also determined the specific 
heats of a number of bodies. Another important research 
remains to be noted. A Yorkshire clergyman, John 
Michell, had conceived the brilliant and ambitious idea of 
measuring directly the gravitational attraction between two 
spheres of lead. It has already been remarked, in con- 
nexion with the Schehallien experiment of Maskelyne and 
Hutton, that the average density of the earth may be 
derived from such a measurement, but quite apart from 
this application, the attempt to demonstrate Newton's 
gravitational force within the four walls of a room con- 
stitutes an efiort of heroic ambition and remarkable fore- 
sight. John Michell had constructed all the necessary 
apparatus, including the torsion balance, which he had 
invented for the purpose. Infirmities of age prevented his 
carrying out the work, and at his death the apparatus fell 
iato the hands of another distinguished clergyman, Francis 
John Hyde Wollaston (brother of the celebrated chemist), 
who, at the time, held the Jacksonian Professorship at 
Cambridge. Wollaston deserves considerable credit for 
handing over the execution of the experiment to the one 
living man who was capable of bringing it to a successful 
issue. The original torsion balance consisted of a wooden 
beam about two yards long, weighing 5J ounces, and 
carrying at each of its ends a leaden sphere two inches ia 
diameter. Cavendish substituted for the beam a metal rod 




John Clerk Maxvoell 



From an engraving in '^Nature " 
hy G. J. Stodart of a photograph 
by Fergus of Glasgow 



John Michell 87 

strengthened by a copper wire which acted as a tie to pre- 
vent bending, and was attached to a vertical suspension. 

On being shghtly displaced from its position of eqniH- 
brium the torsion of the wire by which it was suspended 
would tend to bring the horizontal beam back and make 
it oscillate slowly in a horizontal plane. Two larger leaden 
spheres eight inches in diameter could be brought near the 
ends of the beam, so that their gravitational attraction 
on the spheres attached to the beam would displace it, 
with the result that it would oscillate about the new posi- 
tion of equilibrium. By bringing the larger spheres round 
to the other side of the beam the displacement in the 
opposite direction could be observed and the gravitational 
effect measured. Cavendish fully reaHzed the difficulties 
he would have to encounter in consequence of almost 
unavoidable air currents. Even when the apparatus was 
enclosed in a box the sUghtest difference in temperature 
would cause convection currents and, consequently, irre- 
gular movements of the beam. He, therefore, had to plan 
out a scheme which would allow him to conduct the whole 
of the experiments without entering the room in which 
the apparatus was placed. The observations were taken, 
and the large leaden spheres moved one side of the beam 
to the other from outside. No more dehcate measurement 
had ever been successfully carried out. From the average 
of the number of observations, Cavendish deduced the 
value of 5 -48 for the density of the earth, a number in fair 
agreement with, though shghtly larger than, that obtained 
by Maskelyne and Hutton. The extreme difficulty and 
great charm of the experiment has still in our times 
attracted the most skilled physicists, and the introduction 
of quartz fibres by Mr. Vernon Boys has enabled us to 
increase its accuracy considerably. The final value for the 
average density of the earth as determined by Mr. Boys 
is 5 "5270, so that Cavendish was correct to within one per 
cent. 

John Michell (1724-1793), whose name has been mentioned 
above as the inventor of that most useful and delicate 
apphance, the torsion balance, has also in other directions 
given evidence of great originality of mind. He contributed 



88 Britain's Heritage of Science 

an important paper entitled " Conjectures concerning the 
cause and observations upon the phenomena of earthquakes " 
to the Philosophical Transactions of the Royal Society, 
and was the first to suggest that double stars were more 
hkely to be systems of physically connected bodies than 
accidental coincidences in the directions of two stars which 
might be at great distances one behind the other. This, as 
will presently appear, was subsequently proved by WiUiam 
Herschel to be the case. 

It is not surprising that astronomy has always been a 
favourite study of men of leisure, with a scientific turn of 
mind. As Tyndall, in one of his lectures, said, we are most 
impressed' by what is either exceptionally large or excep- 
tionally small; and the feeling that in examining the 
heavens, our laboratory, no longer confined to a few cubic 
feet, extends through the imiverse, fascinates the human 
mind. Added to this, useful work can be carried on in 
astronomy with comparatively simple though sometimes 
expensive appUances, and to the painstaking, but not 
perhaps, mathematically inclined enthusiast, special pro- 
blems are often ready to hand, which depend on accurate 
registration rather than on extensive knowledge. When, 
as not infrequently happens, the power of dealing with 
the observations is added to the aptitude for observation, 
the amateur can rise to the level of the professional more 
easily than in most other subjects. 

It is impossible to say what position Jeremiah Horrocks 
(1619-1641) might have attained had his life not been 
cut short so early. He died at the age of twenty-two, with 
a remarkable record to his credit. After passing through 
Emmanuel College, Cambridge, as a sizar, he earned his 
living as a teacher at his native place, Toxteth Park, near 
Liverpool. Through WiUiam Crabtree, a wealthy draper 
of Manchester, whose acquaintance he had made, he became 
interested in astronomy, and on his advice studied the 
works of Kepler. Having tested and corrected the tables 
giving the positions of planets which had been pubhshed 
by that astronomer, he formed the conclusion that a transit 
of Venus would occur on the 24th November 1639. This 
happened to be a Sunday, and Horrocks being at that 



J. Horrocks, S, Molyneux 89 

time a curate at Hoole was afraid that clerical duties would 
prevent his observing the transit. He, therefore, asked 
his friend Crabtree to watch independently for the appearance 
of Venus on the solar disc. Fortunately, Horrocks was 
set free before the planet had crossed the sun, and he 
could follow its passage until the time of sunset. This was 
the first time that human eye had witnessed this rare 
occurrence. Among the frescoes by Madox Brown in 
the Town HaU of Manchester one represents this transit 
of Venus. Unfortimately, the pictures being intended to 
commemorate events in the history of Manchester, the 
scene is laid in that city, and Crabtree is made to be the 
central figure, conveying a wrong impression of a great 
historical event. 

The papers left by Horrocks were preserved by Crabtree 
and ultimately published. They show that he had the 
making of a great man of science in him. Before he was 
twenty, he showed how Kepler's laws had to be modified 
in order to fit the motion of the moon, and he suspected 
that these modifications were due to some disturbing cause 
emanating from the sun, as Newton afterwards proved was 
actually the case. He also discovered certain irregularities 
in the motions of Jupiter and Saturn, now known to be due 
to their mutual attractions. 

The name of Molyneux first appears in this country at 
the time of the Norman Conquest through William de 
Moline, from whom the Earls of Sefton . are descended. 
Another family of the same name is derived from Sir Thomas 
Molyneux, who came over from France, settled in Ireland, 
and became Irish Chancellor of the Exchequer. One of 
his great grandsons was Sir Thomas Molyneux, physician 
and zoologist, another WiUiam Molyneux, a philosopher, 
politician, and astronomer. Several of his papers were 
pubhshed in the Transactions of the Royal Society. They 
deal with the erecting eyepiece of terrestrial telescopes, 
the tides and the causes of winds; he also pointed out 
errors which occurred in surveying through neglecting to 
take account of the secular variation of the magnetic 
declination. 

Samuel Molyneux (1689-1728), the son of William, 



90 Britain's Heritage of Science 

followed in his father's footsteps as astronomer, and built 
himself an observatory at Kew. It was here that the 
observations which led to the discovery by Bradley of the 
aberration of light were carried out. Molyneux has not re- 
ceived sufficient credit for the design of the instrument and 
of the measuring appUances on which the successful prosecu- 
tion of the research depended. The idea of testing Hooke's 
method of measuring the so-called " parallax " of stars 
seems to have been due to Molyneux. He worked assiduously 
at the construction of telescopes, one of which he presented 
to the King of Portugal, and left an unpublished MS. on 
optics, which was made use of by Robert Smith in the 
preparation of his treatise. 

The work of William Herschel (1738-1822) brings us 
into touch with modem astronomy. His father was a 
musician in the Hanoverian Army, though the family 
originally came from Moravia. At the age of fourteen he 
accompanied, as an oboe player, a Hanoverian band on a 
visit to England, but orJy settled finally in this country 
in 1757, his health not being strong enough to take part 
in the Seven Years' War. He ultimately went to Hve in 
Bath as a teacher of music, and became director of the 
musical entertainments in that fashionable resort. His 
turn for reading serious books led him to the study of 
Ferguson's astronomy and Smith's harmonics, followed by 
the optics of the same writer. He then decided to take up 
astronomy more seriously; he bought a small Gregorian 
telescope, but not content with this, and, unable to obtain 
a larger instrument with the means at his disposal, he set to 
work with his own hands, and having succeeded in polishing 
a mirror of six-foot focal length mounted it as a reflecting 
telescope. A frequently quoted passage from one of his 
letters, written in 1783, shows the object he had in view : 
" I determined to accept nothing on faith, but to see 
with my own eyes what others had seen before me. I 
finally succeeded in completing a so-called Newtonian in- 
strument, seven feet in length. From this, I advanced 
to one of ten feet, and at last to one of twenty, for I had 
fully made up my mind to carry on the improvement 
of my telescopes as far as it could be done. When I 



William Herschel 91 

had carefully and thoroughly perfected the great instru- 
ment in all its parts, I made systematic use of it in my 
observations of the heavens, first forming a determi- 
nation never to pass by any, the smallest, portion of 
them without due investigation." 

Even the largest of the instruments, mentioned in this 
letter, did not satisfy him, and he determined to improve 
upon it by constructing one of twice its size. This was 
finally mounted at Slough, where he had settled with his 
sister in 1782. The polishing of concave mirrors was at 
that time a serious business. On one occasion he kept 
the tool on the mirror continuously for sixteen hours, and 
with both hands engaged had to be fed by his sister, Caro- 
line, who then kept house for him. His desire to obtain 
larger and larger instruments did not, however, prevent 
Herschel from making good use of those he had completed. 
Surveying systematically the whole of the heavens he was 
soon rewarded by a brilliant discovery. 

Struck by the peculiar appearance of a star that crossed 
his field of view, he examined it with higher magnifying 
powers, and found its apparent disc increased. Two days 
later, a slight change of position could be detected. At 
first it was thought to be a comet, but, ultimately, Saron, 
at Paris, and Lexell, at Petrograd, found that its path in- 
dicated an orbit round the sun of a nearly circular shape. 
It then took its place as a new planet, the first that had 
been discovered in historic times. The name " Georgium 
Sidus," suggested by Herschel, was not generally accepted, 
and was subsequently replaced by " Uranus." The dis- 
covery was a fortunate one for Herschel, as it estabHshed 
his reputation, and, what was more important, led 
George III. to appoiut him his private astronomer, with 
a salary which, though modest, set him free to give up 
his professional work and devote his entire energies to 
astronomy. For a time, he increased his income by making 
and seUtng telescope mirrors, but this ceased to be necessary 
when, a few years later, he married a lady of independent 
means. 

The leading feature of Herschel's work was his strong 
faith in the unity of design which he tried to trace in the 



92 Britain's Heritage of Science 

structure of the Universe. He looked upon the assemblage 
of stars as an organic whole, and endeavoured to find 
regularities in their distribution or arrangement. He thus 
opened put an entirely new branch of enquiry. 

If stars were scattered at random, we should find on 
the average an equal number in all parts of the sky. In 
order to avoid the enormous and practically impossible 
labour of actually counting the total number of stars 
visible in his telescope, Herschel devised a method of 
gauging the heavens, which gave him sufficiently good 
average results. This consists in taking specimens, by 
counting the stars which appear in a number of single fields 
of view near together, and taking the average number of 
stars recorded as an index of the density in this particvdar 
region of the heavens. It is obvious that the number of 
stars is vastly greater in the Milky Way than anywhere 
else, and the question arose whether that dense conglo- 
meration had any relation to the rest of the stellar universe. 
It was, therefore, a discovery of the greatest interest and 
importance to find that the stars throughout the heavens 
increase in density as we approach the region of the Milky 
Way, thus demonstrating that the visible universe is not an 
accidental jumble, but possesses an organized structure. 

Results, of equal interest, were obtained from the close 
investigations on double stars, of which about forty were 
known when Herschel began his work. Having added 
nearly 400 to this number, he set out to measure the relative 
positions of the two components of each doublet, and, 
repeating the measurements from time to time, discovered, 
after twenty years of work, that some of these double stars 
are physically connected, consisting of two huge and 
luminous masses which revolve round each other. 

The organic bond which connects the separate units of 
the universe revealed itself in a striking manner, by Halley's 
discovery already referred to, that many of the stars are 
apparently moving through space with considerable velo- 
cities. Examining the direction and magnitude of the 
observed shifts, Herschel noticed that if the average motion 
be taken in any one region, that average is nearly the 
same in different parts of the sky. As our observations 



William Herschel 93 

can only indicate a motion relative to tlie earth, we must 
conclude that if we consider the system of stars as a whole 
to be at rest, our sun with its planetary system moves 
towards a definite point in the heavens. If, on the other 
hand, we consider the solar system to be at rest, then the 
great majority of stars are drifting in nearly parallel 
directions, and whatever view we may take it is certain that 
the star velocities are not entirely independent of each 
other. The subject is one that has received renewed 
attention in recent years ; it has now been demonstrated 
that there is more than one star-drift, and Herschel's work 
is Ukely to develop into an important department of 
astronomy. 

One further discovery of considerable interest and im- 
portance but belonging to the domain of physics, remains 
to be noted. In order to compare the heating effects 
of the coloured rays of which, as Newton taught us, solar 
light is composed, Herschel placed thermometers in the 
different portions of a spectrum obtained by means- of a 
prism. He noted that the heating powers of the rays 
continuously increased from the blue through the green 
and yeUow to the red. He then discovered that the 
thermometer rose highest when placed outside the red, 
proving that the solar spectrum contains invisible rays less 
refrangible than the red. These rays, though they do not 
affect our eye, become apparent by means of their heating 
effect. Herschel satisfied himself that these invisible rays 
were refracted and reflected according to the ordinary laws. 

The idea of invisible radiations, refrangible Hke light at 
the surface of transparent bodies was at that time entirely 
novel, and must have appeared almost as surprising as the 
discovery of Roentgen rays in our own time. The heat 
radiations were at first looked upon with scepticism, and 
met with opposition in some quarters, even when Wollaston 
soon afterwards proved the existence of other rays beyond 
the violet end of the spectrum which showed themselves by 
their chemical effects. 

The success of experimental investigation depends so 
much on the use of scientific instruments and apphances 
that the important share contributed to the progress of 



94 Britain's Heritage of Science 

science by the designers and makers of instruments deserves 
to be emphasized. Improvements in the design of an instru- 
ment lead not only to increased accuracy but also to the 
saving of time and labour, which is frequently of equal 
importance ; and in this connexion we need not necessarily 
think of the construction of the costly instruments which the 
astronomer now requires, nor of the elaborate appliances 
to be foimd in a modern physical laboratory. The most 
effective instrumental improvements have frequently been 
of the simplest kind, and a handy appliance, such as the 
sUde rule, saves an amount of time which in the aggregate 
may sum up to an astonishing figure. The sUde rule was 
introduced at a surprisingly early time. Almost immediately 
following the introduction of logarithms, Gunter constructed 
a rod with logarithmic divisions engraved on it, but its use 
involved the application of a pair of dividers. The sliding 
arrangement which is the essential feature of the appliance 
was first used by Oughtred (1575-1660), a mathematically 
inclined clergyman, who incidentally introduced the X sign 
for multipHcation and the symbol : : for proportion. 

There is no department of science that depends . on 
instrumental appliances more than astronomy. The con- 
struction of mirrors and lenses, the improvement of clocks 
and the accurate angular division of measuring circles aU 
require skilled labour of the highest kind, while the require- 
ments of navigation severely test the ingenuity of the 
inventor, who has to simplify the instruments and make 
their working independent of that firm support which may 
be obtained on dry land, but is not available on board ship. 

As an instrument of precision the telescope was almost 
useless until some measuring arrangement was introduced. 
A micrometer eyepiece consisting of two metallic edges, 
the distance between which could be altered and measured 
by a screw, was invented by a young astronomer, William 
Gascoigne, a friend of Jeremiah Horrocks and Crabtree, born 
about 1612, and killed in the battle of Marston Moor. The 
Gascoignes are first mentioned in English history when Sir 
William Gascoigne acted as Chief Justice in the reign of 
Henry IV., and his son, George, acquired the reputation 
of a poet, but it is not known whether the astronomer 



W. Oughtred, J, Hadley, G. Graham 95 

descended from them. Crabtree mentions the invention of 
the micrometer in a letter to Horrocks, and the instrument 
itself was exhibited by Townley at a meeting of the Royal 
Society in 1667. Unfortunately it escaped the notice of 
astronomers imtil Huygens had constructed a similar but 
less perfect appUance, and Adrien Angout had produced a 
micrometer in which Gascoigne's edges were replaced by 
sUk fibres. 

If one had to select the instrument which combines the 
greatest simpUcity with the highest precision, there is little 
doubt that one's choice would fall on the sextant, the most 
perfect appliance that has ever been invented. It is mainly 
used on board ship, but it has been successfully employed 
in the United States for accurate surveys on land. No one 
who has not held a sextant in his hand, and seen how, after 
a few days' practice, he could determine the local time to 
the tenth part of a second, and the latitude to a few hundred 
yards, can reahze the beauty of the instrument and the sense 
of power it gives to its user. The inventor, John Hadley, 
was an instrument maker about whose Hfe very Uttle is 
known, though the Royal Society recognized his merits by 
electing him to their Fellowship, and ultimately made him 
a Vice-President. His instrument, the circle of which only 
covered 45°, and which therefore ought more properly to ba 
called an " octant," was first shown to the Royal Society 
in 1744. Hadley also revived the use of reflecting telescopes ; 
the construction of which had shown little progress since 
Newton's time. 

The accuracy of astronomical observations depends in 
many cases on the excellence of the timekeepers employed 
to record the instant at which a star passes the centre of 
the telescopic field of view. Clocks used for the purpose 
are regulated by the swing of a pendulum acting through a 
mechanism called an escapement. The first efficient appli- 
ance of its kind, the anchor escapement, was invented by 
Robert Hooke, and improved upon by George Graham 
(1675-1751), an ingenious clockmaker who was generally 
interested in scientific matters. We owe to him, e.g., the 
discovery of the diurnal variation of terrestrial magnetism. 
In the construction of clocks he introduced an important 



96 Britain's Heritage of Science 

improvement. Owing to the expansion and contraction of 
ordinary materials when the temperature rises or falls, the 
time of oscillation of an ordinary pendulum alters with every 
change of temperature ; but by properly combining different 
materials, the diflSculty may be overcome. Graham attached 
a cylindrical vessel partly filled with mercury to the bob of 
the pendulum; when the rod of the pendulum expands the 
support of the mercury vessel descends, but the mercury 
in the vessel also expands, which tends to raise the centre 
of gravity of the whole arrangement. The expansion of 
the mercury being considerably greater than that of the 
pendulum rod, its volume may be adjusted so that the two 
actions counterbalance each other, and the pendulum may 
be made independent of moderate changes of temper attu:e. 
Another arrangement, the " gridiron " pendulum, was intro- 
duced by John Harrison (1693-1776), the son of a York- 
shire carpenter, who became a surveyor, and settled down 
in London as a watchmaker. His pendulum compensation 
has been very extensively used, but Harrison will chiefly 
be remembered as the inventor of the chronometer. 

The demand for accurate timekeepers suitable for use on 
board ship had become so urgent a question at the time, that 
the Government had offered a reward of £20,000 to anyone 
who would produce an instrument which satisfied certain 
requirements. Harrison soon supplied a " time-measurer " 
or " chronometer " which promised so well that the Govern- 
ment helped him with grants of money and facilities for 
testing his instrument on sea journeys. But it took him 
twenty-six years of continued labour before he obtained the 
full reward, producing a chronometer which, on a journey 
to Jamaica and back, showed an accumulated error of less 
than two minutes; this satisfied the required conditions, 
and the prize was awarded to him. One of the features of 
Harrison's chronometer, showing great ingenuity and manipu- 
lative skill, consisted in the temperature compensation which 
was applied to the balance wheel. 

Next to accurately going clocks, the astronomer requires 
well-divided circles for the measurement of angles. Three 
Enghsh instrument makers secured considerable reputation 
in this work during the eighteenth century. The first of 



John Harrison, Jesse Ramsden 97 

these, Graham, whose name has abeady been mentioned in 
connexion with clocks, worked for Halley and Bradley at 
Greenwich, and supplied an instrument to the Paris Academy 
of Sciences. The second, John Bird (1709-1776), divided 
a number of quadrants for several pubHc observatories, and 
his method of working was considered so good that the 
Government purchased the right of employing it. 

Further improvements were introduced by Jes'e Ramsden 
(1735-1800), the son-in-law of John Dollond, who designed 
an engine for dividing mathematical instruments and re- 
ceived a premium for £315 from the Government for this 
invention. Ramsden was a remarkable man. The son 
of an innkeeper at Hahfax, he became a clerk in a cloth- 
maker's warehouse, after having completed a three years' 
apprenticeship. Two years later, when twenty-three years 
old, he again apprenticed himself, this time with a mathe- 
matical instrument maker, and afterwards estabhshed him- 
self independently. His shop, first opened in 1762, in the 
Haymarket, was transferred later to Piccadilly. He soon 
acquired fame for the excellence of his workmanship, and 
we are told that, though ultimately sixty workmen were 
employed by him, the demand from aU parts of Europe for 
his instruments was greater than could be satisfied. He 
was highly successful in constructing a new equatorial 
mounting for telescopes and a clockwork which drove the 
mirror of a siderostat so accurately that a star could be 
followed for twelve hours ; but it was his skill in dividing circles 
to which he mainly owed his great reputation. There can 
be no doubt that his practice of substituting entire circles 
for the usual quadrants and sectors was soimd in principle 
and contributed much to his success. Every student of 
optics knows " Ramsden's eyepiece," and he also invented 
a double image micrometer. The Royal Society recognized 
his work by awarding him the Copley medal in 1795. 

While clocks and divided circles are necessary parts of 
an astronomer's equipment, he depends primarily on the 
optical performance of his telescopes. Newton had used 
mirrors to focus the beams of light, as he considered it 
to be impossible to do so accurately by means of lenses, 
because rays of different colours, being refracted to a different 



98 Britain's Heritage of Science 

degree in their passage through a lens, come to a focus at 
different points. Hence the images formed by simple lenses 
of glass are coloured. Though the possibility of combining 
several lenses made of different materials had occurred to 
Newton, he had come to the conclusion that the dispersive 
power of substances (which is the power to separate different 
colour's), is proportional to their refractive power, and if 
this were really the case, it would indeed be impossible to 
construct a lens which could bring different coloured rays 
to the same focus. The succeeding history of the subject is 
interesting. Euler asserted that notwithstanding Newton's 
experiments, which he accepted, it should be possible to 
produce achromatism, i.e., images without coloration, by 
means of a combination of lenses. David Gregory had 
already in 1695 expressed similar ideas, and their argument 
depended on the behef that the images formed by the human 
eye are not deteriorated by any colour-dispersion. As the 
rays entering the eye are concentrated on the retina by 
successive refraction through different media, such as the 
cornea, the crystalline lens and the vitreous humour, it 
was argued that it should be possible to produce achromatic 
images by properly combining lenses of different materials. 
Euler's behef that the optical arrangement of the eye pointed 
the way to the construction of achromatic lenses was shared 
by others, and ultimately led to the solution of the problem; 
but the curious point is, that the premise on which the whole 
argument depends is wrong, the eye not being achromatic 
at aU, but subject to the same defects as a simple lens. 

A Swedish mathematician, KJingenstjema, seems to have 
been the first to repeat Newton's experiments with sufficient 
care, when it appeared that the relationship between 
refractive and dispersive powers, which Newton thought 
he had established, did not hold accurately. John DoUond 
(1706-1761), a son of one of the many French refugees who 
came to England after the revocation of the Edict of Nantes, 
had started hfe as a silk weaver in SpitalQelds, but relin- 
quished this occupation and established a workshop for 
optical instruments. Having heard of Klingenstjerna's obser- 
vation, he entered into an independent investigation on the 
optical properties of different kinds of glass, and had the 



John DoUond, Edward Somerset 99 

satisfaction of solving, at last, this most important problem. 
By combining two lenses of different kinds of glass, he could 
produce images in which the colour defect was, though not 
entirely abolished, yet very materially diminished. In this 
discovery he was, however, anticipated by Chester More 
Hall of More Hall in Essex, a barrister, who, in 1833, had 
already succeeded in constructing an achromatic lens. 
DoUond's patent was subsequently challenged on the ground 
of anticipation, but the judgment was upheld in favour of 
DoUond on the ground — containing much common sense — 
that " it was not the person who locked his invention in his 
scrutoire that ought to profit from such invention, but he 
who brought it forth for the benefit of mankind." 

The iniprovements effected in electrical appliances by 
Canton, Henley, Bennett and others have already been 
described, and we may therefore pass on to the more direct 
appMcations of scientific principles to the utilization of power. 
The early steam engines — We should hardly caU them by 
that name now — were little more than toys, useful, perhaps, 
for the special pm-pose for which they were designed, but 
wasteful and costly in their working. It was only when 
James Watt came to apply the scientific methods acquired 
in his intercourse with Joseph Black and John Robison 
that an efficient machine could be evolved. 

We may begin our accotmt of the history of steam 
engines with Edward Somerset, Marquis of Worcester, 
whose romantic personaHty and tragic history form an 

• interesting study. He claims to have accomplished some 
wonderful things in a publication that bears the eccentric 
title : "A century of the names and skantHngs of such 
inventions as at present I can caU to mind to have tried 
and perfected, which, my former notes being lost, I have 
at the instance of a powerful friend endeavoured, now in 
the year 1655, to set down in such a way as may sufficiently 
instruct me to put any of them in practice." But his 

descriptions are so fantastic and vague that doubts have 
been raised whether he had ever gone beyond the forming 
of plans and making of projects, leaving the rest to his 
imagination, which had ample scope to exercise itself 
during a six years' confinement in the Tower of London. 

G 2 



100 Britain's Heritage of Science 

We possess, however, the testimony of an eye-witness who 
had seen near Vauxhall one of Worcester's machines raise 
water through a height of forty feet. Engines were chiefly 
wanted at the time for the pumping of water, more 
especially to clear the mines, and it is therefore, not sur- 
prising that the first practical application of the pressure 
provided by steam should have been made by a miner. 
Thomas Savery's (1650?-1702) machine probably resembled 
that of Worcester, and it is immaterial whether it was 
an independent invention or not. A short description may 
serve to illustrate its mode of work. A cylindrical vessel 
has three tubes leading out of it, each capable o' being 
opened and closed by a stopcock. The first tube joining 
the upper end of the cylinder is connected with a boiler; 
the second (the inlet tube) leads from the bottom of the 
cylinder vertically downwards to a reservoir of water, and 
the third (the outlet tube), also connected to the bottom of 
the cylinder, is bent round so as to lead vertically upwards. 
To start the machine, the cylinder is fiUed with water, and 
the stopcock of the inlet tube closed, while the two others 
are opened. Steam is then admitted, and the water expelled 
through the outlet tube. When the whole cylinder is filled 
with steam the boiler and outlet tubes are closed, and the 
inlet tube opened. The cylinder is cooled and the vacuum 
formed by the condensation of the steam draws a supply 
of water from the reservoir upwards into the cylinder. 
When the cylinder is fiUed, the stopcock of the inlet tube 
is closed, and the process repeated. The height to which 
the water may be raised in this manner depends on the 
pressure of steam employed, which in Savery's engine 
reached up to eight or ten atmospheres, corresponding to 
a height of about 250 feet of water. It wiU be seen that this 
machine contains no piston such as we associate now with 
steam engines, and there is no mechanical transmission of 
motion. Its sole object is the raising of a weight of water 
by the pressure of steam. 

Papin (1647-1714), a French Calvinist who had to leave 
his country on account of his religious opinions, lived in 
England for some time, but ultimately accepted a pro- 
fessorship in a German University. He suggested the use of 



T. Savery, D. Papin, T. Newcomen 101 

a piston, but abandoned the idea in favour of a modified 
form of Savery's engine. 

During his stay in England, Papin took an active part 
in the Proceedings of the Royal Society, and in 1684 was 
appointed temporary curator of that body with a salary 
of £30, in consideration of which he was required to pro- 
duce an experiment at each meeting of the Society. He 
had invented a so-called " bone-digester," to which Evelyn 
in his diary refers in these terms : " The hardest bones of 
beef itself and mutton were made as soft as cheese, without 
water or other hquor, and with less than eight ounces of 
coal, producing an incredible quantity of gravy; and, for 
close of all, a jelly made of the bonea of beef, the best for 
clearness and good rehsh, and the most dehcious that I 
have ever seen or tasted." Papin kept up his correspondence 
with the Royal Society after settling in Germany, sub- 
mitting to them a proposal to apply a steam engine to the 
propulsion of ships, and asking for a grant of £15 for his 
" expense, time and pain " in putting his ideas to the test. 
Papin is also credited with the invention of the safety 
vaive. 

The next successful step in the construction of steam 
engines was taken by Thomas Newcomen (1663-1729), an 
ironmonger of Dartmouth, who seems to have entered into 
correspondence on the subject with Robert Hooke, and, 
together with Cawley, another tradesman of his native 
town, produced a machine which in several ways was better 
than its predecessors. He introduced a cyhnder with a 
piston that could be raised by the pressure of steam, the 
piston rod being mechanically connected with a pumping 
arrangement. The steam was condensed in the cylinder 
itself by a jet of water, and the work was mainly performed 
in the downward stroke, when the atmospheric pressure of 
air pressed the piston down into thfe vacuum formed inside 
by the condensation of steam. Newcomen's engines came 
into general use for the pumping of water. 

In all the attempts made so far, no consideration is given 
to the economical use of fuel, a disadvantage which was 
severely complained of by those who used the engines. 
A new era began with the work of James Watt (1736-1819 



102 Britain's Heritage of Science 

We are all familiar with the story which tells how as a boy 
he watched the steam escaping from a tea-kettle, and dreamt 
of the future of steam-power. Such tales about precocious 
signs of future greatness may have a psychological interest 
when they are well authenticated, and given ia the correct 
perspective of surrounding circumstances; but even then 
we should not be able to estimate their true value unless 
we knew how many boys watched tea-kettles and made 
acute remarks without growing up to be great men. 
When we are told, for instance, of another eminent man 
who as a boy was asked to see what time it was, and returning 
after looking at the clock, said : " I can't tell you what 
time it is now, but when I looked at the clock it was ten 
minutes past three," we are tempted to ask what proportion 
of the boys who could give such an answer became great 
mathematicians, and how many merely great prigs. The 
story of Watt's tea-kettle rests on a memorandum dictated 
by an old lady, a cousin of his, fifty years after the occurrence, 
but the most significant part of her account is not generally 
mentioned. It was not the power of steam that Watt was 
watching, but the condensation into water when the steam 
came into contact with a silver spoon. The incident may 
be accepted as a sign of a scientific and enquiring mind, 
perhaps as a token of his interest in the properties of steam, 
but not as a forecast of his future belief in the powers 
of steam. James Watt came from a family of mathe- 
maticians. His grandfather, Thomas Watt, was a teacher 
of navigation, and his tombstone bears the title : " Pro- 
fessor of Mathematics." His father was a shipwright, 
supplying vessels with nautical instruments, and a mechanic. 
In the latter capacity he made and erected, for the use of 
Virginia tobacco ships, the first crane ever seen at Greenock. 
Growing up in these surroimdings. Watt at an early age 
became familiar with the use of tools, and set up a small 
forge for himself for the making and repairing of instru- 
ments. He left his Scotch home and became apprenticed 
to an instrument maker in London, but bad health obliged 
him to return at the end of the year. When his attempt 
to set up a shop at Glasgow was objected to by the guilds, 
because he had not served his fuU apprenticeship, the 



James Watt 103 

difficulty was overcome by some of the professors who 
had recognized his ability before he went to London, and 
established him as instrument maker to the University. 
This gave Watt the opportunity of entering into intimate 
scientific intercourse with such men as Joseph Black and 
John Robison, and gaining a knowledge of the scientific 
principles of heat. 

It was only in 1764, when a working model of one of 
Newcomen's engines was sent to Watt for repair that his 
mind was directed to the potential value of these machines. 
Watt at once recognized the cause of the enormous waste 
of fuel which constituted the chief defect of the engine. 
When the steam introduced into the cylinder had done its 
work by raising the piston, it had to be condensed before 
the piston could return; this was done by a jet of cold 
water introduced into the cylinder, which, of course, did 
not only condense the steam but also cooled down the mass 
of metal which formed the walls of the cyhnder. When 
the steam was reintroduced, the whole had to be raised up 
again to the temperature of the steam before the piston 
could be lifted. la order to avoid this waste of heat Watt 
saw that the cylinder ought, to be maintained permanently 
at the temperature of the steam, and for this purpose it 
became necessary to condense it, not in the cylinder itself, 
but in another vessel, into which it had to be driven after 
it had done its work. The invention of this separate con- 
denser was Watt's first contribution to the steam engine. 
He settled down in Birmingham with Matthew Boulton, 
a capitahst, and gained experience in the manufacture of 
his improved machines, which were still used exclusively 
for pumping water. 

The next great step was made in 1782. Up to that date 
steam was only admitted to the cylinder on one side of the 
piston, the return stroke being made by the pressure of the 
air against the vacuum formed by the condensation of steam. 
Watt now invented the double-acting engine, in which 
steam is alternately admitted and acts on both sides of the 
piston. The third advance, which briags us still nearer to the 
modern engine, is due mainly to the scientific knowledge 
which Watt had gained of the properties of steam, investi 



104 Britain's Heritage of Science 

gating for himself the connexion between its temperature, 
density, and pressure. Instead of allowing the steam to 
pass into the cylinder during the whole of the stroke. Watt 
saw that a considerable economy could be effected by 
stopping the admission when the stroke had reached a 
certain point, and allowing the pressure of the steam already 
in the cylinder to complete it. It is not necessary to enter 
fxu-ther into the many improvements of detail which the 
steam engine owes to Watt, who, realizing the future that 
was before it, also devised various means by which the up 
and down stroke of the engine could be converted into 
rotatory motion. 

Savery is said to have been the first to suggest that the 
measured power of performance of an engine might be in 
terms of horse-power, but Watt actually investigated the work 
that a horse could do in a given time, and defined one horse- 
power as the rate at which work is done when 33,000 lbs. 
are raised one foot in one minute. 

Watt was of a retiring disposition, due, no doubt, to 
the weakness of health which, in the early part of his life, 
greatly interfered with his work. He speaks of himself as 
" indolent " and " not enterprising," and as being " out 
of my sphere when I have anything to do with mankind." 
His inventions were not confined to the steam engine. He 
constructed a press for copying manuscripts, such as is now 
in common use. It is also claimed on behalf of Watt, 
and with some justification, that he was the first to discover 
the true composition of water as a compound of oxygen 
and hydrogen. The controversy which arose has already 
been referred to (page 85). 

The condenser used by Watt can be easily attached to 
stationary engines, but is inconvenient when an economy 
of space is imperative, as when steam is used for road 
propulsion. The condenser may then be dispensed with, 
but the pressure of steam has to be increased. Bichard 
Trevithick (1771-1833), whose father was the manager of a 
Cornish mine, invented a road locomotive with high pressure 
steam, and conveyed passengers with it on Christmas Eve, 
1801. Some sort of steam vehicle had, however, already 
been built in France by Nicolaa Cugnot as early as 1769, 



Watt, Trevithick, Murdock, Bramah 105 

and William Murdock (1754-1839) is reported to have con- 
structed a carriage drawn by steam about 1786. Never- 
theless, Trevithick was the first to build a locomotive in 
the modern sense, and to use it on the lines of a horse- 
tramway in Wales. Finally, the introduction of two 
cyhnders, the steam escaping from one being utilized to 
increase the work by acting on a piston in the second, may 
be mentioned as being the prototype of the present com- 
pound engines. This innpvation is due to Jonathan Carter 
Hornblower (1753-1815), who, among other things, invented 
a machine for sweeping chimneys by a blast of air. Patent 
difficulties stood in the way of putting the idea of the double 
cyhnder into practice, but it was re-invented and used in 
machinery set up in Cornish mines in 1804 by Arthm: Woolf. 

The name of Murdock recalls that he was the first to 
make a practical use of coal gas as an illuminating agent. 
His father was a Scotch millwright; he entered the employ- 
ment of Boulton and Watt at the Soho Factory, Birming- 
ham, in 1777, and a few years later was sent to Cornwall to 
superintend the fitting of water engines in mines. He esta- 
bhshed himself at Redruth, and is credited with several 
inventions ; there is a tradition that he created a sensa- 
tion among the inhabitants by carrying, to and from the mine, 
a lantern lit by gas supphed from a bag concealed under his 
coat. After his return to Birmingham in 1799, he improved 
his methods for making and storing the gas so much that 
the exterior of the Soho Factory, and soon after the whole 
of the interior, was Mghted with the new illuminant. 

During the last few years of the eighteenth century, 
another great step torward in the transmission of power 
was made when James Bramah (1749-1814) laid the founda- 
tion of a new branch of engineering by the invention of his 
hydrauhc press. Bramah was the son of a Yorkshire 
farmer. Being incapacitated for agricultural labour on 
account of an accident, he started business as a cabinet- 
maker in London, and made a number of inventions, such 
as the lock which is known by his name. He suggested 
improvements in the steam engine, foresaw the possibility of 
propelling ships by screws, and advocated the hydraulic 
transmission of power. 



106 Britain's Heritage of Science 



CHAPTER IV 
(Physical Science) 

The Heritage of the Nineteenth Centxjey 

IN a superficial review of the history of science a new idea 
or a strikiag experiment is associated with an iadividual 
name and a particular date. Hence, we receive a general 
impression that science proceeds by sudden, inspirations ; 
yet, on closer examination, we find that the saUent features 
are connected with each other, and that the great landmarks 
are generally reached only by a succession of intermediate 
steps, some of which may be as important as the last which 
culminates in the final discovery. Time tends to efface the 
intermediate steps, and so it happens that it is only in deaUng 
with the more recent events that we can obtain a correct 
view of the continuity of science. To trace this continuity 
is one of the functions of the historian, but occasionally 
his efforts will faU, and he wiU be faced by what appears to 
be an entirely new departure. Such was Volta's discovery 
of current electricity, which smrprised the scientific world 
in the first year of the nineteenth century. The electrical 
shocks which certain fishes can inflict on those who touch them, 
and an accidental observation by Galvani, an Itahan doctor, 
disclosed a class of phenomena called " animal electricity." 
But there was much confusion of ideas with regard to the signi- 
ficance of the observed facts until Volta, the great Italian 
experimenter, succeeded in separating what was physical 
from what was physiological in Galvani 's results, and so 
laid the foundation of a new science. By discovering the 
electrical effects that could be obtained at the contact of 
two dissimilar metals, Volta was led to those wonderful 
researches which gave us the electric batteryi His previous 



Anthony Carlisle, William Nicholson 107 

work had earned for him the Fellowship of the Royal 
Society in 1791, and desirous of showing his appreciation 
of the honour, he not only contributed an important paper 
to the Philosophical Transactions in 1793, but announced 
his latest and greatest discovery in a letter addressed to 
the President of the Royal Society, Sir Joseph Banks. That 
letter bears the date March 20th, 1800, and appears to have 
been sent in two parts, the second of which was delayed 
in dehvery, so that it could not be read before the meeting 
of the Society, held on June 26th of the same year. In 
the meantime, the &st part of the letter had been privately 
communicated to Sir Anthony CarUsle, the celebrated 
surgeon of Westminster Hospital, and Professor of Anatomy 
to the Royal Academy. CarHsle was mainly interested in 
the physiological effects of electricity, and consulted William 
Nicholson, a man of varied interests, who was employed 
at different times as an official in the East India Company, 
a traveller for the firm of Wedgwood, a school teacher and 
a civil engineer. He had embarked on the pubUcation of 
a scientific periodical — Nicholson's Journal — and relates in 
its fourth volume the important results he obtained by 
experimenting with the battery constructed according to 
Volta's directions. When two brass wires connected with 
the electric poles were immersed in a tube containing water, 
gas bubbles were seen to rise from one of the wires, while 
the other became corroded. The gas proved to be hydrogen. 
On replacing the brass wires by platinum, it was found that 
oxygen was set free as well as hydrogen ; the electroljrtio 
decomposition of water was thus completely effected. This 
was the first step in the brUhant series of experiments by 
which English chemists and physicists traced the connexion 
between chemical and electric action. But we must here 
interrupt our account, and turn for a moment to another 
subject. 

The time had come when the correlation between the 
various physical manifestations, such as light, heat and 
power, forced itself into the foreground. The production of 
heat by mechanical means was effected on a convincing scale 
by Benjamin Thompson, better known as Count Rumford, 
who had entered the service of Bavaria for the purpose of 



108 Britain's Heritage of Science 

organizing the manufacture of implements of war. His 
previous experiments had convinced Jiim that in accordance 
with the views of Robert Hooke and other early physicists, 
heat consisted in a motion of the ultimate particles of a body, 
and as he controlled the machinery at Miinich for making 
guns, he had the opportunity of testing the matter. While a 
cannon was being bored he filled the hollow already formed 
with water, and found that it became hotter and hotter until 
it boiled. The conclusion was obvious : heat could actually 
be generated by mechanical power. 

During an adventurous hfe Rumford rendered active 
services to several countries. His family had settled in 
Massachusetts, where he was born in 1753. At an early 
age he showed mathematical tastes, but occupied himself 
with abortive attempts to discover perpetual motion, and 
with experiments on fireworks. After the outbreak of the 
American war he entered a local regiment of militia on the 
American side, where his position was rendered imtenable by 
the doubt which was cast on his loyalty to the causj of 
freedom. He left the army and, when Boston was evacuated 
in 1776, he came to England, where he was appointed to 
a clerkship at the Colonial Office, rising rapidly within four 
years to the position of Under Secretary of State. In the 
meantime he carried on his scientific pursuits, and was 
elected a Fellow of the Royai Society in 1779. He returned 
for a time to Ameiica on active service, but resigned again 
at the conclusion of the war, with the rank of Colonel. He 
then determined to join the Austrian army, then engaged in 
war with Turkey. While on the way to Vienna he was 
introduced to Prince MaximiUan, the future King of Bavaria, 
and was persuaded to enter the government service of that 
state. With the consent of King George III., who bestowed 
the honour of knighthood upon him, he remained at Munich, 
where he held consecutively the offices of Minister of War, 
Minister o- Pofice, and Grand Chamberlain. In addition to 
the improvements he effected in the Bavarian army, he 
developed the industries of the country and did much to 
mitigate he extieme poverty of a large part of the popula- 
tion. His methods were strongly philanthropic. " To make 
vicious and abandoned people happy," he said, " it has 



Count Rumford, Sir Humphry Davy 109 

generally been supposed necessary first to make them vir- 
tuous. But why not reverse this order? Why not make 
them first happy and then virtuous ? " He adopted the 
name Rumford on being created a Count of the Holy Roman 
Empire in 1791. Some years later he returned to England 
and founded the Royal Institution, which received its charter 
in 1800. His later years were spoilt by an unhappy attach- 
ment he had formed to the widow of Lavoisier, the great 
French chemist, who had suffered death on the guillotine 
during the Revolution. Their marriage took place in 1804, 
but resulted in an uncomfortable hfe for several years, until 
a separation was agreed upon. He died in France in the 
sixty-second year of his age. 

Rumford probably rendered his greatest service to 
science when, in 1801, he selected Humphry Davy for 
appointment as first lecturer on Chemistry and Director of 
the Laboratory at the Royal Institution. Davy (1778-1828) 
had already shown his intense enthusiasm for research, 
though his first attempts at original work were remarkable 
for great power of scientific imagination, rather than for 
sobriety of judgment. A. trial lecture at which Rumford 
was present, settled, however, the question of his appoint- 
ment. 

" I consider it fortunate that I was left much to 
myself when a child, and put upon no particular plan of 
study, and that I enjoyed much idleness at Mr. Coryton's 
school. I, perhaps, owe to these circumstances the little 
talents that I have and their peculiar apphcation." 
These words of Davy's, written to his mother at a later 
date, show that Davy did not estabhsh any reputation 
for studiousness as a boy ; but his Uterary gifts must have 
appeared at an early age, for we are told that the love- 
sick youths of Penzance employed him to write their 
valentines and letters.* Davy's father had died in poor 
circumstances, and the mother estabhshed a miUiner's shop 
in Penzance to provide the means of educating her younger 
children. Humphry, the eldest of them, had then already 

• The account of Davy's life and work is almost entirely derived 
from Sir Edward Thorpe's most excellent and interesting little volume, 
" Humphry Davy — Poet and Philosopher " (Century Science Series). 



110 Britain's Heritage of Science 

spent four years at the Grammar School at Penzance, and 
one at Truro. At his father's death he realized the necessity 
of setting to work seriously, and was apprenticed with an 
apothecary and surgeon practising in Penzance. He then 
began a course of extensive reading covering nearly all 
branches of learning. Metaphysics seems to have more 
especially attracted his attention, and he wrote a number of 
essays on such subjects as "The Immortahty and* Imma- 
teriality of the Soul," " Governments," and " The Credulity 
of Mortals." Some of his aphorisms indicate great originaUty 
of thought, and one almost hears the voice of Poincare in the 
passage in which he declares that : " Science or knowledge is 
the association of a number of ideas, with some idea or 
term capable of recaUing them to the mind in a certain 
order." Turning his attention to experimental research, Davy 
at this period studied Lavoisier's " Elements of Chemistry," 
and formed original, but not very happy, ideas on the 
nature of light, which he communicated to a medical man. 
Dr. Thomas Beddoes, with important results on his future 
life. Dr. Beddoes had a notion that the study of the 
physiological effects of different gases might have important 
therapeutical applications. With this purpose in view, he 
founded the " Pneumatic Institution " at Bristol, and, 
impressed by Humphry Davy's work, he put him in charge 
of the laboratory. The experiments on gases led to results 
of importance. While examihing the properties of nitron 
oxide, Davy observed those remarkable physiological pro- 
perties which give to this gas its familiar name of " laughing 
gas." Mary Edgeworth, a sister of Mrs. Beddoes, thus 
describes the discovery : 

" A young man, a Mr. Davy, at Dr. Beddoes', who 
has apphed himself much to chemistry, has made some 
discoveries of importance, and enthusiastically expects 
wonders will be performed by the use of certain gases, 
which inebriate in the most dehghtful manner, having 
the oblivious effects of Lethe, and at the same time 
giving the rapturous sensations of the Nectar of the 
Gods ! Pleasure even to madness is the consequence of 
this draught. But faith,^ great faith, is,* K believe, 
necessary to produce any effect upon the drinkers, and 



Sir Humphry Davy 111 

I have seen some of the adventurous philosophers who 
sought in vain for satisfaction in the bag of ' Gaseous 
Oxyd,' and found nothing but a sick stomach and a 
giddy head." 
As a result of further experiments with nitrous oxide, 
Davy mentions its power of destroying physical pain and 
suggests its appUcation in surgical operations; but no 
notice of this suggestion was taken for half a century. 
Davy's researches on gases were preceded by the unhappy 
publication already referred to — " On Heat, Light, and the 
Combinations of light, with a new Theory of Respiration," 
in which he tries to demolish Lavoisier's theory that oxygen 
was a compound of an elementary substance and " heat." 
The paper is in great part of a speculative nature, and fuU 
of hasty and iU-considered opinions. He was, no doubt, 
right in his contention that heat is not a substance, but he 
spoils his case by adhering to the behef in the compound 
nature of oxygen, replacing only Lavoisier's " heat " by 
the equally imaginary substance " light." He tries to prove 
by experiments which are not to the point that light is not 
due to the vibrationary motion of an elastic medium, and 
even states that oxygen cannot be produced from oxide of 
lead by heating it in the dark. A statement of this kind 
renders it doubtful whether he was sufficiently careful in 
excluding aU possible sources of error in another experiment, 
described in the same paper, in which two pieces of ice 
were melted in an exhausted receiver by rubbing them 
together. 

The errors of a self-trained, impulsive young man would 
hardly be worth recording were it not for the chastening 
effect which the severe criticisms they evoked had on his 
subsequent work. Davy never forgot his lesson; he 
remained impulsive, but became much more careful in his 
experiments, and avoided speculative theories like a child 
avoids fire when it has burnt its fingers. Within a year he 
pubHshed a letter in Nicholson's Jtmrnal, in which he says : 
" I beg to be considered as a sceptic with regard to my 
particular theory of the combinations of hght, and theories 
of hght generally." Before we leave Davy's activities at 
Bristol, we may quote a passage from one of his letters 



112 Britain's Heritage of Science 

which illustrates his wonderful powers of intuition in hitting 
on the essential points of an experiment : 

" Galvanism " (we should now call it " current 
electricity ") " I have found, by numerous experiments, 
to be a process purely chemical, and to depend wholly 
on the oxidation of metallic surfaces, having different 
degrees of electric conducting power. 

" Zinc is incapable of decomposing pure water ; and if 
the zinc plates be kept moist with pure water, the galvanic 
pile does not act ; but zinc is capable of oxidating itself 
when placed in contact with water holding in solution 
either oxygen, atmospheric air, or nitrous or muriated 
acid, etc., and under such circumstances the galvanic 
phenomena are produced, and their intensity is in pro- 
portion to the rapidity with which the zinc is oxidated." 
Davy took up his position as Assistant Lecturer at the 
Royal Institution in London, and so brilliantly did he 
discharge his duties that his audience was taken by storm, 
and the lecture room was soon filled with enthusiastic 
Usteners. The full title of lecturer was given him at 
once, and the Philosophical Magazine predicted that " from 
the sparkling intelligence of his eye, his animated manner, 
and the ' tout ensemble,' we have no doubt of his attaining 
a distinguished eminence." The control of the subjects to 
be investigated rested at the time with the governing body, 
and the Institution having been founded with a view to the 
practical applications of science, the managers resolved that 
Davy should give a course of lectures on the Principles of 
the Art of Tanning; he received leave of absence during 
three summer months for the purpose of making himself 
acquainted with the subject. Subsequently he was requested 
to devote his energies to agriculture, and the various duties 
which the authorities of the Royal Institution imposed 
upon him took up much time which would have been better 
employed in research work. Nevertheless, he found sufficient 
leisure to return to his favourite study, the chemical action 
of electric currents, with the result that in 1806 he commu- 
nicated a paper to the Royal Society which was made the 
Bakerian lecture of the year. It constitutes a most impor- 
tant contribution to science, and lays the foundation — ^in 




Sir Humphry Davy 



From a painting by Sir Thomas 
Lawrence, in the possession of the 
Royal Society 



Sir Humphry Davy 113 

some respects more than the foundation — of our present 
science of electro-chemistry. The sensation which the paper 
created in England was great; its effect abroad may be 
judged from the fact that the French Academy recommended 
Davy as first recipient of the gold medal, promised by 
Napoleon for " the best experiment that should be made 
in each year on the galvanic fluid." This recognition had a 
special value, owing to its being bestowed in the face of a 
bitter political hostility between France and England, then 
at war with each other. 

Davy continued his researches and in the following year 
was already able to announce another discovery of funda- 
mental importance which forms the subject of his second 
Bakerian lecture. The construction of electric batteries had 
been materially improved by Cruikshank, a surgeon, and 
Davy had modelled his own apparatus on Cruikshank's 
pattern. The metals used were copper and zinc, and two 
of the batteries consisted of 50 and 100 cells respectively, 
the plates in the first measuring six, and in the second, 
four square inches. With the two batteries in series, Davy 
made a determined attempt to decompose the so-called 
fixed alkaUs : soda and potash. When a current is passed 
through the aqueous solution of these bodies, only hydrogen 
and oxygen are set free at the poles. Other experimental 
methods had, therefore, to be tried. As potash at ordinary 
temperatures does not conduct the current sufficiently well 
to show any effect, it was raised to a temperature at which 
it fused, and the current then produced a highly inflammable 
substance, which burst into flame by contact with air. In 
order to isolate that substance, Davy saw that it was 
necessary to conduct the experiment at ordinary tempera- 
tures, and succeeded in doing so by utilizing the hygroscopic 
properties of the substance, which, on exposure to damp 
air, cause it to become covered with moisture. The current 
then passed through the highly-concentrated liquid surface 
layer. With his 150 ceUs Davy found the electrical effect he 
looked for, and was able to isolate metaUic potassium. He 
announced his discovery in these words : 

"■ Under these circumstances a vivid action was soon 

observed to take place. The potash began to fuse at 



114 Britain's Heritage of Science 

both its points of electrization. There was a vlo ent 
effervescence at the upper surface; at the lower, or 
negative surface, there was no hberation of electric 
fluid; but small globules having a high metallic lustre, 
and being precisely similar in visible characters to quick- 
silver, appeared, some of which burnt with explosion 
and bright flame, as soon as they were formed, and others 
remained, and were merely tarnished, and finally covered 
by a white film which formed on their surfaces." 
Sodium was similarly obtained from soda. 
The interest which the announcement of the discovery 
of two new elements created throughout the scientific world 
was accentuated by the peculiar properties which distin- 
guished them from aU known metals. They are both lighter 
than water, and when brought into contact with that liquid 
burst into flame, owing to their great affinity for oxygen. 
The investigation of their chemical properties was most 
difficult, because they oxidize rapidly when exposed to air, 
and can only be preserved by being immersed in naphtha 
or some similar liquid. Though a serious illness interrupted 
Davy's work, he continued to give the Bakerian lecture 
for six successive years, each time adding something to 
our knowledge, mainly in connexion with the researches 
which have already been described. He received the honour 
of knighthood in 1S12, and shortly afterwards informed the 
managers of the Royal Institution that he could not pledge 
himseK to continue his lectures, but was prepared to retain 
his position as Professor of Chemistry and Director of the 
Laboratory without salary. This offer was accepted. In 
the same year he published his " Elements of Chemical 
Philosophy," in which he described the " Voltaic Arc," that 
column of light which is formed between carbon points when 
a current of sufficient electromotive force is passed between 
them. Even Davy's vivid imagination could hardly have 
foreseen the part which this discovery was to play in the 
future history of illumination. The same paper contains 
another important result. Partly anticipating the subsequent 
work of Ohm, the electric resistance of a conductor was 
shown to be proportional to its length directly, and inversely 
to its cross-section. 



Sir Humphry Davy 115 

His connexion with the Royal Institution was finally 
severed in 1813, and during the late autumn of that year he 
set out — accompanied by his wife and Faraday — on what 
he called a " journey of scientific enquiry." He was received 
with great honour in Paris, where he attended the meetings 
of the Academy of Science, which elected him a corre- 
sponding member. On November 29th a paper was read 
to the Academy on a new and remarkable substance dis- 
covered by Courtois, which, when heated, gave out a violet- 
coloured vapour. This was followed a week later by a 
communication from Gay Lussac, pointing out its analogies 
to chlorine and bromine, and proposing the name " iode " 
for it. It is characteristic of the impetuous manner in which 
Davy rushed through a research that, having obtained a 
small quantity of the substance, he at once set to work, and 
on December 20 a letter, in which he described his experi- 
ments, was submitted to the Academy by Cuvier. After a 
few days he forwarded his complete results to the Royal 
Society, proposing the name of iodine as the English 
equivalent for the new substance.' 

Another example of Davy's activity during this journey 
remains to be mentioned. At Florence he made use of the 
great burning-glass belonging to the Accademia del Cimento, 
by means of which it had already been shown in the reign 
of Cosimo III. that a diamond is inflammable when the 
rays of the sun are concentrated upon it. On repeating 
the experiment Davy found that the products of combustion 
consisted almost entirely of carbonic acid, and pronounced 
diamond to be pure carbon. This result had an importance 
greater than that which attaches to the record of a new 
experimental fact; for it was the first weU-estabhshed 
instance of a chemical element existing in two different — 
now called alio tropic — ^forms. 

Shortly after Davy's return to England in 1815, a Society 
that had been formed to discover, if possible, some method 
by which explosions of fire-damp could be prevented, asked 

1 The French Academy began to publish its " Comptes Rendus " 
only in 1835. For a reprint of the papers connected with the dis- 
covery of iodine, the reader is referred to four communications in the 
Annales de Chimie," vol. 87, pp. 304r-329. 

H 2 



116 Britain's Heritage of Science 

his assistance. These explosions claimed many victims, 
and some remedy had become a pressing need. Davy 
acceded to the request with enthusiasm, and offered at 
once to visit some of the mines. The invention of the 
miner's lamp, which, perhaps, has saved more human lives 
than any other contrivance, was the result of Davy's efforts. 
It is not necessary here to describe the principle on which 
it is constructed, but it may be pointed out that the lamp 
embodies a technical application of pure sciencs, which no 
one would have been able to devise without a thorough 
knowledge of the principles of Physics and Chemistry, 
together with a considerable experience in laboratory work. 
The invention was at once appreciated by those whom it 
was intended to benefit, and one can imagine the pleasure 
with which Davy received the following letter signed by 
eighty-three Whitehaven colliers : 

" We, the undersigned, miners at the Whitehaven 

CoUieries, belonging to the Earl of Lonsdale, return our 

sincere thanks to Sir Humphry Davy for his invaluable 

discovery of the safe lamps, which are to us Ufe-preservers ; 

and being the only retiirn in our power to make, we 

most humbly offer this, our tribute of gratitude." 

His services were recognized officially by the bestowal 

of a baronetcy. Davy acted as Secretary of the Royal 

Society between 1807 and 1812; and was elected President 

in 1820. His predecessor, Sir Joseph Banks, had before his 

death expressed his preference for another FeUow, and 

based his objection to Davy on the ground " that he was 

rather too hvely to fill the chair of the Royal Society." 

Davy, however, was elected, and filled the chair to the time 

of his death in 1827. 

No account of Sir Humphry Davy's life would be com- 
plete without reference to his poetic temperament and 
literary talents. Coleridge said of him : " If Davy had not 
been the first chemist, he would have been the first poet 
of his age." By a vivid and impressive style of lecturing, he 
attracted large audiences to the Royal Institution, which 
soon became popular. It was a fortunate day for that 
Institution when Davy was put in charge of the chemical 
department, for serious financial diflBculties were threatening 



Sir Humphry Davy 117 

its existence. The stress was at once relieved by the large 
addition of new members attracted by the engaging per- 
sonality of the young lecturer. 

A significant Hght is shed on the small value then 
attached by the Enghsh Universities to experimental science 
by the fact that none of them ever pubUcly recognized 
Davy's work. The only University honour he received was 
the LL.D. degree from Trinity College, Dublin. 

Yet a great revival of scientific activity had already 
begun at Cambridge, though at the time of Davy's death 
it was mainly confined to the domain of pure mathematics. 
It is sad to think how a spirit of loyalty to its greatest 
ornament should have paralysed that great University for 
almost a century, by compelling a rigid adherence to the 
details of Newton's formal procedure, for it was almost 
purely a question of nomenclature that delayed progress. 
In using the method of " fluxions," which is identical in 
its fundamental ideas with what we now call the Differential 
Calculus, Newton denoted the rate of change of a quantity, 
say M, depending on another quantity, say t, simply by 
placing a dot over the u. If m be the length of path travelled 
over by a point, and t the time, U would represent the 
velocity. Leibnitz, starting from the idea of infinitely small 
quantities, placed a d before the symbol of the variable 
quantity; dt would be an indefinitely small timei and dujdt 
would represent the velocity. From the purely philosophic 
point of view there is much to be said for Newton's notation, 
but as an instrument of research, that introduced by Leib- 
nitz had considerable advantages, more especially in the 
inverse process of iategration. When Cambridge began to 
wake up, Charles Babbage (1792-1871) was among those 
who helped to introduce the methods which had been so 
successf til in the hands of the great French mathematicians 
of the eighteenth century. A special society — the Analy- 
tical Society — having been formed for the purpose, Babbage 
neatly expressed the objects of the society as " advocating 
the principles of pure ' de-ism ' for the ' dot-a,ge ' of the 
University." 

The founder of the new school was Robert Woodhouse 
(1773-1827), Lucasian Professor of Mathematics between 



118 Britain's Heritage of Science 

1820 and 1822, and subsequently Plumian Professor of 
Astronomy. Already in his earliest work he strongly advo- 
cated the continental system of notation, but little progress 
was made at the time. His views began to prevail mainly 
through the efforts of Babbage, combined with those of 
two other Cambridge mathematicians, George Peacock and 
John Frederick Herschel, the son of Sir William Herschel 
the great ast onomer. 

Charles Babbage is widely known in connexion with 
an ambitious calculating machine which he proposed to 
construct. His first machine was designed mainly for the 
preparation of astronomical tables; his second was to 
perform all kinds of arithmetical operations, but it never 
emerged from the state of general design, and no detailed 
drawings were made. His mathematical work, however, 
was not without importance. He was generally active in 
the cause of science. It was partly through his efforts that 
the Royal Astronomical Society was founded, and he strongly 
supported the British Association in its early days. It is 
notewor hy that at the second of its meetings he strongly 
urged that " attention should be paid to the object of 
bringing theoretical science in contact with the practical 
knowledge on which the wealth of the nations depends." 

Babbage occupied for a time the Lucasian Chair of 
Mathematics, but spent the last years of his life in London. 

George Peacock (1791-1858), another important member 
of the new group, occupied for a time the Lowndean Chair 
of Astronomy, which he resigned on his appointment to the 
Deanery of Ely. He played an important part in the founda- 
tion of the Cambridge Philosophical Society, and in the 
early history of the British Association. For the latter body 
he wrote an account of the progress of mathematical analysis, 
the first of the important series of reports in different 
branches which are pubUshed in its annual volumes. 

Of John Herschel we shall have to speak in another 
connexion; his name is introduced here because his earlier 
work deals with mathematical analysis, and helped to 
introduce the differential notation. 

In their endeavours to reform the teaching of mathe 
matics Peacock and Herschel were assisted by William 



Babbage, Peacock, Wbewell 119 

Whewell (1794-1866), whose name will chiefly be remem- 
bered by his " History of the Inductive Sciences," a book 
in three volumes published in 1837, and containing a large 
quantity of useful information. Whewell ultimately became 
Master of Trinity College, and gained great influence in the 
University, but his attitude in later life became strongly 
conservative and antagonistic to aU proposed reforms. 

A new branch of science — " Physical Optics " — emerged 
from the work of Fresnel and Young, and when Arago and 
Brewster had discovered the beautiful colour effects shown 
by polarized light transmitted through plates cut out of 
crystals, mathematicians had a good opportunity of applying 
their talents to test the powers of the wave-theory. Wien, 
as in Arago's experiments, the light sent through the plate 
is confined to a parallel beam, the difficulties are compara- 
tively slight, and were dealt with satisfactorily by the 
French physicists. But a number of parallel beams sent 
through the plate in all directions, and properly focussed, 
show more complicated and very beautifid effects, coloured 
bands being crossed by light or dark brushes of various shapes. 
The mathematical analysis then becomes more formidable, 
especially when the crystals have — as in the case of quartz 
— ^the peculiar property of turning the direction of the light 
vibration. Among those who successfully attacked these 
problems Airy held a distinguished place. 

George Biddell Airy (1801-1892) had a brilliant Univer- 
sity career. He entered the University at the age of eighteen, 
and four years later graduated as Senior Wrangler, and 
obtained the first Smith's prize. In 1826 he was elected to 
the Lucasian Professorship, a position which Newton's name 
has always invested with a certain glamour. 

Though keenly interested in many branches of Physics, 
Airy was more particularly attracted by astronomical pro- 
blems, and when a vacancy in the Plumian Professorship 
occurred in 1828, he became a candidate, and after election 
took charge of the Cambridge Observatory, which had just 
been estabUshed, mainly through the efforts of George 
Peacock. The wide range of subjects enriched by Airy's 
investigations may be illustrated by noting the titles'^of his 
first six contributions to science. These were : "On the 



120 Britain's Heritage of Science 

figure of the earth " ; " On the use of silvered glass for the 
mirrors of astronomical telescopes " ; " On the figure assumed 
by a fluid whose particles are acted on by their mutual 
attraction and smaU extraneous forces " ; " On the principles 
and construction of the achromatic eye-pieces of telescopes, 
and on the achromatism of microscopes " ; " On a peculiar 
defect in the eye and a mode of correcting it " ; " On the 
forms of the teeth of wheels." All these papers mark an 
advance in their subject matter, and they were written 
before Airy had reached the age of twenty-four. 

His investigation on eye-pieces was considered to be of 
sufficient importance for the Royal Society to vote Tn'm the 
Copley Medal, their highest award, in 1831. The paper which 
he wrote on a " peculiar defect of the eye " deals with 
astigmatism. Airy, finding that he could not read with one 
eye, investigated the cause, and observed that the defective 
eye could not properly focus a point of light which was 
drawn out into line. This suggested the method of correcting 
the defect by employing a cylindrical lens. Airy was not 
aware that Thomas Young had already previously described 
the astigmatism of the eye. But Young had only met with 
slight cases, and thought that an ordinary lens slightly 
inclined was sufficient to correct the defect. 

Airy's principal contribution to Physical Optics is con- 
tained in a paper in which the coloured curves observed in 
crystalline plates are mathematically explained and the 
results more particularly applied to the beautiful spiral forms 
seen in quartz under certain conditions. Another paper 
deals with the rainbow, the general explanation of which was 
first given by Descartes. Most people wiU have observed that 
the violet of the rainbow is frequently followed by a dark red 
and a succession of colom-s, sometimes twice repeated. The 
cause of these so-caUed supernumerary rainbows was given in 
a general way by Young, who showed that their appearance 
depends on the interference of light which manifests itself 
when the sizes of the raindrops are nearly equal ; but Airy 
gave the first mathematical treatment of the subject. 

Terrestrial Magnetism was another subject to which 
Airy devoted his attention, more especially after he had 
gone to Greenwich as Astronomer Royal. The connexion 



G. Airy, J, Baden Powell, G. -Green 121 

of astronomy with the problems of navigation has always 
been maintaiaed at the Royal Observatory, and the intro- 
duction of iron ships presented new problems, because the 
ship became magnetic under the influence of the earth's 
forces, and the compass needles were very seriously deflected 
from the normal direction. An iron ship, The Bainbow, 
having been placed at his disposal. Airy was able to deter- 
mine the amount of the deviation experimentally, and 
following up the observations by a mathematical investi- 
gation, he showed how the effects could be compensated 
by placing small permanent magnets near the compass. 

In the work of spreading the new ideas on the nature of 
light, useful help was given by J. Baden Powell (1796-1860), 
the son of a gentleman who at one time was High Sheriff 
of Kent. He graduated at Oxford, took holy orders, and 
devoted himself to mathematical studies while holding 
a Uving in Kent. In 1827 he was appointed Savilian Pro- 
fessor of Geometry at Oxford, where he took an active part 
in advocating University reform. Powell wrote a treatise 
on experimental and mathematical Optics, investigated the 
reflexion of light from metaUic surfaces, and showed that 
highly absorbing bodies in the crystalline state resembled 
metals in some of their optical peculiarities. He also estab- 
lished the commonly used empirical law connecting the 
refractive 'ndices of rays of light with their wave-length. 

Important as these results may be, they only dealt with 
isolated problems, but did not touch fundamental principles. 
The work of George Green (1793-1841) stands on a higher 
level; indeed, had it become more generally known and 
appreciated, it might rank as one of the landmarks of 
science. Green, the son of a mfller in Nottinghamshire, 
entered the University of Cambridge when he was forty 
years old, and had already written a most important 
mathematical investigation, which was published by private 
subscription. This paper dealt with electricity and mag- 
netism, and it was only during the last few years of his life 
that he published his investigations bearing on Optics. 
This part of his work was introduced by a paper on Soimd, 
in which the subject is treated by powerfiJ. methods, now 
famihar to every student of mathematical physics, but 



122 Britain's Heritage of Science 

then quite novel ; it marked a considerable step in the 
philosophical treatment of the subject. As one result of this 
investigation, the complete internal reflexion which occurs 
when soimd passes from one medium to another, possessing 
different elastic properties, was demonstrated in opposition to 
Cauchy, who had come to a contrary conclusion. 

The subject of light is dealt with in a masterly manner 
in two papers. The general properties of elastic media are, 
for the first time, examined mathematically, and hght is 
treated as a special case of waves passing through a perfectly 
elastic body. Green must be considered to be — after Newton 
— the founder ot the Cambridge school of Mathematical 
Physics. He did not — ^like Cauchy and Franz Neumann — 
discuss the causes which give bodies their elastic properties, 
and could, therefore, dispense with any hypothesis on the 
mutual action of molecules, or on the ultimate constitution 
of the luminiferous aether. AU he needed was the assumption 
that its properties were such as to comply with the principle 
of the conservation of energy. That principle had not, at 
that time, been formulated, but appears implicitly in Green's 
work. The investigation solved, under certain suppositions, 
the problem of the transmission, reflexion and refraction of 
waves passing through homogeneous elastic bodies. The only 
question that remained was, whether the observed laws of 
light could be made to agree with the mathematical formulae 
obtained. The two main experimental tests that could be 
applied were the intensities of light reflected at the surface 
of transparent bodies and the laws of double refraction. 
The French physicist Fresnel had broken the ground, and 
obtained satisfactory solutions for both problems, but his 
analysis was not free from serious defects, and the hypothesis 
he applied in one case was inconsistent with that introduced 
in the other. The more rigid treatment of Green, together 
with the subsequent investigations of Stokes, McCullagh and 
Rayhsigh, led to a deadlock, for no consistent hypothesis 
could be framed to fit aU cases. Fortunately Clerk Maxwell's 
electrodynamic theory of light disposed of these difficulties. 

Green's first paper on Electricity and Magnetism is 
considered to be his most important contribution to science, 
but being of a highly technical character, it must suffice to 



George Green, George Stokes 123 

point out that the use of a certain mathematical function 
abeady introduced by Laplace was now employed to the 
greatest advantage under the name " potential," a term which 
has proved of such universal utility in aU branches of physics, 
owing to its nominal as well as real connexion with the 
conception of " potential energy." 

Here begins the golden age of mathematics and physics 
at Cambridge. Its period is coincident with the scientific 
activity of George Gabriel Stokes (1819-1903), which began 
in 1842, and extended, with but slightly diminished vigour, 
to the end of last century. Stokes' position as an investi- 
gator is among the greatest, but his influence cannot be 
measured merely by the record of his published work. He 
united two generations of scientific workers by the love and 
veneration centred in their gratitude for the assistance and 
encouragement which, with kindly and genuine interest, he 
showered upon them out of the wealth of his knowledge and 
experience. Even those who intellectually were his equals 
owed much to his sound and impartial judgment. Turning 
away from the grave which was closing over his lifelong 
friend, Kelvin was heard to say : " Stokes is gone, and I 
shall never return to Cambridge." 

Stokes' first papers dealt with fluid motion, a favourite 
subject, to which he frequently returned. It is impossible 
in an account intended to be intelUgible to the non- 
mathematical reader, to indicate even the general import 
of his fundamental investigations in one of the most difiicult 
subjects of apphed mathematics. The interest attaching to 
the shape and propagation of waves wiU, however, be readily 
imderstood, and the importance of questions of stability, 
which enter so much into the recent advances of aero- 
nautics, does not need emphasizing at the present time. 
Both questions rest on that most careful consideration of 
the fundamental principles of fluid motion, to which Stokes 
applied his great critical powers. 

The subject of fight is, perhaps more than any branch 
of physics, indebted to Stokes. The problems of the aberra- 
tion of light and the phenomena of double refraction were 
the first to attract his attention, and he recurs frequently to 
the question of the constitution of the luminiferous aether. 



124 Britain's Heritage of Science 

He wrote from the point of view of the elastic solid theory 
of light, which now is abandoned, but his papers, and more 
especially that on the Dynamical Theory of Diffraction, have 
lost none of their value. 

Though a keen mathematician, Stokes was equally 
interested in realities, and he has given us at least one 
experimental discovery of primary importance. It was known 
already to the Jesuit Kircher (1601-1680), and to Robert 
Boyle, that extracts of certain woods presented a different 
appearance when examined by transmitted or reflected hght ; 
John Herschel and David Brewster added some material 
facts, and though they tried to theorize on them, they did 
not make much headway in fitting the facts into the general 
framework of Optics. Stokes attacked the problem in the 
true Newtonian manner. StinHght admitted through a sUt 
in a shutter entered the room, and, after passing through 
three prisms, was made to form a spectrum on a screen. 
Solutions of the substances to be examined, such as sulphate 
of quinine or escuhne, were placed in a test tube, and then 
passed along the screen, so that they were successively 
illuminated by the different colours of the spectrum. In the 
red, yellow, green and blue, the substances behaved much 
like transparent liquids, but when placed in violet they 
began to shine, emitting a strong blue light, and this was 
accentuated when the test tube was moved beyond the visible 
spectrum, into what we now call the ultra-violet. The 
existence of such rays had already been proved by means of 
their chemical action, but Stokes widened their range to a 
quite imexpected degree by using prisms made of quartz, 
instead of glass; for the glass, as he showed, strongly 
absorbed those rays. The practical application of these 
researches, extending optical investigations into the regions 
of waves which are too short to affect our eyes, became 
apparent after the introduction of spectrum analysis, and 
Stokes himself, in a subsequent research, investigated the 
ultra-violet spectra of metals. But at the time, the novel 
result emerging from the work was the discovery that the 
substances experimented upon had the power of changing 
the wave-length of the light which fell upon them. This was 
quite contrary to what Newton had taught. Newton was 




Sir George Gabriel Stokes 



From a photograph by 
Fradelle & Yoitng 



G. G. Stokes, J. C. Adams 125 

right, of course, with regard to all phenomena known to 
him, and the proposition that the refrangibility of a ray of 
Ught cannot be altered by reflexion or refraction was a 
great step in advance at the time. As constantly happens, 
however, new facts require a revision of old dogmas, and 
though Brewster could never be persuaded, Stokes showed 
in an absolutely conclusive manner that certain substances 
could, and did, alter the refrangibihty, or, as we now should 
say, absorbed the incident light and emitted it again with 
different periods of oscillation. As fluor spar was one of the 
substances possessing this pecuUar property, Stokes called 
the whole series of phenomena " fluorescence." 

The later years of Stokes' life centred largely in his 
activity as Secretary of the Royal Society. The range of 
his knowledge, the width of his sympathies, and his almost 
infallible judgment, pecuMarly fitted him for a position which 
offered so many opportunities of advising striving men, and 
guiding their researches into profitable directions. He died 
an old man, but his scientific outlook always remained young. 
New ideas pleased him, even when he could not agree with 
them, and he dehghted in any discovery that did not fit into 
estabhshed theories. 

Two years after Stokes graduated as senior wrangler and 
first Smith's prize man, the same honours fell to John Crouch 
Adams (1819-1892). There could be no sharper contrast 
between two men of similar intellectual attainments than that 
which marks the scientific fife of the two mathematicians. 
Stokes freely presented his knowledge and experience to 
others, while to Adams we may apply with greater truth 
what Maxwell said of Cavendish, that he cared more for 
doing the work than for communicating it to others. How 
much of this reserve was due to the events connected with 
his first research it is impossible to say, but it is difficult 
to beUeve that these left him entirely unaffected. For that 
research was an arduous one, and should have led to the first 
discovery of the planet Neptune, if the responsible astro- 
nomers at the time had paid more attention to the calculations 
of the young Cambridge mathematician. A full account of 
the history of the new planet, from the pen of Simon 
Newcomb, is pubUshed in the " Encyclopaedia Britannica," 



126 Britain's Heritage of Science 

and we may here confine ourselves to its salient features. Wlien 
the path of Uranus, the planet discovered by William 
Herschel in 1781, was carefuUy examined by Alexis Bouvard 
of Paris, it was found that it showed irregularities which could 
not be accounted for by the gravitational action of the other 
planets known at the time. Bouvard himself entertained 
the idea that the discrepancies might be due to the attraction 
of an ultra-Uranian planet, and an Enghsh amateur 
astronomer, the Rev. J. T. Hussey, wrote in 1834 to Airy, 
who was then Astronomer Royal, offering to make a search 
for this planet, if some idea of the position could be given 
him. Adams heard of and became interested in these 
discussions as an undergraduate, and the following memo- 
randum, in his own handwriting, dated 3rd July, 1841, is 
stiU preserved : " Formed a design, in the beginning of this 
week, of investigating, as soon as possible after taking my 
degree, the irregularities in the motion of Uranus, which are 
yet unaccounted for ; in order to find whether they may be 
attributed to the action of an undiscovered planet beyond 
it ; and, if possible, thence to determine the elements of its 
orbit, etc., approximately, which would probably lead to its 
discovery." 

Having graduated in 1843, he at once set to work on the 
problem. His first solution was communicated to James 
Challis, the head of the Cambridge Observatory, in September 
1845, and about the Ist of November of the same year he sent 
his calculations to Airy, indicating the position at which the 
new planet might be looked for. Although, according to the 
American astronomer Newcomb, two or three evenings 
devoted to the search could not have failed to make the planet 
known. Airy was not satisfied, but sent a further enquiry to 
Adams, which, apparently, was left unanswered. Mean- 
while. Leverrier, a young French astronomer, had, at the 
suggestion of Arago, taken up the same subject, and made 
an independent calculation, which led to a position of the 
unknown planet agreeing so closely with Adams', that Airy's 
interest became seriously engaged, and he suggested to 
ChaUis, on the 9th of July, 1846, to make a search for the 
planet. Three weeks later Challis started work ia a leisurely 
way, but was hampered by the want of a good star map. 



John Crouch Adams 127 

The delay was decisive, for, on the 18th of September, 
Leverrier, who had apparently no telescope of sufScient 
power at his command, wrote to Galle, an assistant at 
the Berlin Observatory, and the search was commenced 
on the 23rd. Star charts were at the time being prepared 
under the auspices of the Berlin Academy of Sciences, and 
one of them covered the critical region. The same night a 
star was discovered which was not registered in the map, 
and the following night its change of position proved that 
it was the looked for planet. It was afterwards found that 
Challis, in his sweeps, had observed the planet on the dth of 
August, but not having compared his observations with those 
made subsequently, had failed to recognize it as a moving 
object. Had he done so, the first discovery of Neptune would 
have fallen to the credit of Cambridge. The relative merit? 
of Adams and Leverrier were warmly discussed, but history 
quickly disposes of all such questions of priority. Whether 
of two discoverers one is a few weeks ahead of, or behind, 
the other, seems all important at the time, but very soon 
the adjudgment of merit turns upon the manner in which 
the work was carried out rather than on the calendar. 
Nevertheless, when so much seemed to depend on being the 
first in the field, the disappointment of a young man standing 
on the threshold of his career must have been severe, and 
we cannot absolve either Airy or Challis from blame. 

Adams' subsequent work was unostentatious, but always 
sound and thorough. We may note his investigations on 
the secular acceleration of the moon's mean motion and on 
the orbit of thp swarm of meteors known as the Leonides. 

After 1844 a series of eminent men passed in rapid 
succession through the Mathematical Tripos. William 
Thomson (Lord Kelvin) graduated in 1845, and P. G. Tait 
in 1848, but their period of activity is associated with 
Glasgow and Edinbrn-gh rather than with Cambridge. Edward 
John Routh (1831-1907) was born at Quebec and took his 
degree as senior wrangler in 1854. For many years he held 
a unique position as a teacher in his University, and it may 
be said that the Mathematical Tripos in its best days owed 
much of its success to Bouth. Such, at any rate, is the 
testimony of many distinguished men to whose work this 



128 Britain's Heritage of Science 

country owes its pre-eminent position m the history of applied 
mathematics. Routh's " Dynamics of Rigid Bodies " is much 
more than a text-book, and has become almost a classic ; he 
has also given us valuable contributions to the investigation 
of the " stabUity " of motion. 

Second to Routh in the Tripos Mst of 1854 stands Clerk 
Maxwell, one of the men whose work forms one of the 
great landmarks of science. But, as in the case of Kelvin, 
much should be said in addition to what has already appeared 
in the first chapter. The subject of colour vision attracted 
Clerk Maxwell's attention at an early period, and his experi- 
ments on the subject helped to estabUsh Yoimg's physio- 
logical theory which reduced all colour sensations to three 
primary effects. In dynamics his investigations on Saturn's 
rings are fundamental. The conclusion arrived at is " that 
the only system of rings which can exist is one composed 
of an indefinite number of unconnected particles revolving 
round the planet with different velocities, according to their 
respective distances. These particles may be arranged in a 
series of narrow rings, or they may move through each other 
irregularly. In the first case the destruction of the system 
wUI be very slow, in the second case it will be more rapid, 
but there may be a tendency towards an arrangement in 
narrow rings which may retard the process." 

In pure mathematics, Cambridge in modern times gave us 
Sylvester (1814-1897) and Cayley (1821-1895). Both started 
life by being called to the Bar, but soon returned to their 
favourite subject. Sylvester was second wrangler in the 
Tripos of 1837, but, being a Jew, could not take his degree. 
After four years' teaching at University College, London, as 
Professor of Natiffal Philosophy, he accepted the Chair of 
Mathematics at the University of Virginia in 1841. He 
returned to England in 1845, and dm:ing the next ten years 
was connected with a firm of accountants. In 1855 he 
became Professor of Mathematics at the Royal Military 
Academy, Woolwich, but on the foundation of the Johns 
Hopkins University in 1877 he returned to the United States. 
In 1883 he went to Oxford as successor to Henry Smith. 
Sylvester's work dealt mainly with higher algebra and the 
theory of numbers. He possessed great originaUty; his 



J. J. Sylvester, A. Cayley 129 

work is described as " impetuous, unfinished, but none the 
less vigorous and stimulating."* His efforts at poetry 
may be noted, more especially as he possessed the unique 
power of expressing Heine's songs in English verse. He was 
also devoted to music, and at one time took singing lessons 
from Gounod. 

Cayley's contributions range over a wide field of modern 
mathematics, and he ranks with the greatest mathematicians. 
An idea of the nature of his researches may perhaps be given 
by quoting the verses of Clerk Maxwell, composed to help 
the promotion of a fund collected for a portrait to be painted 
by Lowes Dickinson : — 

O wretched race of men, to space confined ! 
What honovir can ye pay to him, whose mind 
To that which lies beyond hath penetrated ? 
The symbols he hath formed shall sound his praise, 
And lead him on through unimagined ways 
To conquests new, in worlds not yet created. 

First, ye Determinants ! in ordered row 
And massive column ranged, before him go. 
To form a phalanx for his safe protection. 
Ye powers of the M** roots of minus one ! 
Around his head in ceeiseless cycles run. 
As unembodied spirits of direction. 

And you, ye undevelopable scrolls ! 

Above the host wave your emblazoned rolls. 

Ruled for the record of his bright inventions. 

Ye Cubic surfaces ! by threes and nines 

Draw round his camp your seven-and-twenty lines — 

The seal of Solomon in three dimensions. 

March on, symboUc host ! with step sublime, 
Up to the flaming bounds of Space and Time ! 
There pause, untU by Dickenson depicted. 
In two dimensions, we the form may trace 
Of him whose soul, too large for vulgar space. 
In "n" dimensions flourished unrestricted. 

In another branch of science William Hallowes Miller 
(1801-1880) was a worthy colleague of the distinguished men 
who encouraged the study of science at Cambridge. He 



iW. R. R. Ball, "A Short History of Mathematics." 

I 



130 Britain's Heritage of Science 

graduated as fifth wrangler in 1826, and was elected to the 
Professorship of Mineralogy three years later. The mathe- 
matical knowledge he had acquired fitted him peculiarly to 
deal successfully with that branch of his subject to which he 
mainly devoted himself. He developed a new system of 
crystallography, which rapidly gained acceptance owing to 
its simplicity and mathematical symmetry. Miller also took 
a great interest in primary standards, and had a large share 
in the reconstruction of the standards of length and weight, 
in 1839, after their destruction in the fire which broke out in 
the Houses of Parhament. 

We must postpone considering the achievements of a 
yoimger generation of Cambridge men, iacluding John 
Hopkinson, George Darwin, John Poynting and others, 
until the earlier work of other seats of learning has been 
dealt with. 

The Scotch Universities claim our first attention. At 
the beguming of the nineteenth century Thomas Charles 
Hope (1766-1844) enjoyed an unrivalled reputation as a 
teacher. It is recorded that in 1823 he lectured to a class of 
575 students. At the age of twenty-one he was appointed 
Professor of Chemistry at Glasgow, but resigned soon after 
to become Assistant Professor of Medicine. In 1795 he 
settled down at Edinburgh, as joint Professor of Chemistry 
with Joseph Black, becoming sole Professor of the subject at 
the latter 's death in 1799. Hope discovered the important 
fact that within a certain range of temper atiu-e just above 
the freezing point, water does not behave like ordinary 
substances, expanding when the temperature is raised, but 
contracts, reaching a point of maximum density near 4° C, 
This is a matter of considerable importance in the economy 
of nature, for when in the cold of winter the temperature 
of a sheet of water sinks below the critical point, the colder 
water is also the lighter. Hence ice first appears as a thin 
layer on the surface, while the main body can be in stable 
equilibrium below at a temperature higher than the freezing 
point. But before the ice can form at all, the whole mass 
must have cooled down below 4° C. Hope also had an 
important share in the discovery of the element strontium. 
A mineral discovered at Strontian in Argyllshire in 1787 



W. H. MiUer, T. C. Hope, J. LesHe 131 

was at first believed to be a carbonate of barium. Dr. Craw- 
ford threw doubt on this, and suggested that it contained a 
new substance, and this was confirmed and definitely proved 
by Hope. 

John Playf air's successor in the Chair of Mathematics at 
Edinburgh, and subsequently in that of Natural Philosophy, 
was John Leslie (1766-1832). After passing through the 
University as a student of Mathematics and then of Divinity, 
he spent a year as private tutor in Virginia, and subsequently 
in the faniily of Josiah Wedgwood, where he devoted his 
leisure to Natural Science, translating Buffon's " Natural 
History of Birds." Returning to his native place. Largo, 
in Fifeshire, Leslie devoted ten years to scientific research, 
and then settled down at Edinburgh University. He received 
the honour of knighthood shortly before his death. LesHe's 
name is generally connected with his researches on radiation, 
which would have been more fruitful had he been less 
dogmatic in upholding what he conceived to be Newton's 
teaching. He refused to recognize the obvious bearing of 
Herschel's discovery of radiations less refrangible than red 
light, and formed artificial and erroneous theories to 
explain the facts. Nevertheless, his experiments on the 
radiative power of different substances were conducted with 
great skill and are of permanent value. The differential 
thermometer, he employed, maintained for a long time its 
reputation as a delicate and trustworthy instrument. We 
owe to him also a valuable method of determining the specific 
heats of bodies by measuring their rate of coolmg. He was 
the first to freeze water by evaporating it rapidly under the 
action of an air pump, the vacuum being maintained by 
sulphuric acid, wMch rapidly absorbed the aqueous vapour 
formed. He was also the first to give the correct explanation 
of the rise of liquids in capillary tubes. 

David Brewster (1781-1868), a man of forceful character 
and great abihty, enjoyed a considerable reputation among 
his contemporaries, but the weight of his influence was not 
always placed in the right scale. Like Leslie, he adhered 
to a verbal interpretation of Newton's doctrine, and in 
face of the rapidly growing and decisive evidence in favour 
of the undulatory theory of fight, his attitude exceeded all 

1 2 



132 Britain's Heritage of Science 

reasonable limits. Even when Fizeau had made his crucial 
experiment and shown that the velocity of light in ordinary 
refracting bodies was smaller than in air and not greater, as it 
should be according to the corpuscular theory, Brewster 
refused to admit the validity of the evidence.* Nevertheless, 
Brewster was a great experimenter, though an imkind 
Nemesis turned his most important investigations into an 
armoury which suppUed effective weapons to his opponents. 
He studied the laws of polarization by reflexion and refraction 
both for transparent and metallic media; he discovered 
the connexion between the refractive index and polarizing 
angle, and the double refraction due to strain. He also first 
examined crystalline plates imder the polariscope in diverging 
light. He was a prolific writer, and contributed many articles 
to the early editions of the " Encyclopaedia Britannica." He 
is said to have given the first impulse to the foundation of 
the British Association, and was one of its chief supporters 
during the first years of its existence.* 

While Brewster was batthng in vain against the tenets of 
modem physics, a young Scotsman, equally distinguished 
as an experimenter, but superior in judgment and scientific 
insight rapidly rose to eminence. James David Forbes 
(1809-1868) was the fourth son of Sir William Forbes, 
seventh baronet of Pitsligo. He entered the University of 
Edinburgh at the age of sixteen, and soon afterwards con- 
tributed anonymously to the Edinburgh Philosophical Journal. 
At the age of twenty -three, which even then must have been 
a quite exceptionally early age, he was elected a Fellow 
of the Royal Society. In 1833 he was appointed Professor 
of Natural Philosophy at Edinburgh University in succession 
to Sir John Leshe, Sir David Brewster being the com- 
peting candidate, and in 1859 he succeeded Brewster in the 

* The authority for this statement is an oral communication by 
Stokes. 

2 In the " Encyclopaedia Britannica," eleventh edition, it is stated s 
" In an article in the ' Quarterly Review,' he threw out a suggestion 
for ' an association of our nobility, clergy, gentry and philosophers ' 
which was taken up by others, and found speedy realisation in the 
' British Association for the Advancement of Science.' " No such 
article can be found in the " Quarterly Review." 



D. Brewster, J. D. Forbes, P. G. Tait 133 

Principalship of the United College of St. Andrews. His 
demonstration of the polarization of heat by all the various 
means by which ordinary light acquires that property, was 
an experimental achievement of the highest rank, and was a 
powerful liiik in the chain which connects the phenomena of 
radiation. In another series of researches, Forbes appears 
as one of the pioneers in the important but often neglected 
field of Geo-physics. He was the first to conduct systematic 
observations on the temperature of the earth, by inserting 
thermometers reaching down to different depths beneath 
the soil, in such a manner that they could be read off without 
disturbing them. Such experiments allow us to measure the 
thermal conductivity of the soil, and the loss of heat of the 
earth through radiation. Later on he determined the thermal 
conductivity of metals, and discovered that this conduct- 
ivity diminished as the temperature increased. During a 
number of visits to Switzerland he investigated the flow of 
glaciers, and showed that the movement of the ice of glaciers 
followed the laws of viscous bodies. The tremors of the 
earth caused by earthquakes also occupied his attention, 
and he constructed an instrument which was not sufficiently 
sensitive, but must be considered as the foreruimer of the 
modern seismographs. 

Passing on to more recent times, the name of Peter Guthrie 
Tait (1831-1900) has already been mentioned as belonging 
to the Cambridge school of mathematics. The work of his 
life was devoted to the Edinburgh University, where his 
teaching of Natural Philosophy exerted a wholesome, though 
perhaps restraining, influence on the many students who 
passed through his hands. While he will be remembered 
chiefly as a vigorous apostle of the doctrine of energy and a 
forceful propagator of sound dynamical ideas, he made 
substantial contributions to science, and the " Elements of 
Natural Philosophy," written jointly by Thomson and Tait, 
though never completed, is a monument " more permanent 
than bronze." Associated with Tait as a prominent Univer- 
sity teacher, the name of Crum Brown, Professor of Chemistry 
between 1869 and 1908, will be remembered by many 
students who passed through his hands. 

George Chrystal (1851-1911), another Cambridge man 



134 Britain's Heritage of Science 

whom death has too soon removed, occupied the Chair of 
Mathematics at Edinburgh from 1879 to the end of his life. 
He was a brilliant teacher, possessing one of those clear and 
critical minds which care more for the quaUty than the 
quantity of their work. Everything that flowed from his 
pen was of the highest standard. He had the distinction 
of being the first to carry out original investigations in the 
Cavendish Laboratory at Cambridge, where he tested the 
truth of Ohm's law to a degree of accuracy far surpassing 
all previous work. He published a " Treatise on Algebra " 
and several papers of a mathematical character. During 
the last years of his hfe he was occupied with an interesting 
investigation on the oscillations of level (" seiches ") in the 
Scotch lakes, initiated by Forel's observations at the Lake of 
Geneva. 

Glasgow University was naturally dominated during a 
great part of last century by Lord Kelvin's prodigious 
activity. His work on heat has already been described; hia 
contributions to the practical applications of science will be 
referred to later, and as regards his researches on hydro- 
dynamics and other parts of Mathematical Physics, the 
reader must be referred to special treatises. 

During a period of forty years, Philip KeUand (1808- 
1879) taught mathematics at the same University, but his 
published work deals mainly with the undulatory theory of 
light, and is concentrated into a few years following his 
degree course at Cambridge 

The University of Glasgow rendered one of the most 
important services that have ever been conferred both on 
science or on industry when, in 1840, it founded, under the 
auspices of Queen Victoria, the first Professorship of Gvil 
Engineering in the United Kingdom. The second holder of 
the Chair, W. J. Maquom Kankine (1820-1872), stands out 
as a man of striking originahty sind a great teacher. Most 
of his early instruction was received at home. Before he 
entered the University of Edinburgh, at the age of sixteen, 
he had already studied Newton's " Principia." He then 
became engaged in various engineering enterprises, until he 
was appointed Professor of Engineering at Glasgow in 1855. 
Rankine was one of the imaginative men who are not satisfied 



G. Chrystal, W. J. M. Rankine, J. Thomson 135 

with the summary of facts contained in a mathematical 
formula, but require a definite picture of atoms and molecules, 
whose dynamical interactions he tried to trace in their details. 
He invented theories on the causes of elasticity, the constitu- 
tion of gases, and the motion which constitutes heat. But 
while most of these theories had to be abandoned, the use 
which he made of them, and the consequences he drew from 
them, remained, because they were founded on true dynamical 
principles, and the results proved in many cases to be inde- 
pendent of the particular hypothesis from which they happened 
to be derived. Inspired by Joule and Kelvin, the dynamical 
theory of heat occupied much of his attention, and he was 
an early convert to the doctrine of the conservation of 
energy. We owe to him the introduction of the term 
" potential energy," one of the happy inspirations which, 
furnishing an appropriate nomenclature, allowed the funda- 
mental principle of the conservation of energy to be expressed 
in a crisp and. impressive form. Among his more technical 
papers, the most important ones deal with stream Unes, 
the efl&cacy of propellers, and the construction of masonry 
dams. Rankine was an accomplished musician, and occa- 
sionally indulged in poetry. Some of the songs composed 
and set to music by himself were published in a separate 
volimie. 

Rankine's successor at Glasgow University, James Thom- 
son, was a man of almost equal distinction. Like his brother. 
Lord Kelvin, he never went to school. The two brothers 
passed through the University together, and James took 
his M.A. degree at the age of seventeen. He was for a time 
apprenticed to Messrs. Fair bairn at Manchester, but bad 
health obliged him to return home, where he occupied himself 
with the invention of appUances for the better utihsation 
of water power. At various periods of his life he returned 
to the subject, and we owe to him several forms of water- 
wheels, a centrifugal pump, and improvements in turbines. 
At a meeting of the British Association in 1874 he described 
a pump for drawing up water by the power of a jet, which 
led to the construction of such pumps on a large scale. Among 
his purely scientific contributions, that on the lowering of 
the freezing point of water by pressure is the most important. 



136 Britain's Heritage of Science 

From purely theoretical considerations, James Thomson was 
able to predict that the freezing point of water must be 
lowered by pressure. His starting point was that water 
increases in volume on being converted into ice, and the 
reasoning depends on an application of the second law of 
thermodynamics. The fact itself was verified soon afterwards 
by Lord Kelvin, and though the change in the freezing point 
only amounts to three quarters of a degree Centigrade for 
100 atmospheres, it yet plays an important part in the 
behaviour of glaciers, for it explains the plasticity of ice 
discovered by Forbes. The binding together of snow by 
the pressure of the hand is also a consequence of the partial 
melting by pressure, and soUdification when the pressure is 
removed. 

Scotland claims also Sir William Rowan Hamilton (1805- 
1868) as one of its great men, though his life was spent in 
Dublin, where his father — a soUcitor — ^had settled as a 
young man. The genius of men possessing exceptional 
mathematical powers frequently shows itself at a very early 
age, and Hamilton was no exception to this rule. But 
even before he had an opportunity of discovering his own 
powers in that direction, he showed a wonderful facility of 
acquiring foreign languages. At the age of thirteen he 
is reported to have learned Persian, Arabic, Sanskrit, and 
Malay, besides the classical and modem European languages. 
At the age of sixteen he had mastered Newton's " Principia " 
and the " Differential Calculus," and soon after began a 
systematic study of Laplace's " Mecanique Celeste." When 
he was eighteen years old Dr. John Brintley, the Astronomer 
Royal for Ireland, is said to have remarked : " This young 
man, I do not say will be, but is the first mathematician of 
his age." He entered Trinity College, DubUn, but before he 
had taken his degree, his career as a student was cut short 
by his appointment to the Professorship of Astronomy at the 
Dubhn University, and he established himself at the Dunsink 
Observiatory. To all students of Mathematics and Physics, 
" Hamilton's Principle " is known as one of the fundamental 
instruments of dynamics, which may be appUed to nearly aU 
natural phenomena. 

Hamilton's first investigation on " Systems of Rays " 



Sir William Rowan Hamilton 137 

led to an optical discovery that created considerable interest 
at the time because it drew attention to a curious phenomenon 
of refraction in biaxal crystals which had not previously 
been noticed. According to Fresnel's theory, there are in 
such crystals two directions such that a ray passing along 
them will emerge as a conical pencil. It follows that, under 
certain experimental conditions, the two spots of light 
produced by double refraction are spread out and joined so 
as to form a ring. Hamilton's prediction was immediately 
verified by Humphrey Lloyd, and was received as a striking 
confirmation of Fresnel's theory. 

The later years of Haroilton's life were spent in developing 
the new calculus of " Quaternions," to which he attached 
great importance; but, though it has yielded methods of 
great elegance, it has not quite fulfilled its early promise, 
and has few adherents at the present time. Some of its 
conceptions, however, permanently survive in the modem 
vector analysis. 

No single teaching institution has a higher record of 
scientific output during the last century than Trinity College, 
DubUn. Humphrey Lloyd, James McCullagh, John Hewitt 
JeUett, George Salmon, Samuel Haughton, George Francis 
Fitzgerald, Charles Jasper Joly are names that any University 
would have reason to be proud of. Lloyd (1800-1881) has 
already been mentioned in connexion with the verification 
of conical refraction. In later years he devoted much time 
to the study of terrestrial magnetism, and took an active 
part in the magnetic survey of Ireland. James McCullagh 
was an eminent mathematician whose contributions to the 
undulatory theory of light take a conspicuous place in the 
history of that subject. JeUett (1817-1888), like McCullagh, 
was a mathematician, primarily attracted more by physical 
and even chemical problems than by pure theory, fie is, 
perhaps, best known for his improvement of the experimental 
methods for studying the rotation of the plane of polarization, 
observed in certain bodies like sugar. George Salmon (1819- 
1904), for many years Provost of Trinity College, confined 
himself to problems of Pure Mathematics, notably in the 
domain of Geometry. Samuel fiaughton (1821-1897) was 
primarily a geologist, but Hs versatile mind made frequent 



138 Britain's Heritage of Science 

excursions into other subjects, partly suggested to him by 
his interest in the structure of the earth, but partly discon- 
nected entirely from his main work, such as his investiga- 
tions on some problems of sound and light and on the 
velocity of rifle bullets. He claimed amongst other achieve- 
ments to have been the originator of the " long drop " in 
capital punishment. 

Of G. F. Fitzgerald (1851-1901) we cannot speak 
without lamenting the loss inflicted on science by his early 
death, He was one of the select few whose genius extends 
beyond the limits of their own productive work, stimulating 
the thoughts and penetrating the efforts of their contempo- 
raries. One of the earhest students of Maxwell's electro- 
magnetic theory, he realized probably more than anyone 
else its wonderful future. Of the practical applications of 
wireless telegraphy he had no thought — ^his interests lay in 
other directions — but he felt that the final proof of the theory 
must be sought in the experimental confirmation of the 
transmission of electro-dynamic waves through space, and 
saw that the difficulty to be overcome was the power 
necessary to convey the energy from the metallic conductors 
to the medium. His thoughts even ran ahead of Maxwell's 
theory, and he escaped the common error of apostles 
of a new doctrine, who adopt the imavoidable limita- 
tions of a first presentment as an immovable dogma, 
mistaking the passing faults of a child for essential features 
of its character. It was a necessary step in the evolution 
of the Faraday-Maxwell conception of electrical action that 
an electric current should be looked upon as the flow of a 
coherent substance satisfying everywhere the condition of 
incompressibility. But when the relation between electrical 
actions and molecular phenomena were considered, the 
laws of electrolysis suggested that, like matter, electricity 
might have an atomic constitution. Most of the professed 
adherents of Maxwell's doctrine would have none of this 
idea. It seemed to them to violate the dogma of incom- 
pressibility. But Fitzgerald recognized that there was no 
real contradiction, and he became one of the great advocates 
of the electron theory. In this, as in other matters, his 
mind was receptive and appreciative of the efforts of others, 



G. F. Fitzgerald, G. Johnstone Stoney 139 

and his generous disposition made him a willing helper of 
all who were seeking advice. Though his influence on con- 
temporary thought was all the greater in consequence, the 
output of his own work was interfered with. 

Scientific education in Ireland owes much to George 
Johnstone Stoney (1826-1911), the uncle of Fitzgerald, and 
for many years, up to the time of its dissolution in 1882, 
the Secretary of Queen's University. During twenty years 
he acted in the same capacity to the Royal Dublin Society, 
an institution foimded in 1731 for promoting the arts and 
industries of Ireland. As an original investigator Stoney 
was distinguished by a philosophical and balanced mind, 
but his work was suggestive rather than conclusive. He 
showed remarkable foresight when he interpreted the true 
significance of Faraday's laws of electrolysis as indicating 
the atomic nature of the centres of electric action, and he 
gave the name of " electron " to the ultimate constituent of 
electricity. 

When the Queen's Universities were founded in 1845, 
the appointment of first Vice-President at Belfast fell to 
Thomas Andrews (1813-1885), a man of remarkable gifts 
and quite exceptional experimental powers. After a course 
of study of chemistry at Glasgow University and— for a 
short time — under Dumas at Paris, he took the degree of 
Doctor of Medicine at Edinburgh, and then returned to 
practise medicine at Belfast. But the call of science was 
too strong, and he accepted the appointment at Queen's 
CoUege, which was combined with the Professorship of 
Chemistry. Andrews' first paper, published ia 1836, dealt 
with a question which has since acquired considerable 
importance : " On the conducting power of certain flames 
and of heated air for electricity." He next devoted him- 
self to the study of the heat developed in chemical com- 
binations. His work gained in importance as he proceeded, 
and together with Tait he was the first to demonstrate the 
true nature of ozone, proving it was only an aflotropic form 
of oxygen. The research for which he is most renowned 
is that dealing with the liquefaction of gases. When Faraday 
had succeeded in liquefying carbonic acid, chlorine, and other 
vapours by pressure, the question naturally arose whether 



140 Britain's Heritage of Science 

all gases could be converted into liquids. Pressure alone 
seemed ineffective with gases like oxygen, nitrogen, and 
hydrogen, but that might have been due to our inability to 
apply sufficient power. Andrews, investigating the condi- 
tions under which carbonic acid could be liquefied, and taking 
exact measurements of the pressure required at different 
temperatures, discovered that there was a critical temperature, 
such that, if the gas be heated above it, no pressure, however 
great, could convert it into a liquid. Previous experiments 
by Cagniard de la Tour and others had foreshadowed such 
a result, and Faraday came very near to the true solution 
rf the problem, but this does not detract from the value of the 
classical research by which Andrews finally established his 
results. We have seen in our own time how, in the hands 
of Sir James Dewar and of the Dutch physicist, Kammer- 
lingh Onnes, the subject has developed into a new branch of 
science, enabling us to investigate the properties of bodies 
at temperatures so low that molecular motion is almost 
annihilated. 

The reputation of Oxford University as a centre of 
research did not, dxu-ing the last centiu-y, rest on its activity 
in scientific pursuits; but it had among its teachers and 
pupils at any rate one man whom any seat of learning would 
have been proud to claim as its own. Henry John Stephen 
Smith (1826-1889) was both a brilliant mathematician and 
a great man. He was bom in Ireland, but after his father's 
death his mother removed to the Isle of Wight, and it was 
there that Henry Smith received his first education. After 
a short time spent under a private tutor, he went to Rugby, 
where he became head boy under Dr. Tait. In spite of 
iU-health, which for some time interrupted his studies, he 
obtained a Balliol scholarship in 1844, the Ireland scholarship 
fa 1848, and a first-class both in the classical and mathe- 
matical schools in 1849. In the meantime he had spent a 
winter in Paris, where in 1847 he attended the lectures 
of Arago and Milne Edwards. In 1861 he was elected 
to the Savihan Professorship of Mathematics as successor 
to Baden Powell. His researches on the theory of numbers 
and the eUiptic function placed him in the front rank of 
mathematicians; and he showed the same perfect mastery 



Thomas Andrews, Henry Smith 141 

over every subject he touched. The reader is referred to 
the excellent obituary notice from the pen of Dr. J. W. L. 
Glaisher for an account of the extent and value of his 
researches.* With regard to his teaching capacity, those 
who remember him wiQ agree with Dr. Glaisher that : " As 
an expoimder of mathematics before an audience he was 
imsurpassed for clearness, and his singular charm of manner 
gave him a remarkable power for fixing the attention of those 
present." 

His sound judgment was often called upon by others; 
he was a member of the Royal Commission on Scientific 
Instruction (1870), and of the Oxford University Commission 
(1877). During the last sixteen years of his life he acted as 
Chairman of the Meteorological Council and devoted much 
time to the work. Quoting again from Glaisher's obituary 
notice : " It is difficult to give an idea of the position 
Professor Smith held in Oxford and in society generally, 
so briUiant were his attainments and so great and varied 
his personal and social gifts." 

Though Henry Smith was the greatest of the scientific 
men who taught at Oxford, mention should be made of 
Odling, the Professor of Chemistry, and Vernon Harcourt, 
inventor of the pentane lamp as a standard of light. The 
optical work of Baden Powell has already been referred to, 
and it wiU be remembered that Sylvester for a time taught 
at the same University, succeeding to the Professor^p 
vacated by the death of Henry Smith. The revival of 
astronomical research at Oxford owes much to the efforts of 
Charles Pritchard (1808-1893), who, on his appointment to the 
Savilian Professorship, succeeded in persuading the authori- 
ties to erect a new observatory, and to provide an adequate 
equipment. Pritchard, after graduating as fourth wrangler 
at Cambridge, had spent nearly thirty years as Headmaster 
of Qapham Grammar School. After his retirement in 1862, 
he undertook some clerical duties, began to take an active 
interest in astronomy, and filled the office of Hon. Secretary, 
and subsequently of President, of the Royal Astronomical 
Society. When he was appointed to the Chair of Astronomy 

1 " Monthly Notices," Roy. Ast. Soc, Vol. XLIV., 1884. 



142 Britain's Heritage of Science 

at Oxford he was already sixty-three years old, but never- 
theless energetically organized the new Observatory. Pritchard 
was one of the early advocates of the use of photography 
in astronomical research, and showed how it could be applied 
to obtain accurate measurements, and in photometric 
determinations. 



143 



CHAPTER V 

(Physical Science) 

The Heritage of the Nineteenth Century — 
contirmed 

THE foundation of the University of London, followed 
by that of the newer Universities, plays so important 
a part in the history of our subject that a few words must 
be said on the origin of the movement. It arose not so much 
out of a feehng that the number of Universities in the country 
was too small, but in consequence of the reUgious exclusive- 
ness of Oxford and Cambridge, which only admitted adhe- 
rents of the Church of England to University honours. In 
October 1828, therefore, a number of Nonconformists of 
various rehgious denominations combined, and University 
College was opened as the " University of London," with 
power to grant degrees. Unfortunately, some influential 
persons, though favourably inclined to the scheme on educa- 
tional grounds, objected to its entire dissociation from the 
national church, and successfully pressed their objections. 
At the present time the difficulty — such as it is — ^would be 
met by the estabhshment of a rehgious Hall of Residence, 
but no one thought of that expedient, and King's College was 
founded for the purpose of combining secvdar teaching with 
instruction in " the doctrines and duties of Christianity, as 
the same are inculcated by the Church of England and 
Ireland." 

The University of London then became a mere examining 
body, granting degrees, without control of the teaching, while 
University College received a new charter, without the power 
of conferring degrees. Among its first Professors was 
Augustus de Morgan (1806-1871), who was elected to the 



144 Britain's Heritage of Science 

post a year after he had graduated at Cambridge as fourth 
wrangler. De Morgan, the son of a C!olonel in the Indian 
Army, was bom at Madras, but brought to England as a 
child. He combined exceptional mathematical talents, 
inherited from his mother, with great powers of exposition, 
and his lectures attracted many men of distinction. Original* 
in his views and his methods, and possessing great strength 
of character, he followed the dictates of his conscience 
without regard to consequences. Shortly after his appoint- 
ment at IJniversity College, he sent in his resignation 
because a^coUeague, the Ptofessor of Anatomy, had been 
dismissed without assigned cause. He subsequently con- 
sented to^be re-appointed when the regulations had been 
altered so as to prevent a repetition of similar incidents. 
Ultimately he severed his connexion with University College 
because the governing body took too narrow a view of the 
religious neutraUty of the college, and refused to appoint 
Dr. Martineau to one of its Chairs on the ground that he 
was pledged to Unitarianism. But we are here concerned 
with his scientific productions. His work on the Differential 
Calculus is one of those rare books which never seem to 
become antiquated. Its introductory chapter gives us what 
is probably the best exposition of the fundamental principles 
of the Calculus that has yet been given. De Morgan's 
" Budget of Paradoxes," reprinted after his death from 
articles that had appeared in the Athenceum, contains, 
besides an historical account of the vagaries of circle-squaring 
and the trisection of angles, the views of the author on many 
subjects. Like many mathematicians, De Morgan was 
devoted to music ; he was a good player on the flute, and had 
also a talent for drawing caricatures. 

Thomas Graham (1805-1869), the first of the series of 
great chemists who have adorneid the laboratories at Gower 
Street, commenced his studies at Glasgow, and after com- 
pleting them imder Hope and Leshe at Edinburgh, returned 
to the former city, where for a short time he held the Chair 
of Chemistry. When in 1837 he was called to University 
College, London, as Professor of Chemistry, he had already 
established his reputation as an original investigator. His 
chief interest was centred in the study of those physical and 



A. de Morgan, T. Graham, W. H. Wollaston 145 

chemical properties which may be expressed in terms of 
molecular motion. The connexion between the density of 
gases and the velocity of their diffusion was first investi- 
gated by him in 1828, but estabhshed with greater precision 
ten years later. The conclusion arrived at, that the velocity 
of the diffusion is inversely as the square of the density, 
proves, in the hght of subsequent investigation, that the 
molecules of different gases have — at the same temperature 
— the same energy of motion. Graham's investigation 
covered the whole field, including the inter-diffusion of 
different gases, their transpiration through capillary tubes, 
and their effusion into a vacuum, the peculiarities being 
carefully examined in each case. A further series of papers 
dealt with molecular motion in liquids, and estabhshed 
the distinction between the inert " coUoid " and the more 
rapidly diffusing " crystalUne " substances. These have had 
important consequences, and we now know that in the col- 
loidal state we are deahng with molecular aggregates of com- 
paratively large dimensions, the greater individual masses 
accounting for the slowness of the movements. Graham's 
experiments on the passage of liquids through certain 
membranes opened out a fruitful field of research on the 
phenomenon called osmosis, which has recently gained 
great importance. In the domain of pure chemistry, a paper 
" On water as a constituent of salts " led to results of interest, 
more especially through the discovery of the polybasic 
nature of phosphoric acid. 

W. H. Wollaston (1766-1825), a medical man who gave 
up his practice in order to devote himself to the study of 
chemistry, had, in the course of his researches on platinum, 
discovered two new elements, palladium and rhodium. 
Investigating the pecuhar power which palladium has to 
absorb hydrogen, Graham came to the conclusion that 
hydrogen, like a metal, could form aUoys, and connecting 
this with the chemical behaviour of this element in other 
respects, he formed the idea that it was the vapour of a highly 
volatile metal, to which he gave the name of " hydrogenium." 
The expectation then raised was that hydrogen when con- 
densed into the liquid or solid form would present the 
characteristic appearance of a metal, but this was not 

K 



146 Britain's Heritage of Science 

confirmed when Sir James Dewar actually accomplished the 
condensation. 

University College during Graham's time had two 
Professorships of Chemistry, that of " Practical Chemistry " 
being held by George Fownes (1815-1849), who, on his 
death four years after the appointment, was succeeded by 
Alexander M. Williamson (1824-1904). like Graham, he 
was of Scotch descent, but his education was cosmopolitan. 
After attending schools in London, Paris, and Dijon, and 
studying chemistry during five years in Germany, he stayed 
three years in Paris and then returned to England. His 
most important contribution to science is that which eluci- 
dated the chemical process by which ether is formed when 
alcohol is brought into contact with hot sulphuric acid. 
Apart from the intrinsic importance of the subject, the 
research illuminated a number of problems in chemical 
dynamics, and led to a better understanding of " catalytic " 
actions, by which the presence of a body induces chemical 
transformations without itself being apparently involved in 
the change. Organic chemistry owes to Williamson many 
other fruitful ideas. In inorganic chemistry his views on 
the constitution of salt solutions, though essentially different 
from our present ideas of " ionization," yet come sufiBciently 
near to them to have prepared the way for the readier 
acceptance of the theory subsequently developed by Arrhe- 
nius. They held the field for a time, and made the process 
of electrolysis more inteUigible* 

Williamson played an important part in the scientific 
life of London ; his was a well-known figure at the meetings 
of the Chemical Society, and he started the publication, in 
its Journal, of the monthly reports of aU papers of a chemical 
nature published elsewhere. He acted as Foreign Secretary 
to the Royal Society during sixteen years, and also assisted 
the efforts made at various times to convert the University 
of London into a teaching body. In 1855, when Graham 
resigned the Chair of Chemistry in University College on 
becoming Master of the Mint, the two Professorships were 
united, and WiUiamson continued to hold the combined 
Chairs until 1886. 

One of Williamson's colleagues at University College, 



A. Williamson, C. Wheatstone 147 

whose brilliant career was cut short by premature death, may 
here be referred to. William Kingdon Chfford (1845-1878), 
second wrangler in 1867, held the Chair of Apphed Mathe- 
matics during eight years, but was stricken with tuberculosis, 
and died in Madeira. He has left many important con- 
tributions both to applied and pure mathematics. 

Among the Professors at King's College appointed at 
or shortly after its foundation were two men of world-wide 
reputation, John Frederick DanieU (1790-1845) and Charles 
Wheatstone (1802-1876). Daniell constructed the first 
electric cell which was free from the irregularities caused by 
polarization, so that constant currents could be obtained. 
He was mainly interested in meteorology, and rendered 
valuable services in insisting on accurate and systematic 
observations of the various phenomena on which the physics 
of the atmosphere depends. His most successfid instrument 
was that by means of which the humidity of the air is 
determined from the temperature at which dew begins to 
deposit. 

Wheatstone began his career as a maker of musical 
instruments, and during the ten years 1823 to 1833 
published a number of papers on sound. In 1831 he was 
appointed to the Chair of Natural Philosophy at King's 
College, and three years later conducted some experiments 
which were devised to measure the velocity with which 
electrical effects are transmitted along a wire, and the 
duration of an electric spark. In these experiments a rotating 
mirror was first used to measure small intervals of time. 
He was also one of the first to recognize the importance of 
Ohm's law, and to insist on accurate standards and good 
methods of measuring electromotive force, resistance and 
current. The Bakerian Lecture for 1843 contains a descrip- 
tion of the methods employed by him, including the arrange- 
ment of wires now fanuliar to every student of science 
under the name of the " Wheatstone bridge." As he points 
out himseK, the arrangement was first used by Samuel 
Hunter Christy (1784^1865), Professor of Mathematics at the 
Military Academy, Woolwich. 

Wheatstone was the first to show how a nimiber of clocks 
can simultaneously be regulated by the electric current. 

E 2 



148 Britain's Heritage of Science 

In Optics he invented the stereoscope and conducted valuable 
experiments on the physiology of vision. At the British 
Association in 1871 he exhibited an instrument by means 
of which the solar time could be determined by utilizing 
the polarization of the blue light of the sky. This method, 
as he explained, has several advantages over the ordinary 
sundial. Wheatstone's spectroscopic observations and his 
contributions to telegraphy wiU be referred to in another 
place (see pp. 154, 188). 

The &st sight that meets the eye of a visitor entering 
the Town HaU of Manchester is the statue of Dalton on 
his left, and that of Joule on his right. These two great men 
found a congenial home in the town which numbered amongst 
its citizens others who, long before it became the seat of a 
University, upheld the dignity and usefulness of its Literary 
and Philosophical Society. Such were Thomas Henry (1734- 
1816), the author of valuable investigations in Chemistry; 
his son, William Henry (1774^1836), who studied the Jaws 
of absorption of gases by Uquids, and William Sturgeon 
(1783-1850), the inventor of the electro-magnet, who started 
life as a shoemaker, entered the army as artillerist, became 
teacher of physics at the military academy of the East India 
Company, and spent the last twelve years of his lite in 
scientific investigations at Manchester. The ambition of that 
town to become the seat of a University dates back to the 
seventeenth century, and though renewed at various times 
long remained imsatisfied. By the will of John Owens, who 
died in 1850, a college was founded, which after a period 
of difficulty rapidly rose to eminence. It numbered among 
its first professors Edward Frankland (1825-1899), whose 
researches were fundamental in the development of modern 
chemistry, and who, next to Davy and Dalton, must pro- 
bably be considered to be the greatest chemist this country 
has ever produced. Having discovered a number of organic 
substances containing metallic atoms as essential consti- 
tuents, he investigated the general laws of the formation of 
chemical compounds, and originated the conception that 
the atom of an elementary substance can only combine with 
a certain limited number of atoms of other elements. This 
led to the discovery of " valency " as the groundwork of 



E. Frankland, H. E. Roscoe 149 

chemical structure. Prankland only stayed six years in 
Manchester; on returning to London, he becaniie' lecturer 
in Chemistry at St. Bartholomew's Hospital, and subse- 
quently Professor of Chemistry at the Royal Institution 
and the School of Mines. The latter years of his life were 
spent in work connected with the examination and purifica- 
tion of the water supply. He was made a K.C.B. in 1897, 
two years before his death. 

When Frankland, in 1857, resigned his position at 
Manchester, the choice of a successor lay between Robert 
Angus Smith (1817-1884) and Henry Enfield Roscoe (1833- 
1915). The former was personally known in Manchester, 
where he resided, and had already done some meritorious 
work on the impurities found in the air and water of towns, 
a subject to which he devoted the greater part of his life. 
Roscoe was only twenty-four years old, but the promise of 
future success was already foreshadowed in his academic 
career, and fortunately for Owens CoUege, whose fortunes 
were then at a low ebb, he was elected to the Professorship. 
At the age of fifteen, Roscoe had entered University College, 
London, where he came under the influence of Thomas 
Graham and Alexander WUHamson. After taking his B.A. 
degree at the University of London, he spent four years at 
Heidelberg under Bunsen. His activity in Manchester is 
marked by the foundation of a school of chemistry through 
which many men of high distinction have passed, and by the 
happy relations which he estabUshed between the industrial 
community and the academic life which was centred in the 
coUege. The prosperity of that institution was soon secured 
by lus strong and genial personality, and when other men 
eminent both in science and Hterature had joined its staff, 
its rise to the dignity of an University became only a question 
of time. Roscoe was one of the first to point out the need 
of technical education in this country, but he did not interpret 
that term in a narrow sense. With him it meant a sound 
scientific instruction directed towards industrial ends, but 
not excluding a wider culture. He served on the Royal 
Commission on Technical Education appointed in 1881, and 
at the conclusion of its labours received the honour of 
knighthood. His earnest desire to spread the knowledge and 



150 Britain's Heritage of Science 

appreciation of science led him to organize a series of 
popular penny lectures which attracted large audiences, 
who had the privilege of listening to such men as Huxley, 
Huggins, Staiiey Jevons, Clifford, and others scarcely less 
eminent. 

Roscoe's first scientific investigations dealt with the 
chemical action of Ught. The subject was suggested by 
Bunsen, and partly carried out in conjunction with him. 
Apart from the purely scientific interest attaching to the 
effect of hght in inducing hydrogen and chlorine to com- 
bine, the research was conducted with the practical object 
of obtaining a means of measuring the actinic value of day- 
light under different atmospheric conditions. His principal 
contribution to pxire chemistry consists in his investigation 
of the element vanadium, which estabHshed its true position 
as a trivalent element of the phosphorus group, and showed 
that the substance BerzeUus had considered to be the metal 
was reaUy its nitride. 

Among Roscoe's colleagues at Manchester who have 
helped to estabhsh the reputation of Owens College as an 
important centre of scientific research, two men stand out 
prominently : BaKour Stewart (1828-1887) and Osborne 
Reynolds (1842-1912). It was probably fortunate that a 
mind of such striking originahty as that of Reynolds was 
never submitted to the discipline of school, though it is 
difficult to believe that even the severest group-education 
could have shaped it into a common mould. His father was 
a clergyman who had passed through the Mathematical 
Tripos as thirteenth wrangler. The son was brought up at 
home, and entered the workshop of an engineer at the age 
of nineteen. He soon found that a knowledge of mathematics 
was essential to work out the problems that presented them- 
selves to him, and he decided to go to Cambridge, where he 
graduated as seventh wrangler in 1867. He then returned 
to the office of a civQ engineer in London, but within a year 
offered himself as a candidate for the newly-founded Pro- 
fessorship of Engineering at Owens College. He remained 
connected with that institution from 1868 to 1905, when 
he retired owing to failing health. In his methods of 
instruction Reynolds was a follower of Rankine ; his lectures 



Henry E. Roscoe, Osborne Rejoiolds "^ 151 

were sometimes difficult to follow, but capable and earnest 
students always derived great benefit from them, and he 
brought up a number of distinguished men who look back 
with gratitude and affection to the inspiration they received 
from his instruction. 

His researches nearly aU possessed fundamental import- 
ance. To quote Horace Lamb^ : — 

" His work on turbine pumps is now recognized as 
having laid the foxmdation of the great modem develop- 
ment in those appliances, whilst his early investigations 
on the laws governing the condensation of steam on metal 
surfaces, and on the communication of heat between a 
metal surface and a fluid in contact with it, stand in a 
sinular relation to recent improvements in boiler and 
condenser designs." 
He laid the scientific foundation of the theory of lubrica- 
tion, and his papers on hydrodynamics have become classical 
both on account of their theoretical importance and practical 
applications. Like Rankine, his mind was not satisfied with 
finding useful applications of his scientific knowledge, but 
he took an active interest in aU questions which touched the 
foundation of elemental forces and atomic structure. He 
was the first to give the correct explanation of Crookes' 
radiometer, and in his later years he tried to formulate a 
structure of matter and aether which should account for 
gravitation as weU as for electrical and other forces. What- 
ever may be the ultimate fate of these speculations, they 
were worked out in a systematic and original manner, and 
incidentally contain results of permanent value. 

Three years after Roscoe's appointment in Manchester, 
Robert Bellamy Clifton was elected to the Chair of Natural 
Philosophy, but resigned in 1865 to take the Chair of Experi- 
mental Physics at Oxford. His successor, William Jack, 
subsequently Professor of Mathematics at Glasgow, was 
interested mainly in the theoretical side of the subject, and 
resigned in 1870. It fell to his successor, Balfour Stewart, 
to organize the department as an effective home of research, 

• Obituary Notice of Osborne Reynolds, " Proo. Roy. Soc," 
Vol. LXXXVIII., p. xvi (1913). 



152 Britain's Heritage of Science 

and to take the first step in that direction by fitting up a 
laboratory, and encouraging students to submit themselves 
to a training in accurate scientific measurements. 

Balfour Stewart was brought up for a commercial career, 
and went out to Australia as a man of business. But his 
scientific ambitions, inspired as a student at Edinbiu-gh 
University, soon made lum return to that University, where 
he became assistant to David Forbes. Between 1859 and 
1870 Stewart acted as Director of the Kew Observatory, 
and devoted his energies mainly to investigations on 
Terrestrial Magnetism. Chiefiy interested in the connexion 
between Terrestrial Magnetism and cosmical phenomena 
such as the periodicity of sunspots, he did not, in the opinion 
of some iafluential members of the Gassiot Committee of the 
Royal Society, which controlled the work of the Observatory, 
pay sufficient attention to the routine of observations. Some 
friction resulted, and the vacancy in the Professorship at 
Manchester gave him the welcome opportunity of changing 
over to a more congenial position. Unfortunately, a few 
weeks after he had delivered his first lecture, he met with 
a serious injury in one of the most terrible railway accidents 
that have taken place in this country. After an interval of 
a year, he recovered sufficiently to take up his work again, 
and though at the age of forty-three his accident had left 
him with the appearance of an old man, his mind remained 
fre-h and yoimg. During the time in which BaKour Stewart 
preside^ over the Physical Department at Manchester, he 
counted among his pupils several men who subsequently 
rose to eminence — among them John Poynting and Sir 
Joseph Thomson. His own work at that time was chiefly 
statistical, dealing with the periodicities of meteorological 
and cosmical phenomena. 

BaKom- Stewart's first and most important work on the 
radiation of heat is much interwoven with the early history 
of Spectrum Analysis, and affords the opportunity of giving 
a brief account of that subject, especially as both in what 
may be called the period of incubation and in its later 
developments this country took a most important share. 

As early as 1752, one Thomas Melville, about whose 
history nothing seems to be known, experimented with 



Balfour Stewart 153 

coloured flames, and noted the yellow colour imparted to a 
flame by soda. His observations were published in a book 
bearing the title " Physical and Literary Essays." Exactly 
fifty years later, William Hyde WoUaston, who has already 
been mentioned as the discoverer of palladium and rhodium, 
examined the blue light at the base of a candle flame through 
a prism, and described the bright bands which appear in its 
spectrum. Young repeated the experiments, and committed 
what is perhaps the one great error of his scientific work, 
when he ascribed the colours seen to effects of diffraction. 
In these and most of the subsequent observations, the light 
to be examined is passed through a sUt, and traversing a 
prism is separated into its components. The eye focussing 
on the slit, with or without lenses, sees it flluminated by 
the various elementary vibrations which the original light 
may emit. These vibrations show themselves, therefore, as 
luminous lines, which are images of the sUt. The whole 
appearance is called a spectrum, of which it is customary to 
speak as consisting of " fines," a misleading term, because it 
impUes that the " line " is a characteristic of the substance, 
while it is only an incident of the instrument by which the 
spectrum is examined. The expression, having been univer- 
sally adopted, may be retained with the understanding that 
it is the position of the line which indicates the nature of the 
fight vibration, and therefore characterizes the luminous body. 
Sir John Herschel investigated coloured flames in 1823, and 
made two significant observations : " The colours thus 
communicated by the different gases to flame afford, in 
many cases, a ready and neat way of detecting extremely 
minute quantities of them," and " no doubt these tints 
arise from the molecules of the colouring matter reduced to 
vapour, and held in a state of violent motion." Fox Talbot 
in 1826 looked at the red fights occasionaUy used to Uluminate 
the stage in theatres. He correctly ascribed a red fine to 
nitre, but befieved the yeUow sodium fine to be due to sulphur 
or water. Eight years later Talbot returned to the subject, 
and clearly pointed out that " optical analysis can distingmsh 
the minutest portions of these substances (fithium and 
strontium) from each other with as much certainty, if not 
more, than any other known method." He also offered the 



154 Britain's Heritage of Science 

remark that " heat throws the molecules of lime into such 
a state of such rapid vibration that they become capable of 
influencing the surrounding setherial medium and producing 
in it the undulations of light." 

In 1845 Wilham Allen Miller (1817-1870), Professor of 
Chemistry at King's CoUege, London, published some observa- 
tions on flame spectra, which were not very accurate, and 
his plates left it doubtful whether the bright bands or the 
dark intervals between them ought to be looked upon as 
the essential feature. This seems to have been one of the 
stumbling-blocks of early investigators when comparing the 
continuous spectra of ordinary flames with the discontinuous 
spectra of incandescent substances. 

An important contribution to the subject was made by 
Wiffiam Swan (1818-1894), who, between 1859 and 1880, held 
the Professorship of Natural Philosophy at St. Andrew's. 
Swan was the &st to introduce (1847) the collimator into 
spectroscopic observations, and in 1857 he examined and 
accurately mapped the spectrum of hydrocarbon flames. He 
discussed the origin of the ubiquitous yellow line and came 
to the correct conclusion that it is due to the presence of 
minute quantities of sodium. 

The spectra of the electric sparks passing between poles 
of different metals were first examined by Sir Charles 
Wheatstone, and described in a communication to the British 
Association in 1835. Unfortunately an abstract only was 
published, but even the short account given ought to have 
drawn attention to the extreme importance of the matter. 
The spectrum of mercury was observed and accurately de- 
scribed, and proved to be identical, whether the spark be taken 
in air, oxygen gas, the vacuum obtained by an air pump, or 
the Torricellian vacuum. From these observations the correct 
inference was drawn that the spectrum is the result of the 
volatilization and ignition (not combustion) of the ponderable 
matter contained in the spark. The spectra of zinc, cadmium, 
bismuth and lead were also obtained by taking the sparks 
from poles of the melted metals. The paper was published 
in full in the Chemical News in 1861, and was then found 
to contain this significant passage : " the number, position, 
and colour of these lines differ in each of the metals 



' Spectrum Analysis 155 

employed. These differences are so obvious that any one 
metal may be instantly distinguished from the others by the 
appearance of its spark, and we have here a mode of dis- 
criminating metalhc bodies more ready even than chemical 
examination, and which may be hereafter employed for 
useful purposes." Wheatstone himself fully realized the im- 
portance of the subject, as is shown by his remark that " the 
peculiar effects produced by electrical action on different 
metals depend, no doubt, on molecular structure, and con- 
tain hence a new optical means of examining the internal 
mechanism of matter." 

So much for what was known of the emission spectra of 
luminous bodies before the date of Ejrchhoff and Bunsen's 
work; let us now turn to the phenomena of absorption. 
WoUaston was the jSrst who mentioned the dark lines which 
traverse the spectrum of solar light, but he seems to have 
looked upon them mainly as Unes separating the different 
colours, though he points out two of them that were not. 
During the researches which Fraunhofer, the famous 
optical instrument maker of Munich, conducted with a view 
to improving the methods of determining the refractive 
indices of different kinds of glass, sunlight was examined, 
and found to contain many fine dark liaes in its spectrum ; 
these are now called " Eraunhofer Unes." A large number 
of them were carefully mapped, and the most prominent 
served him as standards for his measurements; but he 
examined also the light of a luminous flame and that of 
some of the stars and planets. The first experiments date 
back to 1814; nine years later he returned to the subject 
and measured the wave-lengths of the principal lines by 
means of his gratings. He pointed out that by using a blow- 
pipe he could obtain a flame which emits a close doublet 
of yellow light coincident with the solar lines D. Fraunhofer 
examined the spectrum of the " electric Ught," and noticed 
bright lines; he used the spark of an electric machine as 
source of illumination and . apparently took what we now 
know to be the spectrum of air as characteristic of the electric 
source of illumination. Of greater importance are his 
observations on the spectra of the stars and planets, which 
allowed him to recognize that the planets, like the moon, 



156 Britain's Heritage of Science 

have a spectrum identical with that of the sun, but that 
some of the stars, like Sirius, show only a few very strong 
lines. Sir David Brewster in 1834 compared the solar 
spectrum observed by him with Fraunhofer's drawings, and 
noticing additional lines which change with the position 
of the sun, ascribed them correctly to effects produced in 
our own atmosphere. He had already in 1832 referred with 
approval to Herschel's suggestion that the dark Praunhofer 
lines were produced by absorption in the atmosphere of the 
celestial bodies. An interesting observation which ought 
to have attracted attention at the time, but, like many 
others, was only saved from oblivion when the method of 
spectrum analysis had been permanently established, was 
made in France by Foucaidt. In the spectrum of the voltaic 
arc, he noticed the presence of what we now know to be the 
sodium lines, and identified them with Fraunhofer's hne D. 
He found further that on passing the sunlight through the 
arc, these lines became darker, and further discovered that 
the Hnes under certain conditions may be reversed in the 
arc itself. 

In aU these observations many important facts were 
recorded, but the ideas on radiation were vague at the time 
and no effort was made to connect it with absorption. Stokes; 
in his own mind, seems to have been clear on the matter, and 
in private conversation with Lord Kelvin " explained the 
connexion of the dark and bright line (of sodium) by the 
analogy of a set of piano strings tuned to the same note, 
which if struck would give out that note, and also would be 
ready to sound it, to take it up, in fact, if it were sounded 
in air. This would imply absorption of the aerial vibrations, 
as otherwise there would be creation of energy. "^ At this 
stage historically, but in ignorance of much of what has 
been described, BaKour Stewart undertook a comprehensive 
investigation of the subject of radiation and absorption. 
Adopting Preevost's views that equiUbrium of temperature 
means a balance between absorption and radiation, he 

* The quotation is from a letter addressed by Stokes to Sir J. 
Lubbock (afterwards Lord Avebury) ; see G. G. Stokes, " Memoir and 
Correspondence," by Sir J. Larmor, Vol. II., p. 75. 



Spectrum Analysis 157 

applied for the first time the ideas of the principle of con- 
servation of energy to the subject, by considering an enclosure 
impermeable to heat radiations and at a uniform temperature. 
This led him to the conclusion that the internal radiation 
must everywhere be the same and only depend on temperatiu'e. 
The rest follows easily : absorption and radiation must bear 
a constant relation to each other in such an enclosure. He 
illustrated the results by many striking experiments. 

Much has been written about the relative merits of 
several observers who anticipated, in various directions, the 
great work of KirchhofE and Bunsen. But the history of 
science should not aim at assigning marks of merit to 
different investigators. What interests us is how a great 
generalization gradually matures, how it begins frequently 
with the observation of isolated facts, generally overlooked 
at first because their importance is not recognized. It may 
be that some link between the disconnected observations is 
wantiag; it may be that experiment has gone ahead of 
theory or theory may be waiting to be confirmed by ex- 
periment. When the time is ripe, someone with a better 
appreciation of the significance of the facts or a deeper 
insight into their mutual connexion touches the matter 
with a master hand, and presents it in a form which carries 
conviction. Though he may have worked in ignorance of 
what has been done before, he has worked in an atmosphere 
in which previous ideas and tendencies of thought have 
been absorbed, and in general he owes something to the 
pioneers who have gone before him. In some cases the 
succession of events which lead to a discovery may be 
compared to what would happen if a delicate balance carried 
on one side the arguments in favour of a new idea, and 
on the other hand the objections which are brought against 
it. At first the side that bears the objections is much the 
heaviest; as time goes on the difference becomes less 
marked, sometimes by the removal of objections, but more 
frequently by increased evidence in favour of the new idea. 
Ultimately when sufficient weight is put on that side, a point 
is reached when the balance tips over. This is the psycho- 
logical moment when the discovery is accepted, and he 
who adds the last grain is technically the discoverer. Those 



158 Britain's Heritage of Science 

who started loading the scale are then forgotten, unless 
someone with a taste for historical continuity happens to 
come across the record of their work. Especially when some 
national feeling is involved, discussions on priority may then 
be raised, and continued intermiaably, because there wiU 
always be a conflict between those who attach importance 
to the intrinsic merit of an iavestigation and those who 
look only on the actual influence it has had on scientific 
thought. In the strict administration of historical justice, 
oral expressions of opinion like that of Stokes are not 
admitted as evidence; he himself disclaimed any share in 
the discovery of spectrum analysis. But as a testimony 
that the analogy of sotind can be applied to the radiations 
of light and heat, it was a distinct step, and a well ascer- 
tained and clear pronouncement such as that which passed 
between Stokes and Kelvin deserves to be placed on record, 
without detracting from the merit of others. 

In order to appreciate correctly Balfour Stewart's work 
the following consideration is important. If the foundation 
of spectrum analysis be made to depend on such laws of 
radiation as can be derived from the consideration of what 
happens inside an enclosure of uniform temperature, his 
priority is well established. He imdoubtedly was the first 
to reaUze the significance of studying the equilibrium of 
heat inside such enclosures, and led the way in a direction 
of research which has proved to be of capital importance 
in the theory of radiation. But as regards their practical 
bearing on spectrum analysis, too much weight has been 
given to theoretical considerations founded on thermal 
equilibrium. In aU spectroscopic observations, the loss or 
gain of heat is the essential factor. The step which takes 
us from the uniform enclosure to the radiation and absorp- 
tion when there is no equihbrium is not so simple as has 
generally been assumed, and it is safer to accept spectrum 
analysis as being mainly foimded on experiment together 
with such plausible theoretical analogies between sound and 
light as were pointed out by Stokes. In this respect, the 
work of Herschel, Talbot, Wheatstone, and Swan is of 
greater importance in the history of spectrum analysis than 
the theoretical work of Balfour Stewart, who, however, also 



Spectrum Analysis 159 

illustrated his views by striking experiments on the relation 
between radiation and absorption. Incidentally, he corrected 
a wrong idea based on erroneous experiments by a Dr. Bache 
in the United States, who claimed to have shown that, while 
the surface colour greatly affected the absorption, it had no 
effect on the radiation of a body. 

Bearing in mind what has been said, it is not surprising 
. that, notwithstanding aU that had been done before their time, 
Kirchhoff's and Bunsen's work created a deep impression. 
The combination of a physicist and chemist was almost 
necessary to bring out the full significance of the observations ; 
and the accumulated experimental evidence furnished by 
them was complete in itself, and left no doubt as to the 
value of the new method of investigation, which formed not 
only a most delicate test of the chemical nature of substances 
which we handle ia the laboratory, but would also be applied 
to the analysis of any Ught-emitting body however great 
its distance might be. It is well known how the spectroscope 
at once revealed a number of new metals, among them being 
thaUium, which was first identified by Sir William Crookes. 

The further development of the subject disclosed a far 
greater potentiality of the spectroscopic attack than was 
dreamed of by its originators. At first it was considered 
that the spectrum was an atomic property ; in other words, 
that each atom preserved its spectrum when combined 
with other elements, so long at any rate as the substance 
remained in the gaseous state. There was not much oppo- 
sition to the next step, by which compounds were shown 
to have independent spectra, but when it appeared that 
even one and the same element coidd give a number of 
different spectra under different conditions, fresh fields of 
investigation were opened out. In the further elucidation 
of the subject, this country has helped as much as, and 
perhaps more than, any other. It will be sufficient to mention 
the work of Lockyer, liveing and Dewar, and the investi- 
gations of Lord Rayleigh on the Optics of the Spectroscope, 
which, by pointing out the limits of their power for given 
optical appliances, have shown the direction in which an 
extension of these limits is possible. In the investigation of 
the absorption spectra of organic compounds a prominent 



160 Britain's Heritage of Science 

place must be given to Sir William Abney and Walter Noel 
Hartley (1846-1913). 

The success of Manchester in establishing great research 
schools encouraged other cities to introduce university 
teaching into great manufacturing centres. But Man- 
chester had a start of over twenty years, and its record is 
necessarily greater for that reason alone. Nevertheless, some 
of the younger universities soon attracted men of eminence, 
and of these, two stand out prominently, Arthur Riicker 
(1848-1915) and John Poynting (1852-1914), the first Pro- 
fessors of Physics at Leeds and Birmingham respectively. 

Although Riicker was only connected with Leeds Univer- 
sity during eleven years, much of his scientific work origi- 
nated during that time ; and notably his researches on thin 
films, carried on jointly with Professor Reinold. Prom the 
colours of soap bubbles or of similar films their thickness 
may be calculated, but as they thin out, the colour effects 
disappear, and the film is black by reflected light. This 
means that its thickness is less than the wave-length of 
light and can not be measured by the simple optical method. 
In order to investigate the molecular phenomena which 
ultimately lead to the breaking of the film, Reinold and 
Riicker undertook the extremely difficult task of measuring 
the thicknesses of films when they are too thin for the 
colour test to be applied. Their first method consisted in 
determining the electric resistance of the films, the second 
in increasing the number of films, until their aggregate 
thickness became as great as the wave-length of light. 
Both methods led to the same results, and some dehcate 
points in the subject of Molecular Physics were cleared up 
by the investigation. 

It is not possible here to enter more fully into other 
important researches of Riicker, which included the two great 
magnetic surveys of the United Kingdom, carried out in 
association with his friend. Sir Edward Thorpe. Riicker 
was an organizer and administrator of the highest ability, 
and left the mark of his activity on all the institutions with 
which he was connected. In 1886 he was appointed Pro- 
fessor of Physics at the Normal CoUege of Science in London, 
and in 1896 elected Secretary of the Royal Society; both 




James Prescott Joule 



>m a photograph by Lady Roscoe 



Arthur Riicker, John Poynting 161 

positions he gave up when he accepted the Principalship 
of London University in 1901. 

John Pojrnting was the first Professor of Physios at 
Mason College (now the University), Birmingham. He was 
brought up in Manchester, and obtained his first instruction 
in Physics from Balfour Stewart. In due course he went 
to Cambridge, graduated as third wrangler, and was elected 
to a Fellowship at Trinity College in 1878. For a time he 
worked in the Cavendish Laboratory, and in 1880 went to 
Birmingham, where he remained until his death. Poynting 
belonged to the rare type of men who are more critical of their 
own work than of that produced by others. The number 
of his papers is therefore comparatively small, but each 
of them marks some definite and generally important step. 
He broke new ground when he investigated the path along 
which energy may be considered to be propagated in an 
electromagnetic field, and the vector, by means of which he 
represented the magnitude and direction of the transmitted 
energy, has proved to be a fruitful conception. His in- 
vestigations on the " pressure of light " have also led to 
many interesting consequences, which are likely to gain 
considerable importance in questions connected with the 
constitution of the sun and stars. Li another series of 
experiments he attacked the dif&cult problem of gravitational 
attraction and showed how an apparently unpromising 
method may be skilfully appUed so as to give valuable 
results. 

Turning to the share of non-academic workers in the 
recent progress of science, it is not surprising that it tends to 
become less prominent, various reasons combining to render 
it more and more difficult for the so-called amateurs to hold 
their own. It is now generally only in those subjects which, 
in consequence of great specialization, have become almost 
entirely self-contained, that a man who is unable to devote 
his whole time to study can hope to produce original work 
of high quality. The most effectual of the contributing 
causes has, however, probably been the growth of the 
imiversities and their emancipation from the narrow ideas 
of the Middle Ages. There is a university within the reach 
of nearly everyone and men are drawn into the academic 



162 Britain's Heritage of Science 

profession who previously would have had to pursue their 
science in solitude. But when all is said, much valuable 
work is still being done, and was to an even greater extent 
being done last century, by men who can only spare their 
leisure to the pursuit of science. The work of the most 
prominent of them may be briefly summarized. 

Francis Baily (1774^1844), the third son of a banker at 
Newbury, may serve as an example of a man who, without 
exceptional abilities, exerted a great and beneficial influence 
on the science of his time by perseverance, organizing power, 
and an unselfish devotion to its interests. After a long and 
adventurous journey to America, on which he spent three 
years of his early life, he engaged in commercial pursuits. 
While he was earning a considerable fortune, he found time 
to write an important work on the " Doctrine of Interest 
and Annuities analytically investigated and expounded," and 
a similar book on the " Doctrine of Life Annuities and 
Assurances." Through an acquaintance with the chemist 
Priestley, he had developed a taste for experimental enquiry, 
and later he became interested in astronomy, to which 
subject he devoted himself entirely after his retirement from 
business in 1825. He was one of the founders of the Royal 
Astronomical Society, and acted as its secretary during the 
first three years of its existence. He did not himself observe, 
but his critical and historical work proved to be of great 
value. The publication of serviceable star catalogues, first 
for the Astronomical Society and then for the British 
Association, is mainly due to his zeal. His experimental 
work included the investigation of the effects of air resistance 
on the time of swing of a pendulum, and a repetition of the 
MicheU-Cavendish experiment on gravitational attraction. 

John Peter Gassiot (1797-1877), originally a wine 
merchant, was the first who systematically studied the 
luminosity observed when an electric discharge passes 
through gases at low pressure. The glass tubes with metal 
electrodes which he had constructed for the purpose soon 
came into common use under the name of Geissler tubes. 
Gassiot was not only a successfid experimenter, but also 
a benefactor who used his wealth in encouraging and pro- 
moting science. His gift of £10,000 to the Royal Society, 



Baily, Gassiot, Grove, Schunck 163 

to be devoted to the carrying out of magnetical and 
meteorological observations with self-recording instruments, 
has proved to be of special value. 

Lord Justice Grove (1811-1896), while actively engaged 
in practice at . the Bar, found time to invent the electric 
battery which goes by his name, and was, before the days 
of electrodynamos, the most convenient appliance for the 
production of large currents. Many of his electrical and 
chemical experiments were of value, and his book on the 
correlation of physical forces gives proof of a wide outlook 
in science. 

William Spottiswoode (1825-1883), the head of the 
well-known printing firm, was at the same time an eminent 
mathematician, and his scientific attainments were sufELciently 
distinguished to justify his election to the Presidency of the 
Royal Society, an office which he held at the time of his 
death. 

Edward Schunck was the typical man of independent 
means who imselfishly devotes his whole time and wealth 
to the pmrsuit of knowledge. He was born in Manchester 
in 1820, his father having founded an important business 
in that city. He studied chemistry in Germany, and shortly 
after his return to England, settled down to research work 
mainly connected with the colouring matter derived from 
plants. Alizarin, the colouring substance of madder, 
attracted his first attention, and his investigations prepared 
the way for its subsequent artificial production. 

He also made important additions to our knowledge 
of the chemical composition of indigo and chlorophyll. 
His laboratory, containing a finely ornamented room used 
as a library, was beautifully fitted out for piu-poses of 
research. Its contents were left to Owens College by his 
will, and ultimately the laboratory was taken down and 
re-erected as an aimexe to the Chemical Laboratories of the 
Manchester University, where it is now entirely devoted 
to research work. 

Henry Chfton Sorby (1826-1909) was another of the 
busy men of so-called leisure who devote their lives to the 
pursuit of science. His instrument was the microscope, and 
he began investigating the minute structures of minerals 

L 2 



164 Britain's Heritage of Science 

with a view to elucidating problems of geology. By studying 
sections of rocks he laid the foundation of modem petro- 
graphy and, devisiag methods for the examination of metal 
surfaces, he originated a new era in the science of metal- 
lurgy. He became interested in metals because he wanted 
to examine the structure of meteorites. Not being able to 
cut sections sufficiently thin to be transparent, he applied 
acid to the poUshed sm^aces, which then showed patterns 
indicating the manner in which the crystallized parts of 
the body hang together. The same method appUed to ordi- 
nary metals, and more especially to steel, has led to results 
of far-reaching importance in practical engineering. 

It is difficult to assign a correct position in the history 
of science to a man whose work is entirely neglected and 
buried, to be brought to Hght only when its novelty has 
disappeared. Such a man has had no influence in shaping 
scientific thought, yet his merits are as great as if his 
discoveries had been acknowledged at the time. John 
Waterston (1811-1884) probably furnishes the most con- 
spicuous example of a long-continued neglect of work 
which would have marked a great advance in knowledge, 
had it been recognized at the time of its maturity. A paper 
which contains results of the highest value in the theory 
of gases was presented to the Royal Society, but only a 
short and insufficient abstract was printed. In the words 
of Lord Rayleigh : " the omission to pubHsh it at the time 
was a misfortune which probably retarded the development 
of the subject by fifteen years." In the complete investi- 
gation discovered in the archives of the Royal Society by 
Lord Rayleigh and published in the Philosophical Trans- 
actions fifty years after it had been communicated, it is 
shown how the kinetic theory can explain in a simple 
manner the physical behaviour of perfect gases. It is proved 
that the kinetic energy of a molecule is a measure of its 
temperature, whatever the nature of the gas, and it contains 
the discovery — ^though imperfectly demonstrated — that " in 
mixed media the mean square molecular velocity is inversely 
proportional to the specific weight of the molecules." The 
ratio of the specific heats of constant pressure and volume 
is calculated for molecules exhibiting internal motions, only 



H. C. Sorby, J. Waterston, G. Airy 165 

a slip of calculation preventiag the correct result being 
obtained. 

Of Waterston's life very little is known. He was bom 
in Edinburgh in 1811, and showed great aptitude for mathe- 
matics while at the High School of that town. He then 
became Naval Instructor in the service of the East India 
Company. After his retirement he lived in various towns 
of Scotland, and finally at Edinburgh. One evening in the 
spring of 1884, he left his lodgings for his evening walk, and 
was never seen again. It is supposed that he went to Leith 
to look at a new breakwater which was being constructed 
there, and that he accidentally feU into the water and was 
swept away by the tide ; but this rests on surmise only. 

Among professional ISritish astronomers during the last 
century four men stand out prominently : Sir George Airy, 
Sir John Herschel, John Crouch Adams, and Sir David GiU. 
When Airy was called to take charge, first of the Observatory 
of Cambridge and later of the Royal Observatory at Greenwich, 
he had already made his name famous by his mathematical 
and optical investigations, which have been mentioned in 
connexion with his career at Cambridge. In astronomy he 
proved himself to be equally eminent as an administrator and 
investigator. He introduced revolutionary reforms in the 
practice of observatories by insisting on a rapid reduction 
and publication of all observations. After his appointment as 
Astronomer Royal, he set to work at once to reduce the series 
of observations of planets which had accumulated dming 
eighty years without any use having been made of them. 
This was followed up by a simQar reduction of 8,000 lunar 
observations. He was equally energetic in adding to the 
instrumental equipment. When Greenwich was first founded, 
the longitude determination at sea depended to a great extent 
on measuring the distance between stars and the moon. Hence 
accurate tables of the position of the moon were essential, and 
the preparation of these tables has always been considered 
to be the chief care of Greenwich. The observations were made 
with a transit telescope which could only be used when the 
moon was passing the meridian, until Airy in 1843 persuaded 
the Board' of Visitors to take steps for constructing a new 
instrument which would enable him to observe the moon 



166 Britain's Heritage of Science 

in any position. In 1847 this instrument was at work, and 
other important additions to the equipment were made as 
occasion arose. Airy also originated the automatic system 
by which the Greenwich time signals are transmitted each 
day throughout the country. Among his theoretical investi- 
gations in pure astronomy, one of the most important resulted 
in the discovery of a new inequality ia the motions of Venus 
and the earth due to their mutual attraction, and this led to 
an improvement in the solar tables. 

Sir John Herschel (1792-1871) was the only son of the 
great astronomer whose work was considered in a previous 
chapter. After graduating as senior wrangler in 1813, he 
joined a number of friends in their efforts to reform the 
teaching of mathematics at Cambridge. The astronomical 
problems which had occupied the later years of Sir William's 
life then attracted the son, who, after his father's death, 
completed the work on double stars, and pubhshed an 
important memoir on their orbits. 

In 1833 he embarked for the Cape, in order to extend to 
the southern hemisphere the general survey of the heavens 
which his father had carried out in the northern sky. It 
was to a great extent a spirit of loyalty to his father which 
kept him to the subject of astronomy, for his own bent of 
mind drew him more towards physics and chemistry. He 
discovered the solvent power of hyposulphite of soda on 
otherwise insoluble salts of silver, a property which later 
proved so useful in photography. As a writer he was clear 
and effective. His article on " Light " in the Encyclopaedia 
Metropohtana forms an excellent record of what was known 
at the time, and his " OutUnes of Astronomy " may still 
serve as a useful book of reference. 

The work of Adams has already been described in a 
previous chapter (p. 125). 

David Gill (1843-1914), after a period of study at the 
University of Aberdeen, entered his father's business, 
which consisted in the making of clocks. But his interest 
in science, stimulated by the influence of Clerk Maxwell, 
who for a time held a Professorship at MarischaU College, 
soon asserted itself, and he established a physical and chemical 
laboratory in his father's house. Turning his attention to 



Sir John Herschel, Sir David Gill 167 

astronomy, he became acquainted with, and ultimately 
engaged as private assistant by, Lord Lindsay, an enthusiastic 
amateur astronomer, then about to erect a private observatory 
at Dunecht. He accompanied Lord Lindsay in his expedition 
to Mauritius, undertaken for the purpose of observing the 
transit of Venus in 1874. This rare event, as previously 
explained in connexion with its first observation by J. 
Horrocks, serves to determine the distance between the 
earth and the sun, but alternative methods promising more 
accurate results had already been suggested. The relative 
distances of the different planets from the sun being known 
by their times of revolution, we may substitute the measure- 
ment of the distance of any one planet which is in a suitable 
position for the direct determination of the solar distance. 
Certain planets occasionally approach the earth sufficiently 
near to apply this method. As the earth turns round its 
axis, the observer's point of view is sufficiently altered 
between a morning and evening observation to show a 
measurable shift in the position of a planet as compared 
with that of the surrounding stars. While at Mauritius 
Gill found that one of the minor planets, Juno, happened 
to be suitably placed to test the method, and he obtained 
most encouraging results. A good opportunity of pursuing 
the investigation presented itself in 1877, when the situ- 
ation of the planet Mars was exceptionally favourable for 
the purpose. Gill left the service of Lord Lindsay and 
established himself on the island of Ascension. Though the 
results obtained were good. Gill confirmed his conclusion 
that the minor planets were better suited for accurate 
measurements. He, returned to the subject ten years later, 
and a combination of observations of three minor planets, 
made partly by GiU at the Cape and partly by other astronomers 
whom he had interested in the work, has given us the best 
determination of the solar parallax we possess. 

In 1879 GiU was appointed Astronomer Royal at the 
Cape, and he directed the work of the observatory with 
distinguished success until 1906. Unbounded perseverance, 
unrivalled skiU in observing, and an exceptional mechanical 
knowledge which served him in the design of instruments 
were combined in his person to a rare degree. A favourite 



168 Britain's Heritage of Science 

instrument of his, the potentiaUties of which for accurate 
measurements he was the first to recognize, was the helio- 
meter, the essential pari, of which consists of an object-glass 
divided into two halves, which could be made to sUde along 
the dividing Une. If the image of a star formed by one half 
be brought into coincidence with the image of a neigh- 
bouring star formed by the other half, the angular distance 
between the stars is indicated by a suitable measuring 
arrangement. With a telescope of this construction GUI 
instituted a series of observations for the determination of 
steUar parallaxes, which raised the subject up to a higher 
plane. Another important research carried out by GiU with 
the assistance of others was the determination of the mass of 
Jupiter by observations of his sateUites. 

GiU was not only an eminent investigator; large ideas 
originated in his mind, and were pushed forward with 
unlimited energy. He originated the great international 
enterprise for cataloguing and charting the whole sky by 
photography. He afio successfuUy advocated an accurate 
trigonometrical survey of the whole of South Africa, and 
formed a scheme for the measurement of an arc of meridian 
which should run along the thirtieth meridian east of Green- 
wich through the whole length of Africa to the mouth of the 
NUe, and connect by triangulation through the Levant with 
the Roumanian and Russian arcs. He secured the assistance 
of Mr. CecU Rhodes, and the work, though frequently inter- 
rupted, partly through the poUtical troubles in Africa and 
partly through want of money, was proceeding slowly when 
stopped by the outbreak of the present war. 

GUI's scientific activity was continued after his return to 
England, and during the last years of his hfe he endeavoured 
to stimulate the manufacture of optical glass in this country. 
His efforts deserved a better response than they received 
and though they were primarily directed towards securing 
the large blocks required for telescopes, the whole question 
of glass manufacture, which has siace become of such pressing 
importance, was involved. By his death British science lost 
an intensive driving force. 

While professional astronomers carried on their exceUent 
researches the great improvements in the construction of 



D. Gill, Lord Rosse, W. de la Rue 169 

reflecting telescopes during the nineteenth century was 
entirely the work of amateurs. William Parsons, third Earl 
of Rosse (1800-1867), took the first step in 1827. As William 
Herschel had never published his methods, there was no 
estabUshed procedure to shape concave mirrors. Lord Rosse 
had to start from the beginning, and to invent the machine 
for griading and poUshing the speculum metal to the required 
shape. After a number of attempts he was eminently 
successful, and in 1845 completed a mirror six feet in dia- 
meter with a focal length of nearly sixty feet. The structure 
necessary to hold and move such a gigantic telescope pre- 
sented considerable engineering diificulties, but these were 
overcome, with the result that Lord Rosse was soon able 
to announce a number of important discoveries. Many 
luminosities that had been classed as nebulae were found to 
consist of closely packed star clusters. Others remained 
unresolved, and among them the interesting family of spiral 
nebulae was recorded. Further improvements in the methods 
of shaping and polishing mirrors are due to WiUiam LasseU 
(1799-1880) and James Nasmyth (1808-1890). The former, 
a Lancashire brewer, had aheady, in 1820, constructed a 
small telescope with his own hands, being too poor to 
purchase one. Later he improved on Lord Rosse's methods, 
and with a larger instrument discovered two new sateUites 
of Uranus, a satellite of Neptune, and an eighth sateUite of 
Satmrn. James Nasmyth, chiefly known as the inventor of 
the steam hammer, was also much interested in astronomy. 
The sharpness of his vision and quality of his instrument 
is shown by his observations of the granular structure of the 
solar surface which no one had noticed before him. 

Warren de la Rue (1815-1889), a member of the weU- 
known printing form, was a generous supporter of many 
scientiflc enterprises. In early Ufe he had made further 
improvements in the process of shaping concave mirrors, 
and successfully constructed a reflecting telescope. He was 
the first to appreciate the opportunities offered to astronomers 
by the invention of photography, and in 1860 fitted out an 
expedition to observe a total eclipse in Spain. The slow 
acting plates of the time were not sufficiently sensitive to 
show the solar corona which appears during an eclipse, but 



170 Britain's Heritage of Science 

the red flames shooting out from the edge of the sun were 
clearly shown in his photographs. This was an important 
achievement, as there had been some doubt whether these 
so-called protuberances were real phenomena belonging to 
the sun. De la Rue also introduced the daily photographic 
record of the sun, originally carried out at Kew, and now 
at Greenwich and other places in the British Empire. 

So far aU concave mirrors used in reflecting telescopes 
had been made of speculum metal, an alloy of tin and 
copper, which tarnishes in the course of time. A process of 
poHshing almost as troublesome as the original shaping of 
the surface had then to be undertaken. It was, therefore, 
a substantial step in advance when Andrew Ainslie Common 
(1841-1903), an engineer by profession, introduced mirrors 
made of glass sUvered at the surface, for the silvering could 
be renewed without interfering with the shape of the surface. 
Common acquired great skiU in grinding the surfaces of glass ; 
one of his mirrors, three feet in diameter, is now at work at 
the Lick Observatory, and a five-foot mirror forms part of 
the equipment of Harvard. The photograph which Common 
obtained of the nebulae in Orion f&st showed the complicated 
structure of that wonderful object, and was described by 
Sir William Abney as " epoch-making in astronomical 
photography." 

With the introduction of dry plates a new era began for 
Astronomy, and one of the most persevering and successful 
workers in the field was Isaac Roberts (1829-1904), whose 
beautiful collection of photographs of celestial objects, and 
notably of nebulae, form a permanent record which will in 
the future prove of the greatest value. Roberts was a builder 
by profession. In 1890, the year after his retirement from 
business, he moved from Liverpool to Crowborough, in 
Sussex, where the clear air allowed him to produce his 
finest work. 

Until the middle of last century the astronomer was 
confined in his observations to the use of the telescope ; he 
could determine the position of stars,investigate their displace- 
ments in the sky, and examine the structure of star clusters 
and nebulae. Beyond this he was unable to go, iintil the 
invention of the spectroscope gave him the power to extend 



A. Common, I. Roberts, J. N. Lockyer 171 

his range in an unexpected direction. The history of science 
can furnish no more striking instance of an almost unlimited 
field of research suddenly opened out by a simple application 
of a few laboratory experiments. The most successful of the 
workers who utilized the great opportunities provided by 
the new method of Spectrum Analysis were Sir Norman 
Lockyer and Sir William Huggins. Lockyer's first great 
achievement was the observation in broad daylight of the 
prominences which up to that time could only be seen during 
total solar eclipses. He proved that they mainly consisted 
of glowing hydrogen. The merit of the discovery is in no way 
diminished by its having almost simultaneously been made 
by the French astronomer Janssen. Continuing his researches, 
Lockyer established that the upper layer of the sim's atmo- 
sphere, which reveals itself at the edge of the solar disc in 
the form of a bright line spectrum, consisted mainly of the 
lighter metals such as calcium and barium with hydrogen. 
A bright yellow line was also universally present which 
could not be identified as belonging to any Imown element. 
Lockyer conjectured that it was due to an unknown gas 
which he called helium; this gas, as will appear, was subse- 
quently discovered on the earth, and is found to play a most 
important part in modern physics. The identification of 
terrestrial elements in the atmosphere of the sun or stars 
ultimately proved not such a simple matter as was at first 
supposed, because the relative intensities of the lines emitted 
by a luminous body, and sometimes the whole spectrum, 
changed when the conditions were altered. Lockyer turned 
this complication to good account by trying to gauge not only 
the substance itself, but its temperature and physical con- 
dition in the celestial bodies. He was thus led to his meteoric 
hypothesis of the formation and subsequent evolution of the 
solar systems, into which it is not possible to enter here. 

The most memorable discovery with which the name 
of Huggins is connected is the measurement of the velocity 
of stellar bodies in the line of sight. A body moving directly 
towards, or away from, us keeps the same apparent position 
in the sky, but just as the whistle of a locomotive alters its 
pitch when, after approaching us, it passes and then moves 
away, so is the wave of light received by us affected according 



172 Britain's Heritage of Science 

as a star is receding or approaching. Huggins showed how 
this principle can be applied to stellar motion, and thus 
laid the foundation of a branch of astronomy which is 
continuously growing in importance. Previously Huggins 
had, in conjunction with W. A. MiUer, carefuUy mapped 
some star spectra; he also had investigated the spectra of 
nebulae, and found that some of them consisted of glowing 
gases. In subsequent researches he foimd the luminosity of 
comets' tails to be mainly due to carbon compounds. By 
patient and painstaking work Huggins further developed 
the methods of obtaining photographic records of stellar 
spectra, and the important results obtained formed the 
starting point for the many distinguished astronomers who 
have since taken up the work. 

Before leaving the subject of Astronomy reference must 
be made to a notable advance in the construction of re- 
fracting telescopes. During the middle of last century, the 
largest lens made had a diameter of sixteen inches. At the 
exhibition of 1862, Messrs. Chance, of Birmingham, exhibited 
glass discs of crown and flint twenty-six inches in diameter, 
and Mr. Robert Stirling Newall (1812-1889), of Gateshead, 
induced Messrs. Cook, of York, to construct from these 
discs an achromatic lens of twenty-five inches. This was 
successfully accomplished, and the telescope is now doing 
excellent work in the Astrophysical Observatory of Cam- 
bridge. Larger instruments have been made since, but the 
step from sixteen to twenty-five inches is one which deserves 
.a permanent record in the history of the subject. 

Modem astronomy, like other branches of science, depends 
so much on photography that a brief account of the history 
of this interesting and fascinating art may be here introduced. 

The darkening action of light on silver chloride was first 
discovered and investigated by the Swedish chemist Scheele, 
W. H. Wollaston had observed that the colour of the yellow 
gum guaiacum was altered by the action of Ught, and Sir 
Humphry Davy had noted a similar effect in the case 
of moist oxide of lead. The first actual photographic print 
was obtained in 1802 by Thomas Wedgwood (1771-1805), 
who threw shadows on paper moistened with a solution of 
silver nitrate, and obtained prints giving the outlines of the 



W. Huggins, R. S. NewaU, W. Abney 173 

shadows, but his picture was evanescent, as he was unable 
to fix it. Rudimentary as this procedure was, it contained 
the germ of the future contact printing. Next. came the 
work of Daguerre and Niepce in iVance, resulting in the 
well-known daguerreotype. In 1840 Sir John Herschel 
introduced hyposulphite of soda as a fixing agent, and in 
1841 Fox Talbot greatly improved Wedgwood's original 
process, using sUver iodide on paper sensitized by " gallo- 
nitrate of silver." The introduction of collodion as a con- 
venient vehicle holding the silver salts was first suggested 
by G. le Gray, and put to practical use by Frederick Scott 
Archer and P. W. IVy. In the subsequent development of 
the dry plate important progress was due to R. Manners 
Gordon, W. B. Bolton, and B. J. Sayce. The gelatine 
emulsion process was used by R. L. Maddox in 1871 and by 
J. King in 1873, but first introduced in a workable form by 
R. Kennett in 1874. The merit of giving rapidity of action 
to dry plates belongs to C. Bennett (1878). Further progress 
was made by Colonel Stuart Wortley and by W. B. Bolton 
in 1879.1 

The modem theory of photography almost entirely 
depends on the investigations of Sir William Abney. He 
introduced scientific methods in the measurement of the 
sensitiveness of plates, iavestigated the effects of tempera- 
ture, and showed the important influence which the size of the 
sensitive particles had on their behaviour in different parts 
of the spectrum. He was thus able to obtain a silver bromide 
sensitive to the red fight, and was the first to photograph 
the infra-red rays of the solar spectrum. 

A few words should be said about the history of colour 
photography. Lord Rayleigh pointed out in 1887 how 
particles of silver might be deposited in layers half a wave- 
length apart. A "film containing such layers would have the 
power of reflecting copiously that special kind of light which 
had served to form it. This process was actually employed 
to reproduce natural colour effects by M. Lippmann, of 
Paris ; but it suffers from the disadvantage that the correct 

1 For a fuller account of the history of photographic processes, 
see the article on *' Photography," by Sir Wm. Abney, in the 
" Encyclopaedia Britannioa," Xlth ed. 



174 Britain's Heritage of Science 

colours are given only when the light falls on the film at 
the particular angle Tinder which it was originally produced. 
The process of Joly, introduced in 1897, is free from this 
defect ; the principle on which it is based is the same as that 
subsequently employed with great success by "A. Lumiere 
et Fils," of Lyons, whose method of working, however, 
differs materially from that of Joly. 

Photography is looked upon by some as a pleasant 
pastime, by others as an art. The chemical and physical 
properties of matter which allow the rays of light to form 
a latent picture, to be subsequently developed, fixed and 
printed, are in themselves a fascinating study, and there is 
no limit to the utility of photography as an aid in scientific 
ravestigations. Here, as elsewhere, science exerts its greatest 
charm when it forms a connecting Unk between the ordinary 
interests of our daily life and the abstract questions which 
engage the attention of academic philosophers. Thus, 
nearly all problems of geophysics have both an intensely 
practical and a deeply theoretical side. The commonplace 
necessity of defining the boundaries of land leads to the 
demand for accurate maps, and this, again, opens out 
investigations on the figure and size of the earth. One 
question suggests another, until abstruse mathematical pro- 
blems acquire a special interest owing to their connexion 
with the history of the world's formation. Similarly, fore- 
casts of weather that shall be helpful to the farmer demand 
a study of aero-dynamics, involving mathematical treatment, 
combined with experimental work of high precision, and 
the ordinary phenomenon of the tides takes us inevitably to 
problems demanding the genius of such men as Kelvin and 
George Darwin. 

The ordinary making of maps is a task belonging to the 
Government services, and it is to ofi&cers in the Army and 
the officials in charge of the various surveys at home, or in 
the colonies, that we are mainly indebted for our knowledge 
of geodesy. Such work, important as it is, often receives 
insufficient acknowledgment because, being co-operative, the 
share of each man cannot always be clearly defined. But a 
few examples may be given. 

Captain Henry Kater (1777-1835), the son of a sugar 



Henry Kater, Edward Sabine 175 

baker, entered the army and joined his regiment in Madras. 
He had a taste for mathematics, and became assistant to 
WUHam Lambton, who was conducting a survey of the 
Malabar and Coromandel coast. After his return to England 
he took part in the British survey, and turned his attention 
to the improvement of accurate geodetic and astronomical 
measurements. Kater's pendulum is an ingenious arrange- 
ment for eliminating the errors due to an irregular distribu- 
tion of mass in the ordinary pendulum when it is used for 
gravity measurements. The determination of the difference 
in longitude between Paris and Greenwich gave him further 
opportunities for exercising his ingenuity in devising new 
methods of observation. In 1827 Kater was elected 
Treasurer of the Royal Society, and held that position 
during three years. 

General Sir Edward Sabine (1788-1883) organized world- 
wide observations on gravity, and the elements of terrestrial 
magnetism. The importance of his work calls for a short 
account of his Ufe. He was educated at the Woolwich 
Military Academy, and received a commission in the Royal 
Artillery at the age of fifteen. After seeing much active 
service, he returned to England in 1816. Shortly afterwards 
he was appointed astronomer to the Arctic Expedition which 
sailed under Ross in search of the North-West Passage, and 
after his return home took part in a second Arctic Expedition 
imder Edward Parry. In 1823 he undertook an extensive 
journey to measure the value of the gravitational force at 
different points of the earth's surface. In 1830 he was recalled 
to active service, the condition of Ireland necessitating an 
increased military estabhshment. He stayed in Ireland 
until 1837, using part of his time to organize the first 
magnetic survey of the British Isles. During his subsequent 
life, which was entirely devoted to science, he was indefa- 
tigable in getting magnetic observatories estabUshed in 
many coimtries, and promoting further pendulum observa- 
tions, more especially in India, where ever since they have 
formed an important part of the Government Survey's 
work. Sabine was Treasurer of the Royal Society from 
1850 to 1861, and during the following ten years he filled 
the position of President. 



176 Britain's Heritage of Science 

Most distinguished among the Directors of the British 
Survey was Alexander Ross Clarke (1828-1914), who has 
given us the most accurate determiaation so far obtained of 
the size and figure of the earth. He was concerned in several 
of the principal measurements of meridional arcs, and in 
1860 was entrusted with the comparison of the national 
standards of different countries, a most delicate piece of 
work, which required the building of a separate room at the 
Ordnance Sm-vey Office. 

Our account of the progress of Meteorology must be short 
and incomplete, but we may recall William Charles Wells 
(1757-1817), the London doctor who first gave the correct 
explanation of the formation of dew, Luke Howard (1772- 
1864), who classified the clouds, and John Apjohn (1796 
-1880), who showed how to calculate the humidity of the 
air from observations with the wet and dry bulb thermo- 
meter. We must also remember the wonderful balloon ascents 
of James Glaisher (1809-1903), who, reaching a height of 
over 30,000 feet, obtained the first observation of the 
upper air. A kite was used in meteorological work as early 
as 1749 by Alexander Wilson, of Glasgow, and its modern 
application dates from the experiments made in England 
in 1882 by E. D. Archibald. One of the most enthusiastic 
workers in Meteorology, Alexander Buchan (1829-1907), 
studied at Edinburgh and was engaged for some time as a 
school teacher, but in 1860 he was appointed secretary of 
the Scottish Meteorological Society, and was henceforward 
able to devote himself entirely to his favourite study. His 
work on atmospheric circulation possesses considerable im- 
portance, and he was also one of the chief promoters of the 
observatory which, during a number of years, stood on the 
summit of Ben Nevis. 

A discovery of great value to meteorology was made by 
John Aitken, of Falkirk, who in 1883 observed that water 
vapour always requires some nucleus to condense upon. 
The most common nuclei are the dust particles which are 
always present in the atmosphere, and every drop of rain 
or particle of fog contains some solid contamination at its 
centre. The best protection against fog is, therefore, the 
purification of the atmosphere. The condensation of water 



A. Ross Clark, A. Buchan, Q. H. Darwin 177 

on solid matter has been utilized by Aitken in constructing a 
little instrument which allows us to count the number of 
particles of solid matter contained in the air. He found 
that even the cleanest air will contain about 20 particles per 
cubic centimetre, while in London or Paris the number 
generally rises to well over 100,000. 

The work of Sir George Howard Darwin (1845-1912) 
may serve to illustrate how a geophysical problem which ia 
its main features is easily understood, is found to involve 
the whole history of the Universe as soon as we pass from 
the general explanation to the more detailed study required 
to give accurate numerical results. That the tides of the 
ocean are due to the gravitational attraction of the sun and 
moon was known already to Newton, and it can be shpwn 
without difficulty that the explanation agrees in a general 
way with observations. But, if we wish to formulate a 
mathematical theory, we must begin by simplifying the 
problem, and assume the earth to be a rigid soMd sphere 
covered entirely by a layer of water having the same depth 
everywhere. The statement of this problem is simple enough, 
but its solution^ecomes already complicated when the com- 
bined attractions of the sun and moon are considered. Yet 
we are not anywhere near the real tides on the real earth. 
The ocean does not cover the whole globe, it is not of 
uniform depth, and the soM core of the earth is not 
absolutely rigid, but appreciably yields to the disturbing 
forces. When we try to take account of these comphcations, 
even in tl^e roughest manner, we see that there must be a 
fiictional effect tending to retard the rotation of the earth; 
this involves a re-acting force on the moon, and it can be 
shown that this must slowly drive it further away. Hence 
we conclude that there must have been a time when the 
moon was nearer, and the earth rotated more rapidly, and, 
looking still further back, this brings us to the time when 
the moon may have formed part of the earth and ultimately 
separated from it. Can we form an approximate estimate of 
that time ? Such are the questions which occupied George 
Darwin during a considerable part of his life. The whole 
problem does not, of course, affect the earth only, but 
concerns every celestial body. It opens out the whole 

M 



178 Britain's Heritage of Science 

question of the stability of fluid gravitating and rotating 
bodies. George Darwin's own contributions to the subject 
have materially helped to establish a scientific basis for the 
treatment of a subject, fundamental in cosmogony, which 
has fascinated the most powerful mathematical brains in 
recent times. For his other important researches the reader 
must be referred to his collected works, but some reference 
may be made to the time which he ungrudgingly devoted 
to assist all efforts which aimed at an organized co-ordi- 
nation of scientific work, and co-operation between different 
scientific bodies. During thirty years he was a member of 
the Meteorological Council, and of the Treasury Committee 
which superseded it. He actively supported international 
scientific undertakings, and more especially the International 
Geodetic Association, on which he represented England for 
many years; in 1909 he was elected its President. 

Several instances have already been given of the reci- 
procal relation between utilitarian objects and abstract 
scientific truth, and a further example is furnished by the 
work of John Milne (1850-1913). After studying Geology 
and Mineralogy at King's College and the Boyal College of 
Mines, he gained some practical experience in the mines 
of Cornwall and Lancashire, extending his knowledge by 
a course of study at Freiberg, and a visit to the mining 
districts of Germany. In 1875 he was appointed Professor 
of Geology and Mining at the Imperial College in Tokio, 
where he was at once confronted with important practical 
problems arising out of the frequent occurrence of earth- 
quakes in Japan. In order to construct buildings and bridges 
so that they should resist the movements of the foundations 
on which they are built, it is necessary to study, in the 
first instance the nature of these movements. Milne was 
attracted by both the practical and theoretical side of the 
investigation, but as no suitable instruments were available 
for the purpose, he supplied the want, and for a number of 
years his seismographs became the standard instruments. 
Important questions immediately suggested themselves, and 
Milne became the founder of a new science. After his return 
to England, he organized, with the assistance of the British 
Association, in different parts of the Empire and other 



Sir George Darwin, John Milne 179 

countries, a large number of suitable stations at which earth 
tremors were accurately observed. The records of the obser- 
vations, interpreted partly by Milne himself and partly by 
other seismologists, proved to be of the highest interest. 
The waves propagated through the earth from the centre 
of a large disturbance are found to be noticeable with 
dehcate instruments all over the world. We now know that 
the general movement spreads out from the centre of a 
disturbance in three distinct waves, each propagated with its 
own peculiar velocity. The first is a longitudinal wave, which 
passes through the earth Kke a sound wave does through air. 
The second is a transverse wave, arriving somewhat later; 
both these waves reach us by transmission across the body 
of the earth. A third set of waves, which in the records 
appears as an oscillation of larger ampUtude and longer 
period than the rest, spreads over the surface of the earth 
with a velocity of about 3-5 kilometres per second. The 
interval between the arrival of these three tjrpes of waves 
serves to indicate the distance of the centre of the dis- 
turbance, and Prince GaUtzin has shown how the direction 
of the first impulse gives us the direction in which that 
centre lies. Hence it is now possible to locate a distant 
earthquake by means of observations taken at any one 
place where it is stiU able to affect the dehcate instruments 
which, by a self-registering arrangement, are always ready 
to record the waves. 

The scientific interest of the subject Ues in the information 
it is Ukely to yield on the internal constitution of the earth ; 
for some of the waves that reach us, if the centre of dis- 
turbance be far away, have passed through deep regions, 
approaching in some cases the actual centre of the earth. 
The manner in which their path bends roimd owing to 
changes in the elastic properties of the earth at different 
depths is indicated by the direction and magnitude of the 
oscillation which the wave impresses on our instruments. 
It is difficult to interpret completely the observed effect, 
but the investigation has already advanced sufficiently to 
show that important results may still be expected from that 
study of earth tremors which Milne initiated. 

The survey of the history of British physical science has 

M 2 



180 Britain's Heritage of Science 

now been brought to the period when men of the present time 
were called upon to receive the heritage, and do their best 
to hand it on to their successors. The problems of to-day 
may not be seen in their right perspective; yet the last 
thirty years have been so exceptionally fertile in new dis- 
coveries that we may anticipate with confidence the judg- 
ment of posterity on those great advances which have 
revealed an entirely new class of phenomena, and enabled 
us to form views on the structure of matter which, at any 
rate, may be considered to be an advance on our previous 
knowledge. A very brief summary, however, must suffice. 

In the seventies of last century it was generally thought 
that our power to discover new experimental facts was 
practically exhausted. Students were led to beUeve that 
the main facts were aU known, that the chance of any 
new discovery being made by experiment was infinitely 
small, and that, therefore, the work of the experimentalist 
was confined to devising some means of deciding between 
rival theories, or by improved methods of measurement 
finding some small residual effect, which might add a more 
or less important detail to an accepted theory. Though it 
was acknowledged that some future Newton might discover 
some relation between gravitation and electrical or other 
physical phenomena, there was a general consensus of opinion 
that none but a mathematician of "the highest order could 
hope to attain any success in that direction. Some open- 
minded men like Maxwell, Stokes, and BaKour Stewart, 
would, no doubt, have expressed themselves more cautiously, 
but there is no doubt that ambitious students all over 
the world were warned off untrodden fields of research, 
as if they contained nothing but forbidden, though perhaps, 
tempting, fruit. When Crookes, in the year 1874, constructed 
his radiometer, it looked for a short time as if he had 
definitely disposed of such timid and discouraging opinions; 
but, on the contrary, he seemed only to have confirmed 
them. For the apparent repulsion of light observed in the 
radiometer was found to be due to the residual gas in his 
exhausted vessels, and could be explained by the then 
accepted kinetic theory. He had, no doubt, by greatly 
improved methods, discovered a new effect, but this had 



Lord Rayleigh, Sir William Ramsay 181 

only led to perfecting an established theory in an important 
detail. 

The new era begins with Lord Rayleigh 's discovery of 
argon. The research which led to it was originally under- 
taken with a view to testing the hypothesis of William Prout 
(1786-1850), a London doctor, according to whom the atomic 
weights of all chemical elements are exact multiples of that 
of hydrogen. In the course of an accurate determination of 
the density of nitrogen it was found that, when the gas is 
prepared from air by removing aU other known constituents, 
it has a density half per cent, greater than when it is obtained 
directly from ammonia. Rayleigh then drew the conclu- 
sion that the discrepancy was due to some unknown body, 
probably a new gas in the atmosphere heavier than nitro- 
gen. While the research was advancing successfully, WiUiam 
Ramsay "joined the investigation, and the final results were 
published by Rayleigh in conjunction with him. 

Sir Wilham Ramsay (1852-1916) then entered into that 
period of his activity in which discoveries rapidly succeeded 
each other. Sir Henry Miers drew his attention to a certain 
mineral which was known to give out an inert gas when 
dissolved in an acid. This gas was supposed to be nitrogen, 
but Mers thought it might turn out to be argon. Ramsay 
extracted the gas, examined it with a spectroscope, and to 
his surprise found the bright yellow line which appears so 
brilliantly in the light emitted all round the edge of the 
sun and in its protuberances. The gas proved, therefore, 
to be identical with the one spectroscopicaUy discovered 
many years previously by Sir Norman Lockyer, and named 
by him " helium." Subsequently, by applying the process 
called " fractional distillation " to liquid air, Ramsay could 
isolate three additional elements : krypton, xenon, and 
neon. 

In the meantime, experiments on the discharge of 
electricity through gases had made rapid progress. His 
experiments with the radiometer had led Crookes to intro- 
duce great improvements in the construction of the merciu'y 
pumps iised to obtain high vacua in glass vessels. By sending 
electric currents of high potentials through such vessels, 
Crookes investigated the vivid phosphorescent luminosity 



182 Britain's Heritage of Science 

which appears near the negative electrode. Important 
results were obtained in these researches. Investigations by 
other observers which cannot here be described, led to the 
conclusion that gases, which ordinarily are insulators, could 
in various ways be made to conduct electricity, and the 
phenomena suggested that the conductivity was due to the 
formation of carriers analogous to the ions which normally 
exist in liquids. Gases, in fact, could be ionized. The 
stage was now reached where experiments definitely pointed 
to the conclusion that electricity, like water, had an atomic 
constitution. To furnish the proof, it was necessary to 
show that the atomic charge was the same in all cases. The 
experiments with liquids gave no direct measure of this 
charge, but they allowed us to determine its ratio to the 
mass of the carrier. That carrier in liquids is the chemical 
atom, and it was natural at first to suppose that the same 
would be the case in gases ; if so, the matter could be tested, 
as we know the relative masses of different chemical atoms. 
The first experiments made in that direction led to no 
decisive results, though they supplied a method which proved 
useful. The question was finally solved by Sir Joseph 
Thomson, who proved that the carrier of negative electricity 
had a mass much smaller than that of a chemical atom; 
ultimately it was found that, near the kathode of an electric 
discharge through gases, it is actually the atom of negative 
electricity which is set free, and acts as carrier. 

Thomson further determined the charge of the electron, 
the name given to the atom of electricity by Johnstone 
Stoney (see p. 139), and found it to agree with that which 
may indirectly be derived from the electrolysis of liquids. 

There can be no doubt that Sir Joseph Thomson's ex- 
periments wiU be looked upon in future as a landmark in 
the advance of science as great as those that have been 
described in our first chapter. 

Thomson's discovery was aimounced at the British 
Association meeting of 1899. Since then our ideas have 
advanced rapidly, and we now consider corpuscles of positive 
and negative electricity to be the elemental atoms from which 
all matter is built up. In the origination and development 
of this theory Sir Joseph Larmor has taken an active part. 



Sir J. J. Thomson, Sir E. Rutherford 183 

During the last few weeks of the year 1896 some remark- 
able experiments of W. C. Roentgen revealed to us a new 
and quite unexpected class of phenomena. The electric 
discharges in a highly-exhausted vessel were found to be 
capable of generating a radiation — ^now known to be due 
to very short waves — which could penetrate many bodies 
opaque to ordinary light. This was the X-radiation which 
has proved to be of such enormous value in surgery. Their 
investigation indirectly led to our knowledge of a stiU more 
remarkable class of phenomena.. The French physicist, 
Becquerel, whUe trying to find whether the sun emitted 
X-rays, observed a most surprising effect, which could only 
be accounted for by assuming the existence of a new form 
of radiation, essentially different from that of the X-rays. 
Separating the substance that was mainly responsible for it, 
M. and Mme. Curie discovered the new metal radium. This 
is the typical radio-active element, but two other known 
chemical elements — uranium and thorium — proved to resemble 
radium in its peculiar properties. A new science then opened 
out. 

The effects of radio-activity show themselves by their 
power of ionizing air and affecting photographic plates, but 
the first results were extremely puzzHng, and experimenters 
were being led away on a wrong track when Sir Ernest 
Rutherford took up the work. He first discovered that 
thorium and radium gave up gases— the so-called emana- 
tions — which themselves were radio-active. It was the 
disturbing effect of these gases which, diffusing through 
the air of the laboratory, had affected the instruments, and 
led Becquerel and Curie astray; it had to be separated 
from that of the parent substance before the different 
phenomena could be disentangled. By a series of remarkable 
experiments, Rutherford soon cleared up the essential features 
of radio-activity. In conjunction with Frederick Soddy he 
then developed his theory, which now stands on a firm 
basis. Radio-activity was shown to be the result of the 
ejection of corpuscles from the parent body, which thereby 
became transformed into another substance which was 
generally itself subject to further decomposition through the 
emission of other corpuscles. The decomposition proceeds 



184 Britain's Heritage of Science 

at a perfectly defibtiite rate, and the life of any radio-active 
substance can, therefore, be foretold. The ejected particles 
consist either of one or more negative electrons (/3 particles), 
or positively charged corpuscles (a particles); frequently 
both are emitted. The a particle carries twice the charge 
of an electron, and weighs about twice as much as an 
atom of hydrogen : that is to say, as much as a helium atom. 
Rutherford formed the idea that the two might be identical 
and this was experimentally confirmed by Sir WiUiam Ramsay. 
The emanation of radium which emits an a particle in its 
decay was introduced into, and kept in an exhausted tube for 
several days, when it was foimd that the spectrum hne of 
heUum could be clearly seen, though no helium had originally 
been present. This experiment, which gave the proof of 
Rutherford's surmise, was an historical event, as it supplied 
the first definite example of the decomposition of a so -called 
chemical element. For the emanation possesses aU the 
characteristics of such an element and was shown to decom- 
pose spontaneously, helium being one of the products. 
The subsequent development of radio-active experiments 
and theories confirmed the original ideas, and many new 
and interesting facts were brought to Kght.^ These must be 
passed over, and we might here close our account, were it 
not for the briUiant researches of a young man, who promised 
to become one of the great investigators of his time. 

Henry Moseley (1887-1915) was the grandson of Canon 
Moseley, a distinguished mathematical physicist, and the 
son of Professor H. N. Moseley, at one time Linacre Pro- 
fessor of Zoology at Oxford. He took his degree at Oxford, 
but received his scientific training mainly from Rutherford 
at Manchester. After Laue, at Munich, had proved the 
existence of a diffraction effect of crystals on X-rays, and 
Professor WiUiam Henry Bragg had developed and improved 
the methods of observation, Moseley set himself the task of 
determining the fundamental vibrations of the atoms which 
give rise to the X-rays. The research required exceptional 
experimental skill, and great powers of devising new methods 

* For a detailed account of these investigations see Rutherford, 
" Radio-activity." 



Ernest Rutherford, Henry Moseley 185 

of investigation, and the result proved of the highest value. 
The wave-lengths to be measured are less than the thousandth 
part of that of visible rays, and in that region the arrange- 
ment of the lines was found to be the same for all elements ; 
but proceeding from lower to higher atomic weights, the 
spectrum was bodily displaced by a definite amount towards 
the shorter wave-lengths. To see the full bearing of this 
investigation, we must refer to the theory which Rutherford 
had formed on the constitution of atoms, based mainly on 
his experiments on the scattering of a particles by molecules 
of matter. According to that theory, each atom possesses a 
positively charged nucleus of exceedingly small dimensions. 
The nucleus is made up of definite numbers of unit charges, 
and if we arrange the elements in order of their atomic 
weights, it is natural to suppose that the total charge 
increases by one unit as we pass from one element to the next. 
We may take the atomic number (meaning the number of 
charges) as the characteristic of each element, and deal, 
therefore, with figures which are successive integers, rather 
than with the irregiilarly increasing numbers representing the 
atomic weights. Moseley's experiments prove that the high 
frequency spectrum of the elements which he examined is 
completely defined by the atomic number. It may be antici- 
pated that this will prove to be the foundation of a new and 
more precise chemistry, as other properties will be certain 
to be intimately connected with the forces which regulate the 
spectra. In confirmation of this, it may be stated that 
Moseley in fixing the atomic number had to invert the order 
in the case of potassium and argon, and that of cobalt and 
nickel, and in both instances it is found that the chemical 
properties agree with the spectroscopic evidence, and not 
with that of the order of atomic weights. 

Moseley's results, while showing that all elements can be 
placed in a certain definite order almost identical with that 
of the atomic weights, allow us also to discover the gaps 
which we may confidently expect to see fiUed up by hitherto 
undiscovered elements. Eighty-three are known at present 
and Moseley's table of results shows nine gaps between 
argon and the heaviest of the metals, uranium. The total 
number of elements reached, when the gaps are filled, will be 



186 Britain's Heritage of Science 

ninety-three; but some authorities believe ia the existence 
of two further elements lighter than helium. 

Moseley's magnificent researches came to a sudden and 
tragic end. On the threshold of a career of singular promise, 
looking towards a future pregnant with discoveries that 
could not fail to fall to his genius and enthusiasm, he answered 
the call to arms at the outbreak of the war; and a Turkish 
bullet cut short a life precious to the peaceful glory of his 
country, but gladly surrendered in its hour of need. That 
also is a heritage which will go down to posterity. 



187 



CHAPTER VI 

(Physical Science) 

Some Indttsteial Applications 

IT is not intended here to catalogue, much less to discuss, 
the multitude of practical applications of science which 
have originated in this country during the last century. To 
mention merely the manufacture of steel, the building of 
bridges, and the evolution of the modern steam-engine is 
sufiBcient to illustrate the all-pervading influence of science 
on our industries. 

The scientific production of steel originated with Ben- 
jamin Huntsman (1704-1776), a clockmaker of Doncaster, 
who discovered the process of making cast steel by melting 
in crucibles. Starting works in Sheffield, he was the first to 
introduce a material of imiform temper and composition 
which could in the modern sense be termed steel. Much 
might be said on the more recent developments of the steel 
industry by Henry Bessemer (1813-1898), and on other in- 
ventions, such as Sir Charles Parsons' steam-turbine, one of 
the greatest triumphs that engineering s kill has ever achieved. 
But we must content ourselves with a few selected examples 
illustrating the effects of pure scientific research on that 
complex organization of the community which usually goes 
by the name of civflization. 

So much in our modem life depends on the facilities for 
rapid mutual iatercourse that it is curious to note how 
new devices have often supplied the means before there 
was a demand. The capacity of inventing outpaced the 
power of the imagination to understand the use of the inven- 
tion : the supply had to create the demand. Thus, when 
Sir Francis Ronalds (1788-1873) submitted to the Govern- 
ment in 1816 the design of an electric telegraph which he 



188 Britain's Heritage of Science 

had actually tried and found to work with a length of eight 
miles of wire, the reply of the Secretary of the Admiralty 
was that '' telegraphs of any kind are now totally unnecessary 
and that no other than the one now in use will be adopted." 
The word " now " seems to have referred to the conclusion of 
the French war, and the telegraph mentioned as being in use 
was the semaphore. 

Ronalds was the son of a London merchant; his method 
of transmitting signals consisted in charging and discharging 
an electroscope through a long wire. In his experiments he 
used a length of eight rtules of wire, properly insulated and 
embedded in the soil of a garden in Hammersmith. The 
distinguishing feature of his apparatus consisted in an arrange- 
ment founded on the same principle as the one so successfully 
employed in the type-printing arrangement invented at a 
much later date by Hughes. Two discs bearing the letters 
of the alphabet near their circumferences were made to 
rotate with the same speed at the two ends of the line. The 
electroscope placed at the receiving end was discharged from 
the sending end. The sender watched the moment when 
the required letter passed a certain position, and the same 
letter passing the corresponding position at the receiving 
end at the moment of discharge could therefore be read off. 
The two discs were adjusted by means of a signal before the 
message was sent, and it only remained to ensure that the 
discs rotated synchronously dtiring the time it took to send 
the message. Bits of the original wire with its insulating 
covering were dug out later, and are now preserved in the 
Science Museum at South Kensington. 

When the electromagnetic effects of currents had been 
discovered, experiments by Gauss and Weber, Schilling and 
SteinheO. showed how they could be utihzed in transmitting 
signals. These experiments became known in England 
through William Fothergill Cooke (1806-1879), knighted in 
1869) who, in conjunction with Wheatstone, set to work to 
devise a system of telegraphy that could be commercially 
successful. The main difficulty was to reduce the number of 
wires, which were at first thought to be necessary for indi- 
cating the twenty-five letters; in this respect Ronalds had 
been ahead of his successors. The difficulty was overcome 



Telegraphy 189 

by an alphabet of signs introduced by the American inventor 
Morse, but an alternative one-wire system of Cooke and 
Wheatstone in which the letters are directly indicated on a dial, 
though much slower in its working, continued to be employed 
in the British Telegraph Service at stations where it was 
difficult to obtain operators sufficiently practised in the 
Morse code. Subsequent improvements in telegraphy over 
land lines are mainly of technical interest. 

An entirely new set of problems arose when submarine 
cables had to be laid across the oceans. As water is not an 
insulator like air, the conductor which serves for the trans- 
mission of the message has to be surrounded by a non- 
conducting material hke guttapercha. The copper wire inside 
and the water outside separated by an insulating substance 
then act like a condenser which must be charged up before a 
steady electric current can flow through the wire. This 
retards the transmission, and otherwise comphcates the 
effects, so that the ordinary telegraphic apparatus become 
useless. Lord Kelvin's inventive genius soon supplied a 
suitable instrument, but there were other dangers ahead, such 
as the enormous mechanical stresses to which the cables are 
exposed, and the destructive effects of submarine boring 
animals. The credit of overcoming these difficulties is largely 
due to Robert NewaU., whose name has already been 
referred to in connexion with Astronomy. As a practical 
engineer, NewaU had improved the manufacture of wire 
rope to such an extent that quite a new industry may be 
said to have originated through his efforts. He used the 
experience gained by introducing wires to strengthen the 
cables and inventing suitable appliances for paying them out. 
The first commercially successful cable was laid across the 
Straits of Dover in 1857, and the possibility of telegraphic 
communication between Europe and America was then 
opened out. In July, 1857, a cable was ready, and the shore 
end was fixed at Valentia ; but the cable snapped when 
380 nules had been laid. In the following year, after a further 
failure, a cable was finally stretched across the Atlantic ; but, 
unfortunately, Kelvin's instructions were ignored and high 
potential currents were used to transmit the messages, 
with the result that the insulation was completely ruined. 



190 Britain's Heritage of Science 

The next attempt, made after an interval of eight years, 
was again misuccessf ul ; but in 1866 the Great Eastern 
laid its cable without mishap, and was even able to pick up 
the lost end of the one that had broken in the previous year. 
Since then submarine cables, mostly manufactured in Eng- 
land, have rapidly increased, and their total length now at 
work would, if joined end to end, be able to pass ten times 
round the equator. 

The success of cables depends so much on the durability 
of the insulating material that this seems to be the place 
for attention to the services of Thomas Hancock (1786- 
1865), the founder of the india-rubber trade in England. 
His work is weU described in the " Dictionary of National 
Biography," from which the following account is — with a 
few omissions — transcribed. Observing that two freshly 
cut surfaces of india-rubber readily adhered by simple 
pressure, Hancock was led to the invention of the " masti- 
cator," as it was afterwards called, by the aid of which 
pieces of india-rubber were worked up into a plastic and 
homogeneous mass. With the invention of this process, 
which was perfected about 1821, the india-rubber trade 
commenced. Eventually, Hancock became a partner in 
the firm of Charles Macintosh and Company, though he stUl 
carried on his business in London. In 1842 specimens of 
" cured " india-rubber, prepared in America by Charles 
Goodyear according to a secret process, were exhibited ia 
this country. Hancock investigated the matter, and dis- 
covered that when india-rubber was exposed to the action 
of sulphur at a certain temperature a change took place; 
he thus obtained " vulcanized " india-rubber. This was 
patented in 1843. Although Hancock was not the inventor 
of vulcanizing in the strictest sense of the word, he first 
showed that sulphm- alone is sufficient to effect the change, 
whereas Goodyear employed other substances in addition. 
Hancock also discovered that, if the vulcanizing process be 
continued and a higher temperature employed, a homy 
substance, now called vulcanite or ebonite, is produced. 

David Edward Hughes (1831-1900), whose name has 
already been mentioned above, was born in London, but 
his parents emigrated to the United States when he was 




WilHam Thomson, Lord Kelvin 



photograph by Meiisr^ Dickit 



T. Hancock, D. E. Hughes, W. Sturgeon 191 

seven years old. He was connected for a time with a college 
in Kentucky, first as Professor of Music and then as a 
teacher of Natural Philosophy, but gave up the academic 
career, at the age of twenty-three, to supervise the manu- 
facture of the type-printing machine which he had invented. 
Everyone is now famihar with that perfect Mttle instrument 
which distributes typed messages simultaneously aU over a 
city. The income which the inventor derived from it gave 
him the desired leisure for further scientific investigations. 
His most important discovery is that of the microphone, in 
which two pieces of carbon are in loose contact, making 
an electric connexion that is exceedingly sensitive to the 
slightest disturbance caused by a wave of sound or an 
electric impulse. The carbon contact was soon introduced 
into telephone transmitters, and helped much to make tele- 
phones serviceable for ordinary use. In observing the effect 
of electric impulses in carbon contacts Hughes anticipated 
the invention of the " coherer," which made the trans- 
mission of wireless electric messages to great distances 
possible. It is, indeed, related that, so far back as 1879, 
Hughes could detect by the microphone " electric impulses " 
at a distance of 500 yards. ^ The researches on the microphone 
and on another useful instrument, the " induction balance," 
were carried out in England, where Hughes spent the later 
part of his life. 

All industrial appHeations of electricity are based on 
Faraday's discoveries, and Sturgeon's invention of the electro- 
magnet. After it had been shown experimentally by the 
former that an electric current is produced when a wire is 
moved in a magnetic field, it was pretty obvious that appliances 
could be constructed for generating currents by mechanical 
means. There is no indication that at first anyone was aiming 
at currents of great intensity; machines were constructed 
partly on account of their scientific interest and partly to 
be used for purposes of telegraphy. Sturgeon was the first to 
attack the inverse problem of using a current to do mecha- 
nical work, and it has been described in our first chapter 
how Joule started his work by trying to improve the 

1 "' Encyclopsedia Britaimica." 



192 Britain's Heritage of Science 

efiSiciency of electromagnetic engines. Between 1850 and 
1860 many attempts were made to increase the intensity of 
electric currents obtained by electrodynamic induction, but 
the turning point came when, in the spring of 1867, Henry 
Wilde, of Manchester, showed some remarkable experiments 
in the rooms of the Royal Society. In the previous year he 
had already described the main principle on which he rehed 
to increase the intensity of currents that could be obtained 
by electromagnetic induction. A machine constructed accord- 
ing to a model made by Werner Siemens, in which an armature 
rotated in a magnetic field produced by a permanent magnet, 
generated an electric current which fed a second and larger 
machine in which the permanent magnets were replaced by 
electromagnets. These were excited by the first current 
and a much stronger magnetic field was produced : a more 
powerful cmrent was consequently obtained. This was led 
in a third machine round still larger masses of iron, which 
were thus magnetized, and finally a current emerged showing 
effects of surprising intensity. A piece of iron half-an-inch 
thick melted and burned when the current was made to pass 
through it, and a rod of platinum two feet long and a quarter 
of an inch in diameter was also seen to melt. A steam engine 
of 15"h.p. was required to drive the shafts of the machmes. 
Eye-witnesses testify to the great impression created by 
these experiments, and there can be httle doubt that the 
pubUo then first began to recognize the potentialities of the 
electric current. Rapid advances were quickly made, and 
the modern " dynamo-machine " was soon evolved ; Wilde 
himself had already called his machines by that name. 

As soon as commercial interests are involved in scientific 
appliances, new problems of an economic nature arise. The 
weight of metal to be put into the different parts of the 
machinery has to be adjusted so as to obtain the best 
results at the least cost, and other matters have to be con- 
sidered. Apart from some contributions by Lord Kelvin, it 
may be said that the economics of the dynamo-machine 
depend almost entirely on the researches of John Hopkinson, 
who, perhaps, more than any other British man of science, 
combined the commercial faculty with the highest scientific 
attainments. 



H. Wilde, J. Hopkinson, J. A. Ewing 193 

John Hopkinson (1849-1898) was born in Manchester, 
and after studying two years at Owens CoUege entered 
Trinity CoUege, Cambridge. He graduated in 1871 as senior 
wrangler, and in the following year was engaged by Messrs. 
Chance Brothers, glass manufacturers, at Birmingham, as 
engineering manager. In this position he devoted himself 
to the improvement of lighthouse iUumiaation, and intro- 
duced the system of group flashing lights which is now 
extensively used. In 1878 he settled ia London as consulting 
engineer, and during the next few years conducted his 
classical researches on the efficiency of dynamo-machines. 
These were completed later, in conjunction with his brother 
Edward, by laying down the general principles by which the 
performance of any machine may be predicted from its 
design. Another important contribution to electric lighting 
was his invention of the three -wire system of electrical 
distribution. 

The efficient working of most of our electrical machinery 
depends on the magnetic properties of iron, and mention 
must, therefore, here be made of the valuable iavestigations 
of Professor J. A. Ewing, who first clearly pointed out the 
inevitable dissipation of energy which occurs when a piece of 
iron is subject to rapidly alternatiag magnetic forces, as it is, 
for instance, in a transformer. Owing to a property of iron 
which he called hysteresis, and which is a kind of internal 
viscosity brought into action by the rapidly changing orienta- 
tion of magnetic molecules, some of the energy will always be 
converted into heat, and is lost as useful work. In other 
respects also, Ewing has added much to our knowledge of 
magnetism. 

Our electrical industry owes much to Wifiiam Edward 
Ayrton (1847-1908), who was the first to introduce soimd 
methods of instruction in applied electricity. He was 
the most successful and, for a time, the only teacher of the 
subject. He organized the laboratories at Knsbury College, 
and at the Central CoUege, Kensington. Men came from 
aU parts of the world to be trained by him, and he knew how 
to infuse his students with the spirit of research. In the 
early days of the industry, the measuring instruments, 
though suitable for a physical laboratory, could not easUy 



194 Britain's Heritage of Science 

be moved, or protected against the disturbing effects to 
be expected in a large workshop. Ayrton recognized the 
want, and in conjunction with Professor John Perry designed 
a number of reliable and practical instruments that could be 
used in a factory. Some of these inventions have proved of 
permanent value. 

The applications of chemistry to the necessities of the 
nation are predominant in times of war, and hardly less 
universal in times of peace. Two great industries stand out 
on accoimt of their importance, enhanced as it is by the 
interest attached to, and the instructive contrast presented 
by, their historical development. While the alkali manu- 
facture which has been prosecuted so successfully in this 
country is based to a great extent on chemical processes 
originated or perfected by foreign chemists, Leblanc, Solvay, 
and Castner, the coal-tar coloiir industry, founded on pioneer 
work done in England, was unable to hold its own against 
foreign competition. There is this possibly to be said in 
explanation of the difference. The chemistry of the alkali 
manufacture is extremely simple, and the difficulties which 
had to be overcome, though serious enough, were mostly on 
the engineering side ; the colour industry, on the contrary, 
depends, not only in its initial stages but throughout, on 
persistent and organized scientific research, requiring the 
encouragement and support of the manufacturers. The 
institution which is associated with its birth — the Royal 
CoUege of Chemistry — was an exotic growth disconnected 
from any university, and without permanent influence on 
university teaching. Its director, Hofmann, was, at that 
period, concerned with training scientific men rather than 
manufacturing chemists, and no efforts were made to bridge 
the gap between the laboratory and the factory. 

The alkali industry presents a more pleasing history, 
Joshua Ward, of Twickenham (1685-1761), first commer- 
cially produced oU of vitriol in glass globes of forty to fifty 
gallons capacity, and a very important advance was made 
by Dr. John Roebuck, of Birmingham (1718-1794), who, in 
1746, erected the first lead chambers. A name more directly 
connected with the manufacture of alkali is that of Joseph 
Christopher Gamble (1776-1884), who was trained up for 



W. E. Ayrton, Christopher Gamble 195 

the Church, and while passing through his studies at Glasgow, 
attended a course of chemistry under Dr. Cleghorn. He 
became sufficiently interested to carry on privately chemical 
experiments in his leisure time. After taking up his duties 
as Presbyterian minister at Enniskillen, he saw hand-loom 
weavers in his parish working the flax grown by farmers in 
the neighbourhood, and prepared solutions of chlorine to 
assist them in bleaching their linen. Finding that he could 
utilize the residue left over from the production of chlorine in 
producing Glauber salts, he decided to resign his ministry 
and establish chemical works in Dublin. Here he manu- 
factured bleaching powder, using the process patented by 
Charles Tennant (1768-1838), the owner of the St. Rollox 
Chemical Works, now merged in the United Alkah Company. 
He further set up a plant to manufacture the necessary 
sulphuric acid. Salt or brine, another indispensable ingre- 
dient, had, however, to be obtained from a distance, and this 
led him intimately to leave Ireland, and build works at 
St. Helens. There he was associated during ten years with 
James Muspratt, and afterwards with the brothers Cross- 
field, soap-boilers, of Warrington. The trouble arising from 
the damage done to the surroimding country by the noxious 
gases set free in the process of manufacture hampered the 
work considerably, and Gamble was slow to adopt the proper 
remedies. The enmity of his neighbours and ill-health 
ultimately made him abandon his work altogether. 

To appreciate the work done by the chemical manu- 
facturer in Gamble's time, it must be remembered that they 
had generally to manufacture aU the appUances they required. 
Earthenware pots of sufficient size had to be produced, and 
Gamble, blowpipe in hand, made his own thermometers and 
hydrometers. 

" Alkali " is an Arabic word originally apphed to the ashes 
of plants, and subsequently to the products derived from 
these ashes, consisting of carbonate of soda and carbonate 
of potash. The properties of these substances are so similar 
that at first they were not distinguished as separate bodies. 
As chemistry advanced, their metallic bases, sodium and 
potassium, were grouped together under the term " alkali 
metals," but technically, when the alkali industry is referred 

N 2 



196 Britain's Heritage of Science 

to, it includes only the sodium compounds, and of these, 
strictly speaking, only the hydrate and the carbonate ; 
but the manufacture of sodium sulphate and of hydro- 
chloric acid is inseparably connected with the same in- 
dustry. The first successful process of obtaining carbonate 
of sodium is due to Leblano, a French chemist, and one of 
the victims of the French Revolution. Leblanc was born in 
1753, near Orleans. He was first trained in an apothecary's 
shop, but proceeded to the study of medicine, and was 
appointed surgeon to the Duke of Orleans. In 1775 the 
French Academy of Sciences offered a prize for the best 
practical process of producing soda _from common salt. 
There were several competitors, but none of them were 
judged worthy of receiving the prize. Nevertheless, Leblanc 
patented his process, and the Duke of Orleans supplied the 
capital for establishing works on a manufacturing scale. 
But his connexion with that nobleman proved to be his 
imdoing. The Duke was executed, and the works were con- 
fiscated. Leblanc struggled on in dire poverty for thirteen 
years, when his property was returned to him by the Emperor 
Napoleon. But it was too late; he had no capital to start 
afresh, took refuge in a workhouse, and died by his own 
hand. 

James Muspratt (1793-1886), who introduced the Leblanc 
process into England, was bom in Dublin, and as a boy was 
apprenticed to a wholesale druggist; he quarrelled with his 
master, and went to Spain to take part in the Peninsular 
War. His great ambition was to obtain a commission in the 
cavalry; in this he was unsuccessful, and, refusing to accept 
the position in the . infantry which was offered him, he 
followed the army in the wake of the troops. He fell Ul, 
made his way to Lisbon, but could not find a steamer to 
take him home. Ultimately he secured an appointment as 
midshipman in the Navy, and though promoted to the rank 
of second officer, could not adapt himself to the strict disci- 
pline of the Navy. He deserted while the vessel lay in the 
Mumbles roadstead, and returned to Dublin. With the 
knowledge gained during his apprenticeship and a small 
inheritance, Muspratt then began his career as a manu- 
facturing chemist;. He started by making hydrochloric acid 



James Muspratt 197 

and ptussiate of potash. This did hot satisfy his ambitions, 
and when, in the year 1823, the prohibitive salt tax was 
greatly reduced, he determined to work the Leblanc process, 
and crossed over to Liverpool in search of a suitable locality 
to erect his works. Not being provided with sufficient capital 
he continued during a few years the manufacture of prussiate 
of potash, until in 1828 he joined partnership with Christopher 
Gamble and together they erected the St. Helens works. 
Separating again two years later, Muspratt took a new site 
at Newton-le-Willows. The same trouble arose which, as 
has already been mentioned, discouraged Gamble. Newton 
was in the heart of an agricultural district, and the farmers 
very naturally resented having their crops spoiled by the 
fumes of hydrochloric acid. Muspratt's business was so 
seriously interfered with by contiuuous Utigation that he 
abandoned his works in 1850 ; and yet, ever since 1835, he 
might have got over his difficulties had he given a trial to 
the coke tower condenser of William Gossage (1799-1877), 
which had been brought to his notice by the inventor. In 
these condensing towers, the hydrochloric acid, instead of being 
allowed to escape, is collected, and forms a by-product of 
considerable commercial value. Gossage's process enabled 
the alkaU industry to develop with great rapidity, so that in 
the twenty years between 1852 and 1872, the annual pro- 
duction of alkali rose from 26,000 to 94,000 tons. Moreover, 
the invention allowed the AlkaU Acts to be passed and 
strictly enforced, to the great advantage of the coimtry in 
which the works were situated. 

In the Leblanc process, sulphate of soda (salt cake) is 
formed by the direct action of sulphuric acid on salt; the 
sulphate is converted into the carbonate by briaging it into 
intimate contact with limestone and coal, and heating the 
mixture. In another method, which has to a great extent 
replaced that of Leblanc, the salt is acted on by ammonium 
bicarbonate, with the result that sodium bicarbonate and 
chloride of ammonium are formed. The ammonium bicar- 
bonate, which forms the basis of the reaction, is generated 
by saturating a salt solution with the ammonia obtained in 
the recovery of the plant, and forcing carbonic acid gas into 
the liquid. The process was first invented by G. Dyer and 



198 Britain's Heritage of Science 

J. Hemming in 1838, and worked on a small scale in White- 
chapel. Muspratt also had given it a trial at Newton, but 
abandoned it again. After protracted investigations, the 
Belgian chemist, Ernest Solvay, overcame the main manu- 
facturing difficulties, and took out a patent in 1872. In the 
meantime, Ludwig Mond (1839-1909) had settled in England 
at the age of 23, and had gained practical experience with the 
Leblanc process while occupied in some chemical works at 
Widnes. Recognizing the possibilities of the ammonia-soda 
process, he obtained a licence from Solvay, and in partnership 
with Sir John Brunner, founded in 1873 the great chemical 
works near North wich. Further diificulties were experienced, 
but these were gradually overcome, mainly by improved 
devices for recovering the ammonia, on which the commercial 
success of the process largely depends. 

A third method of making alkahes became possible when 
the introduction of dynamo -machines provided an easy 
means of obtaining strong electric currents. Various electro- 
lytic processes were then devised and patented. In the 
Castner-KeUner method, used extensively in this country, 
the kathode of the electrolytic trough is formed by mer- 
cury, and the sodium is transferred by the current from the 
solution to the mercury with which it amalgamates; by a 
self-acting arrangement the amalgam is removed before it 
becomes strong enough to act on the water. That action is 
ultimately allowed to take place in another vessel, where a 
solution of caustic soda is formed. 

Among the chemical engineers of the alkaU trade, Henry 
Deacon (1822-1876) and Walter Weldon (1832-1885) also 
hold distinguished places. They both successfully invented 
independent and quite different processes for the manu- 
facture of chlorine, which are still in use, though partly super- 
seded by electrolytic methods. An important improvement 
in the manufacture of sulphuric acid was made by J. Glover, 
who, in 1866, introduced the important de-nitrating tower. 

In the early forties of last century a determined effort 
to promote chemical research was made in London. With 
the support of Faraday and Brande, it was at first intended 
to attach the necessary laboratories to the Royal Institution, 
but on closer consideration the available space was found to 



L. Mond, W. Weldon, W. Perkin 199 

be insufficient, and it was decided to establish a separate 
institution, under the name Of the Eoyal College of Chemistry. 
The proposal matured largely through the influence of the 
Prince Consort and the Queen's physician. Sir James Clark. 
Temporary accommodation was found in George Street, 
Hanover Square, until a larger building in Oxford Street 
could be adapted. Justus Liebig, whose authority in questions 
of chemistry was paramount at the time, was asked to 
recommend a suitable director for the new institution, and 
ultimately August Wilhelm Hofmann, a young assistant at 
the University of Bonn, accepted the appointment. The 
school was opened in 1845, and Hofmann threw himself 
so heartily into the work that it soon attracted a large 
number of promising pupils. It is, indeed, remarkable to 
find among the early students of the Royal College so many 
men who subsequently rose to eminence ; we note among them 
Sir William Crookes, Sir Frederick Abel, Herbert Macleod, and 
Sir William Perkin. The College continued until 1864, when 
it was absorbed into the School of Mines. Perkin (1838- 
1907) was fifteen years old when he came under the influence 
of Hofmann. After passing through the ordinary training, 
he was appointed honorary assistant to his teacher, and 
henceforward devoted himself to research work. Hofmann's 
own investigations at the time dealt with the organic 
compounds derived from coal-tar; it was a pm-ely scientific 
research, undertaken without reference to any industrial 
applications. Perkin was set to work on anthracite, and, 
though interesting results were obtained, the chief value of 
his early work was the acquisition of the experience which 
he was to turn to such good account later. 

The artificial production, or synthesis, as it is techni- 
cally called, of natural organic compounds was then in its 
infancy, and it was generaUy supposed that if, by abstracting 
or addhig oxygen or water, a compound could be formed 
having the same number of oxygen, carbon, and hydrogen 
atoms as the desired substance, the synthesis was likely 
to be .successful. Hofmann had suggested the artificial pro- 
duction of quinine as a useful subject for research. The 
problem attracted Perkin, and as he was at the time busy 
with other work for his Professor, he decided to pursue the 



200 Britain's Heritage of Science 

investigation ia the private laboratory he had established at 
home. Following the deceptive guidance of the accepted 
doctrine, he tried to synthesize quinine by treating one of the 
coal-tar products with bichromate of potassium, but only 
obtained a dirty reddish-brown precipitate. Maxwell once 
said that he never stopped a man from carrying out an 
unpromising research, because, though he would almost 
certainly not find what he expected, he might find some- 
thing else. Perkin had found something else, and showed 
the proper researching instinct by accepting the hint. 
Replacing the more complicated compound which he had 
used by another coal-tar product, " aniline," he obtained 
an almost black precipitate, which, on further examination, 
proved to have dyeing properties. This led to the discovery 
of aniline purple, later called " mauve," the first of the arti- 
ficial colours. Perkin saw the possibility of a useful application 
before him, and sent a sample of the dye to Messrs. Puller, 
of Perth, who, recognizing its value, repUed : "If your 
discovery does not make the process too expensive, it is 
decidedly one of the most valuable that has come out for a 
long time." 

Perkin resigned his position at the Royal College, and 
with the assistance of his father built a factory at Greenford 
Green, near Sudbury. To supply the dye cheaply, an econo- 
mical method of preparing aniline had to be worked out. 
This was first accomplished by the French chemist B^champ, 
whose share in the work was always fuUy recognized by 
Perkin. The new dye-stuff was brought into the market 
towards the end of 1857, and the demand for it increased 
rapidly. 

The aniline dyes are products which do not occur in nature. 
A fresh departure was made in 1868, when Graebe and Lieber- 
mann succeeded in the artificial formation of aHzarin, the 
dyeing principle of the madder plant. The method used was, 
however, too costly to hold out any hope of competing 
successfully with the product derived du'ectly from the 
plant, which was grown extensively in the south of France. 
Within a year Perkin invented another process that promised 
and attained commercial success. In the meantime, Graebe 
and liebermann had independently been led to the same 



W. Perkin, E. C. Nicholson 201 

method. The Greenford factory, however, was ready to 
start work at once, and until 1873 there was practically no 
competition with the coal-tar dyes produced in this country. 
In his report on the exhibition of 1862, Hofmann 
wrote : — 

" England will, beyond question, at no distant date 
become, herself, the greatest colour- producing coimtry 
in the world; nay, by the strangest of revolutions, she 
may, ere long, send her coal-derived blues to indigo- 
growing India; her tar-distilled crimson to cochineal- 
producing Mexico, and her fossil substitutes of quercitron 
and safflower to China, Japan and other countries, whence 
these articles are now derived." 

This is not the place to discuss the causes which have 
falsified Hofmann's prophecy. The " near future " of his 
prediction is passed, but another future lies ahead of us. 

Perkin also carried on investigations of a great value in 
pure science, even during the busy time of his industrial 
enterprises. He sold his factory in 1874, devoting himself to 
the time of his death to a hfe of scientific research. 

Among the pupils working in the laboratories at George 
Street we find Edward Chambers Nicholson (1827-1890), 
of whom Hofmann, at a later period, wrote : " He United 
the genius of the manufacturer with the habits of a scientific 
investigator." In his first research he determined the con- 
stitution of strychnine. After leaving the Royal College, 
he became associated with Messrs. Maule and Simpson in 
the preparation of various chemical products, turning his 
attention ultimately to colouring matters. His name is 
chiefly connected with the manufacture of " regina purple " 
and " Nicholson's blue." 

A worthy successor of Perkin and Nicholson might, 
with proper opportimities, have been found in Raphael 
Meldola (1849-1915), who, between 1879 and 1885, made 
important discoveries of new dye-stuffs. But though he 
was during eight years connected with a firm manufacturing 
colours, he received little encouragement from his employers, 
and his work bore no immediate fruit. Meldola always held 
the opinion that the decline of the colour industry in 
England was not due, as is commonly asserted, to the 



202 Britain's Heritage of Science 

defects of our patent laws, or other restrictions imposed by 
the legislature of the country, but to the neglect of continued 
scientific research ■within the factory. 

Sir Frederick Abel (1827-1902) has been mentioned as 
one of the students of the Royal College of Chemistry. His 
subsequent work, carried on while he occupied the position 
of Professor of Chemistry at the Royal Military Academy 
and Chemical Advisor to the War Department, dealt mainly 
with the manufacture of explosives. Through his efforts 
guncotton could be made and handled without danger, and 
cordite is the joint invention of himself and Sir James Dewar. 
He also designed the apparatus, legalized in 1879, for the 
determination of the flash point of petroleum. 

The name of Lyon Playfair (1819-1898) deserves to be 
remembered as one who actively encouraged research through- 
out his life, and exercised a considerable amount of influence 
in promoting scientific enterprises. He was bom in India, 
educated at St. Andrews, and subsequently studied medicine 
at Glasgow. Attracted towards chemistry by the teaching 
of Thomas Graham, he went to study the subject under 
Liebig at Giessen. For two years he managed the chemical 
department of some print works in Clitheroe. Though he 
subsequently held for a time the Professorship of Chemistry 
at the Royal Institution in Manchester, at the School of 
Mines in London and at the University of Edinburgh, it 
is neither as a teacher nor investigator, but rather as a con- 
sistent upholder of scientific principles, that he has left 
his mark. He had a considerable share in the organization 
of the Great Exhibition of 1851, and in the foundation of the 
Department of Science and Art. In 1844 he sat on the Royal 
Commission for the examination of the sanitary conditions 
of large towns and public districts, and maintained through- 
out his hfe a great interest in that subject. He served on 
many other Royal Commissions. In 1868, Playfair was 
returned as the first representative in Parliament of the 
Universities of St. Andrews, and in 1885 was elected member 
for the southern division of Leeds. He held office as Post- 
master-General, and later as Vice-President of the Council 
of Education. The honour of a peerage was conferred upon 
him in 1892. 



203 



CHAPTER VII 

Scientific Institutions 

GREAT ideas spring from individual brains, but a com- 
bination of brains working through scientific organi- 
zations may perform important functions in stimulating 
research, accumulating material or carrying out experiments 
which are beyond the means of one man. An organization 
is generally called into existence for a particular purpose, 
but to be permanently successful its constitution must be 
sufficiently elastic to allow a change of methods or even of 
aims when the original need has ceased to be urgent or 
fresh requirements have appeared. This elasticity has, 
indeed, been a distinguishing feature of our own scientific 
institutions, which have generally been able to adapt them- 
selves to the changing circumstances of the time. 

The origin of the Royal Society of London may be traced 
to weekly meetings of men engaged in philosophical enquiries, 
who came together to discuss questions of scientific interest. 
These meetings began about 1645. A few years later 
some of the members moved to Oxford, and independently 
met in that University. The London meetings were inter- 
rupted in 1658, owing to poHtical troubles ; but, after the 
return of Charles II., it was decided to establish a more 
formal organization. A society was then formed which 
met at Gresham College; the King became interested in 
its work, with the result that it obtained a charter in 1662, 
with the title of " The Royal Society." Further privileges 
were given in a second charter,^ which was granted and 
signed on May 13th, 1663, and the regular activity of the 

^ The second charter confers the present title : " The Royal 
Society of London," and adds its purpose : " for promoting Natural 
Knowledge (pro scientia naturali promo venda)." 



204 Britain's Heritage of Science 

Society begins with that date. Twenty-one members were 
named in the charter to constitute the first CotincU. Ninety- 
iovtr additional Fellows were selected by that body shortly 
afterwards, of whom comparatively few are known by their 
scientific work. Men of general culture sympathetic to the 
revival of learning, statesmen, and even poets, were freely 
included. It was not only science that benefited by this 
liberal interpretation of the fimctions of the Society, for, 
quoting Professor Oliver Elton, • " The activities of the 
newly founded Royal Society told directly upon literature, 
and coimted powerfully in the organization of a clear uniform 
prose — the close, naked, natural way of speaking, which the 
historian of the Society, Sprat, cites as part of its programme." 
The meetings of the Royal Society, at first, served mainly to 
promote friendly intercourse between its Fellows; experi- 
ments were shown by a specially appointed " curator," 
subjects were proposed for investigation, and sometimes 
Fellows were asked to undertake particular researches. 
The pubUcation of results did not originally form any 
prominent part of the work, and only gradually gained 
importance. 

The preceding pages have been fid! of examples illus- 
trating the discoveries made by Fellows of the Society; 
we are here concerned with the influence which the Society 
exerted in its corporate capacity. From the beginning it 
a,cted as adviser to the Government in scientific matters, 
and interested itself in the general welfare of the country. 
During the first year of its existence, the King expressed the 
wish that " no patent should be passed for any physical or 
mechanical invention, until examined by the Society." In 
the same year a report was presented and approved by the 
Society " to plant potatoes, and to persuade their friends 
to do the same, in order to alleviate the distress that would 
accompany a scarcity of food." In 1732 it took measures 
to promote the practice of inoculation. In 1750, its assistance 
was invoked for the purpose of improving the distressing 
state of ventilation of prisons, which was the cause of the 
high death rate due to " jaU fever." Sir John Pringle and 

I " Encyclopaedia Britanuica," Article on Snglish Literature. 



The Royal Society 205 

Dr. Hales on behalf of the Society recommended the use 
of ventilators, and these being introduced, the number of 
deaths in Newgate was reduced from seven or eight a week 
to about two in a month. 

In March 1769, the Dean and Chapter of St. Paul's 
requested the Society's advice as to the most effectual 
method of fixing electrical conductors on the cathedral to 
protect it against the dangers of Mghtning. A committee was 
appointed, including John Canton and Benjamin Franklin, 
and reported on the subject; among the recommendations 
adopted by the authorities was that of using the waterpipes 
to serve as conductors between the roof and the ground. 
Three years later a similar request was received from the 
Government to protect powder magazines, and in 1820 the 
Society advised the Admiralty on a system of lightning 
conductors for use on ships which had been proposed by 
Sir Snow Harris. In May 1824 the Council of the Society 
appointed a Committee " for the improvement of glass for 
optical purposes . " Valuable results were obtained with glasses 
prepared under the direction of Faraday, and examined by 
Jolm Dollond and Sir John Herschel. Unfortunately, owing 
to the important electrical experiments which then engaged 
the attention of Faraday, the Committee did not proceed 
with the further proposal to organize the manufacture of 
optical glass for general sale. 

The indefatigable first curator of the Society had, a 
few years after its foundation, formed the nucleus of a 
collection of " natural rarities," and this gradually grew 
into an important coUeotion or " repository," enriched by 
contributions from distant countries. Ultimately, the greater 
part of it was handed to the British Museum, but the follow- 
ing letter, addressed by three Fellows of the Society to the 
Hudson Bay Company in 1777, shows that the specimens 
presented were examined with a view to their general 
utUity : — 

" Having endeavoured to find out whether some of 
the natural productions which you have been so obUging 
as to present to the Royal Society may not furnish 
materials for our manufactures, we take the hberty of 
stating to you the resplt of our enquiry, We have put some 



206 Britain's Heritage of Science 

parts of one of the buffalo's hides into the hands of a tanner, 
and are informed, both by a very experienced leather- 
dresser and bookbinder, that it seems to be as good a 
material as the skin of the Russian buffalo for book- 
binding. If these skins, therefore, can be procured in any 
quantity, the importation may answer well to the Com- 
pany, and no further preparations of the hides wUl be 
necessary in Hudson's Bay, than to dry them properly 
with the hair on, and to take care that the sea water does 
not injure them on the passage. It is supposed that each 
skin brought in this way to England may be worth about 
four shiUings. We also beg leave to present to the Com- 
pany, in the name of the Society, a pair of stockings made 
here from the hair of one of the buffalo's hides, which 
hung near the neck, as also a hat ; but it may be proper to 
inform you, that the greatest part of the materials used 
in the latter is rabbit's hair, as that of the buffalo cannot 
be worked into a proper consistence for this piu'pose, 
without a mixture of some other hair. As you have pre- 
sented to the Society likewise a specimen of a wild swan, 
we have put the skin into the hands of an importer, and 
we shall, perhaps, surprise you when we inform you, that 
if it had been in a state to be properly dressed, it would 
have been worth at least a guinea and a haK; so scarce 
is this commodity at present, and so great is the demand 
for powder-puffs, the best sort of which can only be made 
from swansdown. We have stated, however, that the 
skin sent from Hudson's Bay was absolutely spoilt by 
not being properly prepared, though we are informed that 
nothing further is necessary than the following simple 
process. All the feathers must be pulled off as soon as 
the swan is kiUed, leaving only the down on; after this 
the skin must be cut off along the back, and stripped off 
the body, then take all the fat away, and turning the 
skin inside out, let it dry. As swan-skins, therefore, are 
so valuable an article of commerce at present, and there 
is a probability of procuring many of them from Hudson's 
Bay, it may be worth while for the Company to purchase 
one of them, for the more fully instructing their servants 
in what state they should be sent over." 



The Royal Society 207 

Many scientific expeditions were promoted and organized 
by the Royal Society. Through its efforts the Govern- 
ment was induced to send out well-equipped expeditions 
to observe the transits of Venus in 1761 and 1769, promi- 
nence being given in their representation not only to the 
importance of the occurrence, but to the circumstance that 
the first and so far only observation of this rare event was 
made by the Lancashire curate Horrocks. 

In 1773 representations were made to the Earl of Sand- 
wich, fiiTst Lord of the Admiralty, strongly urging the desira- 
bility of organizing an Arctic Expedition, partly on the ground 
that this might result in the discovery of a passage to the 
East Indies by or near the North Pole. The wishes of the 
Society were complied with ; two ships, the Racehorse and 
the Carcass, were fitted out, and an astronomer accompanied 
the expedition, with instructions drawn up by a Committee 
of the Royal Society. The ships returned without having 
achieved much ; but in two later expeditions, leaving Eng- 
land early in 1818 and in 1819, most valuable scientific 
results were obtained by Colonel (afterwards General) 
Sabine. 

In 1784 the Council of the Royal Society petitioned 
George III. to place funds at the disposal of the Society to 
commence a geodetical survey, with a view to estabhshing a 
trigonometrical connexion between the observatories of Paris 
and Greenwich. The King gave his consent, and Major 
General Roy was appointed to carry out the undertaking. 
This was the origin of the British Siu^vey Office. Its work 
was hampered, at the outset, by the unsatisfactory nature 
of the standards of length. Already, in 1742, the Royal 
Society and the French Academy had instituted comparisons 
between the standards of measures and weights of the two 
countries which led to some improvement, and in 1758 
a committee of the House of Commons enquired into the 
subject; but no legislative action was taken until 1824. 
The question presented considerable difficulties, because 
the two original standards, one dating back to King 
Henry VII., kept at the Tower, and the other made during 
the reign of Queen Elizabeth, kept at the Exchequer, were 
of the rudest description, and did not agree with each other. 



208 Britain's Heritage of Science 

Francis Baily in 1836, referring to the latter, writes : " A 
common kitchen poker, filed at the ends by the most bungling 
workman, would make as good a standard. It has been 
broken asunder and the two pieces have been dovetailed 
together, but so badly that the joint is nearly as loose as that 
of a pair of tongs." In 1816 the Royal Society had received 
from the Secretary of State a request for assistance in 
ascertaining the length of a pendulum vibrating seconds of 
time at different stations of the Trigonometrical Survey. 
This brought the question of standards into prominence, 
and led to much valuable work being done ; but in the final 
construction of the present standards the Royal Astrono- 
mical Society took the lead, under the energetic superin- 
tendence of Francis BaUy. 

Greenwich Observatory, established by Charles II., was, 
from its foundation, closely connected with the Royal Society. 
In 1710 Queen Anne appointed its President and such other 
Fellows as he might nominate to be visitors of the Obser- 
vatory. For some time the Society exercised a real control 
over the work, receiving regular reports, making recommen- 
dations, and collecting the results for publication. At 
present the Royal Astronomical Society is associated with 
the Royal Society in nominating the members of the Board 
of Visitors. The important work carried out at Greenwich 
has been frequently referred to in these pages; it is recog- 
nized as the leading observatory of the world, and fixes the 
time used in aU civilized countries. 

The study of Meteorology owes much to the Royal Society, 
which in 1725 provided at its own expense a number of baro 
meters and thermometers to be used by its correspondents 
in different parts of the world. In 1773 the Council organized, 
under the superintendence of Henry Cavendish, regular 
meteorological observations in its own building, including the 
measurement of temperature, pressure, moistiu-e, and wind 
velocity. These observations were conducted, and published 
annually in the Philosophical Transactions, for nearly sixty 
years. They were discontinued because the situation of the 
building was not considered suitable, and regular observa- 
tions had been established at the Royal Observatory. A 
meteorological department of the Board of Trade was super- 



Greenwich Observatory, Meteorology 209 

seded in 1867 by a Meteorological Committee of the Royal 
Society, which was entrusted with the whole of the meteoro- 
logical work of the country. This was followed, in 1877, by 
the Meteorological Council, consisting of the President and 
four members nominated by the Royal Society, together with 
the Hydrographer of the Navy. Since 1905 a special 
Committee of H.M. Treasury, containing two representatives 
of the Royal Society, is entrusted with the meteorological 
organization of the coimtry. 

In 1842 regular magnetical as well as meteorological 
observations were instituted at Kew Observatory, bmlt 
in 1769 by King George III. for the purpose of observing 
the transit of Venus which occurred in that year. It came 
for a time under the direction of the British Association, 
but was handed over to the Royal Society in 1881 ; it 
passed to the National Physical Laboratory in 1905, and is 
now under the control of the Meteorological Committee. 
The Royal Society continues, however, to administer a Trust 
Pund of £10,000 conveyed to it by John Peter Gassiot, for 
the purpose of providing for magnetical and meteorological 
observations, which are being taken at Kew and Eskdale- 
muir. The directors of Kew Observatory included many 
distinguished men; among them Francis Ronalds, inventor 
of the first electric system of telegraphy, who designed and 
introduced the self-registering meteorological instruments, 
and Balfour Stewart, whose work has been mentioned in 
Chapter V. 

It was chiefly through the influence of General Sabine 
that the Royal Society was, diu'ing many years, the chief 
promoter of the study of Terrestrial Magnetism. Observa- 
tories all over the world were, directly and indirectly, organ- 
ized by that powerful and energetic personahty. The East 
India Company gave valuable help, and when the Royal 
Society in the year 1840 approached the Russian Government, 
a speedy reply was received through the Foreign Ofiice that, 
in consequence of the representations made by the Society, 
Russia had established ten magnetical observatories in her 
Empire, and was willing to provide the funds for a fTirther 
one to be erected at Pekin. 

The National Physical Laboratory was established in 



210 Britain's Heritage of Science 

1899, and placed under the control of the Royal Society. 
Its primary object is to provide proper standards of measure- 
ment for all branches of science, to test materials, to verify 
the indications of instruments and to determine physical 
constants. To serve these purposes, it has to be provided 
with means for carrying out researches on a large scale, more 
especially on problems connected vsith the industrial appli- 
cations of science. The Laboratory is administered by an 
Executive Committee, on which six of the more important 
technical societies are represented. From small beginnings 
the Laboratory has grown, under the directorship of Sir 
Richard Glazebrook, with quite remarkable rapidity, and at 
present its total annual income amounts to £50,000, of which 
nearly two -thirds is received for work done for private firms 
or Government departments. 

With foreign academies the Royal Society has always 
maintained most friendly relationships ; intercourse between 
scientific men of different countries was, indeed, one of its 
primary objects. In May 1661, before the incorporation of 
the Society by Royal Charter, one of its members gave an 
account of the proceedings at a meeting of French scientists 
who formed the nucleus of the future French Academy of 
Science, and in July of the same year a letter was addressed 
to them requesting the interchange of scientific informa- 
tion. In a communication sent to the Council of the 
Royal Society by Christian Huygens during the same month, 
after referring to his observations on Saturn, the author writes 
that the members of the French body were " excited to 
emulation of the Society of London, and proposed applying 
themselves to philosophical experiments ; " and adds that 
this is " a good effect produced by yom: example." The 
" Academic des Sciences " began to meet regularly in 1666, 
but was constituted finally only in the year 1699. The 
intimate relationship between the two scientific societies was 
illustrated in a striking manner when Sir Humphry Davy 
visited Paris while France and England were at war with 
each other. He was received with the highest honours, 
awarded a gold medal (p. 115), and elected a foreign member. 
In the early days of the Society, Mr. Henry Howard 
(afterwards Duke of Norfolk) interested himself in securing 



The Royal Society 211 

correspondents in different parts of Europe, with a view to 
adding specimens of interest to its collection, and obtain- 
ing information of value to the iadustries of the country. 
" Methinks," he writes, " it were worth our knowledge 
whether there are not now some persons in Italy that know 
the old Roman way of plaistering, and the art of tempering 
tools to cut porphyry, the hardest of marbles " ; and, again : 
" I am lately informed that there is a mineral salt plentifully 
to be found in the mines of Calabria, which has this particu- 
larity, that, being cast into the fire, cracks not, nor breaks 
in pieces. A specimen of that also would be acceptable."* 

The first commimication from the then recently estab- 
lished Academy of Sciences at Petrograd was received at 
the last meeting over which Sir Isaac Newton presided. 
After quoting the desire of the Czar to follow the English 
example in encouraging and cultivating science, the letter 
concludes with the assurance that the Russian Academicians 
" are the more inclined to make their addresses to, and 
desire most to have the approbation of, the Royal Society, 
as being the first of its kind, and that which gave rise to all 
the rest." 

The Royal Society has always encouraged the formation 
of scientific bodies of similar aims in other parts of the United 
Kingdom. In 1684 such a society was estabhshed at Dublin, 
with fuU encouragement of the authorities of the Royal 
Society, offered also to a similar effort made at Edinburgh 
in 1705. In 1731 a separate society for the improvement of 
medical knowledge was instituted in the latter city, but was 
re-modelled so as to include other subjects in 1739. It was this 
body which, under the name of " Royal Society of Edin- 
burgh," received its charter in 1783. The great work carried 
out by the scientific men of Scotland and Ireland, described 
in the preceding pages, is a sufiioient indication of the influence 
exerted by the Royal Societies of Edinburgh and Dublin, 
which — as also the Irish Academy of Sciences (founded in 
1782) — have always co-operated with the London Society in 
their common aims. The Royal Society of Arts was founded 
in 1753, for the promotion of Arts, Manufactures, and 

> Weld's " History of the Koyal Society," Vol, I., p. 189. 

2 



212 Britain's Heritage of Science 

Commerce, and the success with which it has worked to 
attain its objects needs no comment. 

When science became more specialized, the need for 
separate societies deaUng with the more technical portions 
of each subject began to grow. These societies now take an 
important share in the promotion of scientific researches. 
The Linnsean Society was founded in 1788, the Geological 
Society in 1807, the Boyal Astronomical Society in 1820, 
and the Chemical Society in 1841. 

What strikes the foreign visitor most when he enquires 
into the working of British scientific institutions is that the 
Royal Society receives no subvention from the Government. 
While in all foreign academies, the members receive an annual 
sum from the State, in England they pay both an entrance 
fee and regular subscriptions. The great French naturaUst, 
Cuvier, has some interesting remarks on the subject.^ The 
Royal Society, the oldest of the scientific academies, is, he 
says, " sans contredit I'une des premiferes par les decouvertes 
de ses membres," and he attributes this to the fact that, as 
it depends for its subsistence on the contributions of its own 
members, the number of Fellows must necessarily be large. 
The more niunerous a body, he argues, the smaller is the 
number of those who control its administration ; hence the 
Council of the Royal Society, in whom the administration 
is vested, is a small body with great powers, and can exert 
a stronger influence on the progress of science than con- 
tinental academies can do. 

So far from the Royal Society having ever received sub- 
ventions by the Government for general purposes, its Council 
resolved unanimously in 1798 to pay into the Bank of England 
a sum of £500 as a voluntary contribution towards the 
defence of the country. Up to that time, the whole expendi- 
ture of the Society was paid out of the entrance fees and 
subscriptions of the Fellows, the only legacy which had 
been received being a sum of £500 from Lord Stanhope, 
paid over in 1786. During the last century the financial 
resources of the Society have, however, been increased by a 
number of valuable endowments. 

1 "Mc'moires de I'lnstitut," 1826, p. 219. 




Thomas Young 



From u portrait by 
Sir Thomas Lawrence 



The Royal Institution 213 

The Society is now entrusted with -the administration 
of certain funds devoted by the Government to definite 
purposes, such as grants towards scientific researches, and 
the publication of scientific Hterature. It has been given 
free use of its apartments, first in Gresham College, later in 
Somerset House, and now in BurUngton House. 

There is no building in the world associated with so 
many classical and revolutionizing researches as that in 
which the Royal Institution is housed. The idea which led 
to its foundation is generally ascribed to Count Rumford ; 
the earhest document referring to the matter is an account 
of a meeting held at the house of Sir Joseph Banks, the 
President of the Royal Society, at which Count Rumford and 
other Fellows of the Royal Society were present. The title 
and purposes of the institution were then defined to be " for 
diffusing the knowledge, and facihtating the general intro- 
duction, of useful mechanical inventions and improvements ; 
and for teaching, by courses of philosophical lectures and 
experiments, the appUcations of science to the common 
purposes of life." 

The idea of research grew up in the time of Young and 
Davy, though Count Rumford must have had it in mind 
when through his influence the latter was appointed as first 
Professor of Chemistry. Much has already been said about 
the work of these two great philosophers, as well as that of 
Faraday, who succeeded Davy. Their successors worthily 
upheld the traditions of the Chairs. John Tyndall (1820- 
1893) was appointed Professor of Natural Philosophy in 
1854, and succeeded Faraday as superintendent of the labora- 
tories in 1866. He spent a useful hfe in scientific research, 
but win be remembered mainly as an advocate of scientific 
prin6iples and popularizer of science. His books have 
inspired many young men to the pursuit of science, and the 
one on " Heat as a Mode of Motion " still deserves to be 
read as a clear exposition of the fimdamental principles of 
heat. 

Sir James Dewar, who now occupies the Chair held by 
Davy and Faraday, has made his name famous through his 
researches on the liquefaction of gases. He was the first to 
liquefy air on a large scale, and subsequently following up 



214 Britain's Heritage of Science 

some earlier work of Worblewsky, he succeeded in not only 
liquefying, but also solidifying, hydrogen. By using liqtiid 
hydrogen, he was finally able to condense helium. He made 
extensive investigations on the properties of bodies at low 
temperatures, and his determination of the specific heats of 
elements as they approach the absolute zero of temperature 
has thrown quite a new light on the laws which up till then 
were believed to connect specific heat and atomic weight. 
Referring to his discovery of the absorptive properties of 
charcoal, we may quote the words of the President of the 
Royal Society in awarding him the Copley Medal in 1916 : 
" Many of the most interesting and important investigations 
made in Physics in recent years would have been impossible 
but for his invention of the method of obtaining very high 
vacua by the use of charcoal immersed in liquid air or 
hydrogen." 

A few words may be said in conclusion on the activities 
of the British Association, which held its first meeting 
at York in 1831. Its object was mainly the same as that 
which in the seventeenth century originated the meetings 
which ultimately led to the foundation of the Royal Society. 
British science in the nineteenth century could no longer be 
confined to the metropolis, and the provision of a more 
intimate and personal scientific intercom'se between men 
residing in different parts of the country became desirable. 
To the outside world the meetings of the British Association 
appear to be confined to annual discussions on a variety of 
subjects; but the main work of the Association is carried 
on throughout the year, and it can claim to have originated 
scientific enterprises of the highest value and importance. 
The introduction of scientific electrical luiits is the result of 
work initiated by the British Association, and in great part 
carried out by one of its Committees. Under the protection 
and with the financial support of the same body, John Milne 
was enabled to estabhsh his international organization for the 
observation of earth" tremors, and the need for the establish- 
ment of a National Physical Laboratory was first advocated 
by Sir Oliver Lodge at one of the meetings of the British 
Association. 

The history of the British Association forms a good 



The British Association 215 

example of the advantages of a liberal and flexible constitu- 
tion, which allows it to adjust its procedure and conditions 
to the ever-changing and increasing requirements of science. 

In concluding that part of Britain's heritage which deals 
with Physical Science, we may express the hope that the 
country will deserve, with increasing justification, the praise 
bestowed upon it by Biot^ : " Souhaiter une chose utile aux 
sciences c'etait avoir d'avance I'assentiment des savants 
d'Angleterre et I'approbation du gouvernement de ce pays 
eclair e." 

1 " Mtooirea de I'lnstitnt de France," 1818. 



216 Britain's Heritage of Science 



CHAPTER VIII 
Biological Science in the Middle Ages 

THROUGHOUT the Middle Ages natural science was a 
study of the written word of ancient writers, whose 
authority went unquestioned. Processes of observation or 
experiment were barely known. To this mediaeval tradition 
the age of the Tudors, in its attitude to scientific study, was 
to a large extent loyal. Authority was still final and definite. 
What Galen and Hippocrates, Aristotle and Pliny had written 
was subject-matter for dispute, for discussion, for argument, 
but not for direct investigation. In the same way the new 
Ught derived from the Arabs, which spread through the 
learned world at the latter end of the twelfth and at the 
beginning of the thirteenth centuries, was treated as a 
matter for dialectics by those who set the written word 
before actual observation or experiment in Nature. 

Let us consider the books in Enghsh at the disposal of 
an average man in the latter half of the sixteenth century. 
Through mediaeval times had drifted a certain " corpus " 
of moralized natural history known as the " Physiologus," 
which was in essence a Bestiarium. It took various forms, 
and was read throughout Europe and the Near East. This 
" Physiologus " was primarily religious in its aim, but dealt 
not only with the animals mentioned in the Bible but with 
other and often mythical monsters. Scientifically the 
zoology of the " Physiologus " was of the poorest; in fact, 
the study of zoology was at its worst during the Middle 
Ages; it had fallen far lower than in classical days. The 
" Physiologus " had its origin in Alexandria in early Christian 
times, and was translated into many tongues, including 
Coptic. It was sometimes fathered upon Ambrose, but is 
older than his day. 

During the eleventh century a certain " Episcopus 



Bartholomaeus Anglicus 217 

incertus," one Theobaldus, made a metrical version of the 
descriptions of twelve of the animals dealt with in this Uttle 
volume. This was published under the name " Physiologus 
Theobaldi Episcopi de naturis duodecim animaUum," the 
earliest printed edition being that issued at Delft in 1487. 
Numerous editions were published in many countries for the 
following century or two, but the contents of the volume 
were in a state of flux, additions and omissions appearing 
in many of the issues. 

But the chief book on natural history in the Middle Ages 
was an encyclopaedia entitled " Liber de Proprietatibus 
Rerum," compiled by the English Franciscan, Bartholomew 
often caUed Bartholomaeus Anglicus, who probably wrote 
some time about 1250, certainly before 1267, and in all 
probabiUty before 1260. Both before and after the invention 
of printing this work had a wide circulation. The " Liber " 
was translated into French by the order of Charles V., into 
Spanish in 1372, then into Dutch, and in 1397 into English. 
It was also the first book printed on paper which had been 
made in England. This book is believed to have been the 
source of much of Shakespeare's knowledge of natural history. 
In 1582 the Rev. Stephen Bateman, D.D., domestic chaplain 
to Bishop Parker, re-issued the English translation made by 
John of Trevisa which had been printed in 1494 by Wynkyn 
de Worde at Westminster. The book was entitled : 

" Bateman uppon Bartholome. His Booke De Pro- 
prietatibus Rerum : newly corrected, enlarged, and 
amended, with such Additions as are requisite, unto 
every severall Booke. Taken foorth of the most approved 
Authors, the like heretofore not translated in English. 
Profitable for aU Estates, as well for the benefite of the 
Mind of the Bodie." Lond. 1582, fol. Dedicated to 
Lord Hunsdon. 
Incomplete translations of Pliny from the French had 
appeared in 1565, and again in 1587. In 1601 Philemon 
Holland, M.D. (1552-1637), in later hfe headmaster of 
Coventry Grammar School — " the translator generall in his 
age," as Fuller calls him — pubUshed a more complete version 
of Pliny under the title " The History of the World, commonly 
called the Natural Historic of Caius PUnius Secundus." 



218 Britain's Heritage of Science 

This treats of all phases of nature, and contains a record 
of all natural knowledge up to the time of the younger Pliny, 
Nor must it be forgotten that the writings of Pliny and the 
" Georgics " of Vir^ were in constant use in the schools. 

In the middle of the thirteenth century Roger Bacon 
had pointed out that " There are two ways of knowing, 
viz., by means of argument and by experiment," but for 
three centuries onwaid it was " argument " which held the 
field. Not that the sixteenth century failed to produce 
enlightened men who were to preach a new doctrine. In 
his educational work " De Tradendis Disciplinis " (1523) 
Vives' advocates " nature study " and even uses the expres- 
sion. He tells us " That although the writings of the old 
Greeks and Romans are the opinions of learned men, yet 
not even all these opinions and judgments are to be accepted." 
Vives recommends that the pupil should first be shown what 
he can most readily perceive by the senses : 

" So will he observe the nature of things in the 
heavens, in clouds and in sunshine, in the plains, on the 
mountains, in the woods. Hence he will seek out and 
get to know many things from those who inhabit those 
spots. Let him have recourse, for instance, to gardeners, 
husbandmen, shepherds, and hunters, for this is what 
Pliny and other great authors undoubtedly did ; for any 
one man cannot possibly make all observations without 
help in such a multitude and variety of directions. But 
whether he observes an3rthing himself, or hears any- 
one relating his experience, not only let him keep eyes 
and ears intent, but his whole mind also, for great and 
exact concentration is necessary in observing every part 
of nature." 
We can but judge the state of zoology in Queen Elizabeth's 
time by the books and writings that have come down to us, 
and if we inquire what books and writings were available, 
they will be found to fall under the three headings, Medicine, 
Keldcraft, and Heraldry. From these subjects the paths 
of progress in that science were advancing and converging. 

' A Spanish educationalist who came to England in 1623 and was 
attached to Henry VIII. 's Court. Later he lectured at Oxford and 
became a Fellow of Corpus Christi College there 



Roger Bacon, Vesalius 219 

The year that saw the birth of Shakespeare -witnessed 
in the remote island of Zante the death of VesaUus, who, 
as a medical student at a hospital in Venice, had rubbed 
shoulders with a young soldier, Ignatius Loyola, who six 
years later founded the Order of the Jesuits. Vesalius, 
who was bom at Brussels on the last day of the year 1514, 
was the first biologist to abandon authority. Dispensing 
with the aid of unskilled barbers, he dissected the human 
body with his own hands. Like Harvey, whose discovery 
of the circulation of the blood dates but three years after 
Skakespeare's death, he 

" Sought for Truth in Truth's own Book, 
The creatures, which by God Himself was writ, 

And wisely thought 'twas fit. 
Not to read Comments only upon it. 
But on the original itself to look." 

At the beginning of his scientific career, hke his master 
Sylvius, Professor at the College of France, VesaUus trusted 
the written word of Galen more than he trusted his own 
eyesight, but in the end his sight and his reason conquered, 
and at last he taught only what he himself could see and 
make his students see. 

Vesahus was the founder of modern anatomy, physiology, 
and, I think we may say, also of modem zoology and 
botany, for the methods of these sciences are one. His 
great work on " The Structure of the Human Body " 
appeared at Basle in 1543, and was beginning to have 
influence in England, but only amongst the learned, well 
before the middle of the sixteenth century. 

His Enghsh pupils, amongst whom was John Caius, 
the third founder of Gonville and Caius College, helped to 
spread his methods and principles in this country. Amongst 
the many pupils of John Caius we may mention Thomas 
Moffett. Comparatively few men in those days hved much 
over fifty years, and Moffett, bom in 1553, died in 1604. 
He joined Trinity CoUege in 1569, but migrated to Caius 
in 1572, where he was nearly poisoned by eating mussels. 
After taking his M.A. degree, he, as was the habit of the time, 
studied abroad and received in 1578 the degree of M.D. 
at Basle where he was a pupU of Felix Plater and of Zwinger. 



220 Britain's Heritage of Science 

The following year he travelled in Spain and Italy, and in 
these countries he made an elaborate study of the silk- 
worm, which doubtless led him to the study of insects in 
general. He not only wrote a poem on the silk-worm, 
but collected notes on the natural history of the Insecta. 
These were published thirty years after his death under the 
title " Insectorum sive Minimorum Animalium Theatrum — 
ad vivum expressis Iconibus super quingentis illustratum." 
An English translation entitled the " Theater of Insects " 
was published as an appendix to Topsell's " History of 
Four-Footed Beasts and Serpents " in 1658. 

Moffett was a many-sided man of science, a practisiag 
physician, a traveller who at Copenhagen had known Tycho 
Brahe, a courtier who took part in both diplomatic and 
military service abroad, a poet and writer of epitaphs and 
epigrams, a keen critic of diet, and for some time a member 
of the House of Commons. 

A friend of MofEett's was Thomas Penny, who entered 
Trinity College, Cambridge, in 1550, and later became not 
only a Prebendary of St. Paul's, but a sound botanist and 
entomologist. Like so many men of the time, Penny 
travelled extensively on the Continent. He visited Majorca, 
Uved in the south of France, and worked in Switzerland 
with Gesner. He is believed to have been with Gesner 
when he died, and he certainly helped to arrange the natu- 
ral history specimens which the great master left. It was 
probably through Penny that Gesner's drawings of butter- 
flies passed into the care of Moffett, whose " Theatrum " 
states on its title-page that it was begun by Edward 
Wotton, Conrad Gesner, and Thomas Penny. 

The contents of books revealing new knowledge diffused 
themselves among the ordinary public in Queen Elizabeth's 
time far more slowly than at present. On the other hand, 
studies were then far less speciaUzed than they now are. 
For example, we find Milton placing medicine in the curri- 
culum of a liberal education, and John Evelyn studying 
" Physics " at Padua. Lord Herbert of Cherbury insists 
on the necessity of a gentleman being able to diagnose and 
treat disorders, and thinks he shovdd have a knowledge of 
anatomy " Whosoever considers anatomy, I believe, will 



Thomas Moffett, Thomas Pemiy 221 

never be an atheist," was one of his recorded sayings. 
Dealing with the matter broadly, I think we may endorse the 
statement of Mr. Foster Watson : " It is noteworthy, that 
in both botany and zoology the main advances were made 
by professed physicians," and we must not forget that Eliza- 
bethan botany was more advanced than Elizabethan zoology. 

Something, however, was learned from husbandry and 
field sport. " Let the student," says Vives in the above- 
quoted passage, '' have recourse, for instance, to gardeners, 
husban<hnen, shepherds, and himters," and in " De rebus 
rusticis " he says : " Let the boy read Cato, Varro, Columella, 
Palladius." " Vitruvius is important for naming with the 
greatest purity and accuracy most objects of the country." 
Virgil with his marvellous account of apiculture and other 
agricultural pursuits was much read during this period. 

The gentlefolk also in Queen Elizabeth's time were much 
interested in the study of heraldry, for, indeed, it was a 
very gentlemanly pursuit. Gerard Legh's " Accedens of 
Armory " (1562) and John GuilUm's " Display of Heraldry " 
(1610) included descriptions of creatures which enabled the 
owners of animal crests and supporters to appreciate the 
nature of what they bore and of what supported them. 

In Ehzabethan times, although a knowledge of physio- 
logy and human anatomy was beginning to emerge; such 
objects as comparative anatomy, morphology, and embryo- 
logy were non-existent. In dealing with the animal king- 
dom, the first need of the earlier writers on zoology was to 
make some sort of classification, and even in the later Tudor 
times such attempts at classification rested almost wholly on 
external characteristics. These arid catalogues of animals 
were usually Hghtened by the addition of notes on their 
habits — often of the quaintest and most bizarre description 
— and by short accounts of such medical properties as the 
fantastic pharmacy of the sixteenth century attributed to 
various beasts. 

With one or two exceptions — astronomy on the physical 
side, human anatomy on the biological — ^the reawakening 
in science lagged a century or more behind the renascence 
in literature and in art. What the leaders of thought and 
of practice in the arts of writing, of painting and of sculpture 



222 Britain's Heritage of Science 

in western Europe were efEecting in the latter part of the 
fifteenth and throughout the sixteenth century began to 
be paralleled in the investigations of the physical laws of 
Nature only at the end of the sixteenth century and through- 
out the first three quarters of the seventeenth. 

Writing broadly, we may say that, during the Stewart 
time, the sciences, as we now class them, were slowly but 
surely separating themselves out from the general mass of 
learning, segregating into secondary units; and from a 
general amalgam of scientific knowledge, mathematics, 
astronomy, physics, chemistry, geology, mineralogy, zoology, 
botany, agriculture, even physiology (tie offspring of anatomy 
and chemistry) were beginning to assert claims to individual 
and distinct existence. It was in the Stewart reigns that, 
in England at any rate, the speciaUst began to emerge from 
those who hitherto had " taken all knowledge to be " their 
" province." Certain of the sciences, such as anatomy, 
physiology and, to a great extent, zoology and botany, had 
their inception in the art of medicine ; but the last two owed 
much to the huntsman and the agriculturist. 

The great outburst of scientific enquiry which occurred 
during the seventeenth century was partly the result, and 
partly the cause, of the invention of numerous new methods 
and innumerable new instruments, by the use of which 
advance in natural knowledge was immensely facilitated. 

The barometer, the thermometer and the air pump, and, 
later, the compound microscope, all came into being at the 
earlier part of the seventeenth century, and by the middle 
of the century were in the hands of whoever cared to use 
them. Pepys, in 1664, acquired : 

" a microscope and a scotoscope. For the first I 

did give him £5 10s., a great price, but a most curious 

bauble it is, and he says, as good, nay, the best he knows 

in England. The other he gives me, and is of value; 

and a curious curiosity it is to discover objects in a dark 

room with." 

Two years later, on August 19th, 1666, " comes by 

agreement Mr. Reeves, bringing me a lantern " — ^it must 

have been a magic lantern — " with pictures in glass, to make 

strange things appear on a wall, very pretty." 



Francis Bacon 223 

As we pass from Elizabethan to Stewart times, we pass, 
in most branches of literature, from men of genius to men 
of talent, clever men, but not, to use a Germanism, epoch- 
making men. In science, however, where England led the 
world, the descent became an ascent. We leave Dr. Dee 
and Edward Kelly, and we strnye at Harvey and Newton. 

The gap between the mediaeval science which still 
obtained in Queen Ehzabeth's time and the science of the 
Stewarts was bridged by Francis Bacon, in a way, but only 
in a way. He was a reformer of the scientific method. He 
was no innovator in the inductive method; others had 
preceded him, but he, from his great position, clearly pointed 
out that the writers and leaders of his time observed and 
recorded facts in favour of ideas other than those hitherto 
sanctioned by authority. 

Bacon left a heritage to Enghsh science. His writings 
and his thoughts are not always clear, but he firmly held, 
and, with the authority which his personal eminence gave 
him, firmly proclaimed, that the careful and systematic 
investigation of natural phenomena and their accurate record 
would give to man a power in this world which, in his time, 
was hardly to be conceived. What he believed, what he 
preached, he did not practise. " I only sound the clarion, 
but I enter not into the battle " ; and yet this is not wholly 
true, for, on a wintry March day, in 1626, in the neighbour- 
hood of Bamet, he caught the chill which ended his life while 
stuffing a fowl with snow, to see if cold would delay putre- 
faction. Harvey, who was working whilst Bacon was writing, 
said of him : "He writes philosophy hke a Lord Chancellor." 
This, perhaps, is true, but his writings show him a man, 
weak and pitiful in some respects, yet with an abiding hope, 
a sustained object in life, onfe who sought through evil days 
and in adverse conditions " for the glory of God and the 
rehef of man's estate." 

Though Bacon did not make any one single advance in 
natural knowledge — ^though his precepts, as Whewell reminds 
us, " are now practically useless " — ^yet he used his great 
talents, his high position, to enforce upon the world a new 
method of wrenching from Nature her secrets and, with 
tireless patience and untiring passion, impressed upon his 



224 Britain's Heritage of Science 

contemporaries the conviction that there was " a new 
unexplored Kingdom of Knowledge Tvithin the reach and 
grasp of man, if he will be humble enough, and patient 
enough, and truthful enough to occupy it." 

To turn to other evidence, the better diaries of any age 
afford us, when faithfully written, as fair a clue as do the 
dramatists of the average intelligent man's attitude towards 
the general outlook of humanity on the problems of his age, 
as they presented themselves to society at large. The 
seventeenth century was unusually rich in volumes of auto- 
biography and in diaries which the reading world will not 
readily let die. The autobiography of the complaisant Lord 
Herbert of Cherbury gives an interesting account of the 
education of a highly-born youth at the end of the sixteenth 
and the beginning of the seventeenth century. Lord Herbert 
seems to have had a fair knowledge of Latin and Greek and 
of logic when, in his thirteenth year, he went up to University 
College, Oxford. Later, he " did attain the knowledge of 
the French, Italian and Spanish languages," and, also, 
learnt to sing his part at first sight in music and to play on 
the lute. He approved of "so much logic as to enable men 
to distinguish between truth and falsehood and help them to 
discover fallacies, sophisms and that which the Schoolmen 
call vicious arguments " ; and this, he considered, should 
be followed by " some good sum of philosophy." He held 
it also requisite to study geography, and this in no narrow 
sense, laying stress upon the methods of government, 
religions and manners of the several states as well as on their 
relationships inter se and their policies. Though he advocated 
an acquaintance with " the use of the celestial globes," he 
did " not conceive yet the knowledge of judicial astronomy 
so necessary, but only for general predictions; particular 
events being neither intended by nor collected out of the 
stars." Arithmetic and geometry he thought fit to learn, 
as being most useful for keeping accounts and enabling a 
gentleman to understand fortifications. 

Perhaps the most characteristic feature of Lord Herbert's 
acquirements was his knowledge of medicine and subjects 
allied thereto. He conceived it a " fine study, and worthy 
a gentleman to be a good botanic, that so he may know 



Lord Herbert, John Evelyn 225 

the nature of all herbs and plants." Turther, " it will become 
a gentleman to have some knowledge in medicine especially 
the diagnostic part " ; and he urged that a gentleman should 
know how to make medicines himself. He gives us a Ust 
of the " pharmacopseias and anechodaUes " which he has 
in his own hbrary, and certainly he had a knowledge of 
anatomy and of the healing art — ^he refers to a wound which 
penetrated to his father's " pia mater," a membrane for a 
mention of which we should look in vain among the records 
of modem ambassadors and gentlemen of the court. His 
knowledge, however, was entirely empirical and founded 
on the writings of Paracelsus and his followers; never- 
theless, he, prides himself on the cures he effected, and, 
if one can trust the veracity of so self-satisfied an amateur 
physician, they certainly fall but httle short of the 
miraculous. 

John Evelyn, another example of a well-to-do and widely 
cultivated man of the world, fond of dancing and skilled 
in more than one musical instrument, was acquainted with 
several foreign languages, including Spanish and German, and 
was interested also in hieroglyphics. He studied medicine 
in 1645 at Padua, and there acquired those " rare tables of 
veins and nerves " which he afterwards gave to the Royal 
Society; while at Paris, in 1647, he attended Lefevre's course 
of chemistry, learned dancing and, above all, devoted himself 
to horticulture. 

But Evelyn's chief contribution to science, as already 
indicated, was horticultural. He was devoted to his garden, 
and, both at his native Wotton, and, later, at Sayes Court, 
Deptford, spent much time in planting and planning land- 
scape gardens, then much the fashion. 

In the middle of the sixteenth century, the fact that 
" nitre " promoted the growth of plants was beginniug to 
be recognized. Sir Kenehn Digby and the young Oxonian 
John Mayow experimented de Sal-Nitro ; and, in 1675, 
Evelyn writes : " I firmly beheve that where saltpetre can 
be obtained in plenty we should not need to find other 
composts to ameUorate our ground." His well-known 
" Sylva," pubhshed in 1664, had an immediate and a wide- 
spread effect, and was, for many years, the standard book 



226 Britain's Heritage of Science 

on the subject of the culture of trees. It is held to be 
responsible for a great outbreak of tree-planting. The 
introduction to Nisbet's edition gives figures which demon- 
strate the shortage in the available supply of oak timber 
during the seventeenth century. The charm of Evelyn's 
style and the practical nature of his book, which ran into 
four editions before the author's death, arrested this decline 
(" be aye sticking in a tree ; it will be growing, Jock, when 
y're sleeping " as the laird of Dumbiedykes counselled his 
son), and to the " Sylva " of John Evelyn is largely due the 
fact that the oak timber used for the British ships which 
fought the French in the eighteenth century sufficed, but 
barely sufficed, for the national needs. 

Pepys, whose naive and frank self -revelations have made 
him the most popular and the most frequently read of diar- 
ists, was not quite of the same class of student to which 
Lord Herbert of Cherbury or John Evelyn belonged. But, 
gifted as he was with an undying and insatiable curiosity, 
nothing was too trivial or too odd for his notice and his 
record; and, being an exceptionally able and hard-working 
Grovemment servant, he took great interest in anything 
which was likely to affect the Navy. He discoursed with the 
ingenious Dr. Kuffler " about his design to blow up ships," 
noticed " the strange nature of the sea-water in a dark night, 
that it seemed like fire upon every stroke of the oar " — 
an effect due, of course, to phosphorescent organisms fioat- 
ing near the surface — and interested himself incessantly in 
marine matters. 

Physiology and mortuary objects had, for him, an interest 
which was almost morbid. He is told that " negroes drounded 
look white, and lose their blackness, which I never heard 
before," describes how " one of a great family was . . . 
hanged with a silken halter ... of his own preparing, 
not for the honour only " but because it strangles more 
quickly. He attended regularly the early meetings of the 
Royal Society at Gresham College, and showed the liveliest 
interest in various investigations on the transfusion of 
blood, respiration imder reduced air pressure and many 
other ingenious experiments and observations by Sir George 
Ent and others. On January 20th, 1665, he took home 



Samuel Pepys 227 

" Micrographia," Hooke's book on microscopy — " a most 
excellent piece, of wMch I am very proud." 

Although Pepys had no scientific training — he only began 
to learn the multiplication table when he was in his thirtieth 
year, but, later, took the keenest pleasure ia teaching it 
to Mrs. Pepys — one could have wished that Mrs. Pepys' 
views had been recorded — ^he, nevertheless, attained to the 
Presidentship of the Royal Society. He had always delighted 
in the company of " the virtuosos " and, ia 1662, three years 
after he began to study arithmetic he was admitted a Pellow 
of their — ^the Royal — Society. In 1681 he was elected 
President. This post he owed, not to any genius for science, 
or to any great invention or generaUzation, but to his very 
exceptional powers as an organizer and as a man of business, 
to his integrity and to the abiding interest he ever showed 
in the cause of the advancement of knowledge. 

It has been said that a competent man of science shoxild 
be able to put into language " understanded of the people " 
any problem, no matter how complex, at which he is working. 
This seems hardly possible in the twentieth century. To 
explain to a trained histologist double 6 functions or to a 
skilled mathematician the intricacies of karyokinesis would 
take a very long time. The iatroduction in all the sciences 
of technical words is due not to any spirit of perverseness 
on the part of modem savants ; these terms, long as they 
usually are, serve as the shorthand of science. In the Stewart 
times, however, an investigator could explain in simple 
language to his friends what he was doing, and the advance 
of natural science was keenly followed by all sorts and 
conditions of men. 

Whatever were the pohtical and moral deficiencies of 
the Stewart kings, no one of them lacked inteUigence in 
things artistic and scientific. At Whitehall, Charles II. 
had his " Uttle elaboratory, imder his closet, a pretty place,"i 
and was working there but a day or two before his death, 
his illness disinclining him for his wonted exercise. The 
king took a curious interest in anatomy; on May 11th, 
1663, Pierce, the surgeon, tells Pepys " that the other day 



' Pepys, January 16th, 1669. 

P 2 



228 Britain's Heritage of Science 

Dr. Gierke and he did dissect two bodies, a man and a woman, 
before the King, with which the King was highly pleased." 
Pepys also records, February 17th, 1662-3, on the authority 
of Edward Pickering, another story of a dissection in the 
Royal closet by the Mng's own hands. 



229 



CHAPTER IX 
Botany 

IT is generally conceded that the first eminent English 
botanist was WiUiam Turner (bom probably between 
1510 and 1515, died 1568), educated at Pembroke College, 
Cambridge. After the manner of his time, Turner was not 
only a botanist but a zoologist ; to his work in this subject 
we shall return later; he was further a most polemical 
divine, and suffered much with the alternate ebb and flow 
of the varying religious faiths which prevailed in the country 
during the Tudor times. Turner's earliest work on botany 
was the " Libellus de re Herbaria novus," 1538, which may 
also be regarded as the first English book on Botany. In 
this he gives, for the first time, the locality of many of our 
native British plants. Ten years later he pubhshed a work 
on "Names of Herbes in Greke, Latin, EngHshe, Duche, 
and Frenche, with the commune names that Herbaries and 
Apothecaries use." His best known work, however, was 
his " Herball," which was published in three parts, the 
first part appearing in 1551, the second when he was exiled 
abroad in 1562, and the third in 1568. This was by no 
means the first " Herball " which had appeared in Enghsh, 
but it had a certain originahty about it and a certain 
independence of view. Turner was especially opposed to 
what he considered superstitions in science, such as the old 
legend about the mandrake ; but at the same time he seems 
to have adopted and perpetuated the fable of the goose-tree 
which bore barnacles from which geese hatched out. He 
did not accept this myth without real enquiry and an effort 
to obtain first-hand information, and he certainly would 
never have written as Gerard wrote that, " he had seen 
these trees with his own eyes, and had touched them with 
his own hands." Turner's days were the days of herbals. 



230 Britain's Heritage of Science 

and one cannot, perhaps, give a better description of what 
a herbal was than by quoting the title-page of Ljrte's (1529- 
1607) Herbal, which was mainly a translation from the 
French of De L'Ecluse, which was itself a translation from 
the " Craijdeboeck " of Dodoens. 

" A niewe Herball, or Historic of Plants, wherein is 
contayned the whole discourse and perfect description 
of all sortes of Herbes and Plantes; their divers and 
sindry Idndes; their straunge Mgures, Fashions, and 
Shapes ; their Names, Natures, Operations, and Vertues ; 
and that not only of those which are here growing in 
this our countrie of Englande, but of all others also of 
foragne Realmes, commonly used in Physicke. First 
set foorth in the Doutche or Almaigne tongue by that 
learned D. Rembert Dodoens, Physition to the Emperour, 
and now first translated out of Frenche into Englishe 
by Henry Lyte, Escuyer." 

This herbal went through several editions, but apart 
from it Lyte made little contribution to English botany. 

One especial merit which Turner had was accuracy of 
observation, and a determination to see what he had to 
describe. Hitherto, knowledge largely depended upon the 
written word of the classical philosophers. Turner pre- 
ferred to record his own experiences rather than to repeat 
" Pliny's Hearsay." He named many British plants, and, 
as Pulteney tells -us, "allowing for the time when specifical 
distinctions were not established, when almost all the small 
plants were disregarded, and the Cryptogamia almost wholly 
overlooked, the number he was acquainted with was much 
beyond what could easily have been imagined in an original 
writer on the subject." 

Although other distinguished herbahsts who followed in 
Turner's path in the main disregarded his work, there is 
no doubt that he started a new era in the study of plants, 
and we shall see later he did the same in the study of animals. 
Another noted herbalist was John Gerard (1545-1612). 
Unlike Turner, he was brought up to be a surgeon, and in 
his youth travelled extensively in Russia, Sweden, Norway, 
and other parts of the Continent. To some extent he re- 
garded plants from the medical point of view, and in what 



The Herbalists 231 

was then the village of Holbom, he grewnearly 1,100 various 
species of " simples." " The Herball or Generall Historie 
of Plantes " is Gerard's claim to fame. Like Lyte's book, 
it was based upon the works of Dodoens, and there was a 
bitter quarrel as to the exact amount of credit due to th« 
author of the English edition. Being a physician, Gerard 
naturally attached considerable importance to the medi- 
cinal side of plants, but he was also a practical gardener, 
and the popularity of his book probably depended to some 
extent upon the fact that it was the first published in 
English of practical use to horticulturists and gardeners. 

One last herbahst may be mentioned, Thomas Johnson, 
again a medical man with a physic garden of his own. He 
was a botanist who travelled in the country inspecting and 
recording the local flora, in fact his first publication was 
on the flora of the county of Kent. But his claim to 
mention depends upon his new edition of Gerard's " HerbaU, 
which he enlarged, re-edited, and published in 1633. He 
added some 800 plants which were unknown, or at any rate 
unrecorded, by Gerard, and increased the number of figures 
by 700, raising the total to over 2,700. Further and de- 
tailed information on herbals may be found^in Mrs. Arber's 
delightful book on the English herbalists. 

At the best, however, these herbals were full of super- 
stitious and often nonsensical statements. They must 
merely be regarded as catalogues, compilations as a rule 
alphabetically arranged, for in the time when they mostly 
flourished, plants had not been systematically sorted out. 
Their affinities had not been estabhshed ; as Professor Green 
says, " a herbal may be compared to a dictionary rather than 
to any other form of book." 

The next outstanding man in the history of British 
botany is John Ray (1628-1705). He dealt with both 
animals and plants, and what httle space we can afford 
for biographical details will be found imder the chapter 
deahng with Zoology. like Turner and like so many other 
botanists, Ray was a clergyman. He marks a new era in 
the history of the science of Botany, partly on account of 
his efforts towards a natural classification of plants, and 
partly on account of his extreme accuracy in the use of 



232 Britain's Heritage of Science 

words. He was, indeed, as Sir J. E. Smith said, " the most 
accurate in observation, the most philosophical in contem- 
plation, and the most faithful in description amongst all 
the botanists of our own or perhaps any other time." In 
his " Methodus Plantarum Nova " (1682), after recognizing 
a certain indebtedness to Csesalpino and to Morison, the 
first Professor of Botany at Oxford, he expounds his system 
of classification and estabhshed, for the first time, the dis- 
tinction between Dicotyledons and Monocotyledons. Also 
here he showed the true nature of buds, and indicated many 
of the Natural Orders which systematists now recognize. 

Unfortimately, like other botanists of the time, he 
retained the unnatural divisions of plants iato trees, shrubs, 
and herbs. Four years later, Ray published his first 
volume of the " History of Plants," and, ia 1688, the second 
volume, the third and final volume appearing shortly before 
his death in 1704. This work contains a description of 
nearly 7,000 plants. In 1690 he re-edited the " Catalogus 
Plantarum Angliae," which was the first manual of systematic 
botany pubhshed ia England, and was in constant use for 
nearly a century afterwards. But Ray was far more than 
a systematist ; in fact, he had a very wholesome and proper 
disinclination for the founding of new species. As far as 
appUances of the times went, he investigated the physiology 
and the histology of plants. His researches on the move- 
ments of plants and the ascent of sap were as complete as 
they could be under the conditions prevailing during his 
lifetime. He, with his colleague Willughby, studied the 
bleeding of fresh-severed portions of the birch and the 
sycamore, both of the branches and of the roots. He was 
inclined, though not definitely decided, to accept the sexu- 
ahty of plants, and supported Grew by his knowledge of 
the reproductive process in the animal Mngdom. However, 
he did not go further than " ut verisimilem tantum 
admittamus." But later, he admitted, the male character 
of the stamens which after aU was giving the whole case 
away. 

Botany, without any doubt, owes a great deal to Ray. 
As Miall has said, " he introduced many lasting improve- 
ments — ^fuller descriptions, better definitions, better asso- 




John Ray 



From an original portrait 
in the British. Museum 



John Ray, Robert Morison 233 

ciations, better sequences. He strove to rest his distinctions 
upon knowledge of structure, which he personally investi- 
gated at every opportunity." He sought for a natural 
system and made considerable steps towards one. In his 
classification he relied largely upon the nature of the fruit, 
but he insisted also upon the importance of vegetative 
habit. He laid stress upon the structure of the seed, appre- 
ciated the fact that it not only contained an embryo, but 
also the substance we now know as endosperm, but which 
he called " medulla " or " pulpa." He made things much 
easier for Linnaeus, as did Linnseus in his turn for 
naturalists who now snule at his mistakes. Both were 
capable of proposing haphazard classifications, a fact which 
need not surprise us when we refiect how much reason we 
have to suspect that the best arrangements of birds, 
teleostean fishes, insects and flowering plants known to 
our own generation need to be largely recast. 

A few words must be said about Eobert Morison (1620- 
1683), a contemporary and to some extent a rival of Ray's, 
and whose system of classification for a time, but for a time 
only, outshone Ray's. Morison was an Aberdonian and a 
Royalist, and having been wounded at the battle of Brigg, 
he removed to Paris, the asylum of many of his countr5mien. 
Here he took up the study of natural science, and ultimately 
became the Superintendent of the fine garden of the Duke 
of Orleans at Blois. On the death of the Duke in 1660, 
Morison returned to England with Charles II., the Duke's 
nephew. Charles gave him the title of " King's Physician 
and Royal Professor of Botany," and made him Superin- 
tendent of the Royal Gardens. Nine years later he was 
elected " Botanic Professor " at Oxford, where he remained 
until his death. 

Ray, who was of humble origin, Uved a simple life, and 
was emphatically an open air naturaUst. Morison, who 
frequented courts and the higher walks of imiversity lite, 
although to a certain extent a field naturahst, more than 
Ray, reUed on the works of his predecessors. After settling 
at Oxford, he gave his whole energies to the production of 
his " Historia Plantarum Universahs Oxoniensis." As an 
example of what he wished the book to be, he published 



234 Britain's Heritage of Science 

a monograph on the Umbelliferce, the first British mono- 
graph devoted exclusively to the elucidation of a single 
large Natural Order. The book was illustrated by some of 
the first copper plates which were produced in these islands. 
Morison endeavoured to trace the systematic relations of the 
members of the family by the aid of a linear arrangement, 
and even attempted a genealogical tree. He divided the 
flowering plants into fifteen classes; but he was only able 
to deal with five of these before his death, though he left 
the four succeeding ones finished. The remainder were 
completed by Jacob Bobart, the Superintendent of the 
Gardens at Oxford. 

Morison's families were too few in number, and conse- 
quently often overcrowded with what later observation has 
shown to be a heterogeneous collection of plants. He 
worked from the particular to the general, beginning with 
the smallest subdivisions and working up to the larger ones. 
Like Ray, he accepted the division of plants into herbs, 
shrubs, and trees; but, unlike Ray, he ignored the dis- 
tinction between monocotyledons and dicotyledons. He 
seems to have been a somewhat selfish man of science, 
self-assertive, taking every credit to himself, while allowing 
httle to his predecessors and contemporaries. 

During the latter half of the seventeenth century the 
second name of quite outstanding merit in the history of 
British Botany — second to that of Ray — ^is that of Nehemiah 
Grew (1641-1712). like Turner, he was educated at Pem- 
broke College, Cambridge, and he subsequently studied 
medicine at Leyden, where he took his doctor's degree in 
1671. For a time he practised medicine at Coventry, and 
later removed to London. He and his contemporary, the 
Italian Malpighi, with whom he was always on good terms, 
are regarded as the founders of vegetable anatomy. He 
was the author of numerous works not all by any means 
confined to botany. The greatest of his contributions to 
that science was the " Anatomy of Plants," issued in 1684. 
Sections I., II., and III. of this volume were second editions 
of the " Anatomy of Vegetables Begun." The anatomy 
of roots and the anatomy of trunks followed. The fourth 
section included the anatomy of leaves, flowers, fruits, and 



Neliemiah Grew 235 

seeds. The book was richly illustrated. Grew undoubtedly 
saw for the first time many structural features ia plants, 
and although he was not always successful in interpreting 
their functions, he added greatly to our knowledge. His 
description of the bean-seed might still be used in a modem 
Elementary Biology Class. He notes the cotyledons, and 
states that the foramen (micropyle) " is not a hole casually 
made, or by the breaking off of the stalk; but designedly 
formed for the uses hereafter mentioned." He recalls that 
when squeezed a bean seed gives rise to many small bubbles 
through " the foramen." He notes the radicle, the plumule, 
and the two seed-lobes, and is aware that the latter are a 
particular kind of leaf — " dissimilar leaves " he calls them, 
and he finds that their parenchyma consists of an infinite 
number of extremely small " bladders." He also notes 
elsewhere that rows or files of " bladders " piled perpendicu- 
larly one above each other at times break in upon one another, 
and so make a " continued cavity." He recognized and 
understood the resin passages in a pine tree, and describes 
the medullary rays. He dwells upon the use of hooks in 
climbing plants, and the fact that the various whorls of a 
flower are arranged alternately. He invented the term 
" parenchyma " and others stUl in use. He was aware of the 
existence of stomata, and considers they were either " for 
the better avulation of superfluous sap or for the admission 
of air." To the flower itself he paid particular attention, 
but failed to grasp the use of pollen. He was, however, the 
first to point out that flowers are sexual, but unfortunately, 
although he is fairly definite on the subject, he made few 
experiments. He also described fuUy and completely the 
sporangia of a fern. 

Grew, like Ray, was a man of great piety, simpHcity, 
and undoubted modesty, and he considered that both 
" plants and animals came at first out of the same Hand, 
and were therefore the contrivance of the same Wisdom." 
Hence he endeavoured to find analogies and homologies 
between animals ajid vegetables, which later work could 
not endorse. like most of his contemporaries he interested 
himself in the ascent of the sap, which he mainly attributed 
to capillarity. He stated that the green colour of a plant 



236 Britain's Heritage of Science 

was dependent upon its exposure to air, but he missed the 
fact that the green colouring matter is dependent upon light. 
He had noticed that many vegetable juices were turned 
green by the addition of alkaUes, and he considered that some 
alkaline properties of the air produced the weU-known colour 
of leaves. He was groping after the fact that air was necessary 
to a plant for its nutrition, though his ideas were by no means 
definite. On the whole his greatest contribution to Science 
is his discovery- of the sexuaUty of plants ; but that is at 
least equalled or more than outweighed by his general contri- 
butions to our knowledge of the anatomy of plants and to 
the science of Botany in almost all its aspects. 

The last half of the seventeenth century is distinguished 
by the two names of Ray and Grew. Ray, unfortunately, 
had no successor. Stephen Hales, with whom we now deal, 
was the soHtary follower of Grew until comparatively modem 
times. 

Stephen Hales (1671-1761) was bom in Kent and belonged 
to the same family as Sir Edward Hales, titular Earl of 
Tenterden, the weU-known Royahst. He was educated at 
Corpus Christi College, Cambridge, where he was admitted 
a Fellow in 1602-1603. As a resident of Cambridge he 
" scoured the fields for Ray's plants," and worked in the 
" laboratory at Trinity College." 

In 1708-1709 he became perpetual curate of Teddington, 
Middlesex, in which parish, although he held from time to 
time other benefices, he mainly resided. Living not far from 
Kew he was the friend of the royalties, and although Horace 
Walpole called him " a poor good primitive creature," he 
was greatly admired and respected by them, and was a 
close friend of Pope's, whose will, in fact, he witnessed. 

Sir Francis Darwin draws attention to the fact that 
Hales' scientific work falls iato two main classes : (1) physio- 
logical and chemical, (2) inventions and suggestions on 
matters connected with health and agriculture. It is with 
the former we have mainly to deal. 

Hales, as we have pointed out, was the single successor 
in the eighteenth century of Nehemiah Grew, but in his 
time scientific men were less speciaUzed than they are now, 
and Hales was not only a leader in vegetable physiology, 




Stephen Hales 



'•'rom a portrait by Thomas Hudso 



Stephen Hales 237 

but an active researcher in animal physiology. He, in fact, 
introduced into both fields of Physiology the process of 
weighing and measuring. His experiments on the loss of 
water which plants suffered by evaporation and on the 
absorption of water by roots are classic, and still remain 
of the greatest importance. His suggestion that the ascent 
of the sap is not from the roots only but must proceed from 
some power in the stem and branches, has recently met with 
a certain amount of corroboration. He introduced a new 
method by ever seeking a quantitative knowledge of the 
various phjrsiological functions he was enquiring into. He 
experimented on the amount of rain and dew on special 
areas of the ground, and on the expansive force that peas 
exhibit when they absorb water, and explained variations 
in pressure from hour to hour on the rate of growth of the 
various members of the plant-organism, and aU by methods 
which are still in use. He was one of the first to oppose 
the older views on the circulation of sap — ^views which had 
certainly retarded progress — and at any rate he had some 
inkling that air is a source of food to plants. He also had 
a clear idea of the importance of scientific knowledge in its 
practical application to agriculture. Without any doubt, 
the Englishman Hales must be regarded as the founder of 
that very important science. Plant Physiology. 

Hales was a man of many inventions, and he devoted 
his extraordinary ingenuity largely to improving ,the lot 
of oppressed mankind. He invented various artificial 
ventilators which were used in granaries, ships, and prisons, 
and, so far as one can make out, the health of the prisoners 
greatly benefited by the introduction of his appliances. 
He also experimented on the distillation of salt water to 
make it fresh, on the preservation of various forms of food 
for sea voyages, on methods for cleaning harbours, and he 
devised an instrument for deep-sea dredging which, together 
with a large number of other mechanical contrivances, 
occupied his ever active mind. 

Hales was evidently a lovable, kindly character, and 
without doubt was the greatest physiologist of his age, and 
of many later ages. 

One other man of science, although not a botanist, must 



238 Britain's Heritage of Science 

be mentioned here because of his profoundly important 
discovery in connexion with the function of leaves. It was 
the chemist Joseph Priestley (1733-1804), who, while working 
on the investigation of the air, states : " I have been so 
happy as by accident to have hit upon a method of restoring 
air which has been injured by the burning of candles, and 
I have discovered at least one restorative which nature 
employs for this purpose. It is vegetation." He records 
in 1778 that the green deposit in some vessels which he was 
using for his experiments gave off very " pure air," and 
discovered that this exhalation was given off when the algse, 
as they proved to be, were exposed to sunlight. 

Thomas Andrew Knight (1759-1838) was the only out- 
standing physiologist between Hales and the rise of the modern 
school, and even he was more prominent as a horticulturist 
than as a physiologist. He was educated at Balliol College, 
Oxford, and, being in the possession of ample means, settled 
first in Herefordshire and later at Downton, where he resided 
until his death. He made the acquaintance of Sir Joseph 
Banks, who was at that time seeking, on behalf of the Board 
of Agriculture, certain correspondents who would answer 
questions relating to agriculture in their several districts. 

Knight was the second President of the Horticultural 
Society, which had been founded in 1804. He was elected 
in 1810, and occupied the Presidential Chair until his death. 

His physiological investigations began with enquiries as 
to the circulation of sap, and one of the methods of his 
investigations was ringing the trees. He failed, however, 
to appreciate the part that the leaf plays in nutrition, and 
that the " fimction of the sap is to supply nutritive materials 
to the various tissues and to circulate the manufactured 
products of the leaf." 

But, as Professor 6reen reminds us. Knight's work on 
the ascent and descent of sap " did much that was not only 
instructive for the time," but " was destined to remain with 
little modification among the fundamental facts of science." 
He made certain anatomical discoveries in connexion with 
these physiological experiments, and he incidentally investi- 
gated the transpiration or, as it was then called, " the 
perspiration," of the leaf, and showed that it was chiefly 



Thomas Andrew, T. A. Knight 239 

carried on by the under surface. His most important work 
was, however, his investigations into the relation of plants 
and their growth to the condition of their environment. 
He had noticed that, however seeds are placed during 
germination, the radicle attempts to descend into the earth 
and the shoot attempts to ascend into the air. He used a 
water-mUl wheel in his garden, a wheel which revolved 
rapidly on a horizontal axis on the edge of which he placed 
his germinating seeds. He found that the shoots, no matter 
how they were pointed at first, gradually turned their points 
outwards from the circumference of the wheel, whilst the 
radicles grew inwards, so that " in a few days their points 
all met in the centre wheel." By this device Knight added 
a new apparatus in the investigation of growth. Later he 
paid much attention to the tendrils of Ampelopsis and the 
clasps of ivy, noting that they showed a tendency to grow 
away from the Ught. Much of his scientific work had 
a utilitarian bias, and he published many papers of a strictly 
horticultural nature. 

In the management of his estate at Downton he experi- 
mented continually on the raising of hybrids, and bred a 
large number of new varieties of fruits and vegetables, many 
of which stiU bear his name. 

Knight was a man of great patience and great perseverance, 
and seems to have had a charming personality, warm-hearted 
and generous, a Mttle hasty at times, but of great kindness. 

iiithough Linnaeus (1707-1778) does not come within 
the scope of this volume, a few hnes must be devoted to the 
great influence his views had on Enghsh thought. Without 
being a great investigator he remodelled the art of description. 
He introduced new and concise terms. He re-established 
the binomial nomenclature of plants, and he devised an 
artificial method of classification by means of which a com- 
petent botanist could determine the genus and species of 
almost any flower. But he was more of a co-ordinator than 
an investigator. He added few new facts to science, and, 
as Professor Green states, " we cannot find that either he 
nor any of his immediate pupils made a single discovery of 
any importance." His great talents lay in organization. He 
had a gift for sorting but things and putting them into what 



240 Britain's Heritage of Science 

he considered the right place. His sexual system of classifi- 
cation was, as he himself felt, a merely temporary one, but 
it caught on and for fifty years did much to hinder the pro- 
gress of real scientific enquiry into the natural relationships 
of plants inter se. 

His name leads us on to Sir J. E. Smith (1759-1829), a 
friend of Sir Joseph Banks. In fact it was at his breakfast 
table that the news came that the mother of Linnaeus had 
recently died, and that his collections were offered for sale. 
Smith, who was a man of considerable means, purchased 
the collections for a thousand guineas, and although the 
Swedish Government are said to have sent a man-of-war to 
retrieve them whilst they were yet at sea, they eluded the 
pursuit — if there was a pursuit — and were landed in England 
and arranged as speedily as possible by Smith, with the aid 
of Sir Joseph Banks and his librarian Dryander. This 
episode decided Smith to abandon the study of medicine 
and take up that of botany, and to him the foundation of 
the Linnsean Society is due. He was the author of many 
books, and in 1790 he collaborated with Sowerby in the 
production of Sowerby's " English Botany," which extended 
over thirty-six volumes, and in which he was responsible for 
practically all the letter-press. Another notable work of 
his, published in 1807, was an " Introduction to Physio- 
logical and Systematic Botany," and the last seven years of 
his life he devoted to the " English Flora." 

We now turn to a class of men of science in which England 
has always been pre-eminent — the scientific explorer and 
collector. 

One of the earliest of these, Sir Hans Sloane (1660-1753), 
started life as a doctor, having studied medicine at Paris and 
MontpeUier. He was well acquainted with the leading men 
of science of his period, and for a time lived with Thomas 
Sydenham. His great opportunity came in 1687, when he 
accompanied, as physician, the Duke of Albemarle, Governor 
of Jamaica, to the West Indies. Owing to the death of the 
Duke, his stay in the islands was curtailed, but he came 
back in 1689 with 800 species of plants and settled down to 
medical practice. He became Secretary to the Royal Society 
in 1693, and, while he was busily at work on his collections, 



T. A. Knight, Sir Joseph Banks 241 

found time to contribute a number of papers to the Philo- 
sophical Transactions. 

On the death of Sir Isaac Newton he followed him as 
President of the Royal Society, and occupied the chair for 
twenty-eight years, until 1740. Perhaps his greatest con- 
tribution to botany was in connexion with the Physic 
Garden of Chelsea. He had purchased the manor of that 
village in 1712, and on retiring from practice settled on his 
estate. This included the site of a " Physic " garden estab- 
lished, in 1673, by the Apothecaries' Society, and Sloane 
handed, in 1722, the fee simple of the property to that body, 
subject to certain conditions. His name is commemorated 
on the Cadogan Estate in the West End of London by Sloane 
Square and Hans Place. 

A second explorer, " the greatest Englishman of his time," 
traveller and prominent collector, was Sir Joseph Banks 
(1743-1820), who was educated both at Harrow and Eton. 
At school he was so immoderately fond of play that his 
masters foimd great difSculty in fixing his attention on his 
studies, but at the age of fourteen, impressed by the beauties 
of flowers in the country lanes, he decided to study botany, 
and probably his real education was largely due to the women 
who were then, as they are now, collecting " simples " for 
druggists' shops. At Oxford, where he found no lectures were 
being delivered on his favourite subject, he obtained per- 
mission to procure a teacher to be paid by the students, and 
coming over to Cambridge he brought back with him to his own 
university Israel Lyons, the astronomer and botanist. I wonder 
if any student has ever attempted such an enterprise since ! 

Banks was a wealthy man and was able to indulge 
his passion for travelling. His first journey was to New- 
foundland, and after his retiurn, via, Lisbon, he came across 
Dr. Daniel Solander, the faithful pupU of Linnaeus, who 
subsequently accompanied him in his voyage round the 
world, for Banks left England in August 1768 on Captain 
Cook's Endeavour. The scientific part of the expedition was 
financed by Banks, and he was accompanied not only by 
Dr. Solander but by two artists and two attendants. It 
would take too much space to dwell upon that remarkable 
voyage, Banks was collecting not only plants, but animals. 



242 Britain's Heritage of Science 

and noted, as an ancient writer said, " ye beastlie devices 
of ye heathen." At a spot they christened Botany Bay, 
owing to the wealth of plant life in the district, kangaroos 
were observed for the first time. 

The Endeavour returned in the spring of 1771, and Banks 
very shortly afterwards made arrangements (which ulti- 
mately fell through) to accompany Captain Cook on a second 
voyage in the Resolution. Being disappointed over this 
expedition. Banks visited Iceland with his scientific staff 
and Dr. Solander. This was the last of his travels. 

He became President of the Royal Society in 1778, and 
held that distinguished office until his death. For a time his 
reign was a troubled one. The secretaries had assumed, as 
secretaries often do, a power which belonged to others, and 
Banks was determined to put this right. The dissensions 
that followed led to a secession of several members, but the 
majority remained and harmony was once more restored. 

The contributions that Banks made to science by personal 
investigation were comparatively few, but he was a great 
patron of Natural History, and although he wrote little, 
he was the cause of much writing by others. He made his 
collections accessible to men of science, and his house in 
Soho Square was a rallying spot for those interested in 
Natural History. His library was one of the finest then 
existing, the catalogue of it by Dryander exists in five 
volumes. The Ubrary is stiU kept in a room by itself in the 
British Museum. Although apparently a bit of an autocrat, 
he was a generous and far-seeing man, and those who knew 
him best undoubtedly loved him most. 

The Linnaean system was destined to disappear, and 
during the first decades of the nineteenth century it was 
being gradually replaced by a more natural and scientific 
scheme of classification. In this, England practically led 
the way, and, indeed, Professor Green tells us that with 
Robert Brown began " a long line of taxonomists of the 
greatest brUliance, who not only outshone all their prede- 
cessors, but carried the nation's prestige in botany .to a pitch 
that had not been reached even under the influence of Ray." 

Brilliant and stimulating as were the speculations of 
the French School from De Jussieu to De Candolle, the 



Sir Joseph Banks, Robert Brown 243 

English were at least their levels in the study of the 
herbarium. Where they outshone all other nations was in 
their world-wide explorations, their vast collections of extra- 
European plants, which laid the foundation of the science 
of geographic botany and afforded the material which was 
destined to form the basis of the speculations as to the 
" Origin of Species " which were so prominent a feature in 
the latter part of the nineteenth century. 

Robert Brown (1773-1858), one of the most brilliant 
men of science Europe has produced, was the son of the 
Episcopalian minister in Montrose. He was educated partly 
at Aberdeen and partly at Edinburgh, where, for the first 
time, he showed the interest which never afterwards failed 
him in the science of botany. In 1795 he obtained a double 
commission as Ensign and Assistant Surgeon in the Fife- 
shire Regiment of Pencible Infantry, and proceeded to 
Ireland. In 1798, being sent to England on a recruiting 
service, he became the friend of Sir Joseph Banks, who 
was destined to help him in no common measure. It was 
owing, indeed, to Banks that he resigned his commission and 
started on his memorable voyage to Australia and Tasmania. 
He left Portsmouth in 1801 under the command of Captain 
Ehnders, and was away about four years. The South Coast 
of Austraha, the tropical part of the East Coast and part 
of the North were explored before Flinders was compelled 
to return to England by the bad state of his ship. The 
botanists, however, remained in Austraha for another year 
and a half, and extended their investigations to Tasmania 
and other islands. Altogether about 4,000 species of plants 
were collected, and on his return to England in 1805 these 
great collections, added to those which Sir Joseph had 
brought back from Captain Cook's circumnavigation of the 
globe, and those due to other explorers, were now thoroughly 
worked out by Brown. As Asa Gray remarks : 

" It was the wonderful sagacity and insight which 
he evinced ia these investigations which, soon after his 
return from Austraha, revealed the master mind in 
botanical science, and ere long gave him the position of 
almost unchallenged eminence, which he retained without 
effort for more than a century." 

Q2 



244 Britain's Heritage of Science 

The result of these researches was the work " Prodromus 
Florae Novse HoUandiae et Insulae Van Dieman," a work 
marked by singular accuracy of detail set forth in precise 
and clear language ; it showed, moreover, a profound mastery 
of the principles of classification. 

Another important publication of Brown was his mono- 
graph on the Proteacem, which contained one of his first great 
contributions to Histology, namely, that deaUng with the 
structure of the seed. Brown was also the first to recognize 
the true nature of the seed in Gymnosperms. He paid 
much attention to the structure of the flower and the 
methods of pollination, especially in the Natural Orders 
OrchidecB and Asclepiadece. In fact, so important did his 
work appear to foreigners, that Humboldt dedicated his 
" Synopsis Plantarum Orbis novi " to him in the following 
words : " Roberto Brownio Britanniarium glorise atque 
omamento." We have no space to foUow further his tireless 
work on classification. 

Brown, who had succeeded Dryander as librarian to 
Sir Joseph Banks in 1810, at the latter's death in 1820 
succeeded to the use and enjoyment of his collections and 
library, together with the house in Soho Square, where 
for nearly sixty years he had pursued his investigations. 
More than once during his life he had been offered professor- 
ships, but he was essentially a researcher, and preferred 
the quiet of Soho Square, which has been so weU described 
by Dickens in the " Tale of Two Cities." Indeed, the 
character of Dr. Manette might almost have been drawn 
from Brown, for, as a friend wrote of him, " I loved him for 
his truth, his simple modesty, and, above all, for his more 
than woman's tenderness. Of aU the persons I have known, 
I have never known his equal in kindliness of nature." 

Before passing on, one must not omit to mention that 
in his monograph on the Orchidece Brown first announced 
the discovery of the nucleus in the vegetable cell. He is 
also the discoverer of the so-called Brownian movement — 
an irregular trembling motion of very small particles sus- 
pended in liquids — which becomes visible under the micro- 
scope, when high magnifying powers are applied. It is 
connected with the thermal motion of the molecules of 



John Lindley 245 

the liquids, and has gained some importance in recent 
years. 

Although Brown did much to undermine the Lumsean 
system, it was not by a frontal attack so much as by 
courteously and consistently ignoring it. 

John Ijndley (1799-1865) took more direct action. lind- 
ley was bom near Norwich, where he was educated. His 
father was a nurseryman, and throughout his life Lindley 
showed a particular interest in all horticultural matters. In 
1819 he went to London, and shortly afterwards was 
appointed Garden Assistant Secretary to the Horticultural 
Society, and in 1830 Secretary to the Society. It was his 
efforts, combined with those of Bentham, which rescued the 
Society from financial disaster, and organised the very 
Buccessfid series of exhibitions of flowers and vegetables, 
the first " flower-shows " recorded in Great Britain. 

In 1829 he was elected Professor of Botany at University 
College, London, and was the first occupant of that Chair. 
His lectures were singularly concise and clear, and attracted 
large classes. Throughout his life he was a constant advocate 
of a natural system of classification as opposed to the 
artificial one of Linnaeus, and in 1829 he published a " Synopsis 
of the British Flora," which was one of the first attempts 
to arrange British plants on a basis of natural affinity. The 
following year, in an Introduction to the " Natural System 
of Botany," he put forward, tentatively, his natm-al classifi- 
cation. He helped Loudon to bring out his " Encyclopaedia 
of Gardening," wrote much for the " Penny Encyclopaedia," 
collaborated with Hutton in the " Fossil Flora of Great 
Britain," and with Sir Joseph Paxton in a work entitled 
" Paxton's Flower Garden," and in 1821 started the well- 
known " Gardener's Chronicle," which he edited for twenty- 
five years. 

Although experts do not admit that Lindley achieved 
any permanent success in framing his classification, he was 
undoubtedly a great taxonomist. He was celebrated for the 
completeness of his descriptions of the several Natural Orders 
and valued for his clear discussions on their inter-relation- 
ships. He was an extremely hard worker, and took a large 
share in administrative work; towards the end of his life 



246 Britain's Heritage of Science 

he acted for the Government in the preparation for the 
Great Exhibition of 1851, and undertook the entire charge 
of the Colonial Department in the following Exhibition of 
1862. Lindley's only son is the present Lord Lindley. 

Bom in the same neighbourhood and educated at the 
same school a few years before Lindley, Sir WiUiam Jackson 
Hooker (1785-1865) was another example of a biologist 
who commenced his scientific life as a traveller. In 1809, 
on the advice of Sir Joseph Banks, he visited Iceland, but 
unfortunately lost his collections by the burning of the ship 
on the return voyage. He wished to accompany Sir Robert 
Brownrigg, the recently appointed Governor of Ceylon, but 
the disturbed state of the Island prevented his carrying 
out his intentions. 

In 1820 he accepted the Professorship of Botany at 
Glasgow, where he was singularly successful as a teacher. 
In 1841 he was appointed Director of the Royal Gardens at 
Kew, and we shall have to consider later Ms work there. 
He had always been a great collector, and his herbarium, 
which was far the richest ever accumulated in his lifetime by 
any one man, was bought by the nation after his death. 
Though much engaged in ofiicial duties, he was, neverthe- 
less, a great writer, and produced over one hundred memoirs 
and volimies on Economic and Systematic Botany. He was 
particularly happy in his relations with the officials in the 
Greater Britain beyond the seas, and inaugurated a series 
of Colonial floras, which have proved of great value. He 
was one of those men always anxious to help others, and he 
readily placed his knowledge and his collections at the 
disposal of younger men. So busy a hfe left Uttle time 
for society, but Darwin records " his remarkably cordial, 
courteous, and frank bearing." 

Another contemporary was George Bentham (1800-1884), 
a nephew of Jeremy Bentham. He was brought up abroad, 
and had a wide acquaintance with the flora of Southern 
France. In 1821 he returned to England, and at once made 
the acquaintance of the leading botaniste of the time, and 
very soon took a prominent position himself as a systematic 
botanist. He contributed the " Flora of Hong Kong " and 
the " Flora Australiensis " to Sir William J. Hooker's 



W. J. Hooker, G. Bentham, J. D. Hooker 247 

Colonial Floras. But his great work was the " Genera 
Plantarum," in the execution of which he was associated with 
Sir Joseph D. Hooker. One must not forget to mention 
his " Handbook of the British Flora," published in 1858. 
He was a man endowed with a gift of accuracy, discrimina- 
tion and precision, and with infiiute powers for hard work. 
He handled collections of plants from every quarter of the 
globe, and, as one of the most distinguished contemporaries 
remarked, he possessed " an insight, of so special a character 
as to be genius, into the relative value of characters for 
practical systematic work — a sure grading of essentials and 
non-essentials." 

Bentham was an untiring worker, and it was character- 
istic of him that having finished, after a year's incessant 
work for the " Genera Plantarum," whose pubUcation 
extended from 1862-1883, the Orchidacece on a certain 
Saturday afternoon, he bade the attendant at the Herbarium 
to bring down the material for commencing the much more 
difficult group of the Grasses. It is impossible here to enu- 
merate the numerous papers and memoirs which Bentham 
published, and one can only sum him up by saying that he 
was one of the greatest systematic botanists who ever lived ; 
his colleague. Hooker, said of him " There is scarcely a 
Natural Order that he did not more or less remodel." 

A contemporary of Bentham and the vounger son of Sir 
W. J. Hooker was Sir Joseph Dalton Hooker (1817-1911). 
The younger Hooker is another example so common in 
British biological science of men who approach their subjects 
through extensive travel. Inspired by his father he, as a 
boy, took an intense interest in botanical research, but, 
like aU young men, he was eager to travel, to see the world. 
He quahfied as a Doctor of Medicine at Glasgow, and was 
delighted when Sir James Clark Ross offered to take him 
as assistant surgeon and analyst on his ship the Erebtis to 
the Antarctic. When the expedition returned in 1843, 
Hooker devoted himself to pubUshing the botanical results 
of the voyage. These fiUed sis quarto volumes. 

At about this date the intercourse between Darwin and the 
younger Hooker became closer, and there was a constant inter- 
change of correspondence between the two contemporaries. 



248 Britain's Heritage of Science 

Hooker's researches, especially on the flora of the Gala- 
pagos, had convinced him that there was an evolution in 
space. On the one hand he found that the plants of 
neighbouring hills, though related, differed in detail; on 
the other hand, identical species were often found on hUls 
separated by many thousand miles of ocean. Hooker was 
the first to whom Darwin confided his theories of natural 
selection, and he read for his friend the proofs of the first 
sketch of the " Origin of Species." In fact, Darwin wrote 
to him " for years I have looked on you as a man whose 
opinion I valued on any scientific subject more than anyone 
else in the world." 

In 1845 J. D. Hooker was appointed Botanist to the 
Geological Survey, and for a time turned his attention to 
fossil botany. But his love of travel was not yet sated, 
and in 1847 he started to explore the Himalayas. He spent 
part of two years in exploring Sikkim, and for a time was 
imprisoned. He also explored part of Nepal, and visited 
territory which has not even yet been re-investigated. He 
penetrated some way into Tibet, and one afternoon at his 
house in Sunrdngdale he received a telegram from the Lhassa 
Expedition of 1903, stating that they had got as far as he had 
previously penetrated, and congratulating him upon the 
usefulness of his survey. Having explored Eastern Bengal 
and the Khasia HiUs, he returned to England in 1851, and 
in 1855 he was appointed Assistant Director to his father at 
Kew, and ten years later succeeded his father as Director. 

On his return form India, he immediately commenced, 
in conjunction with Thomas, the first volume of the " Flora 
Indica," which, however, also proved to be the last, as it 
was planned on too ambitious a scale. In 1860 he visited 
and examined considerable areas of Syria, and about this time 
he was contemplating his celebrated " Genera Plantarum." 
But the call of the world still held him, and in 1871 this 
indefatigable traveller, accompanied by John Ball and Maw, 
made an expedition into Morocco. They were the first 
Europeans to ascend the Tagherot Pass, nearly twelve 
thousand feet high. 

In 1873 Hooker became President of the Royal Society, 
and he made a real effort to bring that Institution into closer 



Sir Joseph Dalton Hooker 249 

touch -with the social life of the community. He was suc- 
cessful in raising the sum of £10,000 to aid the somewhat 
exiguous resources of the Society. In 1877 he obtained 
leave of absence to visit the Eocky Mountains of Colorado 
and Utah, and added much to our knowledge of the fossil 
flora of those districts, and later he returned to his first love 
and made a determined effort to complete his " Flora of 
British India," which was accomplished in seven volumes 
during the next fourteen years. In 1885 he retired from the 
Directorship of Kew, and was succeeded by Sir WiUiam 
Thiselton-Dyer, but he never ceased working. 

Hooker was the recipient of numerous honours, including 
the O.M., which was personally presented to him at Sunning- 
dale, to which village he had retired, on behalf of King 
Edward VII. on his ninetieth birthday. 

Hooker stands out as the greatest authority the world 
has yet produced on the subject of the Distribution of Plants ; 
although he did much other work, this alone confers on him 
immortality. 

Hooker was capable of enduring great physical fatigue, 
capable of working continuously with very short intervals of 
sleep. Somewhat highly strung he disliked pubUc functions, 
- though when forced to do so he could make an eloquent and 
stirring speech. He was extremely kind and courteous, and 
always ready to help the younger men. He retained his 
faculties to the last, and continued to work to the end of his 
long, laborious, and successfid life. 

We have seen that most of the progress of the physiology 
of plants was due to British workers; but naturally in the 
last quarter of the eighteenth century Great Britain had to 
some extent remained isolated from the science of the 
continent, and the currents of botanical thought flowed at 
somewhat different angles on the two sides of the Channel. 
We shall see later how Huxley inaugurated a new departure 
in the teaching of biology, and with him came the laboratory. 
Hitherto the botanists had been content with their botanic 
gardens, their herbaria, and with a few roughly devised 
physiological instruments. With " the coming of the labora- 
tory," however, things altered. Huxley had round him an 
ardent body of young workers. His Sist demonstrators 



250 Britain's Heritage of Science 

were Michael Foster, Ray Lankester, and Rutherford, and 
later Newall Martin (who collaborated with his chief in the 
production of the " Elementary Biology "), Thiselton-Dyer, 
and Vines. The coming of the laboratory was slower at 
the Universities, but with the arrival of Foster at Cambridge, 
and the return for a time of the old Cambridge men, Martin 
and Vines, laboratory instruction became part of the normal 
course. 

The modern study of Cryptogamic Botany in England 
may almost be said to begin with the works of MUes Joseph 
Berkeley (1803-1889). like so many English botanists he 
was in Holy Orders. Coming from OuncQe and Rugby to 
Christ's College, Cambridge, he came under the influence of 
Henslow, and took his degree in 1825. At first he worked 
on the Algae, but in 1836 he published, in connexion with 
Smith's " Enghsh Flora " the section which dealt with the 
fungi, and this was the earliest of his many contributions 
on this group. He was the first to throw light upon the 
fungoid organism Phytophtkera infestans, which caused the 
potato disease connected with the appaUing famine in Ireland 
in 1846. 

Between 1844 and 1856 his " Decades of Fungi " were 
published and were amongst the most conspicuous of con- 
temporary publications on this subject. Berkeley paid 
particular attention to the diseases of plants, and contributed 
a series of articles to lindley's newly-established " Gardener's 
Chronicle." For many years he was the authority at Kew 
on Cryptogamic Botany. He described the fungi collected 
by his fellow-collegian, Darwin, on the Beagle, and his classical 
knowledge was of great use to Bentham and Hooker in their 
" Genera Plantarum." His large collections of algaa were left 
to Cambridge, whilst his fungi went to Kew. 

During his Hfetime he was easily leader in the taxonomy 
of the subject, and he may almost be said to have started 
a new line of research. His most distinguished successor 
was Marshall Ward, who will be dealt with more fuUy under 
the Cambridge School. 

The great majority of the earher botanists hitherto 
mentioned lived and worked in London, but a small minority 
carried on their researches in country houses or, mor€ often, 



M. J. Berkeley, W. Sherard, C. G. Daubeny 251 

in country parsonages. But there are other centres of 
activity in England, though none of them, tiE the re-awakening 
of science at the end of the nineteenth century, produced 
men of very outstanding talent. 

We have seen that Morison was the first Professor of 
Botany at Oxford — he was appointed Professor in 1669— 
although when he was appointed the Botanic Garden at 
Oxford had already been in being for thirty-seven years. 
His successors, however, were people of comparatively little 
importance ; the Professorship was always very inadequately 
endowed. In 1728 William Sherard (1659-1728), who was 
more of a patron of science than a man of science, left by 
will a sum to re-endow the Professorship, which was now 
named after him, and this was at first occupied by the German 
Dillenius (1687-1747), who was undoubtedly one of the great 
botanists in Great Britain during the eighteenth century; 
but his work, though painstaking and laborious, showed little 
originality and insight. His knowledge, however, was great, 
and was recognized by his contemporaries at the time. 
Perhaps his greatest work was the " Historia Muscorum," 
which appeared in 1741. As Professor Green says, "it is 
a work of colossal laboiu-, but it is impossible to avoid a 
certain feeling of disappointment with the " Historia," not that 
it was not good but that it might have been so much better." 
Dillenius was, however, conservative in his thought, and a 
man without a great faculty for new enterprise. After his 
death, botany again feU under a cloud at Oxford, and for 
a time at any rate Cambridge took the lead. 

One must, however, mention Sibthorp (1758-1796), who, 
always impressed with the relation of his science to agri- 
culture, founded the Professorship of Rural Economy which 
now bears his name. 

In 1834 the School of Botany at Oxford woke up. Pro- 
fessor Charles Giles Daubeny (1795-1867) of Magdalen College 
was, as men of science were in those days, very versatile, he 
was almost equally distinguished as a geologist, a chemist, 
and a botanist. And again, after the manner of those times, 
he did not hesitate to hold contemporaneously three pro- 
fessorships. For in 1822 he became Professor of Chemistry, 
and only resigned it in 1855, and in 1834 Sherardian Professor 



252 Britain's Heritage of Science 

of Botany, and in 1840 Sibthorpian Professor of Rural 
Economy. It is not our intention in this volume to deal 
■with agriculture, but one might at least indicate that he 
■was one of the earliest to throw light on the principles involved 
in the rotation of crops, to investigate the constituents of 
plant ashes, to sho^w the difference between " the total amount 
of the salts contained in the soil and the amount available 
for use by the plant," and above aU he had a keen appreciation 
of the part that the fungi play in diseases of plants. 

Daubeny remodelled the beautiful Botanic Gardens at 
Oxford and founded the Botanic Museum. He was a keen 
supporter of Darwin's views of Natural Selection, and spoke 
strongly in their favour at the meeting of the British 
Association in 1860. 

If we now turn to Cambridge we again find no name of 
absolutely outstanding merit until the re^vival of science at 
the end of the nineteenth century. 

A few words should, however, be said about the second 
Martyn, who succeeded his father to the Professorship in 
the year 1761. Thomas Martyn (1735-1825) was a parson, 
and in 1762 he was elected to succeed his father to 
the Chair of Botany, which he held for the astonishing 
period of sixty-three years. He was, however, as professors 
were apt to be in those times, largely non-resident, and he 
ceased lecturing altogether in 1796. But for many years 
before that date he had been out of residence, and only 
returned from time to time to what was obviously an 
uminterested audience. 

Henslow (1796-1861), who succeeded Martyn, was a 
different kind of man, and did much to encourage the advance 
of science in many directions. For a time he held the Chair 
of Mineralogy, having been appointed at the age of twenty- 
six, together ■with the Chair of Botany, but he devoted 
most of his energy to the latter subject, and his lectures 
attracted large audiences. He used many illustrations, and 
for the first time introduced what was later destined to 
develop into practical laboratory work. He reorganized 
the Botanic Garden, and during his time it was moved to 
its present site, and for the first time organized systematic 
excursions in the neighbouring country. His success in 



T. Martyn, H. Marshall Ward 253 

interesting Suffolk farmers in his parish in the application 
of Botany to Agriculture was notable. He is renowned 
not for any strikingly remarkable original contributions to 
science, but for taking a leading part in reorganizing the 
scientific spirit of Cambridge. 

The only other botanist of eminence connected with 
Cambridge was Professor Marshall Ward (1854-1906). He was, 
in a way, a successor of Berkeley, and although he always 
was very nervous of the encroachment of what is known as 
" technical research " on the purer kind, his own researches 
were without exception of practical utilitarian value. Ward, 
like Berkeley, was educated at Christ's College, and afterwards 
studied in Germany. For a time he was teaching at Owens 
College, Manchester, and later he was Professor of Botany 
in the Forestry Department of the Royal Engineering CoUege 
at Cooper's HUl; he was appointed Professor at Cambridge 
in the year 1895. One of his earhest researches involved a 
visit to Ceylon, where he investigated the hfe-history of the 
fungus that attacks the leaves of the coffee plant, which in 
fact destroyed the coffee trade of that island. He worked 
out the life-history of this pathogenic fungus, and was largely 
instrumental in inducing the planters to take up the planting 
of tea. 

Throughout his life Ward was largely occupied with the 
study of bacteria and fungi, to which he contributed much 
of first-rate importance. During his professorship the 
present School of Botany was erected and eqtiipped,' and 
at the time of its erection it was, and still is, second to none 
in Great Britain in size and completeness of equipment. 

The history of Botany in Scotland and in Ireland 
shows, as at first was the case in Cambridge and Oxford, no 
particularly outstanding names. The University Chair in 
Edinburgh was founded in 1695, and was first filled by James 
Sutherland (1639-1719), who, in 1667, had succeeded in estab- 
lishing and stocking a small botanic garden. At Glasgow, 
from the year 1719, Botany no longer had a distiact professor, 
the subject beiag taught by the Professor of Anatomy, a 
separate Chair reappearing only in the year 1818. The first 
occupant of this double chair was Thomas Brisbane, a man 
who entertained so strong a dishke to dissection, that it is 



254 Britain's Heritage of Science 

believed he never taught anatomy at all. It cannot be said 
that his teaching in botany in any way compensated for this 
silence in anatomy. The cmious conjimction of the two 
professorships did not produce anyone of any particular 
eminence in botanic science. R. K. Greville (1794-1866), 
who held no official post, was, however, establishing a great 
reputation for his knowledge of cryptogamic botany, in 
which subject he is said to have done more than any botanist 
of his times. 

Hooker, whose work is mentioned elsewhere, succeeded 
Graham as Professor of Botany at Glasgow, and for a time 
the chief activity in this science was in the western rather 
than the eastern university. 

On Graham's succeeding to the Chair ia Edinburgh, 
Botany agaiu revived, for he was an able lecturer, a man 
of great activity, and he organized botanical excursions for 
his pupils. 

He was succeeded by J. H. Balfour (1808-1884), a brilliant 
teacher and a most genial man, called by his pupils " woody 
fibre." He was known best, perhaps, as a teacher than as 
an investigator, and, as was usual during the times in which 
he Uved, his researches were largely of a systematic kind. He 
was the first, however, to introduce the use of the microscope 
into the Class-room. 

The Irish records of botanical research are at least as 
scanty as those of Scotland. The first authentic authority 
on plants was Caleb Threlkeld (1676-1728), but his book, 
under the ambitious title of " Synopsis Stirpium Hibemi- 
carum," was little more than a herbal. 

A lectureship was established at Trinity College in 1711 
and associated with it was a small Physic Garden. In 1786 
the lecturer, who was at that time Edward HQl, was raised 
to the status of a professor. His chief work seems to have 
laid in the botanic garden and in starting the herbarium. 
Amongst his successors perhaps Professor WiUiam Allman 
should be mentioned. He was succeeded by a succession 
of able men, but none of them pre-eminently able. 

This brief survey of the history of British Botany shows 
that there is ever a steady current of research and investigation 
going on in these islands and with here and there a temporary 



Summary 255 

lull, men. of world-wide importance were constantly emerging 
from the high level of their contemporaries. Hales, no doubt, 
laid the foundation of scientific plant physiology, even Sachs 
has said that his " Vegetable Staticks " " was the first com- 
prehensive work the world had seen which was devoted to 
the nutrition of plants and the movement of their sap . . . 
Hales had the art of making plants reveal themselves. By 
experiments planned and cunningly carried out he forced 
them to betray the energies hidden in their apparently 
inactive bodies." Grew was one of the earliest and greatest 
investigators of plant anatomy, and, as we have said above 
may be regarded as joint founder with Malpighi of the science 
of vegetable anatomy. Robert Brown was regarded by his 
contemporaries as the first botanist of his age, and he it was 
who for the first time took into account the development 
of plants as well as the structure of the mature and adult 
forms. He and John Lindley did much to establish a 
natural system based on the widest iavestigation possible 
in their times. Sir Joseph Hooker may almost be said to 
be the inventor of phyto-geography. Professor Bower writes 
of him : — " and so we have followed . . . this great man 
into the various lines of scientific activity which he pursued. 
We have seen him excel in them all. The cumulative result 
is that he is universally held to have been, during several 
decades, the most distinguished botanist of this time. He 
was before aU things a philosopher. In him we see the 
foremost student of the broader aspects of plant-life at the 
time when evolutionary belief was nascent." 

In the Stewarts' time, as we have seen, British science 
led the world, and ever since our men of science have held 
their own ia comparison with the men of science of the 
nations which can boast of an old civQization and far 
surpassed, both in amount and in originaHty, that of nations 
whose civilization only dates back to a few himdred years. 



256 Britain's Heritage of Science 



CHAPTER X 
Zoology 

IN 1544 William Turner, the leading naturalist of his 
time, pubhshed his " Avium Praecipuarum quarum apud 
Plinium et Aristotelem mentio est, brevis et succincta 
historia," dedicated to Edward Prince of Wales, after- 
wards Edward VI. Turner had been educated at Pembroke 
College, Cambridge, where he knew Latimer and learned 
Greek from Ridley. He travelled much abroad, and became 
an M.D. of Ferrara and subsequently of Oxford. Later in 
life he was ordained, and in 1550 he was appointed Dean 
of Wells, a post he was compelled to quit on the accession 
of Queen Mary. His business in life was theological con- 
troversy and he wrote many polemical works, but his 
pleasure was in natural history. He contributed a letter 
on British fishes to his friend Conrad Gtesner, with whom 
he had worked at ZiU'ich, and with whom he constantly 
corresponded. As an example of the zoology available in 
the Great Ehza's times, we may quote Turner's description 
of the grouse. 

" Of the Lagopus" from Pliny. 

" The Lagopus is in flavour excellent, its feet shaggy 
as in a hare have given it this name. Otherwise, it is 
white, in size as the Columbi; it is not eaten except in 
the land of which it is a native, since it is not tameable 
while Uving, and when killed its flesh soon putrefies. 
There is another bird of the same name, differing but 
in size from the Cotumices, most excellent for food with 
yellow saffron sauce. Of this Martial makes mention 
in the following verse : — 

" If my Flaccus delighta in the eared Lagopodes.'' 



W. Turner, E. Wotton, John Caius 257 

Although this may seem to indicate that Turner was a 
mere translator and compiler, this is not the case. As 
Mr. A. H. Evans tells us : 

" While attempting to determine the principal kinds 

of birds named by Aristotle and PUny, he has added 

notes from his own experience on some species which had 

come under his observation, and in so doing he has 

produced the first book on Birds which treats them in 

anything Uke a modern scientific spirit . . . nor is 

it too much to say that almost every page bears witness 

to a personal knowledge of the subject, which would be 

distinctly creditable even to a modem ornithologist." 

A contemporary of Turner's, Edward Wotton (1492- 

1555), bom at Oxford and elected a Fellow of Magdalen, 

travelled for several years in Italy. He took his M.D. at 

Padua, and later held high ofi&ce in the College of Physicians, 

and has been described as " the first Enghsh Physician who 

made a systematic study of natural history." His book, 

"De DifEerentiis Animalium," published two years before 

Turner's Historia and dedicated to the same patron, acquired 

a European reputation. The copy of this book, a fine foUo, 

in the British Museum, is said to be " probably unsurpassed 

in typographical excellence by any contemporary work." 

"De DiSerentiis Animalium" was deservedly praised by 

contemporary writers for its learning and for the elegance 

of its language. 

Dr. Caius (1510-1573), in his terse style, wrote "De 
Canibus Britannicis libellus," 1570, and this was " drawne 
into Englishe " under the name " Of Englishe Dogges," by 
Abraham Fleming in 1576, and pubUshed in London. Caius 
wrote his little book as a contribution to Conrad Gresner's 
"History of Animals," but owiag to Gesner's death it was 
not incorporated in that work. For, from the sixth year of 
Henry the Eighth until the death of Queen Elizabeth, aU 
the learned men of Europe who were interested in Nature 
turned to Gesner, the incomparable naturalist of Zurich 
(1516-1565), amongst whose many works of great import- 
ance the stupendous "Historia AJiiimaUum" is perhaps the 
most, remarkable. 

In the year 1607, Edward Topsell, a member of Christ's 



258 Britain's Heritage of Science 

College and, in the matter of livings, somewhat of a pluralist, 
published, under the title " The Historie of Foure-Footed 
. Beastes," an abstract of Gesner, and in the next year followed 
it up with " The Historie of Serpents," both illustrated with 
charmingly quaint, if inaccurate, woodcuts. Topsell had, 
what the modem zoologist must have (but the possession 
in his time was less common), a sound knowledge of 
Grerman, and to this knowledge his books owe much. 
These works give us a fair idea of what the educated in those 
days knew of zoology in all its aspects, and that these aspects 
covered a far wider area than, with the present expansion 
of knowledge, we can now contemplate under this single 
science, is shown by the title-page to Topsell's magnificent 
quarto volume : 

" The History of Foure-Footed Beastes. Describing 

the true and lively figure of every Beast, with a discourse 

of their several! Names, Conditions, Kindes, Vertues (both 

naturall and medicinaU), Countries of their breed, their 

love and hate to Mankinde, and the wonderful worke of 

God in their Creation, Preservation, and Destruction. 

Necessary for all Divines and Students, because the 

story of every Beast is amplified with Narrations out 

of Scriptures, Fathers, Phylosophers, Physitians, and 

Poets : wherein are declared divers Hyerogliphicks, 

Emblems, Epigrams, and other good Histories, collected 

out of all the Volumes of Conradus Gesner, and all other 

Writers to this present day. By Edward Topsell. 

London, Printed by WiUiam Jaggard, 1607." 

Falconry also played a part in the Zoology of the later 

Tudor times. During the reign of Queen Elizabeth this 

sport was " much esteemed and exercised." People of all 

classes eagerly took part in it. To quote Mr. Harting : 

" The rank of the owner was indicated by the species 
of bird which he carried. To a king belonged the ger- 
falcon; to a prince, the falcon gentle; to an earl, the 
peregrine; to a lady, the merlm; to a young squire, 
the hobby ; while a yeoman carried a goshawk ; a priest, 
a sparrowhawk; and a knave, or servant, a kestrel." 
The sport was, however, expensive, for it took much 
time and devotion to train the birds. The falcon, in those 



E. Topsell, F. Willughby, J. Ray 259 

times, as the flying machine is in ours, was in the air, and 
just as one now hears om* undergraduates discussing carbu- 
retters, air-locks, sparking-plugs, and various vintages of 
petrol, so in the times of Queen Elizabeth, the keen young 
men of Shakepeare's Plays discussed the various kinds of 
hawks and their habits. 

In our last chapter we have sketched the contribu- 
tions which Ray had made to the science of Botany ; but 
he has further claims on our regard. He and Francis 
WUiughby, both of Trinity College, Cambridge, attacked 
similar problems in the animal kingdom. Willughby was 
the only son of wealthy and titled parents, while Ray was 
the son of a village blacksmith. But the older universities 
are great levellers, and Ray succeeded in infusing into his 
fellow student at Cambridge his own genuine love for 
natural history. With Willughby, he started forth on his 
methodical investigations of animals and plants in all the 
accessible parts of the world. Willughby died young and 
bequeathed a small benefaction and his manuscripts to his 
older friend. After his death, Ray undertook to revise and 
complete his " Ornithology," and therein paid great attention 
to the internal anatomy, to the habits and to the eggs of 
most of the birds he described. Further, he edited WiUughby's 
"History of Fishes," but perpetuated the mistake of his 
predecessors in retaining whales in that group. In rather 
rationalistic mood, he argues that the fish which swallowed 
Jonah must have been a shark. Perhaps the weakest of 
their three great histories — "The History of Insects" — was 
such owing to the fact that Ray edited it in his old age. The 
Ray Society for the pubUcation of works on Natural Science 
was founded in his honour in 1842. 

Robert Hooke, a Westminster boy and, later, a student 
at Christ Church, was at once instructor and assistant to 
Boyle. The year that the Royal Society received their 
charter, they appointed Hooke curator, and his duty was 
" to furnish the Society " every day they met with three or 
four considerable experiments. This formidable task he 
fulfilled in spite of the fact that " the fabrication of instru- 
ments for experiments was not commonly known to work- 
men," and that he never received " above £50 a year and 

B 2 



260 Britain's Heritage of Science 

that not certain." Hookewas a man of amazing versatility, 
very self-confident, attacking problems in all branches of 
science, greatly aiding their advance, but avid of fame. 

" In person but despicable, being crooked and low in 

stature, and as he grew older more and more deformed. 

He was always very pale and lean and latterly nothing 

but skin and bone." 

His book " Micrographia " is the record of what a modem 
schoolboy newly introduced to the microscope would write 
down. Yet he was undoubtedly, although not a lovable 
character, the best " mechanic of his age."^ {See also p. 55.) 

John Tradescant ( ? ?1637) is by some beUeved to have 

been a Dutchman, but his name is an English name, and he 
seems from an early age to have owned land in Essex, a most 
English county. One of his earliest works was entitled : 
" A voiag of ambasad ondertaken by the Right honour abl 
Sr Dudlie Digges in the year 1618," which is a narrative of 
a voyage round the North Cape to Archangel, where they 
arrived at the neighbouring monastery of St. Nicholas on 
the 16th July 1618, when Tradescant immediately began 
botanizing, collecting, and ultimately sending a number of 
northern plants to various friends abroad and making notes 
upon some twenty -four wild species. This was the first 
account pubUshed of the plants of Russia. In 1620 he 
voyaged south instead of north, having joined the expedi- 
tion of Mansell and Sir Samuel Argall against the Corsairs 
of Algiers, and amongst other rarities brought back by him 
was the Algerian apricot. In 1625 he was in the service of 
the Duke of Buckingham, and writes to an agent in Virginia 
that it was the Duke's wish that he should " deal with all 
merchants from all places, but especially from Virginia, 
Bermudas, Newfoundland, Guinea, Binney, the Amazon, 
and the East Indies, for all manner of rare beasts, fowls, 
and birds, shells, furs, and stones." On the death of the 
Duke, Tradescant became gardener to the King and Queen, 
and it is suggested that it was about this time that he 
established his physic garden and museum at South Lam- 
beth. The physic garden was one of the first established 
in our kingdom, and Pulteney recalls that Tradescant 

» WaUer's " Life of Hooke," 1705. 



The Tradescants 261 

was the first who brought together any considerable collec- 
tion of subjects of natural history. His name is immor- 
talised in the genus Tradescantia, a spider- wort which he 
had introduced from Virginia. Parkinson, in his " Paradisus 
terrestris," speaks of the elder Tradescant as " a painful 
industrial searcher and lover of all nature's varieties," and 
having " wonderfully laboured to obtain aU the rarest fruits 
he can hear of in any place of Christendom, Turkey, yea, 
or the whole world." 

His only child, John Tradescant (1608-1662), was bom 
at Meopham, Kent, and apparently succeeded his father as 
gardener to Queen Henrietta Maria. In 1637, the younger 
Tradescant was in Virginia gathering all varieties of ferns, 
plants, and shells for the museum at Lambeth, and in 1656 
he pubUshed his " Museum Tradescantianum : or collection 
of rareties preserved in South Lambeth, near London." In 
this task he was assisted by his friend Ashmole, and the 
book, which runs into 179 pages, contains hsts of birds, 
mammals, fish, shells, insects, minerals, war instruments, 
utensils, coins, and medals. It is interesting to note that 
he had a complete " dodar " from the island of Mauritius. 
This was the celebrated stuffed dodo of which the head and 
foot are still preserved at Oxford. The complete body had 
been studied by WiUughby and Ray. On the 12th December 
1659, Ashmole notes in his diary that " Mr. Tradescant and 
his wife told me they had been long considering upon whom 
to bestow their Closet of Curiosities when they died, and at 
last had resolved to give it unto me." Ashmole had built 
himself a large brick house near Lambeth adjoining that 
which had been Tradescant's, and shortly after its comple- 
tion removed the collection to his new house, and in 1677 
he announced his intention of giving his collection to the 
University of Oxford, on condition that a suitable building 
be built to receive it. This was erected from the design of 
Sir Christopher Wren, and the collections were transferred 
to Oxford in 1683, when the name of Tradescant was rather 
unjustly sunk in that of Ashmole. 

There was a lull in Zoological Science during the 
eighteenth century in our islands, and only the names of 
one or two outstanding zoologists appear. That of Thomas 



262 Britain's Heritage of Science 

Pennant (1726-1798) must not, however, be forgotten. In 
his boyhood he received a copy of Francis Willughby's 
" Ornithology," and to that he attributed Ms interest in 
natural history. He was for a time an undergraduate at 
Queen's College, Oxford, but did not proceed to a degree. 
Shortly after leaving Oxford he travelled through Cornwall 
and studied the minerals and fossils of the county, and in 
1754 he travelled in Ireland, but here he kept a very imper- 
fect diary, " such," he adds, " was the conviviaUty of the 
country." In 1765 we find him visiting France and staying 
with Buffon. He also visited Voltaire at Femey, whom he 
found " very entertaining and a master of English oaths " ; 
on his return journey at the Hague he met the celebrated 
Pallas. The first part of his " British Zoology " appeared 
in 1766, and his " Synopsis of Quadrupeds " five years later. 

At various times in his Ufe, Pennant thoroughly 
explored much of the British Islands, and made copious 
notes on the fauna, especially on the birds of the coast. In 
1781 he published " A History of Quadrupeds," which was 
a new and enlarged edition of his " Synopsis," and three 
years later his " Arctic Zoology " appeared. Arctic explora- 
tion has always fascinated our British naturalists. 

Pennant certainly occupies a leading position amongst 
the zoologists of the eighteenth century, and although he 
did not reach such a high standard as Buffon, he was a 
really learned man, and he had an undoubted faculty for 
making dry and obscure things readable and plain. 

Although, as we have said above, British zoology suffered 
under a lull during the eighteenth century, the two Hunters, 
WilHam and John, helped with Pennant to keep the sacred 
flame alight. 

William Hunter (1718-1783) was bom in Lanarkshire 
and educated at Glasgow University. He first came to 
London as dissector to Dr. James Douglas, whose son he 
tutored, and with him he travelled on the Continent. 
Later, he was remarkably successful as a lecturer, being 
eloquent, competent, and capable of illustrating his dis- 
courses with practical dissections. His success as an 
obstetric surgeon was great, and he was appointed Physician 
Extraordinary to Queen Charlotte in 1764. 



Thomas Pennant, The Hunters 263 

During his comparatively long life he had accumulated 
a notable collection of anatomical and pathological speci- 
mens, and in 1765 he proposed to build a museum to house 
them, and to spend several thousands of pounds on the 
building, in addition to -which he was prepared to endow 
a professorship. The ofEer which he had made to the 
Government, however, fell through, and subsequently he 
undertook, at his own expense, to carry out the project 
without Government aid, and he built his well-known 
institution in Great Windmill Street. By 1783 he reckoned 
that his collections had cost him over £20,000. 

Unfortunately he and his brother John quarrelled, or 
at least differed, the cause beiug that William claimed the 
credit of more than one discovery which John seems to 
have made. His collections, which by the time of his death 
included minerals, shells, corals, coins, rare manuscripts 
and books, together with his great obstetrical collection, 
were ultimately left to the University of Glasgow. William 
Hunter's claim to a place in these pages is that he was both 
a great collector, a great investigator, and a great teacher. 

His younger brother, John Himter (1728-1793), came to 
London in 1748 to assist WiUiam, and soon showed a real 
genius for anatomy. He became a " Master of Anatomy " 
of the Surgeons' Corporation and a pupil at St. George's 
Hospital, where for a time he was house surgeon. Also he 
resided for some terms at Oxford, where, he says, " they 
wanted to make an old woman of me, or that I should stuff 
Latin and Greek at the University, but," he added signifi- 
cantly, pressing his thumb on the table, " these schemes I 
cracked Uke so many vermin as they came before me." 

John was more of an investigator than William, but a 
far less able teacher. He traced the descent of the testis 
in the foetus, as Aristotle is said to have done before him, 
he investigated the placental nerves, studied the nature of 
pus, investigated the absorbing power of veins, and in con- 
junction with his brother endeavoured to determine the 
course and function of the lymphatics. 

After abandoning his partnership with William he served 
abroad with the British Army in Portugal and elsewhere, 
and became a great authority on gun-shot wounds. On 



264 Britain's Heritage of Science 

returning to London in 1763, he began to practise as a 
surgeon in Golden Square, and here he first started on his 
famous collections. The menagerie at the Tower and other 
private zoological gardens served him with material, and he 
spared neither time nor money to add to his museum. In 
1764 he built himself a house at Earl's Court, Kensington, 
which was properly fitted for macerating, injecting, and 
dissecting the bodies of animals, and was also provided 
with cages for keeping them alive. His sympathy was in 
no way confined to the vertebrates, for he had ponds in 
which he tried artificially to produce pearls in oysters, and 
he was very fond of bees, though ia truth his real passion 
was for the fiercer kind of camivora. 

John Hunter helped a number of men who have left 
their mark in the medical profession. Perhaps the most dis- 
tinguished of these was Edward Jenner, but Astley Cboper, 
John Abemethy, Henry Cline, James McCartney were also 
of the company. In 1783 he built a large museum, with 
lecture-rooms, in Leicester Square, and about this time he 
made his well-known discovery on the collateral circulation 
by anastomosing branches of blood-vessels. 

In character he seems to have been impatient and rather 
rough, incapable of readily expounding the information that 
he had acquired — ^information that was mostly from direct 
observation, for he read but httle. He was a strong Tory, 
and it is stated that he would rather have seen his museum 
burning than show it to a democrat. Hunter stood at the 
head of British surgery, but he was more than a surgeon, 
he was an aU-round anatomist, with wide and scientific 
views as to what hfe meant. His claim to appear in these 
pages is that he was also a great comparative anatomist, 
though his zoology was always secondary to his siu:gery. 
By his will his museum was offered to the British Govern- 
ment on reasonable terms, and in case they refused it was 
to be sold to some foreign State or put up to auction. 
National finance in 1793 was, however, at a low ebb, and 
Mr. Pitt showed no eagerness to complete the purchase. 
Six years later the Government recommended the collection 
should be bought for £15,000, knowing well that it was 
worth a great deal more. However, the purchase was 



John Hunter, Richard Owen 265 

completed and the collection was offered to the Royal 
College of Physicians. On their refusal to accept it, it was 
offered to and accepted by the Corporation of Surgeons, 
which next year became the Royal College of Surgeons, 
and from 1806 the Hunterian Collection has been housed 
in Lincoln's Inn Fields. At the present time this original 
nucleus of the College museum comprises one-fifth of the 
specimens therein exhibited. 

The most dominant zoologist in the first half of the 
nineteenth century was Sir Richard Owen (1804r-1892), who 
was born at Lancaster and was educated at the grammar 
school of that town with WiUiam Whewell, the author of 
the " History of the Inductive Sciences." When he was 
sixteen he was apprenticed to a surgeon, and here his love 
of anatomy at once found scope. Later he matriculated 
at Edinburgh, and attended the extra-mural course of 
lectures on anatomy given by Dr. John Barclay, who, as 
Owen himself testified, has an " extensive knowledge of 
vertebrate anatomy." In the spring of 1835 he joined 
St. Bartholomew's Hospital, London, having passed the 
examination of the Royal College of Surgeons, and later 
set up in private practice near Lincoln's Inn Fields. He 
became lecturer on Comparative Anatomy at his hospital in 
1827, and after a short interval he was appointed Assistant 
Conservator of the Hunterian Museum of the Royal CoUege 
of Surgeons. The Conservator was then WiUiam Chft, who 
had done so much to preserve Hunter's Museum in the 
long interval between his death and its transference to 
the Royal College of Surgeons. In 1831 Cuvier invited 
Owen to Paris, where he attended Cuvier 's and Geoffrey 
St. HUaire's lectures in the Jardin des Plantes. 

Owen was well known as a writer of monographs on 
many rare animals, and the first of these was his memoir 
on the " Pearly Nautilus," which placed him, as Huxley 
says, " in the front rank of anatomical monographers." 
In the early forties, he succeeded Chft, whose daughter 
he had married, as Conservator to the Royal College of 
Surgeons. But before this, in 1836, he had been made the 
first Hunterian Professor of Comparative Anatomy at the 
CoUege, which involved the annual delivery of twenty-four 



266 Britain's Heritage of Science 

lectures, and these he continued to give for a period of 
twenty years. 

Owing to the influence of the Prince Consort, the 
British Court was, in Owen's time, more interested in 
science than it has been since his death, and Owen became 
of considerable influence in court and in society circles. 
In 1845 he was elected a member of that exclusive body 
" The Club," founded by Dr. Johnson., In 1852 the Queen 
gave him the cottage called Sheen Lodge, in Richmond 
Park, where he lived for forty years. 

There seems Uttle doubt that in the middle of the last 
centiu-y Owen was recognized throughout the world as the 
first anatomist of his day; but his position at the College 
of Sm-geons was at this time becoming difficult. Eriction 
arose between him and the Governing Body, and in 1856 
he readily accepted the offer made to him by the Trustees 
of the British Museum to undertake the newly created post 
of Superintendent of the Natiwal History Department in 
the Museum. This post he held until 1884. He added 
greatly to our knowledge of animal structure by his success- 
ful dissection of many rare forms, such as the Pearly 
Nautilus, Limulus, Lingida, Apteryz, and others, and, follow- 
ing on the Hnes of Cuvier, he was particularly successful in 
reconstructing extinct vertebrates. Another considerable 
advance he made in science was his introduction of the 
terms " homologous " and " analogous." 

The accommodation afforded by the Museum at Blooms- 
bury for Natural History specimens was totally inadequate, 
and as early as 1859 Owen submitted a report to the Trustees 
setting forth his views as to the proper housing of the 
National collections. After the usual delays attendant upon 
aU Government action, land was purchased at South 
Kensington, on which ten years later the present buildings 
rose. They were opened to the public in 1881. Owen failed, 
however, to achieve many of his desires. A lecture theatre, 
such ■ as exists in the MetropoHtan Museum of Natural 
History in New York, is even now still lacking, and, he 
adds, " no collection of zoological specimens can be regarded 
as complete without a gallery of physical ethnology." This 
also is still wanting. A third of his wishes, a gallery of 



Richard Owen, Charles Darwin 267 

Cetacean skeletons, was only achieved under his successor, 
Sir William Flower. The fact was, as Sir William pointed 
out, that the division of the Museum into four departments, 
each with its own head, left Owen practically powerless. 
Increased age added to the difficulties, and in 1883 he 
resigned his post and spent the remaining nine years of his 
hfe in retirement in his beautiful cottage at Sheen Lodge. 

Owen was widely read, fond of music and the drama, 
and a man of striking personality. But, owing to his 
faculty for acrimonious controversy, he was rather an 
isolated zoologist, standing alone and going his own way. 
His power of work was prodigious : not only did he pub- 
lish iimumerable papers in aU the scientific journals, but a 
large number of books, the titles of which are set forth in 
the " Dictionary of National Biography." 

On the same day, the 12th February 1809, upon which 
Abraham Lincoln first saw the light, was born, at the 
" Mount," Shrewsbury, a httle child destined as he grew 
up to alter our conceptions of organic life perhaps more 
profoundly than any other man has ever altered them, 
and this not only in the subjects he made his own, but in 
every department of human knowledge and thought. 

As to the man, two estimates of his character may 
be quoted, one by a student who lived on terms of close 
intimacy with Darwin when at Christ's CoUege, Cambridge, 
the other the considered judgment of one who knew and 
loved and fought for Darwin in later lite. 
Mr. Herbert says : 

" It would be idle for me to speak of his vast 
intellectual powers . . . but I cannot end this 
cursory and rambling sketch without testifying, and I 
doubt not aU his surviving coUege friends would concur 
with me, that he was the most genial, warm-hearted, 
generous, and affectionate of friends ; that his sympathies 
were with aU that was good and true; and that he had 
a cordial hatred for everything false, or vile, or cruel, 
or mean, or dishonourable. He was not only great, but 
pre-eminently good, and just, and lovable." 
Professor Huxley, speaking of the name of Darwin, says : 
" They think of him who bore it as a rare combination 



268 Britain's Heritage of Science 

of genius, industry, and unswerving veracity, who earned 
his place among the most famous men of the age by sheer 
native power, in the teeth of a gale of popular prejudice, 
and uncheered by a sign of favour or appreciation from 
the of&cial fountains of honour; as one who, in spite of 
an acute sensitiveness to praise and blame, and notwith- 
standing provocations which might have excused any 
outbreak, kept himself clear of all envy, hatred, malice, 
nor dealt otherwise than fairly and justly with the 
imfairness and injustice which was showered upon him; 
while, to the end of his days, he was ready to listen 
with patience and respect to the most insignificant of 
reasonable objectors." 
Although the Darwin family trace their ancestry to about 
the year 1500, we need not, here, go further back than 
Charles's grandfather, Erasmus (1731-1802). This distin- 
guished physician, the author of the " Loves of the Plants " 
and of " Zoonomia," transmitted to his grandson his bene- 
volent and sympathetic character and a remarkable charm 
of manner, as well as his great stature. 

In many respects Erasmus Darwin was in advance of 
his times. He was, for instance, a great advocate of temper- 
ance, and Mr. Lucas has lately reminded us of his inhuman 
advice : " If you must drink wine, let it be home-made," 
surely the shortest cut to total abstinence yet devised by 
the wit of man. 

He wrote innumerable verses in the somewhat stilted 
style of the period. They were immensely admired by his 
contemporaries, and Cowper, who could have had little or 
no sympathy with most of Darwin's views, wrote in 
conjunction with Halley a poem in his honour which 
begins : — 

" No envy mingles with our praise, 
Tho' could our hearts repine 
At any poet's happier lays, 

They would, they must, be thine." 

The third son of Erasmus, Robert Waring Darwin, was 
the father of Charles. Like his father, he was a physician, 
and for many years he enjoyed a large practice at Shrewsbury. 
He married Susannah, the daughter of his father's friend. 




Charles Darwin 



From a photograph by 
Messrs. Maull & 1-ox 



Erasmus Darwin, Charles Darwin 269 

Josiah Wedgwood, of the well-known pottery works at 
Etruria, Staffordshire. 

In his charming and frank fragments of autobiography 
Darwin recalls many incidents of his own childhood. As 
a boy he early developed a taste for collecting plants, shells, 
minerals and other natm-al objects, and he was at pains to 
learn their names. He tells a curious story of himself 
pretending that he could alter the colour of flowers by 
watering them with coloured fluids, curious because at his 
age boys are not as a rule interested in such problems 
of vegetable physiology. It is characteristic that in the 
earUest portrait of him, a charming crayon sketch in which 
his youngest sister Catherine also appears, he is depicted 
holding a pot of flowers in his hands. At the age of nine 
he was sent to the school at Shrewsbury, then in its picturesque 
old biiildiags in the town ; he was a boarder there, and thus 
had, as he says, " the great advantage of living the life of a 
true schoolboy." He remained at school until he was sixteen, 
and then his father, thinking he was not doing much good, 
sent him to join his elder brother, who was studying medicine 
at Edinburgh University. At this period, Uke his grand- 
father, his father and his brother, Darwin was destined to 
study medicine, and he attended the medical course, which 
consisted entirely of lectures, all of them, with but one 
exception, " intolerably dull." Apart from the lectures, 
which were evidently almost useless, Darwin acquired a 
good deal of miscellaneous information whilst at Edinburgh; 
he did much collecting along the shore, learnt the art of the 
bird-stuffer, frequented two or three societies, and doubt- 
less, as is the habit of those of his age, took part in many 
and interminable discussions. He also became an ardent 
sportsman and was especially enthusiastic about shooting. 
Apparently, however, his heart was not in his medical 
work, and in 1827 his father proposed that he should become 
a clergyman, and with this in view decided to send him to 
Cambridge. 

The Admission Book at Christ's College contains the 
following entry : — 

" Admissi stmt in Collegium Christi a Pesto Divi 

Michaehs 1827 ad Fes um eiusdem 1828 : 



270 Britain's Heritage of Science 

[No. 3.] 

Octobris 15. Carolus Darwin admissus est pensionarius 

minor sub Mro Shaw." 
Charles Darwin came into residence in the Lent Term 
of 1828. 

Late in life men are apt to look back upon their College 
days with a somewhat exaggerated regret for lost oppor- 
timities, and Charles Darwin felt that at Cambridge his 
" time was wasted, as far as his academical studies were 
concerned, as completely as at Edinburgh and at school." 
But this must not be taken too literally. He seems to have 
passed his University examinations with ease, and a letter 
recording his joy at getting through the " Little-Go " shows 
that he at any rate took them seriously. 

Apparently Darwin's experiences at Edinburgh had given 
him a distaste for lectures, and it is unfortunate that this 
distaste kept him away from the teaching of Sedgwick. He 
attended, however, the botanical lectures of Henslow, which 
were then crowded with students as well as with senior 
members of the University, and he revelled in the excursions 
which Henslow used to conduct, on foot or in coaches, or 
down the river in barges, " or to some more distant place, 
as to Gamlingay, to see the wild lily of the valley and to 
catch on the heath the rare natterjack." He was, in fact, 
known to the senior members of the University as " the 
man who walks with Henslow," and the man who walked 
with Henslow did not spend three years at Cambridge wholly 
in vain. 

Amongst other absorbing pursuits was that of collecting 
insects, especially beetles. He was first interested in ento- 
mology by his cousin, W. Darwin Fox, of Christ's, who 
had kindred tastes and with whom he frequently corre- 
sponded — in fact, most of the letters written from Christ's 
CoUege that remain were addressed to him. 

Darwin received his degree on April 26, 1831, and it was 
during this term and the subsequent Easter term, when he 
was stiU in residence, that Henslow persuaded him to begin 
the study of geology. There must have been something 
unusual about Darwin, for he seems to have made friends 
with men much older than himself, and some of them, one 



Charles Darwin 271 

would imagine, not very approachable. He records how 
he used to waUs home at night with Dr. Whewell; and 
rejoices in his friendship with Leonard Jenyns. He became 
the friend of Adam Sedgwick, and in August 1831 he 
accompanied him on a geological survey in North Wales. 
It was on returning from this trip that he found a letter 
from Henslow informing him that Captain Pitzroy was 
wiUing to give up part of his cabin to any young man who 
would volunteer without pay to act as naturalist on the 
classical voyage of the Beagle. Captain Fitzroy was going 
out to survey the southern coast of Tierra del Fuego and 
to visit some of the South Sea Islands, returning by the 
Indian Archipelago. 

Captain Fitzroy, like Mrs. R. Wilfer, was a " disciple 
of Lavater," and took exception to the shape of Darwin's 
nose. " He doubted whether any one with my nose could 
possess sufficient energy and determination for the voyage." 
But on acquaintance his doubts soon vanished, and the 
captain and his naturalist became close friends. 

Space forbids any account of the voyage of the Beagle. 
As far as Darwin is concerned, it took place at what is, 
perhaps, the period of life when the mind is most original. 
Many of the great creative ideas of thought appear to be 
engendered between the age of twenty and thirty years, 
and although much may be added later, the foundation of 
man's Ufe work is usually laid then. Darwin, as he records, 
" worked to the utmost during the voyage from the mere 
pleasure of investigation and from " his " strong desire to 
add a few facts to the great mass of facts in Natural Science." 

He retittned to England in October 1836, and two months 
later, on December 13, Darwin settled again in Cambridge, 
but only for three months. 

Whatever feehng Darwin had about the education that 
he received at Cambridge, he had a real love for the place, 
to which he sent aU but one of his sons; and it is good to 
read the following lines in his autobiography : " Upon the 
whole, the three years I spent at Cambridge were the most 
jojrful of my happy Ufe." 

Early in the year 1839 Darwin married his cousin, Emma 
Wedgwood, and for nearly four years they kept house in 



272 Britain's Heritage of Science 

Upper Gower Street. The sustained toil and the discomforts 
of the voyage had injured Darwin's health, and he and his 
wife led a Ufe of " extreme quietness." During this period, 
he states, " I did less scientific work, though I worked as 
hard as I possibly could, than during any other equal length 
of time in my Ufe. This was owing to frequently recurring 
un wellness and to one long and serious illness." His health, 
indeed, prevented his regular attendance at scientific and 
other gatherings which are among the few attractions London 
can offer over the country, and in 1842 he removed to the 
secluded Kentish village of Down. The chief attraction of 
the place was its quietness, " its chief merit," as Darwin 
writes, " is its extreme riu-ality." The house stands a 
quarter of a mile from the village, whose peaceful charm 
has been but little altered in the last sixty-seven years. 
And here it was he says : "I can remember the very spot, 
whilst in my carriage, when to my joy the solution occurred 
to me." The " solution " was " natural selection by means 
of the siffvival of the fittest." 

Here for forty years Darwin lived and laboured, in spite 
of ill-health which often laid him aside for weeks, his daily 
task always confined to very few hours of work. We need 
not follow further the details of this happy Ufe, but one 
event, and that a well-known one, may briefly be referred 
to. Darwin's work was so cathoUc, its bulk so great and 
its effect so stimulating, that few have reaUsed how vast 
was the output of scientific work which, though often an 
invalid, he gave to the world. The extent of the work has 
been perhaps a Uttle overshadowed by the immense import- 
ance of that great generaUzation known as Natural Selection. 
Sir Wm. Thiselton-Dyer haa reminded us that Darwin Ues 
beside Newton in Westminster Abbey, and he adds : "It 
is the singular fortune of an illustrious University that of 
two of her sons, one should have introduced a rational order 
into the organic and the other into the inorganic world." 

In 1908 was celebrated the Jubilee of the reading of a 
Paper at the Linnean Society entitled, " On the Tendency 
of Species to form Varieties; and on the Perpetuation of 
Varieties and Species by Natural Means of Selection." This 
was the joint production of Charles Darwin and of Alfred 



Charles Darwin, Alfred Wallace 273 

Russell Wallace, and was laid before the Society by Sir 
Joseph Hooker and Sir Charles Lyell. The history of this 
Paper is well known, but it is so creditable to both these 
high-minded and honourable men that I may briefly repeat 
it, and in doing so I cannot do better than use the noble 
words* of Wallace : — 

" The one fact," said Wallace, " that connects me 
with Darwin, and which, I am happy to say, has never 
been doubted, is that the idea of what is now termed 
' natural selection ' or ' survival of the fittest,' together 
with its far-reaching consequences, occurred to us 
independently, and was first jointly announced before this 
Society fifty years ago. 

" But what is often forgotten by the press and the 
pubHc is, that the idea occurred to Darwin in October 
1838, nearly twenty years earUer than to myself (in 
February 1855); and that during the whole of that 
twenty years he had been laboriously collecting evidence 
from the vast mass of literature of Biology, of Horti- 
culture, and of Agriculture; as weU as himself oarrjdng 
out ingenious experiments and original observations, 
the extent of which is indicated by the range of subjects 
discussed in his ' Origin of Species,' and especially in that 
wonderful store-house of knowledge — ^his ' Animals and 
Plants under Domestication,' almost the whole materials 
for which works had been collected, and to a large extent 
systematized, during that twenty years. 

" So far back as 1844, at a time when I had hardly 
thought of any serious study of nature, Darwin had 
written an outline of his views, which he communicated 
to his friends. Sir Charles Lyell and Dr. (now Sir Joseph) 
Hooker. The former strongly urged him to publish an 
abstract of his theory as soon as possible, lest some other 
person might precede him — but he always refused till 
he had got together the whole of the materials for his 
intended great work. Then, at last, Lyell's prediction 
was fulfilled, and, without any apparent warning, my 
letter, with the enclosed Essay, came upon him, like a 

' The Darwin-'WaUaoe Celebration. The Linnean Society, London, 
1908, pp. 5-7. 



274 Britain's Heritage of Science 

thunderbolt from a cloudless sky ! This forced him to what 
he considered a premature publicity, and his two friends 
undertook to have our two papers read before this Society. 
" How different from this long study and preparation 
— this philosophic caution — ^this determination not to 
make known his fruitful conception till he could back 
it up by overwhelming proofs — was my own conduct. 
The idea came to me, as it had come to Darwin, in a 
sudden flash of insight : it was thought out in a few 
hours — was written down with such a sketch of its various 
applications and developments as occurred to me at the 
moment, — then copied on thin letter-paper and sent ofi 
to Darwin — all within a week. / was then (as often 
since) the ' young man in a hurry ' : he, the painstaking 
and patient student, seeking ever the full demonstration 
of the truth that he had discovered, rather than to achieve 
immediate personal fame." 
It is a remarkable fact that both naturalists owed their 
inspiration to the same source. Both had read the " Essay 
on Population," written by a modest clergyman named 
Malthus, a book which on its appearance was met with a 
storm of execration; both saw in it the demonstration of 
that " struggle for existence " which surrounds us on aU 
sides, and both and they alone of all the readers of Malthus) 
saw that the necessary consequence of this struggle for 
existence was that the fittest alone survive. This concep- 
tion, " an essentially new creative thought," as Helmholtz 
described it, explained the method of that evolution which 
since the time of the Greeks has been at the back of man's 
mind. It thus rendered the fact of evolution acceptable 
and even inevitable in the minds of aU intelligent thinkers 
and brought about changes in our attitude to the organic 
world and indeed in our whole relation to life greater, perhaps, 
than have ever been produced by any previous thought of 
man. 

There were, of course, many British evolutionists before 
Darwin, amongst whom may be mentioned Charles Darwin's 
grandfather, Erasmus Darwin, Wells, Patrick Matthew, 
Pritchaid, Grant, Herbert — all these writers advocated, and 
some even hinted at, natural selection. Above aU, Robert 



Natural Selection 275 

Chambers, whose " Vestiges of Creation " remained anonymous 
until after his death, strongly pressed the view that new 
species of animals were being evolved from simpler types. 

During the incubatory period of Darwin's great work, as 
Alfred Newton has remarked, systematists, both in zoology 
and botany, had been feeling great searchings of heart as 
to the immutability of species. There was a general feeling 
in the air that some light on this subject would shortly appear. 
As a recent writer has reminded us, 

" in studying the history of evolutionary ideas, we 

must keep in mind two distinct lines of thought, first, 

the conviction that species are not immutable, and that 

by some means or other new forms of life are derived 

from pre-existing ones. Secondly, the conception of some 

process or processes by which this change of old forms and 

new ones may be explained." 

Now, as we have seen, the first of these lines of thought 

had been accepted by many writers. Darwin's great merit 

was that he conceived a process by means of which this 

evolution in the organic kingdom could be explained. 

It has been somewhat shallowly said, said in fact on the 
day of the centenary of Darwin's birth, that " we are upon 
very unsafe ground when we speculate upon the manner in 
which organic evolution has proceeded without knowing 
in the least what was the variable organic basis from which 
the whole process started." Such statements show a certain 
misconception, not confined to the layman, as to the scope 
and limitations of scientific theories in general, and to the 
theory of organic evolution in particular. The idea that 
it is fruitless to speculate about the evolution of species 
without determining the origin of life is based on an erroneous 
conception of the true nature of scientific thought and of the 
methods of scientific procedure. For Science, the world of 
natural phenomena is a complex of procedure going on in 
time, and the sole function of Natural Science is to construct 
systematic schemes forming conceptual descriptions of 
actually observed processes. Of ultimate origins Natural 
Science has no knowledge and can give no account. The 
question whether living matter is continuous or not with 
what we call non-living matter is certainly one to which an 

S 2 



276 Britain's Heritage of Science 

attempted answer falls within the scope of scientific method. 
If, however, the final answer should be in the affirmative 
we should then know that all matter is living, but we should 
be no nearer to the attainment of a notion of the origin of 
life. No body of scientific doctrine succeeds in describing in 
terms of laws of succession more than some hmited set of 
stages of a natural process ; the whole process — if, indeed, it 
can be regarded as a whole — must for ever be beyond the 
reach of scientific grasp. The earUest stage to which Science 
has succeeded in tracing back any part of a sequence of 
phenomena itself constitutes a new problem for Science and 
that without end. There is always an earlier stage and to an 
earliest we can never attain. The questions of origins 
concern the theologian, the metaphysician, perhaps the poet. 
The fact that Darwin did not concern himself with questions 
as to the origin of life nor with the apparent discontinuity 
between living and non-living matter in no way diminishes 
the value of his work. The broad philosophic mind of the 
great Master of inductive method saw too fully the nature of 
the task he had set before him to hamper himself with 
irrelevant views as to origins. 

No well-instructed person imagines that Darwin spoke 
either the first or the last word about organic evolution. 
His ideas as to the precise mode of evolution may be, and 
are being, modified as time goes on. This is the fate of all 
scientific theories; none are stationary, none are final. 
The development of Science is a continuous process of evolu- 
tion, like the world of phenomena itself. It has, however, 
some few landmarks which stand out exceptional and 
prominent. None of these is greater or will be more enduring 
in the history of thought than the theory associated with 
the name of Charles Darwin. 

But in reading his writings and his son's admirable " Life " 
one attains a very vivid impression of the man. One of 
his dominant characteristics was simplicity — simplicity and 
directness. In his style he was terse, but he managed to 
write so that even the most abstruse problems became clear 
to the public. The fascination of the story he had to tell 
was enhanced by the direct way in which he told it. 

One more characteristic. Darwin's views excited at the 



Organic Evolution 277 

time intense opposition and in many quarters intense hatred. 
They were criticised from every point of view, and seldom 
has a writer been more violently attacked and abused. Now 
what seems so wonderful in Darwin was that — at any rate 
as far as we can know — he took both criticism and abuse 
with mild serenity. What he wanted to do was to find the 
truth, and he carefully considered any criticism, and if it 
helped him to his goal he thanked the critic and used his 
new facts. He never wasted time in repl3dng to those who 
fulminated against him, he passed them by and went on 
with his search. 

It is a somewhat remarkable fact that whilst the works 
of Darwin stimulated an immense amount of research in 
Biology, this research did not at first take the hne he 
himself had traced. With some exceptions, the leading 
zoological work of the end of the last century took the form 
of embryology, morphology, and palaeontology; and such 
subjects as cell-Uneage, the minute structure of protoplasm, 
life-histories, teratology, have occupied the minds of those 
who interest themselves in the problems of life. Among 
all these Unes of research man has been seeking for the 
solution of that secret of nature which at the bottom of his 
heart he knows he wiU never find, and yet the pursuit of 
which is his one abiding interest. Had Francis Balfour 
Hved we should, probably, have sooner returned to the broader 
Unes of research as practised by Darwin, for it was Balfour's 
intention to turn himself to the physiology— fusing the term 
in its widest sense — of the lower animals. Towards the 
end of the nineteenth century, stimulated by Galton, Weldon 
began those series of measurements and observations which 
have culminated in the estabhshment of a great school of 
Eugenics and Statistics in London. With the beginning of 
the twentieth century came the rediscovery of the neglected 
facts recorded by Gregor Mendel, Abbot of Brunn, some 
years before, and with that rediscovery an immediate and 
enormous outburst of enthusiasm and of work. Mendel 
had placed a new instrument in the hand of the breeder, 
an instrument which, when he has learnt to use it, may give 
him a power over all domesticated animals and cultivated 
crops undreamt of before. We are getting a new insight 



278 Britain's Heritage of Science 

into the workings of Heredity and we are acquiring a new 
conception of the individual. The few years which have 
elapsed since men's attention was redirected to the principles 
first enunciated by the Abbot of Brunn have seen a School 
of Genetics arise at Cambridge, and an immense amount of 
practical experiment on inheritance has also been done in 
France, Holland, Austria, and especially in the United States. 
As the work has advanced new ideas have arisen and earlier 
formed ideas have had to be abandoned; this must be so 
with every advancing science. ' But it has now become 
clear — at any rate to some competent authorities — ^that 
mutations occur, and occxu- especially in cifltivated species; 
and that these mutations may breed true seems now to 
be estabhshed. In wild species also they apparently occur, 
but whether they are as common in wild as in cultivated 
species remains to be seen. If they are not, in my opinion, 
a most profitable Une of research would be to endeavour to 
determine what factor exists in cultivation which stimulates 
mutation. 

To what extent Darwin's writings would have been 
modified had Mendel's work come into his hands we can 
never know. He carefully considered the question of 
mutation, or as they called it then, saltation, and as time 
went on, he attached less and less importance to these 
variations as factors in the origin of species. Ray Lan- 
kester has recently reminded us that Darwin's disciple and 
expounder, Huxley, " clung to a Uttle heresy of his own as 
to the occurrence of evolution by saltatory variation," and 
there must have been frequent and prolonged discussion on 
the point. That " little heresy " has now become the ortho- 
doxy of a number of eager and thoughtful workers who have 
been at times rather aggressive in their attacks on the 
supporters of the old creed. 

The pubUcation of " The Origin of Species " naturally 
aroused immense opposition and heated controversy. But 
Darwin, as we have said, was no controversialist. Huxley 
wrote shortly after his death : 

" None have fought better, and none have been more 

fortunate, than Charles Darwin. He found a great truth 

trodden underfoot, reviled by bigots, and ridiculed by all 



G. Mendel, C. Lyell, T. Huxley 279 

the world ; he lived long enough to see it, chiefly by his 
own efforts, irrefragably established in science, insepar- 
ably incorporated with the common thoughts of men, 
and only hated and feared by those who would revile, 
but dare not. What shall a man desire more than this ?" 
Darwin, also, was fortunate in his supporters, though some 
of the leading biologists of the time — conspicuous among 
them was Owen — ^rejected the new doctrine. In Hooker, 
on the botanical side, in Huxley, on the zoological side, and 
in Lyell, on the geological side, he found three of the ablest 
inteUects of his country and of his century as champions. 
None of these agreed on all points with their leader, but 
they gave more than general adherence to his principles, 
and a more than generous aid in promulgating his doctrine. 
Lyall was an older man, and his " Principles of Geology " 
had long been a classic. This book inspired students who 
became leaders in the revolution of thought which was 
taking place in the last half of the nineteenth century. One 
of these writes : 

" Were I to assert that if the ' Principles of Geology ' 
had not been written, we should never have had ' The 
Origin of Species,' I should not be going too far : at all 
events, I can safely assert, from several conversations 
I had with Darwin, that he would have most imhesi- 
tatingly agreed to that opinion." * 
Sir Joseph Hooker, whose great experience as a traveller 
and a systematic botanist, and one who had at his time 
the widest knowledge of the distribution of plants, was of 
invaluable assistance to Darwin on the botanical side of his 
researches. Those who knew Hooker wiU remember him 
as a man of ripe experience, sound judgment, and a very 
evenly-balanced mind. But all these high and by no means 
common qualities were combined with caution, and with a 
critical faculty, which was quite invaluable to Darwin at 
this juncture. Huxley was of a somewhat different tempera- 
ment. He was rather proud of the fact that he was named 
after the doubting apostle ; but, whatever Huxley doubted, 
he never doubted himself. He had clear-cut ideas, which 
he was capable of expressing in the most vigorous and 

1 J. W. -Judd. 



280 Britain's Heritage of Science 

the most cultivated English. Both on platform and on paper 
he was a keen controversialist. He contributed much to 
our knowledge of morphology. But never could he have 
been mistaken for a field-naturalist. In the latter part of 
his life he was drawn away from pure science by the demands 
of public duty, and he was, undoubtedly, a power in the 
scientific world. For he was ever one of that small band 
in England who united scientific accuracy and scientific 
training with influence on the political and ofiicial life of 
the country. 

As has already been said, the immediate effect of the 
publication of " The Origin of Species " and of the acceptance 
of its theories by a considerable and ever-increasing number 
of experts did not lead to the progress of research along the 
precise lines Darwin himself had followed. The accurate 
description of bodily structure and the anatomical com- 
parison of the various organs was the subject of one school 
of investigators : RoUeston's " Forms of Animal Life," 
re-edited by Hatchett Jackson, Huxley's " Vertebrate and 
Invertebrate Zoologies," and Milnes Marshall's " Practical 
Zoology " testify to this. Another school took up with 
great enthusiasm the investigation of animal embryology, 
the finest output of which was Balfour's " Text-book of 
Embryology," published in 1880. Members of yet another 
school devoted themselves to the minute structure of the 
ceU and to the various changes which the nucleus undergoes 
during ceU-division. Animal histology has, however, been 
chiefly associated with physiology and, as this chapter is 
already greatly overweighted, we have had to leave physio- 
logy on one side. The subjects of degeneration, as shown, 
by such forms as the sessile Tunicata, the parasitic Crustacea 
and many internal parasitic worms, with the last of which 
the name of Cobbold is associated, also received attention, 
and increased interest was shown on the pathogenic influence 
of internal parasites upon their hosts. 

Towards the end of our period, a number of new schools 
of biological thought arose. As Judd teUs us : 

" Mutationism, Mendelism, Weismannism, Neo-La- 

marckism. Biometrics — with which the name of W. F. R. 

Weldon will ever be associated — ' Eugenics ' began to 



Alfred Russell Wallace 281 

be exploited. But all of these vigorous growths have 
their real roots in Darwinism. If we study Darwin's 
correspondence, and the successive essays in which he 
embodied his views at different periods, we shall find 
that variation by mutation (or per saltum), the influence 
of environment, the question of the inheritance of ac- 
qiiired characters, and similar problems, were constantly 
present to Darwin's ever open mind, his views upon them 
changing from time to time, as fresh facts were gathered." 
Like everjiiliing else, these new theories were deeply 
rooted in the past. 

We have already alluded to Alfred Russell Wallace 
(1823-1913) and to the magnanimity with which he and 
Darwin treated each other in the matter of their simid- 
taneous discovery of the causes which had brought about 
" The Origin of Species." Wallace was one of the last 
of the great traveUing naturalists and collectors. He 
explored the Amazon with his friend Bates in the years 
1848-1852. Two years later he visited and lived for some 
years in the Indo-Malay Islands, and in both parts of the 
globe he accumulated a vast series of facts from which 
some of his widest generalisations sprang. 

Wallace had a fine gift for writing, and his " Malay 
Archipelago " is one of the most fascinating books in a 
naturahst's Ubrary. Perhaps his most celebrated books are 
his " Geographical Distribution of Animals " and " Island 
Life," pubUshed in 1876, for, as Professor H. F. Osborn 
reminds us, " Wallace takes rank as the founder of the 
science of zoo-geography." " Wallace's Line " between 
BaU and Lombok, the frontier between the Indian and 
Australian regions, will ever recall his fame in this branch 
of science. 

He was a man of strong humanitarian instincts and 
devoted a considerable amovmt of time in trying to devise 
plans to help mankind and the state, and although many of 
his views did not commend themselves to the majority his 
sincerity was always fully recognized. 

We must now return to many zoologists of about 
Darwin's period who more than held their own as compared 
with some continental claimants of scientific superiority. 



282 Britain's Heritage of Science 

Although George James Allman (1812-1898) was Pro- 
fessor of Botany at Dublin, he achieved his most marked 
success as a zoologist. He left Dublin in 1856 on his 
appointment to the Regius Professorship of Natural History 
in the University of Edinburgh. He was, hke so many men 
of science, a good artist, and had exceptional skill in drawing 
on the blackboard, and was a very popular lecturer, and he 
took especial pleasvue in taking his pupils on dredging 
expeditions in the Firth of Forth and inducing them to 
study marine organisms in the living state. His great work 
on the Gymnoblastic Hydrozoa, published by the Ray 
Society, is stated by his biographer to have been without 
doubt the most important systematic work dealing with the 
group of Coelenterata that has ever been produced. " The 
excellence of the illustrations alone would almost justify 
us in placing this work in the first rank of zoological treatises." 
But he was equally an authority on certain groups of Polyzoa, 
and it should be recalled that he it was who invented the 
terms " ectodemi " and " endoderm," besides a great many 
other useful expressions, such as " coenosarc," " tropho- 
some " and " gonosome," and many others. But above all 
he did much to clear up the difficulty of defining species in 
the Coelenterata. 

Thomas Henry Huxley (1825-1895), a few years younger 
than Wallace, was, as we have seen, another of Darwin's 
supporters. He started life as a surgeon and, like Darwin, 
owed much of his early reputation to a sea voyage. He 
made a four years' cruise in H.M.S. Rattlesnake, 1846- 
1850, during which he especially devoted himself to the 
study of marine organisms. He was the fiist to dissociate 
the hydrozoa from the star fishes, and the parasitic worms 
and the infusoria, which had formed portions of Cuvier's 
old group Badiata. He did much to clear up the relations 
of the Medusa to the Hydroid, and he dwelt especially on 
the two-layered condition of their body wall, pointing out 
its analogy with the gastrula. Shortly after his return to 
England in 1850, he was elected a Fellow of the Royal 
Society at the unusually early age of 26. 

As a morphologist, Huxley made immense advances. 
Apart from his work on Coelenterates, he investigated the 



Thomas Huxley, William Flower 283 

structural life-history of the Ascidians, wrote on the 
Mollusca, and undertook a series of investigations into 
fossil vertebrate forms, researched on Aphis and on croco- 
diles, cleared up the mystery of the vertebrate skull, 
and, in fact, covered an extremely wide area of investi- 
gation. But Huxley was not only a great morphologist, 
he was a great teacher and a great organiser. His text 
books on the comparative anatomy of the Vertebrate and 
of the Invertebrate were the starting points of many a 
zoologist's career. His " Elementary Biology," which he 
wrote in collaboration with NewaU Martin, marks an epoch. 
He was also a great lecturer, and although not fond of public 
speaking, he was remarkably able, concise, and even 
eloquent. He spared no pains, and would write and re- 
write an address until he had got it into what he considered 
a satisfactory form. Further, as he himself wrote of 
Priestley, he was " a man and a statesman before he was 
a philosopher," and Huxley took a leading part in public 
affairs, sat on a large number of Royal Commissions and 
departmental committees. He was a member of the first 
School Board of the City of London, and by his popular 
lectures made a real attempt to interest the working men 
and all others in the importance of science. He was, for a 
time, the Biological Secretary of the Royal Society, and in 
this post took a large part in organizing the Challenger 
Expedition of 1872-1876. He was elected President of the 
Royal Society, but four years later was compelled to resign 
on account of iU-health. He was the recipient of innumerable 
honorary degrees and memberships of foreign societies, and 
in 1892 was honoured by being made a Privy Councillor. 

Owen's successor. Sir William Flower (1831-1899), was 
trained at the University of London as a medical man, and 
after touring on the Continent, he joined the army, and 
was assistant surgeon in the 63rd Regiment during the 
Crimean Campaign, the trials of which were so severe that 
his health weib afiected, and he had to retire from the army 
and retiu^ to London. For a time he practised, but in 
1861, was appointed Conservator of the Museum of the 
Royal College of Surgeons, and here he found his career. 
This unique museum was greatly increased under Flower. 



284 Britain's Heritage of Science 

The President of the Royal Society said, when presenting 
Sir William with a royal medal, " it is very largely due to his 
incessant and well-directed labours that the Museum of 
the Royal College of Surgeons at present contains the most 
complete, the best ordered, and the most accessible collec- 
tions of materials for the study of vertebrate structures 
extant." 

Flower succeeded Huxley in the Hunterian Professor- 
ship at the Royal College of Surgeons, and his lectures met 
with great success, in fact, he was soon becoming the fore- 
most authority on mammals, and his work on " Mammals, 
Living and Extinct," which he published in London in 
conjunction with Lydekker, is still regarded as a classic. 
Perhaps if he had a favourite group it was the Cetacea, and 
when he succeeded Owen as Superintendent of the Natural 
History Museum at Kensington, he took the greatest 
pleasure in having a large room specially constructed to house 
their gigantic skeletons. His weU-lmown " Osteology of 
Mammals," in which he was assisted by Dr. Hans Gadow, 
was, even if a little dry, one of the most accurate and com- 
plete of student's books. Another side of his work was 
Anthropology. He published innumerable papers on the 
various races of mankind, fully utUising the valuable material 
he had at the Royal College of Surgeons. In 1879 he was 
elected President of the Zoological Society, and held the 
position until his death. His energy greatly increased the 
value and use of the gardens. In 1898 failing health com- 
pelled him to retire from the position. Sir Wilham was 
a handsome, weU-set-up man, always courteous to strangers, 
with a ready, fluent address. 

One of the unexpected results of Darwin's investigations 
was to induce a number of the younger school of zoologists 
to take up the study of Embryology. The most brilliant 
of these was Francis Maitland Balfour (1861-1882). He 
was educated at Harrow and at Trinity College, Cambridge. 
Even as a student — acting imder the advice of Michael 
Foster, at that time Praelector of Physiology in Trinity 
College — ^he devoted himself to clearing up some points in 
the development of the chick. After taking his degree in 
1873, he worked on the embryonic history of the Elasmo- 



W. Flower, F. M. BaHour, A. Sedgwick 285 

branch fishes at the Zoological Station at Naples. This 
research gained him a Fellowship at Trinity College. 

He was appointed lecturer on Animal Morphology at 
Cambridge, and soon became the founder of an extremely 
vigorous and active school of zoologists. His best known 
work is, of course, his " Treatise on Comparative Embryo- 
logy," the first volume of which appeared in 1880, and the 
second in the following year. It was a masterly review of an 
enormous number of observations scattered over a world- 
wide Hterature, and its production involved a wide and 
careful reading of multitudinous papers. He had remark- 
able critical faculty, and a wonderful gift of insight and 
intuition, so that his book threw light on many a doubtful 
point. When he was but 27, he was elected a Fellow of 
the Royal Society, and, if he had chosen, he might have 
succeeded Rolleston as Professor at Oxford. Edinburgh 
also coveted him; but he remained faithful to his own 
University, and, in the spring of 1882, a special Professorship 
of Animal Morphology was instituted for him at Cambridge. 

Balfour died by a tragic accident in the Alps in the 
summer of 1882, and in Mm died a young man of great 
performance, and even greater promise. He was a man of 
singular charm, and, as Professor Michael Foster wrote, 
" he was high-minded, generous, courteous, a briUiant 
fascinating companion, a steadfast friend. He won, as few 
others did, the hearts of all who were privileged to know 
him." 

We must necessarily deal but shortly with a few more 
names : — 

George John Romanes (1848-1894), whose researches on 
the physiology of the nervous and locomotor system of 
jeUy-fishes and echinoderms, and whose speculations on the 
principle of Selection will preserve his name. 

Adam Sedgwick (1854-1913), a great nephew of the 
geologist, by Ms researches on Peripatvs did much to eluci- 
date the mystery of the Coelom in Arthropods, and so show 
a possible connexion between tMs group and lower ammals. 
His views on the cell theory are now coming to their own. 
For a year or two he was Professor of Zoology at Cambridge, 
and at the time of Ms death he was Professor at the Royal 



286 Britain's Heritage of Science 

College of Science and" Technology, in London, and though 
he was by no means a fluent lecturer, he was a stimulating 
and inspiring teacher. 

Walter Frank Raphael Weldon (1860-1906), another 
Cambridge man, succeeded Moseley as Professor at Oxford. 
He was a brilliant teacher, full of enthusiasm, and did much 
sound morphological work. The last years of his lite he 
devoted to the subject of Biometrics, and he was the co- 
founder with Karl Pearson of Biometrika. 

The mention of Biometrics recalls the name of one who, 
though not a zoologist in the strict sense of the word, deserves 
a distinguished place in the history of our subject. Francis 
Gal ton (1822-1911) began active life as a student of medicine, 
but, on his father's death, inherited independent means and 
abandoned the professional career. He spent some time on 
an extensive journey in Africa, but his mind soon turned 
to science. It was, probably, his experiences as a traveller 
that directed his attention, at first, to meteorology, and he 
did some useful work in that subject. On the publication 
of the " Origin of Species," Galton at once adopted the 
views advocated by Charles Darwin, who was his cousin. 
He then became interested in the laws of heredity, and during 
a series of years endeavoured to introduce scientific measure- 
ments into the study of a subject in which previously quali- 
tative estimates were considered sufficient. Feeling the 
want of proper statistics, he instituted, during the National 
Health Exhibition in 1884, an anthropometric laboratory, 
for the purpose of collecting satisfactory data. This was 
the forerunner of the present biometric laboratory at 
University College, London. Following up suggestions by 
Sir William Herschel and Dr. Foulds, who had proposed the 
use of " finger-prints " as a means of identifying persons. 
Galton proved the method to be reliable, and devised a 
workable scheme for classifying the prints so as to make 
them serviceable for rapid identification. He was also the 
originator of the word " Eugenics " for the study of the 
methods of improving the human race by breeding from the 
best, and restricting the offspring of the worst ; and he must 
be considered to be the founder of that branch of science. 
Endowed with exceptional originality and a sympathetic 



W. F. A. Weldon, F. Galton, E. R. Lankester 287 

mind that allowed him to co-operate effectively with other 
men, he rendered many useful services to science. He was 
knighted in 1909, two years before his death. By his will 
he left a sum amounting to about £45,000 for the foundation 
of a chair of Eugenics in the University of London, expressing 
the wish that Karl Pearson should be the first occupant of 
the chair. 

One of the rules laid down for the writers of this book 
is that living authors should only be mentioned when their 
work is so much interwoven with that of others whose 
activities have been noticed that a wrong impression would 
be created by omitting all reference to them. Professor 
Sir E. Ray Lankester has added so much to our conceptions 
of the morphology of the animal kingdom, so much more 
than any other living man, that a short account of his re- 
searches must be given. Mention must be made of his 
investigation into the embryonic cell gland of the Mollusca, 
his researches in the distribution of haemoglobin in the 
Invertebrata, the wonderful way in which he, in collabora- 
tion with one of his pupils, cleared up the structure of the 
Lamellibranch giU, his work on the anatomy of the Limpet, 
and the even more important series of investigations which 
led to the assignment of Limulus to its proper position 
amongst the Arachnids. He was the first to observe an 
intracellular parasite (in the red corpuscle of the frog), but 
from the scales of fossil fishes to the details of the Okapi, 
there are few subjects in Zoology that do not owe something 
to the investigations carried on by Lankester from 1862 
to 1905. His name wiU ever be associated with the very 
important and fundamental conception of the ccelom, and 
his views on this subject are set forth at length in Part II. 
of his Treatise on Zoology. With this theory must be 
associated his views on Phleboedesis, a name given to the 
theory that the lacunar blood-holding spaces forming the 
hsemocoel of the Mollusca and the Crustacea have no 
connexion with the ccelom, although they encroach in 
certain animals on the space occupied by the coelomic 
cavity. The discussion of how his theory differs from that 
given in " Die Coelom Theorie " of the Hertwigs is set out 
in the abovs-meutioned treatise. 



288 Britain's Heritage of Science 

In addition to these fundamental conceptions which have 
done so much to clear up the structure of widely differ- 
ing animals, Lankester has introduced many new terms 
which have proved of permanent value in the science of 
zoology. Amongst these may be mentioned " nephridium," 
" blastoderm," " stomodeum," " proctodeum." Further, 
he introduced the terms " homogeny " and " homoplasy," 
to distinguish between the two very different senses in which 
" homology " had previously been used. 

As a maritime nation, Great Britain has led the way in 
exploring the plant Ufe and animals of the sea, the chemical 
and physical nature of the sea water, and the geological 
structure of the subaqueous earth. As long ago as 1749 
Captain Ellis found that a thermometer, lowered on separate 
occasions to depths of 650 fathoms and 891 fathoms respec- 
tively recorded, on reaching the surface, the same tempera- 
ture, namely, 53°. His thermometer was lowered in a 
bucket ingeniously devised so as to open as it descended 
and close as it was drawn up. The mechanism of this instru- 
ment was invented by the Rev. Stephen Hales, D.D., to 
whom we have referred above. Dr. Hales was an ingenious 
soul and the author of many inventions, amongst others, 
he is said to have suggested the use of the inverted cup 
placed in the centre of a fruit-pie in which the juice 
accumulates as the pie cools. His device of the closed 
bucket with two connected valves was the forerunner of 
the numerous contrivances which have since been used for 
bringing up sea-water from great depths. The colour of 
the sea and its salinity had also received attention in early 
days, notably at the hands of the distinguished chemist, 
Robert Boyle. 

The invention of the self-registering thermometer by 
Cavendish in 1757, provided another instrument essential 
to the investigation of the condition of things at great 
depths, and it was used in Lord Mulgrave's expedition to 
the Arctic Sea in 1773. On this voyage attempts at deep- 
sea soundings were made, and a depth of 683 fathoms was 
registered. During Sir James Ross's Antarctic Expedition 
(1839-1843) the temperature of the water was constantly 
observed to depths of 2,000 fathoms. His uncle, Sir John 



Marine Zoology 289 

Ross, had, twenty years previously, on his voyage to 
Baffin's Bay, made some classical somidings. One, two 
miles from the coast, reached a depth of 2,700 feet, and 
brought up a collection of gravel and two living crustaceans ; 
another, 3,900 feet in depth, yielded pebbles, clay, some 
worms, Crustacea, and corallines. Two other dredgings, 
one at 6,000 feet, the other at 6,300 feet, also brought up 
living creatures; and thus, though the results were not at 
first accepted, the existence of animal hfe at great depths 
was demonstrated. 

With Sir James Ross's expedition we may be said to 
have reached modern times; his most distinguished com- 
panion. Sir Joseph Hooker, died as recently as 1911. It is 
impossible to do more than briefly refer to the numerous 
expeditions which have taken part . in deep-sea exploration 
during our own times 

Professor Edward Forbes, who " did more than any 
of his contemporaries to advance marine zoology," joined 
the surveying ship Beacon in 1840, and made more than one 
hundred dredgings in the .^gean Sea. Mr. H. Goodsir sailed 
on the Erebus with Sir John Franklin's iU-fated Polar 
Expedition; and such notes of his as were recovered bear 
evidence of the value of the work he did. In 1868 the 
Admiralty placed the survejdng ship Lightning at the disposal 
of Professor Wyville Thomson and Dr. W. B. Carpenter 
for a six weeks' dredging cruise in the North Atlantic; and 
in the following year the Porcwpine, by permission of the 
Admiralty, made three cruises under the guidance of 
Dr. W. B. Carpenter and Mr. Gwynne Jeffreys. 

We owe to Forbes (1815-1854) the delimitation of this 
zone of depth usually distinguished in European and other 
seas. These are the Littoral zone, the Laminarian zone, 
the CoraUine zone, and the region of the deep sea corals. 
The last two zones are now generally known as the Conti- 
nental Shelf and the Continental Slope, and to these must 
be added the floor of the deep ocean, a region which in 
Forbes' time was regarded as uninhabited. Forbes, after 
a very varied career, ultimately became a Professor at 
King's College, London, and Curator of the Museum of the 
Geological Society. His work in connexion with palseonto- 

T 



290 Britain's Heritage of Science 

logy -will be described in the chapter on Geology. He is 
undoubtedly the leading natiu'alist of the earlier half of the 
nineteenth century, a man of wide interests and of great 
popularity, one who lived a full life, one who promoted 
science, and who rendered a real service to every branch of 
Biology. 

Another naturalist of the same period was Phillip Henry 
Gosse (1810-1888). As a young man he lived in Newfound- 
land, and here it was he began the serious study of Nature. 
His first work was on the Entomology of Newfoundland. 
Later, he travelled extensively in North America. On 
returning to England in 1839 he wrote his " Canadian 
Naturalist." A few years later he was in Jamaica, collecting 
and describing the native fauna and sending many specimens 
home. His " Birds of Jamaica," illustrated by a series of 
magnificent plates, is well known. But, perhaps, Gosse's 
name wiU live longer as a researcher on Marine Inverte- 
brates. He particularly occupied himself with the zoophytes 
and made a great hit with his book " The Aquarium," which 
did much to stimulate amateurs to observe the httoral 
fauna. His most serious contribution to science, however, 
was his study of the sea anemones, Actinologia britannica 
(1855-1860); but it must not be forgotten that he colla- 
borated with Dr. Hudson in the fascinating two volumes 
which these joint authors published in 1866 on the Rotifera. 

Towards the end of 1872 H.M.S. Challenger left England 
to spend the following three years and a half in traversing 
aU the waters of the globe. This was the most completely 
equipped expedition which has left any land for the investi- 
gation of the sea, and its results were correspondingly rich. 
They have been worked out by naturalists of all nations, 
and form the most complete record of the fauna and flora, 
and of the physical and chemical conditions of the deep, 
which has yet been published. Since the return of the 
Challenger there have been many expeditions from various 
lands, but none so complete in its conception or its 
execution as the British Expedition of 1872-1876. 

The results of the exploration of the sea by the Challenger 
have never been equalled. In one respect, however, they 
were disappointing. It had been hoped that, in the deeper 



Marine Zoology 291 

abysms of the sea, creatures whom we only know as geo- 
logical, fossiUzed, bony specimens, might be found in the 
flesh; but, with one or two exceptions — and these of no 
great importance — these were not found. Neither did any 
new type of organism appear. Nothing, in fact, was dredged 
from the depths or found in the tow-net that did not fit 
into the larger groups that already had been established 
before the Challenger was thought of. On the other hand, 
many new methods of research were developed during this 
voyage, and with it will ever be associated the names of 
Wyville Thompson, mentioned above, Moseley, John Murray 
and others who, happily, are still with us. 

A few words should be said as to the part played by 
cable-laying in the investigation of the subaqueous crust of 
the earth. This part, though undoubtedly important, is 
sometimes exaggerated; and we have seen how large an 
array of facts has been accumulated by expeditions made 
mainly in the interest of pure science. The laying of the 
Atlantic cable was preceded, in 1856, by a careful survey 
of a submerged plateau, extending from the British Isles 
to Newfoundland, by Lieutenant Berryman of the Arctic. 
He brought back samples of the bottom from thirty-four 
stations between Valentia and St. John's. In the following 
year Captain Pullen, of H.M.S. Cyclops, surveyed a parallel 
line slightly to the north. His specimens were examined by 
Huxley, and from them he derived the Bathybius, a primeval 
slime which was thought to occur widely spread over the 
sea-bottom and to be the most primitive form of living 
matter. The interest in this " Urschleim " became merely 
academic, when John Y. Buchanan, of the Challenger, showed 
that it is only a gelatinous form of sulphate of Ume, thrown 
down from the sea-water by the alcohol used in preserving 
the organisms found in the deep-sea deposits. It was 
characteristic of Huxley to acknowledge his mistake and 
never to mention the subject again. 

TJje important generajlzations of Dr. Wallich, who was 
on board H.M.S. Bulldog, which, in 1860, again traversed 
the Atlantic to survey a route for the cable, largely helped 
to elucidate the problems of the deep. Wallich noticed 
that no algce lived below the 200 fathom Une; he collected 

T 2 



292 Britain's Heritage of Science 

animals from great depths, and showed that they utilize 
in many ways organisms which fall down from the surface 
of the water; he noted that the conditions are such that, 
whilst dead animals sink from the surface to the bottom, 
they do not rise from the bottom to the surface; and he 
brought evidence forward in support of the view that the 
deep-sea fauna is directly derived from shallow-water forms. 
In the same year in which Wallich traversed the Atlantic, 
the telegraph cable between Sardinia and Bona, on the 
African coast, snapped. Under the superintendence of 
Fleeming Jenkin, some forty miles of the cable, part of it 
from a depth of 1,200 fathoms, were recovered. Numerous 
animals, sponges, corals, polyzoa, molluscs, and worms were 
brought to the surface, adhering to the cable. These were 
examined and reported upon by Professor AUman, and 
subsequently by Professor A. Miliie Edwards; and, as the 
former reports, we " must therefore regard this observa- 
tion of Mi. Fleeming Jenkin as having afforded the first 
absolute proof of the existence of highly organized animals 
Uving at a depth of upwards of 1,000 fathoms." The 
investigation of the animals thus brought to the surface 
revealed another fact of great interest, namely, that some 
of the specimens were identical with forms hitherto known 
only as fossils. It was thus demonstrated that species 
hitherto regarded as extinct are still living at great depths 
of the ocean. 

Throughout the century repeated attempts had been 
made to classify the members of the animal kingdom on 
a natural basis, but, until their anatomy and, indeed, their 
embryology had been sufficiently explored, these attempts 
proved somewhat vain. As late as 1869 Huxley classified 
sponges with Protozoa, Echinoderms with Scolecida and 
Tunicates with Polyzoa and Brachiopoda. By the middle 
of the century, much work had been done in sorting out 
the animal kingdom on a natural basis, and Vaughan 
Thompson had already shown that Flustra was not a hydroid, 
but a member of a new group which he named Polyzoa. 
He, although hardly remembered now, demonstrated that 
Cirrepedia are not molluscs by tracing their -development, 
he established the fact that they began hfe as free-swimming 



F. D. Godman, 0. Salvia 293 

Crustacea ; he, again, it was who showed that Pentacrinus is 
the larval form of the feather-star, Antedon. 

The custom of naturalists to go on long voyages was 
still maintained, and during the nineteenth century, many 
other expeditions besides that of the Challenger, left Great 
Britain to explore the natural history of the world, some 
under public, some under private, auspices. They are too 
numerous to mention. But a word must be said about the 
wonderful exploration of Central America which has just 
been completed, under the auspices of F. D. Godman and 
O.Salvin. The results are incorporated in a series of magni- 
ficently illustrated quarto volumes which have been issued 
during the last thirty -six years. Mfty-two of these relate 
to zoology, five to botany, and six to archaeology. Nearly 
40,000 species of animals have been described in these 
volumes, about 20,000 being new species, and nearly 12,000 
species of plants. There are few remote and partially 
civilized areas of the world whose zoology and botany are 
on so secure a basis, and this is entirely owing to the muni- 
ficence and enterprise of the above-mentioned gentlemen. 

With regard to our own shores, one of the features of 
the latter part of the nineteenth century has been the 
estabhshment of marine biological stations, the largest of 
which is that of the Marine Biological Association at Ply- 
mouth. The Gatty laboratory at St. Andrews, the labora- 
tories at Port Erin in the Isle of Man, and at Cullercoats, 
have also, for many years, being doing admirable work. 
All these establishments have devoted much technical skiU 
and time to solve fishery and other economic problems 
connected with our seas. 



294 Britain's Heritage of Science 



CHAPTER XI 

Physiology 

HARVEY (1578-1657), who, like Newton, worked in one 
of the two sciences which, in Stewart times, were, to 
some extent, ahead of all the others, was imdoubtedly the 
second man of outstanding genius in science in the seventeenth 
century. Harvey, " the httle choleric man " as Aubrey 
calls him, was educated at Caius College, Cambridge, and 
at Padua, and was in his thirty-eighth year when, in his 
lectures on anatomy, he expounded his new doctrine of 
the circulation of the blood to the College of Physicians, 
although his " Exercitatio " on this subject did not appear 
till 1628. His notes for the lectures are now in the British 
Museum. He was physician to Charles I., and it is on record 
how, during the battle of Edgehill, he looked after the 
young priaces as he sat reading a book under a hedge a little 
removed from the fight. 

In the chain of evidence of his convincing demonstration 
of the circulation of the blood one link, only to be supplied 
by the invention of the compound microscope, was missing. 
This, the discovery of the capillaries, was due to Malpighi, 
who was amongst the earliest anatomists to apply the com- 
pound microscope to animal tissues. Still, as Dryden has it — 

" The circling streams once thought but pools of blood — 
(Whether life's fuel or the body's food). 
From dark oblivion Harvey's name shall save." * 

Harvey was happy in two respects as regards his dis- 
covery. It was, in the main, and especially in England, 
recognized as proven in his own lifetime, and, again, no 
one of credit claimed or asserted the claim of others to 
priority. In research, all enquirers stand on steps others 
have built up; but in this, the most important of single 
contributions to physiology, the credit is Harvey's and 

^ Epistle to Dr. Charleton. 




William Harvey 



Urom a fainting by Cornelius Janssen 
now at the College of Physicians 



William Harvey 295 

almost Harvey's alone. His other great work, " Exercita- 
tiones de Generatione Animalium," is of secondary import- 
ance. It shows marvellous powers of observation and very 
laborious research; but although, to a great extent, it led 
the way in embryology, it was shortly superseded by the work 
of those who had the compound microscope at their command. 
The poet, Cowley, a man of wide culture, wrote an " Ode 
on Harvey," in which his achievement was contrasted with 
a failing common to scientific men of his own time, and, 
so far as we can see, of all time : — 

" Harvey sought for Truth in Truth's own Book 
The Creatures, which by God Himself was writ; 

And wisely thought 'twas fit, 
Not to read Comments only upon it. 
But on th' original itself to look. 
Methinks in Arts great Circle, others stand 
Look't up together. Hand in Hand, 

Every one leads as he is led. 

The same bare path they tread, 
A Dance like Fairies a Fantastick round. 
But neither change their motion, nor their ground : 
Had Harvey to this Road confin'd his wit, 
His noble Circle of the Blood, had been untrodden yet." 

Harvey's death is recorded in a characteristic seventeenth 
century sentence, taken from the unpubhshed pages of 
Baldwin Harvey's " Bustorum Aliquot ReUquise " : — 

" Of WiUiam Harvey, the most fortunate anatomist, 
the blood ceased to move on the third day of the Ides 
of June, in the year 1657, the continuous movement of 
which in aU men, moreover, he had most truly asserted 

'Ev re Tpo\a rravrts cai ev\ rrcuTi rpo^^oi ' 

1 The writer is indebted for this quotation to Dr. Norman Moore's 
" History of the Study of Medicine in the British Isles," Oxford, 
1908. He may here add a short note on the " Tabxilae Harveianae," 
presented in 1823 by the Earl of Winchelsea to the Royal College of 
Physicians. Sir Thomas Barlow, in his Harveian Oration of 1916, 
threw much doubt on these " Tavole " having belonged to Harvey; 
and Dr. Archibald Malloch, of the Canadian Army Medical Corps, 
has, in his recently published lives of Sir John Finch and Sir Thomas 
Baines, brought forward almost conclusive evidence that these 
" Tavole " belonged to the former of these two gentlemen, and were 
brought by him from Padua, where, with his friend, he had studied 
medicine. 



296 Britain's Heritage of Science 

Among other great physiologists and physicians, the 
Swiss, Sir Theodore Turquet de Mayerne (godson of Theodore 
Beza), who settled in London in 1611, has left us " Notes " 
of the diseases of the great which, to the medically minded, 
are of the greatest interest. He almost diagnosed enteric, 
and his observations on the fatal illness of Henry, Prince of 
Wales, and the memoir he drew up in 1623 on the health 
of James I., alike leave Uttle to be desired in completeness 
or in accuracy of detail. 

Before bringing to a close these short notices of those 
who studied and wrote on the human body, whole or dis- 
eased, a few hnes must be given to John Mayow (1640- 
1679), of Oxford, who followed the law, " especially in 
the summer time at Bath." Yet, from his contributions 
to science, one might well suppose that he had devoted 
his whole time to research in chemistry and physiology. 
He it was who showed that, in respiration, not the whole 
air, but a part only of the air breathed in, takes an active 
part in respiration, though he called this part " by a different 
name, he meant what we now call oxygen." '■ 

Mayow showed that dark venous blood is changed to 
bright red by taking up this unknown substance, and thus 
was very near to discovering oxygen, for he fully grasped 
the idea that the object of breatlung is to cause an inter- 
change of gases between the air and the blood, the former 
giving off what he called its " nitro aero " constituent 
(oxygen) taking away the " vapours engendered by the 
blood." He was the first to find the seat of animal heat 
in the muscles, to describe the double articulation of the 
ribs and spine, and he discussed the function of the^ inter- 
costal muscles in an entirely modem spirit. Had he been 
spared he undoubtedly would have gone far, but he died 
in Covent Garden at the too early age of thirty-five, having 
been married a Uttle time before " not altogether to his 
content." 

Thomas Sydenham was one of the first physicians who 
was convinced of the importance of constant and prolonged 
observation at the bedside of the patient. He passed by 

1 Foster, Sir Michael, " The History of Physiology," Cambridge, 
1901. 



Physiology and Medicine 297 

all authority but one — " the divine old man Hippocrates," 
whose medicine rested also on observation. He, first in 
England, " attempted to arrive at general laws about the 
prevalence and the course and the treatment of disease 
from chnical observation." He was essentially a physician 
occupied in diagnosis, treatment and prognosis. When he 
was but twenty-five years old, he began to suffer from gout, 
and his personal experience enabled him to write a classic 
on this disease, which is even now unsurpassed. 

Francis Glisson, like Sydenham, was essentially English 
in his upbringing, and did not owe anything to foreign 
education, ffis work on the fiver has made " Glisson's 
capsule " known to every medical student, and he wrote 
an authoritative book on rickets. He, like Harvey, was 
educated at GonviUe and Caius College, and, in 1636, 
became Regius Professor of Physic at Cambridge, but the 
greater part of his life he spent at Colchester. 

A contemporary of Mayow was Richard Lower (1631- 
1691), of CornwaU. He was the first to perform the operation 
of directly transfusing blood from one animal to another. 
In 1669 he injected dark venous blood into inflated lungs, 
and found it became scarlet. This he attributed to something 
which was being absorbed from the air which was being 
passed through the lungs. In his " Tractatus de Corde " 
he gave a more accurate description than anybody had 
hitherto given of the structure of the heart, including its 
innervation, and, having at his disposal more exact apparatus, 
he was' able somewhat to expand and complete Harvey's 
exposition of the physiology of that organ. 

Lower was for a time assistant to Thomas WilUs (1621- 
1675), whose name is commemorated by the " circle of 
WilMs " at the base of the brain. The " Cerebri Anatome " 
of the latter (1664) was the most complete and detailed 
account of the nervous system that had been pubUshed 
up to this time, though his hypotheses as to the functions 
of the parts he described left much to be corrected later. 
In the preparation of this work he had been helped by 
Lower and Sir Christopher Wren, who drew the illustrations. 
Willis was as distinguished a physician as he was a 
physiologist. 



298 Britain's Heritage of Science 

A name that is sometimes overlooked in the history of 
British Science is that of Clopton Havers (? 1650/60-1702). 
He was for a time educated at St. Catherine's Hall, Cam- 
bridge, but left the University without taking a degree. 
He took the M.D. at Utrecht in 1685, and practised in the 
city of London. But he was an anatomist as well as a 
physician, and was the first to give an adequate account 
of the structure of the bone, and this in his chief anatomical 
work " The Osteologia Nova, or some new Observations 
of the Bones and the parts belonging to them." His name 
is commemorated by the Haversian Canals, a name which 
is stiU used to designate those smaller channels of the bone 
through which the blood-vessels pass. 

British animal physiology, which had started magni- 
ficently with Harvey, and had continued under Mayow, 
de Mayeme and others, was carried forward by Stephen 
Hales (1677-1761). He was a bom experimenter, and, as 
a student, worked in the " elaboratory of Trinity College," 
which had been estabUshed under the rule of Bentley, ever 
anxious to make his college the leader in every kind of 
learning. We have said something about the contribution 
of Stephen Hales to vegetable physiology, but he was no 
less brilliant as an animal physiologist. In the second part 
of his statical essays, entitled " Haemadynamics " (1733), 
a real advance is recorded in the physiology of circulation. 
Hales invented the manometer, with the aid of which he 
was able to make quantitative estimates of blood-pressure, 
and measure the velocity of the blood-current. He knew 
how to keep blood fluid with saline solutions. He studied 
the shape and form of muscles in contraction and at rest, 
and had a considerable knowledge of secretion. He worked 
much on gases and paved the way for Priestley and others 
by devising methods of collecting them over water. Of 
him. Sir Francis Darwin writes : — 

" In first opening the way to a correct appreciation 
of blood-pressure Hales' work may rank second in 
importance to Harvey's in founding the modem science 
of physiology." 

He was a master of scientific method and the greatest 
physiologist of his century. There were, however, many 



S. Hales, W. Hewson, T. Young 299 

others, and Professor Langley has summarized the work 
of some of them in his " Sketch of the progress of the 
discovery in the eighteenth century of the autonomic 
nervous system."^ 

In the eighteenth century a most distinct advance in 
animal physiology was made north of the Tweed by Joseph 
Black, whose work in Physics and Chemistry has already 
been described (see p. 65). Investigating the properties of 
carbonic acid gas or " fixed air," as it was then called, he 
noted that " fixed air " is also present in expired air, and 
is physiologically irrespirable, though not toxic. 

WiUiam Hewson (1739-1774), a pupil of the Hunters (see 
Chapter X.), became assistant to them, and John Hunter 
left him in charge of his dissecting room when abroad with 
the army. For a time Hewson was in partnership with 
WiUiam Hunter. It was he who discovered the existence of 
lymphatic and lacteal vessels in birds, reptiles and fishes, 
a fact which was of great importance in view of the opinions 
held by the Hunters that absorption is the function of these 
vessels ; for hitherto the opponents of this view had pointed 
to the absence of these organs in the lower vertebrates. 
A more important work was embodied in his experimental 
enquiry into the properties of blood (1771). Hewson showed 
that when coagulation of the blood is delayed by cold or by 
the addition of neutral salts, a coagulable fiuid may be 
separated from the corpuscles. He further showed this 
fluid was an insoluble substance which could be precipitated. 
According to Hewson's view, coagulation was due to the 
formation of this substance which he called " coagulable 
lymph," and which we now call " fibrinogen." For a time 
his work was forgotten, but now at last its value is fully 
recognized. 

The Quaker physician, Thomas Young, whose brilliant 
work in Physics has been described in our first chapter, was 
the founder of the science of Physiological Optics. He 
studied under John Hunter, and amongst his early discoveries 
he showed that the accommodation of the eye to different 
distances is due to changes in the curvature of the crystalline 

' Journal of Physiology, Vol. L., 1916. 



300 Britain's Heritage of Science 

lens. He gave the first description of astigmatism of the 
eye, and showed how it coiild be corrected by tilting the 
lens, through which the object is looked at; but Young 
had only come across a slight case of the defect. More 
pronounced cases require cylindrical lenses, as subsequently 
shown by Airy (p. 120). He also laid the basis of the theory 
that colour vision is due to retinal structure corresponding 
to red, green, and violet, and apphed it to the explanation 
of colour blindness. Young advanced Physiology also in 
other directions, and in the Croonian Lecture, delivered in 
1818, he stated the laws covering the flow of blood to the 
heart and arteries. 

Thomas Addison (1793-1860), from Cumberland, was a 
briUiant pathologist, and owing to his not being a very 
successful practitioner, lived almost entirely on his teaching 
and hospital work. He was the first to employ electricity 
in the treatment of various spasmodic disorders and heart 
disease, and, together with John Morgan, he wrote the first 
book in our language on the action of poisons on the living 
body. He described pernicious anaemia, and in his work 
" On the Constitution and Local Affection of Disease of the 
Supra-renal Capsules," he described that disorder which is 
always associated with his name. This book is now regarded 
as the starting point of a long series of studies into the diseases 
of the ductless glands. 

A third researcher from the north of England was Sir 
William Bowman (1816-1892), born in Cheshire, the well- 
known ophthalmic surgeon. He contributed much to the 
science of physiology. He it was who discovered and 
described striated muscle, basement membranes, the ciliary 
apparatus of the eyeball; but perhaps he is best known for 
his research on the kidney, his theory being that while the 
tubules and plexus and capillaries ^re the parts mostly 
concerned in the secretions of urea, Uthic acid, etc., the 
malpighian bodies were the organs which separated the 
watery constituents from the blood. 

With the arrival of Michael Foster (1816-1907) in Cam- 
bridge as Praelector in Physiology at Trinity College in 1870, 
began an era of great activity in biological research in that 
ancient University. This subject had been by no means 



T. Addison, W. Bowman, M. Foster 301 

neglected under Professor Sir George Humphry, Professor 
Clark, and others, but Foster brought with him new methods 
and new conceptions. Owing to the religious tests demanded 
in those times by the older Universities, Foster had been 
educated at the University College, London, and after 
practising as a country doctor for a very few years, he 
became a teacher in Practical Physiology at his old College, 
and in 1869 he was elected Professor in succession to Sharpey. 
He also succeeded Huxley as Fullerian Professor at the Royal 
Institution. For twenty-two years he acted as Biological 
Secretary to the Royal Society, and in 1899 he presided over 
the British Association at their meeting at Dover, in which 
year he was created a K.C.B. In the year 1900 he was 
elected M.P. for the University of London, but lost his seat 
six years later by the small majority of twenty-four votes; 
it makes one shudder to recall that a man of such outstanding 
merit should have said : " Not tiU I became a Member of 
Parliament did I understand what power meant." 

When the new Statutes came in at Cambridge, a Pro- 
fessorship of Physiology was established, in 1883, and Foster 
was the first to hold it. He did but little in original research, 
but was the cause of a vast amount of research in others. 
Still he was to some extent a pioneer in the study of Histology 
and introduced the staining of sections with log-wood or 
hssmatoxylin. He was notable as a teacher, and founded 
one of the finest Schools of Physiology that has ever existed. 
He was a brilliant writer and a masterly organiser, and 
undoubtedly one of the best lecturers and after-dinner 
speakers in the last quarter of the nineteenth century. 

On arriving in Cambridge he introduced courses of 
practical demonstrations modelled on those which Huxley 
was carrying on at about the same time in London, and from 
the first he was siurounded by a brilliant group of students, 
amongst whom were Balfow (see page 284), Walter Gaskell, 
Sheridan Lee, J. N. Langley, NewaU Martin, Sherrington, 
George Adami, Henry Head, and many others. Foster's 
text-book of Physiology, the first edition of which appeared 
in 1876 and was followed by five others, was a classic, and, 
although in so changing a subject, it was almost impossible 
to keep pace with the advances of a growing science, it 



302 Britain's Heritage of Science 

was, for its time, one of the most inspiring of authoritative 
books. Foster published many other books, all of them 
remarkable for clear and scholarly diction and a real charm 
of style, for, like so many men of science, Foster wrote the 
purest EngUsh. The latest of all, " A History of Physiology 
during the Sixteenth, Seventeenth, and Eighteenth Centuries," 
has been of the greatest use in the compilation of these chapters. 
In 1887 he founded the Journal of Physiology, the first of 
its kind in the EngUsh language, and remained sole editor of 
it till a few years before his death. 

His great organizing powers were shown in the foundation 
of the Physiological Society and the International Congress 
of Physiologists. As Secretary of the Royal Society, he 
took a leading part in the estabhshment of the International 
Association of Academies and the International Catalogue 
of Scientific Papers. He was a member of numerous Royal 
Commissions, and had to a marked extent the ear of the 
Government. If Foster told the Treasury a certain thing 
ought to be done, it usually was done. 

Amongst the most brilliant pupUs of Foster was Walter 
Holbrook Gaskell (1847-1914), a member of the well-known 
Liverpool family to which Mrs. Gaskell the novelist also 
belonged. Gaskell came up to Cambridge in 1865, as a 
mathematician, at the unusually early age of 17 and some 
months. Fom: years later he took his degree as twenty- 
sixth wrangler. He then started to study medicine. A 
year later he fell under the magnetism of Foster, and imme- 
diately began a series of works which have made his name 
one of the best known in the history of modem physiology. 

His work falls mainly under three heads. He began his 
researches by studying the innervation of blood vessels in 
striated muscles, and was gradually carried on to the investi- 
gation of the small arteries of the heart with varying reactions 
of the blood. He found that small additions of alkali 
increased their tone, and small additions of acid decreased 
it, and he was one of the first to recognize that there is a 
chemical control in the organs and tissues as well as a nervous 
one. Later he turned his attention to the innervation of 
the heart and the cause of the heart beat. At that time it 
was held that the nerve cells present in the tissues of the 



Michael Foster, Walter Gaskell 303 

heart control its beat. But there is some evidence that the 
nerves were not the sole controlling cause, and in a series 
of masterly papers Gaskell expounded the view of the 
muscular origin of the beat, and showed how the beat is 
conducted in the four chambers of the heart. Recently- 
great advances have been made in the application of physio- 
logical methods to the clinical examination of the heart, and 
this great help to suffering humanity is largely based upon 
Gaskell's work. His studies on nerves led him on to investi- 
gate the structure, origin, and connexions of the sympa- 
thetic nervous system. He described the relations of these 
ganglia with the spinal cord, and gave an accurate inter- 
pretation of their mode of action. His last book, the proof 
sheets of which he finished correcting the day before the 
stroke which ended his Ufe, is entitled " The Involuntary 
Nervous System." 

In the early nineties he turned away from his normal 
work to investigate the action of chloroform on the heart. 
A Commission had been formed and financed by the Nizam 
of Hyderabad to investigate the cause of death under 
chloroform. The Commission reported that death was 
usually due to the action of the respiratory centre. On 
re-investigating, with the assistance of Dr. L. Shore of 
St. John's College, Cambridge, it was found that chloroform 
had a direct weakening effect on the heart, and that respira- 
tion is not the only factor to be watched when that anaesthetic 
is administered. 

Gaskell's work had always been rather on the morpho- 
logical side, and his third line of enquiry was into the origin 
of vertebrates from invertebrates. His work on this subject 
is a monument of ingenuity and a monument of patience. 
In his view, vertebrates had been derived from some possible 
crustacean or arachnid-Uke ancestor, and his investigations 
into the structure and histology of Limulus and of the larval 
lamprey added vastly to our knowledge of these organisms. 
But in spite of all his ingenuity and all his patient persistence, 
he failed to carrry conviction to the heart of his critics, and 
all we can say about it is that his theory, like other theories 
of the origin of vertebrates from invertebrates, is still 
unproven. 



304 Britain's Heritage of Science 

Gaskell was a man of broad views. Every new fact he 
succeeded in establishing he used as a basis for further 
generalization. He took comparatively small part in the 
management of the University, but from time to time and 
whenever really needed, he was willing to place his services 
at the disposal of what was considered the reforming party 
in University pohtics. 

During the first half of the nineteenth century, Physiology 
when it was taught at all was almost invariably taught by 
medical men in active practice at the various London and 
other hospitals. As a rule the doctor predominated over 
the physiologist, and physiology in those days was not so 
clearly defined a science as it has since become. Perhaps 
the most outstanding name of this period is WiUiam Sharpey 
(1802-1880). He was educated in Edinburgh, and was a 
pupil of I)r. John Barclay, Extra-mural Lecturer at that 
university. He subsequently studied at Paris. On re- 
turning to England he started a private practice, but he 
lacked a good bedside manner, and w^is obviously unsuited 
for the duties of a practitioner, so from 1826 onwards he 
devoted himself entirely to pure science. He spent some 
years abroad trudging the roads in true medieval style from 
one university town to another in Central Europe, and in 
1829 he established himself as a teacher in Edinburgh. Later 
he succeeded James Quain as Professor of Anatomy and 
Physiology in what was then the University of London, and 
is now known as University Ciollege, Gower Street, and here 
for the first time a complete course of lectures on Physiology 
were deUvered by one who was purely a physiologist. He 
was a bom teacher, and his lectures were models both in 
matter and form. For a time he was Secretary to the Royal 
Society and a member of the General Council on Medical 
Education and Registration. 

Sharpey was a master of sound judgment, extraordinary 
memory, and one who could deeply interest his pupils in the 
subject he had at heart. Amongst his scholars were Michael 
Poster and Burdon Sanderson, the latter of whose work at 
London and Oxford notably carried on the tradition of his 
master. Although Sharpey was a man of force and power 
he, like Michael Foster, was perhaps more instrumental in 



W. C. Sharpey, L. C. Wooldridge 305 

getting published the work of his students than of publishing 
his own; but the few papers, which are enumerated in the 
" Dictionary of National Biography " under his name, are 
papers of permanent value. 

We have mentioned before that men of science were less 
speciahzed at the earlier part of our period than they have 
now become. Even the holding of professorial chairs in the 
earlier part of the nineteenth century usually involved 
teaching in more than one science. Up to the year 1866, 
the professor of anatomy at Cambridge was responsible for 
the teaching of zoology as well as for that of anatomy. In 
many other places, the professorship of zoology was respons- 
ible for what teaching there was in animal physiology, as 
at Manchester, where W. C. WiUiamson combined the chairs 
of botany, geology, zoology and animal physiology. In the 
London hospitals, strictly scientific subjects were taught by 
doctors in practice who were on the staff of the hospital. 

It is quite impossible to detail the varied and successful 
activities of the numerous physiologists who have worked 
during the last forty years. Conspicuous amongst them was 
Wooldridge. He was a pioneer. He was convinced that 
many of the chemical and quasi-chemical problems presented 
by the processes of life had been attacked too much by 
laboratory methods remote from the animal itself. He 
turned to the coagulation of blood as a tj^e of such processes, 
and decided that an analysis of the phenomenon must involve 
observations upon the reactions offered by the living animal. 
He developed the technique of injecting extracts of tissue 
and organs into the circulation, and rapidly obtained results 
which gave new conceptions to physiology. 

He did not Uve to produce a finished theory of blood 
coagulation, but it is not too much to say that his work 
initiated the modem studies of immunity, and was the 
foundation of what is almost a new science. 

It is not proposed to enter into the consideration of the 
enormous advances that English men of science have con- 
tributed to the practice of medicine and the alleviation of 
pain. Sir James Young Simpson (1811-1870) discovered 
chloroform, thereby immensely improving the possibilities 
of operations, and to a quite unbelievable extent reducing 



306 Britain's Heritage of Science 

pain, not only of our poor sufEering humanity, but of the 
animal creation. Edward Jenner (1749-1823) led the way 
with vaccines and for the first time introduced the practice 
of preventive innoculations. Sir Charles Bell (1774-1842) 
cleared up the relations between the functions of the anterior 
and posterior roots of the spinal column, and made numerous 
other discoveries on the nervous system; and Lord Lister, 
whose father had almost re-invented the compound micro- 
scope, made many discoveries, by far the most important 
of which was his definite discovery of the part played by 
micro-organisms in wounds. The antiseptic principle in 
the practice of surgery dates from him and from his time, as 
Dr. F. H. Garrison says, " when his body was laid to rest 
in Westminster, England had buried her greatest surgeon." 

It is impossible to deal with more than but a very few 
of the distinguished physiologists who were working at the 
close of the last century. One of these, however, must be : 
Charles Smart Roy (1854-1897), who was educated at 
St. Andrews and the University of Edinburgh. He fought 
through the Turco-Serbian War, and whilst in Epirus 
invented his frog cardiometer. For a time he was assistant 
at Strassburg University, and here it was that he invented 
the instrument which is best known in connexion with his 
name, the Renal Oncometer, for the study of the variations 
of the blood-flow through the kidney. Later, as George 
Henry Lewes Student, he worked with Foster at Cambridge, 
and in 1884 was elected to the Fellowship of the Royal Society, 
and shortly afterwards was appointed first Professor of 
Pathology in the University of Cambridge. 

Hampered by ill-health and by want of accommodation 
at the laboratory, he nevertheless produced work of great 
value, and he succeeded in training a number of students 
of great eminence, amongst whom J. G. Adami, W. Hunter, 
Alfred Kanthack, Lorrain Smith, W. Westbrook, and Lewis 
Cobbett, deserve record. 

With Adami he carried out a long series of researches on 
the mammahan heart, which involved the invention of the 
cardiac-plethysmograph and the cardio-myograph, which 
greatly helped to overcome the mechanical difficulties of the 
subject. But he by no means confined his attention to this 



E. Jenner, J. Lister, C. S. Roy 307 

branch of pathology. He had been instrumental in checking 
a cattle plague in the Argentine RepubUc by protective 
inoculation, and in 1885 proceeded to Spain to investigate 
an outbreak of cholera which threatened to be serious. 

As a lecturer he showed httle interest in his pupils, but 
to a researcher he was kindness itself, and unremitting in 
his helpful aid. He was one of the few who at that time 
were convinced that aviation was coming, and he made 
several experiments on flying machines. 



308 Britain's Heritage of Science 



CHAPTER XII 
Geology 

IN tracing the progress of any line of scientific research 
it very often happens that our enquiries are largely 
centred round the life of one man. It may be that he has 
only collected and put into shape ideas which have been 
growing in men's minds when at last a flash of genius has 
illuminated the paths of research and the wisdom of many 
has been crystallized by the wit of one. 

It may be that a fortuitous display of phenomena not 
before exhibited has appealed to the imagination of men, or 
combinations of opportunity and talent have started local 
intelligence upon the paths of observation. 

The striking variety and obvious relations of surface- 
features and rock-characters in England have undoubtedly 
had much influence in starting geological observations in 
this country. England is only a small bit of the contorted 
western margin of the uplifted Eurasian continent. The 
great folds which brought it all up within reach of denudation 
are traversed here and there by belts of more sharply 
crumpled rock which give pause to the periodically encroach- 
ing seas. More than one such system of plications has pro- 
duced the frilled edge of western Europe with its association 
of harder and softer rocks and has thus formed the natural 
breakwaters which have held back for imtold ages the 
tremendous biUows of the Atlantic Ocean hurled against 
them by the South- West winds. In tracing the progress of 
English Geology by reference to the lives of those who have 
done most to promote it we shall soon find that it was seldom 
mere accident that started them on their way. 

We cannot satisfactorily discuss the influence of indivi- 
duals upon Greological discovery without realising that 



William Smith 309 

England's place on the globe and consequent geographical 
features have made her a Geological microcosm in which 
almost every known formation is represented in some part 
of the surface, and that the secrets of her structure and history 
are best disclosed in the mountainous regions of Scotland, 
the Lake District, and Wales, rather than in the less disturbed 
and more regularly disposed strata of the eastern and southern 
counties. It has thus been ia the more complicated regions 
of the north and west that most of her prominent geologists 
have been born or have found the sphere and stimulus of their 
investigations. 

Many a surveyor had observed the obvious fact that as 
we proceed across the country various kinds of rock appear 
at the siirface one after another, and these have been laid 
down On plans and maps for economic purposes; but the 
careful work and shrewd intelUgence of William Smith 
(1769-1839), in the beginning of the nineteenth century, 
led him to infer that these did not He side by side Uke the 
pieces in a Chinese puzzle, but rested on one another like 
the tiles on a roof in regular succession, and that older rocks 
crept out below the newer layers in a constant order. Here 
we had the principle and mode of succession of rocks once 
and for all estabhshed. 

This, however, was not aU that we owe to William Smith, 
for though fossils had been previously collected he now 
discovered that different plants and animals which lived and 
died and were buried in the rocks were characteristic of 
different beds and were followed by different forms of life, 
and that the difference in these fossil remains enabled him 
to detect to which formation of the adjoining district an 
isolated patch of rock was most related. 

Here we find the recognition of a chronological sequence 
of the stratified rocks and of the possibiUty of identification 
by means of the organic remains contained in them. The 
first accoimt of this discovery that every bed contained 
characteristic and pecuKar fossils by wluch it could be 
identified was issued in 1799 by WiUiam Smith, and in 
1815 he embodied the results of his twenty years of obser- 
vation in the field in the first Geological Map of England 
and Wales and part of Scotland. His^work appeared to 



310 Britain's Heritage of Science 

Sedgwick of such fundamental importance that he called 
Smith " the Father of English Geology."^ The majority 
of the names, Lias, Gault, Qunch, etc., which he applied 
to the sedimentary formations in England, were only 
names used by local workmen for certain kinds of deposit, 
but they have been retained and are now the alphabet of 
stratigraphical classification throughout the world. 

As the work of examining the visible crust of the earth 
proceeded men must often have raised the question how did 
Nature bring about these vast changes ? 

Dr. James Hutton (1726-1797), who in qualifying himself 
for the Degree of Doctor of Medicine had familiarized himself 
with the methods of scientific research, had many interesting 
questions forced upon his notice in the cultivation of his estate 
in Norfolk. These he attacked by strict inductive methods, 
but the theory which has always been most especially asso- 
ciated with his name and which now forms the foundation of 
geological research relates to the manner of the building up 
of the crust of the earth and the production of its subse- 
quent modifications. These, he contended, had been brought 
about by agents and processes stiU seen in active operation 
somewhere on the earth, and in 1785 he communicated to the 
Royal Society of Edinburgh these conclusions. John Playfair 
(1748-1819), his pupil, published in 1802 his classic work 
~ entitled " Illustrations of the Huttonian Theory of the Earth," 
and demonstrated the igneous origin of granite and the work 
of the agents of erosion in the production of scenery. It often 
happens that a disciple of the originator of a new idea says 
and writes more in defence of the theory than the original 
author himself. We heard more about evolution from 
Huxley than from Darwin. 

Many fierce controversies arose around and about the 
principal matters in dispute between Huttonians and Wer- 
nerians as to the relative importance of fire and water in 
geological phenomena, all of which have had the useful effect 
of turning men to seek facts from Nature in support of their 
own several views. 

The school of Catastrophists which had indulged in wild 



iproc. Geol. Soc., Vol. I.,; p.. 279. 



, 'SS'^yS^S^^SS^i^^^^i&MiM^ 




Charles Lyell 



From a daguerreotype by J. E. Mayal 



J. Hutton, J. Playfair, C. Lyell 311 

speculations on the causes of changes in the earth's physical 
and organic history had their fallacies exposed by the work 
of the successors and followers of Hutton and Playfair. For 
from the seed sown on English soil by these two pioneers 
sprang the sound healthy tree of Uniformitarianism throwing 
out many branches brightened often by the flowers of genius 
and eloquence, laden with the rich fruit of patient research 
and honest criticism, sometimes warped by opposing acci- 
dents but always deep-rooted and sound at the core. Many 
a good workman helped to till the soil, but one name stands 
out in bold relief over the entrance to the garden of EngUsh 
Geology. Sir Charles Lyell (1797-1875) was a barrister who 
turned to geology when he found that an increasing weakness 
of sight prevented his following other pursuits for which he 
had been more specially trained. Lyell is the man to whom 
Enghsh Geology owes most. For half a century he supported 
the Uniformitarian theory, training the growing plant, 
checking unwholesome growths. LyeU watched the progress of 
research into the modem changes of the earth and its inhabi- 
tants, distinguished the true from the false, and dismissed 
the evidence for that which was not yet proven. His great 
work entitled " The Principles of Geology " was first pub- 
lished in 1833, and its publication marks an epoch in the 
history of Geology. 

It is a long and winding way from the region of specu- 
lation in which Werner and his disciples here and abroad 
sought to find out how basalts were precipitated out of 
an aqueous mixture, to the hardly won ground on which 
Alfred Harker and his friends and pupils now urge with 
persuasive accumulation of experiment and observation how 
each ingredient was segregated according to its affinities 
out of the eutectic magma which is now regarded as an 
inferential fact. 

Many strong men helped on the work, some, like 
Dr. Samuel Allport about the beginning of the 70's, quietly 
collecting material, others, like David Forbes, testing and 
criticising and giving out freely in discussions from the vast 
stores of knowledge thus acquired, others teaching and writing 
like TeaU, to whom we owe the first text-book on British 
Petrography. 



312 Britain's Heritage of Science 

Much of the research falls within the sphere of Chemistry, 
but it is to the mi roscope and its accessories that we owe 
most of the advances made. 

Henry Clifton Sorby (1826-1908) may be regarded as the 
pioneer along this line. He read a paper on the subject before 
the Geological Society in 1857 describing the structure of 
crystals as giving an indication of the origin of minerals and 
rocks. These he studied by means of thin slices, a method 
which he had previously, in 1850, applied to the study of 
limestones. Sorby was followed by the Rev. Prof. Bonney, 
an accompUshed scholar and keen controversialist, who 
grasped at once the value of these new instruments of 
research, vindicated Sorby, and by his academic teaching 
and writings brought the new methods into the prominent 
and popular position which they now occupy. 

" La paleontologie suive les marteaux "' was a phrase in 
which it was sought at a recent International Geological 
Congress' to point out that it generally happened that the 
collections of fossils which have furnished the materials for 
comparative study or for the discrimination of important 
series of strata owed their existence to the accident that they 
were obtainable round the home of some keen investigator 
who, working single-handed or gathering round him a band of 
hke-minded friends, had availed himself of his special oppor- 
tunities. In this way aU available exposures in the district 
were well searched ; the strata were called after the localities 
where they were first or best seen, and genera and species were 
named after some one whom it was desired to honour or 
some character that appeared distinctive. In offering a 
comparative sketch of the development of stratigraphical 
research in Britain we may take the names of the pioneers 
alphabetically, chronologicaUy, or topographically, and the 
above considerations will soon convince us that a bio- 
graphical sketch of the founders leads us at once to a con- 
sideration of the locality in which their discoveries were 
made. We can hardly select a better example in illustration 
of this than the district round St. David's. Here the oldest 
rocks ia the British Isles were seen, folded and contorted it 

* Bept. International Geol. Congress, Petrograd, 



H. C. Sorby, H. Hicks 313 

is true, but still revealing a definite order of succession among 
the varieties of Uthological character. There are there older 
granitoid masses succeeded by overlying volcanic series. 
Dr. H. Hicks (1837-1899), a young local medical practitioner, 
attacked this difficult problem in the latter half of the 
nineteenth century, and gave the latinized local names of 
Dimetian and Pebidian to the two principal divisions. Pro- 
fessor Bonney, E. B. Tawney, and others soon took up the 
work and were in time able to draw up a sketch of the history 
of that early metamorphic series. Similar rocks were dis- 
covered elsewhere in the same position with reference to the 
fossiliferous formations and, though differing in details, were 
easily co-related with the typical series of St. David's. These 
had been noticed by earUer stratigraphical geologists, but 
were passed over with only a short description. There was, 
however, Uttle doubt about the Archaean Rocks (as they 
came to be called) of North Wales, of the Midlands, where 
they have been described by Callaway and others, and of 
North-West Scotland, where a new difficulty was introduced 
by the wondrous earth movements which left these as well as 
some newer rocks folded, broken, displaced, and crushed, 
often beyond recognition. The researches of Dr. Hicks and 
his able exposition of his progressive views on the Archaean 
Rocks are sufficient to prove what geologists owe to the 
accident of his residence at St. David's; but there was yet 
more left for him to discover. Resting upon the denuded 
surface of the Archaean Rocks were the Basement Beds of 
the Cambrian separated from the pre-Cambrian Rocks by 
a vast interval of time. The Survey had passed over the 
district without detecting any trace of fossils in these beds, 
but Hicks resided there, and his hammer left httle untried. 
He found fossils in these early Cambrian beds and, incited 
to closer search, he found them in lower and lower beds till 
there was hardly any horizon from which he had not pro- 
cured new species and new genera. This brought Salter, 
one of the most acute of paleontologists, to his side. These 
unexpected discoveries are recorded in the name given to a 
trilobite, seventeen inches long, which was called Paradoxides 
Davidis, the specific name connecting it with St. David's. 
The subdivisions in which these various forms occurred 



314 Britain's Heritage of Science 

were named from the localities where they were first or best 
revealed to the hammer of the geologist, and so the lists of 
the earliest fossiUferous rocks and their fossils are filled with 
names dear to the tourist and the artist. 

The correlation of these by means of their fossils with 
the rocks exposed in other areas rapidly followed, as, for 
instance, by David Homfray, at Portraadoc, and soon the 
unexpected Paradoxides and its associates were recognized 
among the lowest beds of the fossiliferous rocks all the 
world over. 

Other systems were determined in course of time : the 
home of T. T. Lewis (1801-1858), of Aymestry, is still marked 
by the Aymestry Limestone, while the position of the Llan- 
dovery Rocks as now defined by the Survey was determined 
by Dr. Wilh"ams, of Llandovery. The Llandovery Rocks were 
subsequently cut ofi from the Caradoc Sandstone, and their 
true position correctly fixed by Sedgwick under the name 
May Hill Sandstone. A region so fuU of promise as the 
borderland of Wales attracted Sir Roderick Murchison (1792- 
1871), who, in the first half of last century, collated the 
evidence and gave to the world in 1893, in his magnificent 
work, the Silurian System beautifully illustrated by Sowerby. 
The name Silurian is derived from the Silures of South Wales, 
the ancient tribe which so long withstood the invading 
Romans. 

In the meantime Prof. Adam Sedgwick (1785-1873), 
stimulated by the work of Jonathan Otley in Cambria, and 
with a personal acquaintance from childhood with the rocks 
of the North of England, was attracted by the charms of a 
wild and almost unexplored country, and threw aU his energy 
into the work of unravelling the succession of stratified rocks 
exposed in the mountains of Cambria. His results were given to 
the world in papers published by the Geological Society during 
the same period and in other works in which the fossils were 
figured and described by Salter and McCoy. It is to Sedgwick 
that Geology owes the name Cambrian for the oldest known 
group of fossiliferous rocks; and it was his genius which 
introduced order into our knowledge of the older Palaeozoic 
rocks of the North of England and Wales, and laid the founda- 
tions for subsequent work in the complicated regions where 



R. Murchison, A. Sedgwick, H. Delabeche 315 

they are developed. Sedgwick's influence on the modem 
school of geologists is difficult to overestimate. 

At the close of the Silurian Period there was an irregular 
sinking of the land. The old surface was worn down and the 
material for new lands buUt up from the products of the 
waste. England was in the region of most constantly recurring 
movements ; and it so happened that during the period that 
now supervened the British Isles formed part of the margin 
of Eurasia, in which there were more limited hydrographical 
areas. In one place corals grew in bright clear water, while, 
not far off, lagoons and swamps favoured the growth of a rich 
semi-tropical vegetation, with a fresh or brackish water fauna 
in which fish abounded. The beds with this later facies 
received the name of Old Red Sandstone. Local geologists 
were led to study the exceptionally rich deposits which 
occurred near their homes, and thus the fishes of the Old 
Red Sandstone in Scotland arrested the attention of Hugh 
MiUer, one of whose fascinating books was a description of 
this formation. 

Sir Henry Delabeche (1796-1855) was attracted to the 
tongue of land which runs out to meet the Atlantic on our 
south-west coast. He recognized that mapping, mapping, 
mapping, was the chief essential for the understanding and 
recording of the geological structure of a country. He long 
worked single handed at the district, and pubUshed treatises 
and memoirs which are still classic works. But his crowning 
achievement was the estabUshment of the Government 
Geological Survey, which has developed into a great school 
of geological research, and proved the model on which all 
similar institutions have been organized. 

John Phillips (1800-1874), the Oxford Professor of 
Geology, was bom on the great rim of rocks which hold the 
South Wales Coal field as in a basin. From its sweUing hiUs 
and crags it was called the Mountain Limestone, a name by 
which it is still commonly known. PhiUips was drawn away to 
Yorkshire, where he soon found himseK on the very same 
Carboniferous rocks, on which, as well as on the secondary 
rocks which succeeded them, he wrote admirable treatises. 

The nomenclature followed the hammers of these leaders 
of research, but now, alas, students caimot avail themselves 



316 Britain's Heritage of Science 

as fully as they might of these geological classics, because 
hardly any of the fossils retain the name originally assigned 
to them. Names, instead of being regarded as a means of 
recalling the forms referred to, have become a means of 
forcing on the world new theories of classification which have 
to be changed again when later authors are impressed by 
the value of other similarities or differences. 

In the working of coal mines and quarrying of limestones 
of the Carboniferous formation opportunities are offered to 
the hammers of the palaeontologists and stratigraphists to 
follow the exposed rocks, and so we find the same story 
repeated. Witham, Binney and Williamson collected the fish 
and the plants from the coal measures near Manchester; 
and Lindley and Hutton devoted their attention to the study 
of the vegetable remains 

At the close of the Carboniferous period there again 
ensued a period of local destruction of older beds, followed 
by the deposition of fresh rocks of the New Eed Sand- 
stone. Vast movements of continental masses were taking 
place and hydrographical areas became stUl more limited 
in extent and consequently more varied in their results. So 
much, however, did they present a general uniformity 
in the character of the sequence and in their prevailing 
colour that these basement beds of this new system, 
the so-called Poikilitic or Variegated series of PhiUips, came 
to be known as the New Red Sandstone. The lower part 
gave rise to much controversy, as it was by some con- 
sidered the equivalent of the Permian of Russia, and by 
some bracketed with the underlying Carboniferous rocks. 
Passing by these details of classification we find that the 
study and nomenclature of these deposits in parts'of England 
were determined by the home of Qiarles Moore (1815-1881), 
near Gloucester and Dr. E. P. Wright (1834^1910), at 
Cheltenham. W. H. Fitton and G. A. Mantell in the South 
of England elucidated the sequence of relations of the Jurassic 
and Cretaceous beds and utilized their local opportunities of 
adding to our geological knowledge of these formations and 
their fossils. 

Thus we see that biographical notices of the early geo- 
logists carry us to their homes round which the recreations of 



Palaeontology 317 

leisure hours enabled them to work out in detail the succession 
of the rocks and the distribution of their organic remains. 
The names attached to the formations and now in common 
use throughout most of the world prove that England has 
contributed most largely to the estabhshment of the sequence 
of events in the earth's history and to laying the foundations 
of a rational system of classification of the strata. 

Amongst the Tertiary rocks Sir Joseph Prestwich (1812- 
1896) and Edward Forbes (1815-1854) traced the succession 
of beds particularly in the London and Hampshire basins 
and demonstrated the value of the now generally adopted 
terms Pleistocene, Phocene, Miocene and Eocene which Lyell 
had first appUed early in the last century. 

Much good work has been done by British Palaeonto- 
logists apart from the collecting of fossils in the field, where 
Palaeontology is the handmaid of Stratigraphy. 

For instance, Thomas Davidson (1817-1885) during the 
last decades of the nineteenth century was examining and 
comparing the Brachiopoda which played so large a part in 
the life-history of the older rocks, while field geologists far 
and near sent up to him the results of what their hammers 
had yielded, thus supplying him with more and more material 
and availing themselves of his every ready and untiring 
help to discriminate between zones by means of their fossils. 

Edwards and Haime did the same for corals. J. W. Salter 
(1820-1869) had established many of the recognized genera 
of trilobites in the course of his investigations of the faunas 
of the older rocks between the years 1840 and 1855. 
McCoy's labours covered a wide field, but his chief work lay 
amongst the fossils of the older rocks. To James de Carle 
Sowerby (1787-1871) we owe many of the names of fossils 
which have a cosmopolitan distribution. Sir Eichard Owen's 
(1804-1892) researches amongst fossil vertebrates gained him 
the reputation which was due to his remarkable acumen and 
minute knowledge of anatomy. 

While pointing out where, how, and why British geologists 
were pressing on special research we must not forget those 
who, having acquired wide and accurate knowledge of many 
branches, have collected and sifted the evidence and given 
the results of their labours in the form of text-books, and 



318 Britain's Heritage of Science 

memoirs to which students may turn for the latest and most 
up-to-date views on each advancing front. Here we must 
mention the two Geikies. Dr. James GeiMe (1839-1915), 
besides valuable memoirs on general geology, has given us 
a summary of the arguments in favour of a correlation of 
astronomical cycles with geological periods. Sir Archibald 
Geikie has in text-book after text-book met the wants of 
every age, and, in the clear and attractive language which 
Scotsmen seem to have by nature, or to have evolved the 
method of acquiring by education, has kept generations of 
students supplied with accurate information as to the state 
of the evidence on the many questions raised in the progress 
of an advancing science. 

This may be called an age of text-books, many of them 
entithng their authors to a foremost place among those 
who are helping on the progress of science, but we cannot 
here even give a Ust of their names. 

We are too apt to attach such importance to our modem 
theories that we forget what a great advance an earlier 
hypothesis had often made on pre-existing views. It was a 
shrewd observation which induced the clever and courageous 
Dean Buckland (1784r-1856) to maintain that a large part 
of the superficial deposits which are seen heaped up on the 
tops and flanks of the highest hiUs and filliag the deepest 
valleys of the North of England must have had an entirely 
different origin from the alluvial deposits such as we see 
being laid down now, and to venture on the bold suggestion 
that there had been in quite recent times a great sub- 
mergence and that the sea once swept over the land and left 
as the result of the deluge these tumultuous deposits hence 
called Diluvial. 

Wider travel and more detailed work, however, showed 
a closer analogy between most of these so-called Diluvial 
formations and the masses of debris carried on, in, or under 
the ice and left at its foot when the glaciers or ice sheets 
melted. Agassiz pointed this out and a grand company of 
Scotch and other geologists immediately set to work on the 
details of every section to prove or disprove the truth of 
each new suggestion. 

In the domain of Economic Geology William Smith's 



Economic Geology 319 

observations were primarily connected with tlie question 
of soils; while Farey's descriptions in 1811 and 1813 of the 
Derbyshire Coal Measures and lead mines and of the dis- 
location of the strata were of practical value. To questions 
of water-supply Prestwich's attention was specially drawn, 
and the possible extension of the Coal Measures beneath the 
South-East of England was maintained as far back as 1855 
by Godwin Austen, whose geological conclusions have now 
been verified. 

The energy of geologists still Uving amongst us does not 
slacken and the reputation of British workers in this branch 
of science is well maintained, while the application of the 
results of geological research to economic purposes is having 
an ever-increasing stimulus given to it. 



INDEX 

(Where proper names occur more than once, the principal entry, generally 
containing a short biographical notice, is printed in italics) 



PAGE 

Abel, Sir F. - 199,202 

Abemethy, J. ■ 264 

Aberration of light 62, 70 

Abney, SirW. - - 160,173 
Absorption, spectrum analy- 
sis - - 155-9 
Acad^mie des Sciences 97, 115, 120 
Achromatism of lenses 98, 99 
Acoustics, see under Sound. 
Adami, J. G. 301, 306 
Adams, J. C. - - 125-7 
Addison, T. - 300 
Aeronautics : 

First hydrogen balloon 68 
Glaisher's balloon as- 
cents • 176 
Roy's experiments 307 
isiz - 318 
Agriculture 252, 253 
Air: 

Boyle's law - 75 

Composition of 85 

Liquid - 213 

Airy, Sir G. B. - - 70, 119, 126 

Astigmatism - 120 

Organization of observa- 
tories - - - 165 
Aitken, J. 176 

Alizarin colours - 163, 200 

Alkali, manufacture of - 194 
Allman, G. J. - - 282 

Marine research - 292 

AUman, Prof. W. 254 

AUport, S. - - 311 

Alluvial deposits 318 

Alpha particles - - - 184 
Ansemia, pernicious, dis- 
covery of - - - 300 
Analjrtical Society - - 117 
Anaxagoras - - 14 

Anaximenes - - - 8 



PAGE 

Andrews, T. - 139, 140 

Angout, A. - - - 95 
Aniline dye discovered 200, 201 
" Animal " electricity - 106 

Anti-septic surgery - 306 

Apjohn, J. - - - 176 

Arago 19,119,126,140 

Archer, F. S. - - 173 

Archibald, E. D. - - 176 

Arctic expeditions, see under 

Expeditions. 
Argon, discovery of - - 181 
Aristotle - - - 14,216 
Arrhenius - 146 

Asclepiadeae - - . 244 
Ashmole, E. - 261 

Ashmolean Museum, founda- 
tion of - - 261 
Astigmatism, discovery of 120, 300 
Atom - - - 14 
Atomic Theory - - 15 
Numbers - 185 
Austen, G. - - - 319 
Ayrton, W.E. - - - 193 



Babbage, C. 
Baohe, Dr. 
Bacon, F. 
Bacon, R. 
Baily, F. - 



117,118 

- 159 

223 

7,8,218 

162, 208 



Baines, SirT.,/oo«note -295 
Balloons - - 68, 176 

Balfour, P. M. - 277,284, 301 
Balfour, J. H. - - 254 

Banks, Sir J. - 116,247,243 

Founding of Royal In- 
stitution - 213 

Agricultural research - 238 
Barrow, I. ... 49 

X 



322 



Index 



PAGE 

Barclay, J. - - 265 

Bartolomaeus Angelicus 217 

Basement membranes 300 

Bateman, S. 217 

B6champ 200 

Beoquerel, H. 183 

Beddoes, T. 110 

BeU, Sir C. - 306 

Bennett, A. - 80 

Bennett, C. - 173 

Ben Nevis Observatory 176 

Bentham, George - 245, 246 

Berkeley, M. J. - 250 

Bernard, E. - - 49 

Bernoulli, Daniel 33 

Berryman, Lieut. 291 

Berzelius - - 150 

Bessemer, Henry 187 

Beta particles - 184 

Bevis, J. - 81 

Binney, E. W. 316 

Biometrics 286 

Bird, J. - - 97 

Birmingham University - 160 
Black, J. -14, 65-S, 130, 299 

Bleaching - 195 

Bliss, N. - 63 
Blood : 

CSroulation of - 294 
Coagulation of - 299, 305 
Pressure, first estimates 298 
Transfusion of, dis- 
covery - 297 
Bolton, W. B. - - 173 
" Bone-digester " - 101 
Bonney, T. G. - 312,313 
Boscovich - - 70 
Botany - - - 229-256 
Crjrptogamic - - 250 
Boulton, M. » 103 
Bouvaid, A. - - 126 
Bowman, Sir W. - 300 
Boyle, B. - -14, 73-6, 124, 288 
Boyle lectures - 74 
Boyle's law - 75 
Boys, V. - - 87 
Bradley, J. 61, 70, 97 
Bragg, W. - 184 
Brahe, Tycho - - - 57 









PAGE 


Brain, circle of Willis, 


dis- 




covered - 






297 


Bramah, J. 






105 


Bramah lock 






105 


Brande, W. T. 


- 


39, 


198 


Brewster, D, 


69, 


119, 


124, 






131, 


, 156 


Briggs, H. 






48 


Brinkley, J. 






136 


Brisbane, T. 




- 


253 


British Association 


. 


132, 


,214 


British Museum 




266, 


, 267 


Brouncker, Lord 






51 


Brown, Crum 






133 


Brown, R. 




243, 


,255 


Brownian movement 


- 




244 


Brunner & Mond 






198 


Buchan, Alexander 






176 


Buchanan, J. Y. 






291 


Buckland, W. 






318 


BufEon 


- 


- 


262 


Bunsen 


149, 


,150, 


157 



Cables, submarine 189,190, 
291, 292 

Caius, J. - - - 219, 257 

Calculus - ■ 53 

Cambrian formation 314 

" Canon Mirificus " - 7 

Canton, John 80, 205 

Capillaries, discovery of - 294 

Capillarity - 83, 131 
Carbonic acid, discovery of 66 

Condensation of - 140 

Carboniferous formation 316 

Cardio -myograph 306 

Cardiao-plethysmograph 306 

Carlisle, Sir A. - - 107 

Camot, Sadi - - 27, 29 

Carpenter, W. B. 289 

Castner - 194 

Castner-Kellner process 198 

Catalytic action 146 

Cauchy - - - 122 

Cavendish, Lord C. - 83 

Self-registering thermo- 
meters - . . 288 



Index 



323 



PAGE 

Cavendish, Henry 14, 69, 73, 83-6 
Density of earth - 87 

Law of inverse square- 81 
Meteorological observa- 
tions organized 208 
Cawley - 101 
Cayley, A. - 128, 129 
Cells, nucleus of - 244 
ChaUis, James 126, 127 
Chambers, R. - 275 
Chance, Messrs. 172 
Charles II., interest in 

science - - 57, 203, 227, 233 
Chemical Society - - 212 
Chemistry, industrial appli- 
cation - 194-202 
Chloroform, discovery of 305 
Action on heart - 303 
Chrystal, G. 133 
Christy, S. H. 147 
Chronometer - 96 
Chromosphere, spectrum of 171 
Ciliary apparatus of eyeball 300 
Circle of WilUs - ■ 297 
Circles, divided - 96, 97 
Circulation of blood 294 
Clarke, A. B. 176 
Clausius, R. - 28 
Clifford, W. K. 147 
CUft, W. 265 
Clifton, R. B. 151 
Clocks : 

Anchor escapement 95 

Temperature compen- 
sation - - - 96 
Coagulation of blood - 299, 305 
Coal-tar industry, history of 

199-201 
Cobbett, L. 306 

Coherer - 191 

Coke tower condenser, in- 
vention of - 197 
Colloids 145 
Colour : 

Dispersion - - ' -54, 98 
Photography 173 

Thin plates 19 

Vision - 128, 300 

Comet, Halley's - - 59 



FAOE 

Common, A. A. - - - 170 
Compass : 

Early knowledge of 3 

Improved by Airy - 121 

Conductivity, see under Heat. 

Conservation of energy 8, 22, 135 

Cooke, Sir W. F. - - 188 

Cooper, A. - 264 

Coral - - - - 317 

Cordite 202 

Corporation of Surgeons - 265 

Corpuscular theory of light 17 

Cotes, R. - 56 

Coulomb - - 69, 70 

Courtois 115 

Crabtree, W. 88, 89, 95 

Crawford 131 

Critical temperature 140 

Crookes, Sir W. - 151, 199 

Electric discharge 181 

Radiometer - 1 80 

Thallium, discovered 159 

Cruikshank - 113 

Cryptogamic botany - 250 

Crystalline structure 130, 312 

Crystallography 130 

Ougnot, N. - 104 

CuUen, William - - 65 

Curie, M. and Mme. - - 183 

Cuvier - - 115,265,282 

On organization of Royal 

Society - 212 



Daguerreotype 


173 


Dalton, J. 


15, 36, 40 


Daniell, J. F. 


- 147 


Darwin, C. 


267-281, 286, 




246, 248 


Darwin, E. 


- 268, 274 


Darwin, F. 


- 236 


Darwin, G. H. - 


- 177, 178 


Darwin, R. W. 


268 


Daubeny, C. G. - 


251 


Davidson, T. 


- 317 


Davy, Sir H. - 


21, 37, 109, 172, 




210, 213 



X2 



324 



Index 



Davy's lamp 116 

Deacon, H. - - 198 
" De Diflerentiis Animal- 

ium" - - 257 

Degradation of energy 30 

Delabeohe, Sir H. - 315 

Delambre 60, 63 

De la Kive - 39 

De la Eue, W. 169 

De la Tour, C. 140 

Deluc - - 66 

De Mayeme, Sir T. T. 296 

Demooritus 14 

De Morgan, A. 143 

Desaguliers, J. T. 71 
Descartes, B. 12, 49, 120 
Dewar, Sir J. : 

Cordite, invention of - 202 
Liquefaction of gases 140, 213 
Solidification of hydro- 
gen - 146 
Spectrum analysis 159 
Diamond, nature of 115 
Differential calculus 49, 53 
Notation 117 
Diffraction - 19 
Digby, Sir K. 225 
Dillenius, J. J. - 251 
DUuvial deposits - 318 
Dispersion of colours- 58, 98 
Dissipation of energy - 29 
Dodo - - 261 
DoUond, J. 98, 205 
Dryander - 242, 244 
Dufay - - - 79 
Dyeing industry 194, 199-201 
Dyer, G. - - 197 
Dynamo machine - 192, 193 



Earth : 




Density of - 


64, 86, 87 


Tremors 


214 


Earthquakes 


- 88 


Ebonite • 


- 190 


Edwards, A. M. 


140, 292, 317 



PAGE 

Electric arc - - 114 

Battery - 106, 147, 163 
Spark - - 78 

Telegraph - - 187-189 
Theories 31, 33, 79, 81, 182 
Units - - - 214 

Electricity, atmospheric 205 

Conduction of - -71, 78 
Discharge through gases 78, 
85, 182 
Early researches - 5 

Frictional - -80, 81 

in Fishes - - 83 

Industrial applications 

of - 187-194 

Low of inverse squares 69, 81 

Medical applications - 300 

Electrolysis - - 21, 107 

Electrolytic production of 

metals • - 113 

Electro -magnet, invention of 148 
Electro-magnetic : 

Induction - 20, 191 

Theory of Ught - 32, 138 
Electro -magnetic engine 24 

Electrometer - - 70 

Electron theory 138, 139, 182 

Electroscope, gold leaf 80 

Electrostatics 31, 81, 82 

EUis, Capt. - 288 

Embryology 284, 295 

Energy : 

Conservation of 8, 22, 28, 136 
Dissipation of 29, 30 

Kinetic - 23 

Potential 23, 123, 135 

Transmission of 161 

Engine : 

Dynamo - 192 

Electro-magnetic - 192 

Steam - - 99-106 
Ent, Sir G. - - 226 

Erosion, geological eSeots - 310 
Eskdalemuir observatory - 209 
Eugenics - - 277, 280, 286 
Euler - - - 98 

Evelyn, J. - 220, 225, 226 

Evaporation, cooling pro- 
duced by - - - 65 



Index 



325 





FAQE 




PAGE 


Ewing, J. A. 


193 


Foucault - 


156 


Expeditions : 




Fownea, G. 


146 


Antarctic 


247, 288 


Fox, W. D. 


270 


Arctic 


207, 288 


Fraookland, E. 


148, 149 


Beacon 


289 


Franklin, B. 


79, 205 


Beagle 


271 


Franklin, Sir J. - 


- 289 


BuOdog 


- 291 


Fraunhofer 


155, 156 


Central America, 


God- 


Freezing mixtures 


- 76 



man and Salvin - 293 

Challenger 283, 290, 291 

Cyclops - 291 

Endeavour 241, 242 

Erebus - 247, 289 

Lightning - 28fl 

Porcupine - 289 

Racehorse ■ - 207 

Battlesnake, Huxley 282 



Freezing point, influence of 

pressure - 136 

French Academy of Science - 97, 

115, 210 

Fresnel, A. J. 1 9, 20, 54, 1 1 9, 

122, 137 

Fry, P. W. - 173 



Falconry - ■ 258 

Faraday, Michael : 

Electro -magnetic induc- 
tion, discovery of 20, 31, 
37,43,191,198,213 
Inductive capacities 82 

Optical glass 205 

Farey ... 319 

Fibrinogen 299 

Fire-damp 115 

Fitton, W. H. - - 316 

Fitzgerald, G. F. - 137, 138 
Fitzroy, Capt. 271 

Fizeau . 132 

Flamsteed, J. 57 

Fleming, A. 257 

Flora : 

Australiensis 246 

Colonial 247 

of Hong Kong 246 

Indica - . 248 

Flower, Sir William 267, 283 

Fluorescence - 124 

Fluxions - 35, 53, 117 

Forbes, E. - - 289, 317 

Forbes, J. D. 752,136,311 

Fossils - - 309, 312 

Foster, Sir M. - 250, 300, 304 

on F. M. Balfour - 285 



Galileo 
Galen 
Gadow, H. 
GaUtzin, Prince 
Galle 

Galton, Sir F. 
Galvani, L. 
Galvanism 
Gamble, J. C. 



5, 8, 9 
216, 219 

- 284 

- 179 

- 127 
277, 286 

- 106 
112 

194-197 



Gas, illuminating, first used - 105 
Gay-Lussac 37, 115 

Gas sylvestre - 66 

Gascoigne, W. - 57, 94 

Gasea : 

DiHusion of - 145 

Kinetic theory of - 33 

Liquefaction of 139, 212, 213 
Transpiration of - 145 

Viscosity of - - 34 

Gaskell, W. H. 301, 302, 303, 304 
Gassiot, J. P. - 162, 209 

Geikie, Sir A. 318 

Geikie, J. 318 

Geissler tubes 162 

Gellibrand, H. 68 

Geodetical Survey 207 

Geological Society - 212 

Geological survey. Govern- 
ment - - 315 
Geology - 308-319 



326 



Index 



PAGE 

Geometry, analytical - 49 

Geo-physics - - 133 

Gerard, J. - 229, 231 
Gesner, C. 220, 256, 257, 258 

Gilbert, W. 3 

Gill, Sir D. 166-8 

Glaciers - - 133, 136 

Glaisher, J. W. L. 141 

Glaisher, James 176 

Optical 81, 168, 205 

Glazebrook, Sir R. 210 

GUsson, F. 297 

Glover, J. - 198 

Godman, F. D. 293 

Goodsir, H. 289 

Goodyear, C. - 190 

Gordon, R. M. 173 

Gossage, W. - 197 

Gosse, P. H. 290 

Gout - 297 

Qraebe - - 200 

Graham, G. 95, 97 

Graham, T. 68, lU, 145, 202, 254 
Granite, igneous origin 310 

Gravitation 10, 11, 53, 64, 86 

Gray, Stephen - - 78 

Greaves, J. - 49 

Green, G. 121 

Greenwich Observatory 57, 

165, 207, 208 
Greenwich time, automatic 

transmission of - 166 

Gregory, family of 52 

Gregory, D. 52, 98 

Gregory, J. 52 

Gresham, Sir T. - - 47 

Gresham CoUege - 46, 47, 203 

Greville, R. K. - 254 

Grew, N. - - - 232, 234 
Grove, W., Lord Justice 163 

Guericke's air-pump 75 

Guillim, J. - 221 

Gunter - 94 



Hadley, J. 
Haime 



95 
317 



FAQE 

Hales, S. 204, 236, 255, 

288, 298 
Hall, C. M. 99 

HaUey, E. 58-60, 92 

HaUey's comet - 59 

Hamilton, Sir W. R. 136 

Hamilton's principle - 136 

Hancock, T. 190 

Harcourt, V; 141 

Harker, A. - 311 

Harris, Sir Snow 205 

Harrison, J., chronometer 69, 96 
Hartley, W. - - 160 

Harvey, W. 219, 223, 294 

Haughton, T. 137 

Havers, C. ■ 298 

Hauksbee, F. 77, 78 

Heart : 

Structure of - 297, 303 

Cardiac -plethysmograph 
audcardio-myograph, 
invented- - - 306 
Heat : 

Conductivity of 133 

Equivalent of 26 

Latent - 66, 86 

Mechanical theory of - 25, 
29, 108, 135 
Polarization of - - 133 
Radiation of 76, 93, 

131, 152, 158 
Radiations 93 

Specific, method of cool- 
ing- - 131 
Heliometer - - 168 
HeUum - 171, 181, 184 
Liquefaction of - 214 
Hemming, J. 198 
Henley, W. - 80 
Henry, T. - 148 
Henry, W. 148 
Henslow, J. 253, 270 
HeracUtus 8 
Heraldry - 221 
Herapath - • - 33 
Herbert of Cherbury, Lord 

220, 225 
Herbert, J. - - 267, 274 
Heredity, MendeUan theory 278 



Index 



327 



PAOB 

Hsrschel, Sir John 118, 124, 

156, 166 
Hyposulphite, in photo- 
graphy - - 173 
Coloured flames 153 
Optical glass manufac- 
ture - - - 205 
Herschel, Sir W. 88, 90, 126, 169 
Discovery of Uranus - 91 
Finger-prints 286 
Infra-red rays 93 
Star drifts - 93 
Hicks, H. - - 313 
Hieroglyphics, Egyptian 37 
Hill, E. - 254 
Hippocrates - 216, 297 
" History of Fishes " - - 259 
" Historic of Foure-Footed 
Beastes " and " Historic 
of Serpents " - 220, 258 
" History of Insects " - 259 
Hofmann, A. W. 194, 199, 201 
Holland, P. 217 
Homfray, D. - - 314 
Hooke, B. 17, 55, 77, 259 
Anchor escapement - 95 
Mechanical theory of 

heat - 108 

Pepys on 227 

WaUeron - - 259 

Hooker, Sir J. D 247, 255, 

279 289 

Hooker, Sir W. J. - - ' 246 

Hope, J. C. - - 130, 131 

Hopkinson, J. - 193 

Homblower, J. C. - - 105 

Horrocks, J. - 88, 89, 95, 207 

Horse-power, first use of 

term - 104 

Hortioultviral Society- - 245 
Howard, Henry (Duke of 

Norfolk) - - 210 

Howard, L. - 176 

Hudson, Dr. 290 

Hughes, D. - 190 

Huggins, Sir W. - - 171 

Humboldt - 244 

Hume, D. - 65 

Hunter, J. - - 263-5 



FAGB 

Hunter, W. - 263 

Huntsman, Benjamin - 187 

Hussey, J. T. - 126 

Hutton, C. 64, 70, 86, 87 

Hutton, James - 70, 245, 310, 316 

Huxley, T. H. 249, 279, 282, 

291, 301 

on Darwin 267, 278 

on Owen - 265 

Huygens, C. 9, 17, 51, 95, 

'^ 210, 211 

Hydraulic press - 105 

Hydrogen, generated by 

electrolysis - 107 

SoUdified 214 

Hydrogenium 145 

Hysteresis 193 



Illuminating gas, first used - 105 
Infra-red rays, Herschel 93 

Ingenhouse, Dr. - 81 

Inoculation - 204, 306 

Instruments, scientific, con- 
struction of - 94, 95 
Interference of light 19 
Integral calculus 53,117 
Inverse square, law of, in 
gravitation - 10, 53 
In electricity 69, 81 
Iodine, discovery of - - 115 
Ionization - - - 146 
Ireland, Royal Society of, 

Dublin - . - 211 

Irish Academy of Sciences - 211 

Irish universities, botany at 254 

Physical science at 137 

Irvine . - - - 67 



Jack, W. 
Jail fever - 
Janssen 



151 
204 
171 



328 



Index 





PAGE 


Jeffreys, G. 


289 


Jellett, J. H. 


137 


Jenkin, F. 


292 


Jenner, E. 


264, 306 


Jenyns, L. 


- 271 


Joly, C. J. 


137, 174 


John of Trevisa 


217 


Johnson, Thomas 


2.'!1 



Joule, J. P. 23, 28, 31, 40, 191 
Equivalent of heat 26 

Velocity of molecules 33 

Journal of Physiology 302 



Kanthack, A. 306 

Kater, Capt. H. - 174 

Kater's penduliun 175 

KeUand, P. - 134 

Kelvin, Lord (W. Thomson) 42, 

123, 127, 134, 136 

Appreciation of Joule - 41 

Economics of dynamo 

engine - - 192 
Electric replenisher 80 
Second law of thermo- 
dynamics - 28 
Submarine cables 189 
Kennett, R. 173 
Kepler 8, 10, 53 
Kew Observatory 209 
King, J. - - . 173 
King's College, London, 

fovmdation - - 143 

Kiroher - - 124 

Kirchhoff - - 157 

Kite, meteorological 176 

Klingenstjema - 98 

Knight, T. A. - - 238 

Krypton, discovery of 181 



Lacteal vessels in birds, dis- 
covery of - 299 
Langley, J. N. - 299, 301 
Lankester, Sir E. R. - 250, 278, 
287, 288 



PAGE 

Laplace - - - 20, 123 
Larmor, Sir J. - 182 

LasseU, W. 169 

Latent heat, see under Heat. 
Laughing gas - -110 

Lavoisier - - - 14, 65 

Leblanc 194, 196, 197, 198 

Lee, S. H. 301 

Leeds University - 160 

Legh, G. - - 221 

Le Gray, G. 173 

Leibnitz - 117 

Length and weight stand- 
ards, reconstruction 130 
Leslie, J. - - 131 
Leverrier, U. J. J. 126, 127 
LexeU - - - 91 
" Liber de Proprietatibus 

Rerum " - 217 

Liebermann - 200 

Life statistics 60 

Liebig, J. - 199, 202 

Light : 

Aberration of 62, 70 

Conical refraction 137 

Corpuscular theory of 17 

Electro-magnetic theory 

of - - - 32 

Fluorescence 125 

Infra-red rays - - 93 

Polarization - 19, 147 

Refraction 53, 81, 98, 121 

Spectroscopy 152-159 

Wave theory 17, 18, 55, 56, 

122, 123 

Lighthouse illumination 193 

Lightning conductors - 205 

Lindley, J. - 245, 255, 316 

Lindsay, Lord 167 

Linnaeus - - 233, 239 

Linnsean Society - 212 

Lippmann, G. - - 173 

Liquefaction of gases - 139, 213 

Lister, Lord - 306 

LivetDg, G. D. - - 159 

Load-stone, origin of word - 4 

Lockyer, Sir J. N. 159, 171, 181 

Logarithms - 7, 48 

Lloyd, H.- - 137 



Index 



329 



PAGE 

Lodge, Sir O. - - 214 
Locomotive, first - 104 
Lower, Biohard - - 297 
London, University of, foun- 
dation 143 
Loudon - - - 246 
Lubrication, theory of 151 
Lumiere et Fils, colovir 

photography - - 174 
Lyell, Sir C. 273, 279, 311, 317 
Lymphatic vessels in birds, 

discovery 299 

Lyte, H. - 230 

Lyons, I. - 241 



McCartney, J. - 


- 264 


McCoy - 


- 314, 317 


MoCullagh, J. 


122, 137 


Maclaurin, C. 


56 


Macleo^, H. 


- 199 


Maddox, R. L. 


■ 173 



Magnetism, terrestrial 4, 120, 

152, 209 

Declination - 3 

Diurnal variation 95 

Inclination - 4 

Secular variation - 58 

Malpighi - - - 255 

Malthus, T. R. - - 274 

Manchester University 148, 160 

Mantell, G. A. - - 316 

Marine biological stations 293 

Marine zones - - 289 

Martin, N. - - 250, 301 

Martyn, T. 252 

Maskelsme, N. 63, 86, 87 

Mason College - 161 

Matthew, P. - 274 

Matter, atomic theory 15 

Electron theory - 182 

Maxwell, J. Oerk 8, 43, 44, 200 

Electro-magnetic theory 

of light - - - 32 

Kinetic Theory of Gases 34 

On Cavendish - - 82 

on second law of ther- 

mo-dynamics - 30 



PAGE 

Mayow, J. 55, 225, 296 

Medicine and surgery - - 262, 

263, 306 
Meldola, R. - 201 

Melville, T. 152 

Mendel, G. - 277, 278 

MendeUsm - 280 

Mercator's projection - - 48 
Meteorology 147, 176, 208, 209 
Michell, J. - 86, 87, 88 

" Micrographia " - 55, 260 
Micrometer, invention of 94 

Double image 97 

Microphone - - - 191 
Miers, Sir H. - 181 

Milky way 92 

Miller, H. 315 

MiUer, W. A. - 154 

Miller, W. H. 129 

Milne, J. 178, 214 

Milton, J. - - ■ - 220 

Miner's lamp, invention of - 116 
Moffett, T. - - 219 

Molyneux family 89 

Molyneux, Samuel 61, 89, 90 

Mond, L. - 198 

Moore, C. - - - 316 

Morse code ■ - 189 

Morison, R. 232, 233, 234, 251 
Moseley, H. N. - 291 

Moseley, H. 184, 185 

Motion, laws of - 9 

Mulgrave, Lord - - - 288 
Multiple proportion, law of- 16 
Murchison, Sir R. 314 

Miirdock, W. - 105 

Murray, J. - 291 

Muscle, striated - - 300 

Muspratt, J. 195, 196, 197, 198 



Napier, John, of Merchiston 6 
Nasmyth, James - 169 

National Physical Labora- 
tory - - 209. 214 
Natural selection 272, 274 



330 



Index 



PAGE 

Nautical Almanac - 37, 63 

Nautilus, Pearly 265 

Navigation, influence on 

science - 47, 63, 96 

Nebulae - - - 169, 170 

Spectrum of - 172 

Neon, discovery of 181 

Neptune, discovery of 125-7 

Neumann, F. - 122 

NewaU, E. 172, 189 

Newcombe, S. 125, 126 

Newcomen, T. - 101 

Newton, Sir Isaac - - 33, 

34, 52, 76, 211 

Fluxions - 35, 53 

Gravitation - 10, 11 

Laws of motion - - 9 

Light 53-56, 98 

Tides- - - 177 

Nicholson, E. C. - 201 

Nicholson, W. - 80, 107 

" Nicholson's blue " - 201 

Nicholson's Journal 107,111 

Niepce, J. N. - 173 

Nitrogen, isolation of - 68 

Nitrous oxide - - 1 1 1 

Noble, WilUam - - 50 

Norman, Robert 3 

North- West Passage - 175 

Nutation, of earth's axis - 63 



Odling, W. - 141 

Ohm 82, 114 

Ohm's law - - 134, 147 

Oncometer, renal - 306 

Ounes, Kamerlingh 140 

Optical instruments 90, 97, 98, 
169, 170, 172 
Optics, physiological - 299 

(See cUso under Light.) 
OrohidesB - - 244, 247 

Origin of Species 248, 273 

Reception of 279, 286 

" Ornithology," Willughby's 259 





PAGE 


Osmosis, G. 


145 


Otley, J. - 


314 


Oughtred, W. - 


94 


Owen, Sir R. 


- 265-7, 317 


Owens, John 


- 148 


Owens College - 


148 



PaUadium, discovery of 145 

Papin, D. 100, 101 

Parallax, stellar - 61, 90, 168 

Parry, E. - 175 

Parsons, Sir C. 187 

Pascal - - 76 
Patents examined by Royal 

Society - 204 

Paxton, Sir J. - 245 

Peacock, G. 118,119 

Pearson, K. - 286, 287 
Pendulum : 

Anchor escapement - 95 

" Gridiron " 96 

Kater's 175 

Pennant, Thomas 262 

Penny, T. - 220 

Pentane lamp - 141 

Pepys, S. - - 222, 226 

Perkin, W. - 199-201 

Petrograd Academy 209, 211 

Petrography - 164 

Phillips, J. - 315, 316 

" Phlogiston " 14, 84 
Photography : 

Astronomical - 168-170 

Colour - - 173-4 

History 166, 172-4 
Physic Garden : 

Chelsea 241 

Dublin 254 

Lambeth 261 

"Physiologus-- - 216 

Physiology 294-307 

of plants 237, 249 

Phyto-geography 255 

Phytophthera inf estans 250 

Picard - - 10, 11 

Pigot, T. - - 50 



Index 



331 



PAGE 

Plants ; 

Binomial nomenclature 
of - - 239 

Classification of, natural 
system - 245 

Physiology of - 237, 249 
Playfair, J. 70, 131, 310 

Playfair, L. - - - 202 
Pliny - - 216, 217, 257 
" PoikiUtio " - 316 

Poisson - - 20 

Polarization of heat - - 133 
Polarization of light 19, 147 

Pond, J. - 60 

Potassium, discovery of 113 

Potential - - - - 123 
Poynting, John 152, 160, 161 

Powell, J. Baden 121, 140, 141 
Prestwich, Sir J. 317, 319 

Prevost - - 156 

Priestley, J. 14, 84, 238 

Pringle, Sir J. - - 204 

Pritchard, C, astronomical 

research 141 

Pritchard, M. - 274 

" Principia " 10 

Professorships : 

Dates of foundation - 46 
ProteacesB 244 

Prout, W. 181 

Pullen, Capt. - 291 

Ptmip, air 75, 181 

Turbine 151 

Pythagoras - 8 



Quaternions 



137 



Radiation of heat, see under 

Heat. 
Radio-activity - - 183 

Radiometer - 151, 180, 181 
Raditun, discovery of 183, 184 
Rainbow, explanation 120 



PAGE 

Ramsay, Sir W. 181 

Ramsden, J. ■ 81, 97 

" Ramsden's eyepiece " 97 

Rankine, W. J. M. - - 134 
Ray, J. - 231, 233, 259, 261 
Rayleigh, Lord - 122, 159, 164 
Discovery of argon - 181 
First step in colour photo- 
graphy - - 173 
Refraction, see under Light. 
Renal oncometer 306 
Respiration 296 
Reinold, A. 160 
Reynolds, O. - - 23, 26, 150 
Rhodes, Cecil - - 168 
Rhodiimi, discovery of 145 
Rickets - 297 
Roberts, I. 170 
Robison, J. 65, 68, 81 
Rocks, arrangement in layers 309 
Roebuck, J. 194 
Roemer, O. - 62 
Roentgen, W. C. 183 
Romanes, G. J. - - - 285 
Ronalds, Sir F. 187, JSS, 209 
Roscoe, H. E. U9, 150 
Ross, Sir James 288, 289 
Ross, Sir John 289 
Rosse, Lord 169 
Routh, E. J. 127 
Roy, Maj.-Gen. 207 
Roy, C. S. - 306 
Royal Astronomical Society 

208, 212 
Royal College of Chemistry 

194, 199 
Royal College of Physicians 265, 
294, 295 
Royal College of Surgeons 265, 283 
Royal Institution, founda- 
tion - - 109, 213-4 
Royal Society - 51,77,203-213 
Royal Society of Arts 211 
Royal Society of Dublin - 211 
Royal Society of Edinburgh 211 
Rubber, commercial produc- 
tion of 190 
Riioker, A. - 160 
Rumford, Count 27, 107, 108, 213 



332 



Index 



PAGE 

Russian Academy comTmini- 
cations to Royal Society - 

209, 211 
Rutherford, D. - - - 68 
Rutherford, Sir E. 183 



Sabine, Gen. Sir E. 175, 207, 209 

Safety lamp 116 
Safety valve, invention of - 101 

Salter, J. W. 313, 314, 317 

Salmon, G. - 137 

Salvin, O. - 293 

Sanderson, Sir B. - 304 
Sandstone : 

Red, new - - 316 
Old - - 315 
Sap, ascent of 232, 238 
Saron - - 91 
Saturn's rings - 128 
Savery, Thomas 100, 104 
Scheele - 172 
SchehaUien experiment 64, 86, 87 
Scottish imiversities, scienti- 
fic activity 64, 130 
Schimck, Edward 163 
Sea, exploration of - - 288 
Sedgwick, A., sen. 271, 310, 314 
Sedgwick, A., jun. 285 
"Seiches" - - 134 
Seismology 133, 178, 214 
Semaphore - 188 
Sextant, invention of - - 95 
Sexuality of plants 235, 236 
Sharpey, W. - 304 
Sherard, W. - 251 
Shore, L. - 303 
Sibthorp, J. J. 251 
Siemens, W. 192 
Silurian rocks - - 314 
Simpson, Thomas 56 
Simpson, Sir J. Y. - 305 
Slide rule, invention of 94 
Sloane, Sir H. - 240 
Smith, Adam 65, 68 
Smith, H. J. - 140-3 
Smith, Sir J. E. 232, 240 
Smith, L. - 306 



PAGE 
Smith, Robert - 71, 90 

Smith, R. A. - - 149 

Smith, W. 309, 318 

SneU ... 53 

Sodium, discovery of - 114 

Soddy, F. 183 

Solander, D. - 241, 242 

Solar system, motion in 

space - - 93 

Sorby, H. C. - 163, 312 

Sound - - 50, 71, 77 

Sowerby, J. de C. 317 

Solvay, E. - 194, 198 

Spottiawoode, W. - 163 

Spectroscopy - 153-159 

Applied to Astronomy - 

171-172 
Spirit level - - 56 

Stanhope, Lord - 212 

Star catalogue 57, 162 

Star-drifts 93 

Stars, double -88, 92 

Steel, scientific production 187 
Steam engine : 

Invention of - 99-105 
Propulsion of ships 101 

Turbine - - 187 

Stewart, Balfour 150, 152, 209 
Theory of exchanges 158 

Stewart, M. - - - 56 
Stereoscope, invention of 148 

Stokes, G. G. - 20, 32, 123-5 
Radiation and absorp- 
tion 157, 158 
Stoney, G. J. 139, 182 
Strontium, discovery of 130 
Sturgeon, W. 24, 148, 191 
Survey - - 174, 207 
Sutherland, J. - 253 
Swan,W. - 154 
Sydenham, T. 296 
" Sylva " 225 
Sylvester, J. J. 128, 141 
Symmer, R. - 79 



Tait, P. 6. 


127, 133, 139 


Talbot, F. 


- 153, 173 


Taylor, B. 


- 77 



Index 



333 



PAGE 

Tawney, E. B. 313 

TeaU,J. J. H. - 311 

Telegraphy : 

Invention of 187 

Submarine- 189 

Wireless - 33 

Telescope, reflecting 52, 54, 169, 

170 

Refracting- - 54, 172 

Temperature, critical 140 

Tennant, C. - 195 

Terrestrial magnetism, see 

under Magnetism. 
Thales 8 

Thallium 159 

" Theater of Insects " 220 

Theobaldus - 217 

Thermodynamics : 

First law 23 

Second law of 26, 28 

Thermometer - 83 

Self-registering 288 

Thin films, thickness mea- 
sured - - - 160 
Thiselton-Dyer, Sir W. - 249, 
250, 272 
Thompson, B., see Rumford, 

Count. 
Thompson, Vaughan - - 292 
Thomson, James 135, 136 

Thomson, Sir Joseph - 152, 182 
Thomson,WiUiam, see Kelvin, 

Lord. 
Thomson, Wyville 289, 291 

Thorpe, Sir E. - - 109, 160 
Threlkeld, Caleb - 254 

Tides - 177, 178 

Time signals - - 166 

Topsell, E. - 220, 257 

Torpedo - - 83 

Torsion balance, invention 

of - - 86, 87 

Townley, R. - 75, 95 

Tradesoant, John, the elder 260 
Tradesoant, John, the younger 261 
Transit of Venus, see under 

Venus. 
Transpiration of gases - 145 

Trevithiok, R. - 104, 105 



PAGE 

Trinity College, Dublin 137-139 

Turbine : 

Engine - - - 187 
Pumps ... 161 

Turner, W. : 

Botany 229, 230 

Zoology - 256 

TyndaU, J. - 88, 213 

Type printing machine 191 



Ultra-violet rays - - 124 
Uniformitarian theory 311 

University College, founda- 
tion of - - 143-146 
Uranus, discovery of - 91 



Vaccines, first used - - 306 
Vacuum tubes, invention of 162 
" Valency " - 148 

Vanadium - - - 150 

Venus, transit of - 52, 63, 88, 
167, 207, 209 
Vernier ... 56 

Vertebrate, origin of, re- 
search - - 303 
Vesahus - - - 219 
Vines, S. H. 250 
Viscosity of gases - 34 
Vives - - 218, 221 
Volta, A. - 80, 106 
Voltaic arc 114 
Vulcanite, invention of - 190 
Vulcanization 190 



Wallace, A. R. 
WalUoh, Dr. 
WaUis, John 
Waltire 
Ward, Joshua 
Ward, M. 



273, 281 

291, 292 

50 

85 

- 194 

250, 2S3 



334 



Index 



PAGE 

Water : 

Composition of - 85 

Compressibility of - 80 
Electrolytic decomposi- 
tion of - 107 
Maximmn density of 130 
Waterston, J. - 164 
Watson, W. - 81 
Watt, J. - 69, 70, 101-104 
Composition of water 85 
Wedgwood, T. 172 
Weights and measures, stan- 
dards -49,130,207,208 
" Weismannism " 280 
Weldon, Walter - 198 
Weldon, W. R. F. 277, 28S 
Wells, W. 0. 176 
Wemerian theory of geology 

310, 311 
Westbrook, W. - - 306 

Wheatstone, Sir C. - 147, 148 



Stereoscope invented 
Speotrmn analysis 
Telegraphy - 

" Wheatstone bridge " 

Wheler, G. 

WheweU, W. 

WUcke, J. K. 

Wilde, Dr. Henry 

Williams, Dr. - 

Williamson, A. M. 

Williamson, W. C. 

Willis, T. - 

Willughby, F. 



148 
154 
188 
147 
78 
119, 223, 271 

- 66 
59, 192 

314 

- 146 
305, 316 

- 297 
232, 259, 261 



FAO£! 

Wilson, A. - - - 176 

Witham . - - 316 

WoUaston, F. J. H. 86 

WoUaston, W. H. : 

Chemical discoveries 145 

Spectrum analysis 153, 155 
Photography - 172 

Woodhouse, R. 117 

Wooldridge 305 

Woolf, A. - 105 

Worcester, Marquis of, Edw. 

Somerset - 99, 100 

Wortley, Col. Stuart 173 

Wotton, E. 220, 257 

Wren, Sir C. - 51, 297 

Wright, Edward - 48 

Wright, E. P. - - . 316 



Xenon, discovery of 181 

X-ray, discovery of - 183 

See also Radio-activity. 



Young, T. - 18, 37, 119, 153, 213 
Brougham's criticism of 20 
Explanation of super- 
numerary rainbows 120 
Physiological optics 128, 299 



Zoology 



256-293 



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