THE LIBRARY 
 
 OF 
 
 THE UNIVERSITY 
 OF CALIFORNIA 
 
 PRESENTED BY 
 
 PROF. CHARLES A. KOFOID AND 
 MRS. PRUDENCE W. KOFOID 
 
jf. f 
 
 
 + A~^t^t 
 
 A />^^x^iL^e^^ ^e^^y 
 
 PROGRESS OF SCIENCE, 
 
ALLA 
 
 SORELLA SUA 
 
 L' AUTORE 
 
 (TVucsto 
 
PROGRESS OF SCIENCE 
 
 ITS ORIGIN, COURSE, PROMOTERS, 
 AND RESULTS. 
 
 BY 
 
 J. VILLIN MARMERY. 
 
 WITH AN INTRODUCTION BY 
 
 SAMUEL LAING. 
 
 " He dies not who gives life to learning." ALL 
 
 LONDON: CHAPMAN AND HALL, LD. 
 
 1895. 
 {All rights reserved.] 
 
F. M. EVANS AND CO., LIMITED, PRINTERS, 
 CRYSTAL PALACE, S.K. 
 
PUBLISHERS. 
 
 I HAVE now had time to read Mr. Marmery's book, and 
 find it a work of great learning and research, conveying in 
 a clear and intelligible form a mass of most useful and 
 interesting history of the Progress of Science, from its first 
 dawn in Egypt and Chaldaea, through the Greek, Arabian, 
 Mediaeval, and Modern periods, down to the present day. 
 It comprises also brief memoirs of the illustrious men to 
 whom we are indebted for the principal discoveries of 
 Science, from Thales and Pythagoras down to Darwin and 
 Herbert Spencer, and I can confidently recommend it as 
 alike interesting and instructive. 
 
 S. LAING. 
 
 " ROCKHILLS," SYDENHAM, 
 
 December i$th, 1894. 
 
PREFACE. 
 
 THE history of science is a sealed book, generally speaking. 
 To the multitude of readers, including in it scientific 
 students, an historical thread conducting them through the 
 bewildering field of science cannot fail to prove a welcome 
 gain. Men, as a rule, accept the fact of to-day as it 
 stands without troubling themselves about the gradual steps 
 taken in the past to reach it. They have neither the leisure 
 nor the inclination to probe the obscurity of past ages 
 themselves. They leave this task to the historian. Nor 
 have they the inclination and leisure, pressed onward as 
 they are by their daily work, to follow the historian if 
 his account is at all bulky. Time fails them. Some, no 
 doubt, have tried to become acquainted with the subject, 
 but despite its extraordinary fascination, most have given 
 up the attempt from lack of perseverance -, for very limited 
 indeed is the number of those who, commanding the time 
 and feeling the curiosity, have the application to undertake 
 the reading, say, of the twenty-four volumes of Herbert 
 Spencer, or only the half-dozen inadequate volumes of 
 
viii PREFACE. 
 
 Whewell. A Cyclopaedia presents an amount of matter 
 accurate and varied enough to satisfy the casual inquirer, 
 but the facts conveyed being fragmentary, the onus of 
 mentally constructing a continuous account lies on himself. 
 The reader wants to see a palace, with its foundations, 
 vaults, walls, storeys, stairs, halls, corridors, strong-rooms, 
 store-rooms, loft, roof, skylight; he wants also to under- 
 stand the process of construction ; and he only sees scattered 
 heaps of bricks, cut granite and marble blocks, timber, 
 cement, tiles, good material to build, but no building. A 
 Cyclopaedia, besides, is both cumbrous and expensive 
 hence inaccessible to most people. In this busy age of 
 ours, people want small books on large subjects. They 
 read the newspapers, which give them information for 
 business purposes ; the reviews, which sum up the trifling 
 questions or the stirring events of the hour ; novels, which 
 afford them amusement not great works.* These are 
 addressed to men of science, to men of exceptional learning 
 or great intellectual activity. Yet there is no doubt that 
 any subject will interest the public, just as it will the 
 student, if it be presented in a desirable form a form at 
 once concise, clear, cohesive, and attractive. And if this 
 be a desideratum, it should be supplied. Does the public 
 generally care for science ? If it involves labour or mental 
 effort, the question must be answered in the negative ; if 
 
 * In a town of 130,000 people, which enjoys the benefit of a public 
 lending library, the Essays of Herbert Spencer had in six months been 
 issued eighteen times, and of the eighteen readers out of the whole 
 population who had felt desirous of becoming acquainted with the 
 philosopher's views in their simplest form, not one had read the three 
 volumes through, for the writer of the present work found pages uncut 
 in them ! 
 
PREFACE. ix 
 
 it involves none, and awakens pleasurable curiosity, the 
 public will follow the expositor of it with eagerness and 
 delight. 
 
 The present work has been undertaken with this view, 
 and if it effect only part of the results expected from it, 
 it will have accomplished the object of the Author. A 
 history of science does not yet exist. Partial attempts have 
 been made, some deserving popularity although lacking 
 accuracy or completeness. Of these, Arabella Buckley's is 
 admirably done so far as it goes. Its attractive clearness 
 is beyond praise. But if its accuracy is generally unim- 
 peachable, the gaps which it presents are a grave historical 
 imperfection. Again, this or that science has been adequately 
 treated in a separate historical form ; other works, such as 
 Watts' Dictionary of Chemistry, which constitutes an in- 
 exhaustible mine of profound science, are real monuments 
 of learning ; but colossal as they are, they can be useful 
 to the historian as a source of unexcelled information as 
 regards one branch of research only. H. Spencer, too, 
 has enough material in his works to compose a magnificent 
 history of science; but such a history, we repeat, has yet 
 to be written. The book we now offer the reader is a mere 
 sketch, a simple outline of a vast subject, roughly chalked 
 as it were on the black-board, a thread in the labyrinth, 
 very slender indeed, but sufficiently strong to conduct the 
 inquirer safely from the Greek world to our own without 
 leading him astray. Facts of first-class importance only 
 have been taken into account and connected together so 
 as to show the continuity of scientific development and its 
 natural evolution. This evolution has gone through five 
 
x PREFACE. 
 
 successive stages, equal in interest if unequal in magnitude : 
 the Greek, the Arabian, the Mediaeval, the Revival, and 
 the Modern. This, then, is a modest survey of science, 
 with its origin, growth, and results, and is addressed to the 
 student and the general reader. 
 
 And as scientific history rather than science itself is the 
 main object in view here, the majority of the facts recorded 
 are merely stated and enumerated, without those explanatory 
 details which would be indispensable in a didactic work ; 
 yet, now and then, the statement has been enlarged upon 
 so as to enable the reader to perceive the importance, the 
 bearings, and the consequences of a scientific fact. This 
 occurs especially in the sketch of the Modern period, for 
 the Author felt that if he confined himself to the simple 
 definition of a law, or the mere enumeration of discoveries, 
 the reader would probably fail to draw right inferences or 
 apprehend the full significance of the case. Besides, more 
 interest is naturally attached by readers to a recent dis- 
 covery which they have witnessed, so to speak, and about 
 which the whole world may be ringing, than to an older 
 one. They see the railway engine, the telegraph, the electric 
 light, and they welcome an explanation which, exempt from 
 technicalities, enables them to understand the cause of their 
 power. They have heard of the spectroscope, and naturally 
 again they will welcome a brief description which makes 
 plain to them the beauty of its principles, the range of its 
 effects, and the extent of the benefits it bestows. The 
 meagreness of details, consistent with the limited plan of 
 the book and prevalent in some portions of it, has then 
 occasionally been abandoned, and replaced by comparative 
 
PREFACE. xi 
 
 copiousness, so as to satisfy the reader's intuitive desire 
 of knowledge. Yet, we repeat, this work is chiefly his- 
 torical, and is not meant to teach any of the sciences, 
 although it sets forth their beauty, their grandeur, and their 
 resources. 
 
 But as a review of scientific achievements embraces the 
 mode without which they could not have been effected, the 
 method of scientific research has necessarily been described ; 
 and as a great deal of misconception generally exists with 
 regard to its discoverer, the writer of this book has not 
 shrunk from facing the great difficulty which arises from 
 the mistaken view on the subject. Accuracy imposed on 
 him a double duty : that of ascribing the discovery of the 
 method to the philosopher to whom it is due, and that of 
 dethroning from his usurped reputation the man to whom 
 it is wrongly assigned. This was the more imperative as 
 the progress of modern science is said by many to be 
 almost entirely owing, not to the men who actually brought 
 it about, but to the influence of one who was in every way, 
 not only a stranger to science and its method of research, 
 but who would have arrested scientific advancement if he 
 had swayed the influence popularly attributed to him. The 
 rectification of the facts has partly been made before this by 
 famed and competent men, but the repetition of the fallacy 
 has nevertheless recurred over and over again, in season 
 and out of season, as if nothing had happened writers 
 taking no trouble to verify the substance of their state- 
 ments, and endorsing, often without the least suspicion of 
 inaccuracy, what an author of repute has without due 
 scrutiny once advanced as a fact. So much and so fre- 
 
xii PREFACE. 
 
 quently has this been the case in this instance that the 
 fallacy has taken deep root. To eradicate, then, the old- 
 standing fiction thus propagated, it was necessary to thrash 
 the question out, to face it from several points of view, and 
 bring forward a variety of proofs which facts furnish against 
 the error. 
 
 If, however, the great name of Francis Bacon is stripped 
 of its scientific glamour, the name of Roger Bacon, to 
 whom adequate justice has never been done, will, by com- 
 pensation, be inscribed in a very high place in the sanctuary 
 of science ; and England's scientific repute will gain by 
 the act of fairness performed by the Author a circumstance 
 at which all Englishmen, fond of truth as they are, will be 
 sure to rejoice with conscious pride, as they will recognise in 
 him the precursor of the men who have made their country 
 the greatest representative nation of science. With Francis 
 Bacon, as a jurist, a moralist, a statesman, an historian, or 
 a dramatist, whatever claim he may have to these titles, we 
 have nothing to do ; we have dealt with him in his scientific 
 capacity only i.e. as a natural philosopher. 
 
 The value of this book lies in the amount of information 
 it conveys the work of some four hundred men of science 
 being considered. Its value is slightly increased by an 
 Appendix^ which, for the purpose of substantiating some of 
 the statements made in the work, contains quotations which 
 would have overweighted the historical account if inserted in 
 the main text. Definitions which may be unfamiliar to some 
 readers will also be found there. 
 
 The arrangement of the work, it may be added, has been 
 devised in such a manner as to present every series of facts 
 
PREFACE. xiii 
 
 in groups the surest means to make a deep impression on 
 the reader's mind. 
 
 The Author begs to acknowledge his most grateful 
 obligations to the numerous writers whose names appear 
 in the following pages, and who have enabled him to carry 
 out his scheme as well, he fondly hopes, as his plan admitted. 
 For part of the scientific matter he has incorporated, he is 
 particularly indebted to Pouchet, Comte, H. Spencer, Liebig, 
 De Maistre, Brewster, Whewell, Draper, Ganot, Rodwell, 
 S. Laing, and Jevons ; for some of the historical and philo- 
 sophical appreciations he has enunciated, he owes much 
 inspiration to the brilliant works of G. H. Lewes, Prevost- 
 Paradol, Lecky, and John Morley, who are recognised by all 
 impartial minds, not safe guides only, but, among the dis- 
 tinguished throng of philosophers, as some of the foremost 
 representatives of modern thought. 
 
CONTENTS. 
 
 CHAPTER I. 
 EARLY KNOWLEDGE METHOD OF RESEARCH. 
 
 Museums and Exhibitions Common knowledge and science Con- 
 crete and abstract knowledge Utility, an incentive of science 
 Chaldasan and Egyptian sciences Early Greek philosophers 
 Thales, Anaximander, Pythagoras, Anaxagoras Plato's de- 
 ductive process Aristotle's Induction His syllogism His 
 knowledge of natural history, physiology, psychology, astronomy, 
 physics, politics, etc. Founder of the Objective Method . 
 
 CHAPTER II. 
 SCIENCE IN ANTIQUITY. 
 
 Drawbacks to progress mathematics ; instruments ; slavery ; con- 
 tempt for industry ; climate ; preconceived theories^ material 
 substances ; political economy Interaction of the sciences 
 Necessary elements of progress means of transport ; per- 
 petuation of ideas ; transformation of the Earth's surface ; 
 health and morality ; social and international intercourse 
 Great advances in antiquity despite drawbacks . . . . 15 
 
 CHAPTER III. 
 PROGRESS IN ANTIQUITY. 
 
 Discoveries of the Greeks from Hippocrates to Ptolemy The 
 
 Alexandrian school The Museum The Serapion . . .19 
 
 CHAPTER IV. 
 PROGRESS AMONG THE ARABS. 
 
 Science in Persia The Arabians become the custodians of science 
 Character of the Arabian civilisation The Khalifs The 
 Arabian cities Houses and palaces Schools Arts of life 
 Wealth, luxury, revenue Industry and commerce Liberal 
 
xvi CONTENTS. 
 
 policy and government Men of science and their discoveries : 
 Ben Musa, Alhazen, Averroes, Giaber, etc. Jews of Spain 
 Great inventions Learned institutions Our mediaeval scholars 
 Arabian pupils Contrast between Islam and Christendom . 28 
 
 CHAPTER V. 
 PROGRESS IN THE MIDDLE AGES AND DURING THE REVIVAL. 
 
 Heroic character of the mediaeval scientists Legacy of the mediaeval 
 period to us Great inventions Prominent men of science and 
 their discoveries Nearly all the sciences fixed on experimental 
 bases Immense progress in practical and plastic arts Learned 
 societies founded " Dark Ages " a misnomer .... 50 
 
 CHAPTER VI. 
 NUMEROUS CAUSES OF SCIENTIFIC PROGRESS.X/ 
 
 Political movements of the mediaeval era The Crusades Dis- 
 appearance of drawbacks Growth of industry and commerce 
 Creation of commercial wealth Capital Progress in art, 
 literature, invention Social improvement due to the gradual 
 abolition of slavery and serfdom Scientific growth, partly due 
 to the Arabians of Spain Encyclopaedic works Influence of 
 Astrology and Alchemy Filiation of great discoveries, and 
 interaction of the sciences . *. : > , ; . . , ^ . . 68 
 
 CHAPTER VII. 
 ROGER BACON versus FRANCIS BACON. 
 
 Albertus Magnus's Natural History Parallelism between Roger 
 and Francis : delusions shared by both ; errors discarded by 
 Roger ; sound notions in common Roger Bacon, one of the 
 five greatest men of ten centuries Roger as a mathematician, 
 a chemist, a physicist, an astronomer The telescope He is 
 the founder of the Experimental School . . . . -74 
 
 CHAPTER VIII. 
 CHARACTER OF THE REVIVAL. 
 
 Duration of the Revival Period Early emigration from Con- 
 stantinopleNicholas V. and Cosmo de' Medici 1453 Capture 
 of Constantinople ; invention of Printing Effects of these two 
 events The Classic School Plato and Aristotle studied The 
 Revival delayed by the Great Schism 91 
 
CONTENTS. xvii 
 
 CHAPTER IX. 
 THE SCIENTISTS OF THE XVTH AND XVlTH CENTURIES. 
 
 PAGE 
 
 Mathematicians ; naturalists ; anatomists and physiologists ; 
 observers ; Experimentalists Tycho Brahe, Gilbert, Harvey 
 Special eminence of Leonardo da Vinci and of Galileo The 
 latter discovers the permanency of Law ; formulates the three 
 laws of motion ; reveals the immensity of the Universe with the 
 telescope Kepler's laws Leonardo da Vinci's injunctions to 
 rely upon experiment, induction, and verification Bacon 
 denounces these achievements and opposes his own to them . 96 
 
 CHAPTER X. 
 MODERN SCIENCE. 
 
 Difficulty of such a survey Vastness of the subject Classification 
 of the Sciences by Comte ; by Spencer First Group : Botanists, 
 Anatomists, and Palaeontologists, Physiologists, Biologists, 
 Anthropologists, Philologists, Sociologists : their discoveries . 109 
 
 Second Group Geologists, Physical Geographers, and their 
 discoveries . . . . . . . : ../,, . . 159 
 
 Third Group Chemists, and their discoveries "Y l- . . . 172 
 Fourth Group Mathematicians, and their discoveries . . .191 
 Fifth Group Astronomers, and their discoveries .... 198 
 Sixth Group Physicists, and their discoveries . . . "... 215 
 Seventh Group Eminent practical men, and their inventions . 260 
 
 CHAPTER XI. 
 THE VALUE OF INSTRUMENTS. 
 
 Instruments among the ancients They add power to the senses 
 Impossibility of scientific advancement without them The 
 telescope ; the microscope ; the prism ; the thermometer ; the 
 compass ; the pendulum ; the barometer ; lenses ; the camera 
 obscura; the battery ; mathematics The importance of cork, 
 glass, etc. Accuracy -of instruments 266 
 
 b 
 
xviii CONTENTS. 
 
 CHAPTER XII. 
 SUMMARY OF FOUR CENTURIES OF SCIENCE. 
 
 PAGE 
 
 I. Foundation: The XVIth century Great discoveries Spirit of 
 free inquiry Practical bent of inquirers Formulation of the 
 inductive process Discovery of law. II. Constitution: The 
 XVI Ith century Grand laws discovered Astronomical 
 advance Mathematics are extended Laws of motion 
 Advance in physics Physiology. III. Expansion: The 
 XVI I Ith century Great expansion of astronomy Appear- 
 ance of geology and electricity, etc. Biology vastly extended 
 Steam machinery Discovery of several physical laws La- 
 place's Hypothesis. IV. Universality the feature of the 
 XlXth century The age of steam, electricity, machinery, steel 
 Laws of light, sound Importance of chemistry Geology 
 and biology Law of evolution . . . . . . . 269 
 
 CHAPTER XIII. 
 SCIENTIFIC COUNTRIES. 
 
 The four leading nations in science : Italy ; France ; Germany ; 
 England Other nations The country at the head of the 
 scientific world : England Natural causes of the supremacy of 
 England 279 
 
 CHAPTER XIV. ^ 
 GENERAL RESULTS. 
 
 Capital importance of some discoveries and applications of scientific 
 j aws The world transformed, both in its material and its moral 
 aspects The unfathomable mystery of Creation . , __ . 285 
 
 CHAPTER XV. 
 
 MATERIAL EFFECTS OF SCIENTIFIC PROGRESS. 
 
 How industry promotes social improvement The growth of milling 
 Immense importance of the invention of the Water-Mill ; of 
 the Wind-Mill ; of the Steam Flour-Mill Every industry has 
 similar effects Early benefactors forgotten How pure science 
 promotes well-being and civilisation : Physiologists ; physical 
 geographers; electricians Division of labour multiplies the 
 agents of production 289 
 
CONTENTS. xix 
 
 CHAPTER XVI. 
 MORAL EFFECTS OF SCIENTIFIC PROGRESS. 
 
 FACE 
 
 Material welfare does not constitute the best part of civilisation 
 Importance of political economy Adherence to its principles 
 promotes peace ; the improvement of the social system ; inde- 
 pendence ; democracy ; liberty and order Gunpowder led to 
 the improvement of the governmental system Influence of the 
 scientific spirit on religion and religious government : a higher 
 conception of the Creator Disappearance of the belief in 
 sorcery : humane government ensues The demonstration of 
 natural laws brings in kindly feelings Abolition of burning 
 and torture Improvement of the penal code Spirit of men- 
 dacity disappears Rapid spread of modern philanthropy Our 
 debt to the XVI II th century " Love one another ". . . 297 
 
 APPENDIX A. 
 TABLE OF EMINENT MEN OF SCIENCE 312 
 
 APPENDIX AA. 
 DEFINITIONS OF THE SCIENCES 314 
 
 APPENDIX I. 
 ARISTOTLE ON EXPERIENCE 322 
 
 APPENDIX II. 
 ARISTOTLE ON INDUCTION 324 
 
 APPENDIX III. 
 ARISTOTLE ON THE SYLLOGISM 325 
 
 APPENDIX IV. 
 LEONARDO DA VINCI'S PHYSICS 326 
 
 APPENDIX V. 
 SIR DAVID BREWSTER ON INDUCTION 328 
 
 APPENDIX VI. 
 DESCARTES' ACHIEVEMENTS 329 
 
 INDEX . . , . ., 331 
 
THE READER will find in 
 
 Chapter XI. page .'./ . . 266 
 
 XII. . .'-..,.. 269 
 
 xiii. ' . . : . . . 279 
 
 XIV. ...... 285 
 
 passages which give an idea of the treatment of general views. 
 
 At the end of each section (say Biology, or Geology, or Chemistry, etc.) 
 are to be found brief remarks of historical and philosophical importance. 
 
 The march of a science can be traced from beginning to end in the 
 successive notices of its promoters. The whole progress of Electricity, 
 for instance, can be found in the notices on 
 
 PAGE 
 
 Gilbert .... VI. ' '. './ - 9 8 
 
 Guericke . . . . . - . . . . 216 
 
 Franklin . . . .... . 220 
 
 Galvani and Volta . ..> 224 and 225 
 
 Physicists ( Biot and Oersted . . . . . 230 and 232 
 
 Faraday and Wheatstone . . . .236 and 240 
 
 Steinheil 241 
 
 Thomson ...... .. . . 253 
 
 Crookes and Tesla 257 and 259 
 
AUTHORS CONSULTED. 
 
 ABBOTT . Bacon and Essex. 
 
 AGASSIZ , .. ..=... . Etudes sur les Glaciers. Essay on 
 
 Classification. 
 
 AIRY . Elementary Astronomy. On Gravitation. 
 
 ALLEN, GRANT . . . Life of Darwin. 
 
 AMPERE .-..'. . . Observations Electro-Dynamiques. 
 
 ANTHROPOLOGICAL JOURNAL. 
 
 ARAGO Biographies of Scientific Men. Eloge de 
 
 Laplace. Eloge de Fresnel. Vie et 
 Travaux de Herschel. 
 
 ARGYLL - . .' ' . . Reign of Law. 
 
 ARISTOTLE . . -. . Works. 
 
 ASA GRAY . .' .". . Botany. 
 
 BABBAGE . . . . Ninth Bridgewater Treatise. 
 
 BACON, ROGER . . . Opus Majus. Opus Tertium. De Mir. 
 
 Pot. 
 
 BACON, FRANCIS . . . Works (Spedding-Ellis Edition). 
 
 BADEN-POWELL . . . History of Natural Philosophy. The 
 
 Unity of Worlds and of Nature. 
 
 BALFOUR, F. M. . . . Treatise of Comparative Embryology. 
 
 BALFOUR STEWART . . On Heat. Lessons in Elementary Physics. 
 
 BALL . . . . '. . A Short History of Mathematics. Experi- 
 mental Mechanics. 
 
 BEALE, LIONEL . 1; 2 . On Protoplasm. 
 
 BECCARIA . . ... Dei Delitti e delle Pene. 
 
 BECKMANN . . .,...:. History of Inventions. 
 
 BENNETT . . . . Text-Book of Physiology. 
 
 BERNARD . ... LeQons de Physiologic ExpeVimentale. 
 
 BIOGRAPHIE UNIVERSELLE (Nouvelle). 
 
xxii AUTHORS CONSULTED. 
 
 BLACK Elements of Chemistry. 
 
 BLUMENBACH . . . System of Comparative Anatomy. Skulls 
 
 of All Nations. 
 
 BOOLE . . . . Laws of Thought. 
 
 BouiLLET .... Dictionnaire des Arts et des Sciences. 
 
 BRANDS Manual of Chemistry. 
 
 BREWSTER .... Martyrs of Science. Life of Newton. 
 
 Optics. On New Philosophical Instru- 
 ments. 
 
 BUCKLE . . . . History of Civilisation. 
 
 BUCKLEY .... Short History of Natural Science. 
 
 BUCKNER .... Force and Matter. 
 
 BUFFON .... Histoire Naturelle. Epoques de la Nature. 
 
 BURN . . . . . Handbook of Object Teaching. 
 
 CARPENTER .... Physiography. On the Microscope. 
 
 CATO De Re Rustica. 
 
 CHURCH, R. W. . . . Bacon. 
 
 CLARKE . . . .A Table of Specific Gravity for Solids 
 
 and Liquids. 
 
 CLERK MAXWELL . . See MAXWELL. 
 
 CLIFFORD .... The Elements of Dynamics. Seeing and 
 
 Thinking. 
 
 COMTE Philosophic Positive. 
 
 CONDORCET .... Progres de 1'Esprit Humain. 
 
 COOKE Elements of Chemical Physics. 
 
 COPE The Origin of the Fittest. 
 
 CROLL Climate and Time. 
 
 CUVIER Histoire des Sciences Naturelles. Revolu- 
 tions du Globe. Ossements Fossiles. 
 The"orie de la Terre. 
 
 CYCLOPAEDIA . . . Lardner's. 
 
 CYCLOPAEDIA . . . Rees'. 
 
 DALTON . ' ... . Chemical Philosophy. 
 
 DARWIN .... Origin of Species. Descent of Man. The 
 
 Variation of Animals and Plants. 
 
 Fertilisation of Orchids. 
 DAVIES, BARNARD . . Thesaurus Craniorum. 
 
 DAVY Works. 
 
 DE MAISTRE . . . (Euvres. 
 
 DESCARTES . . . .La Methode. 
 
 D'ORBTGNY .... Dictionnaire des Sciences Naturelles. 
 
 DRAPER .... Intellectual Development of Europe. 
 
 Conflict between Religion and Science. 
 DRINKWATER . . . Life of Galileo. 
 DUNCAN .... Heroes of Science. 
 DUPUIS Origine des Cultes. 
 
AUTHORS CONSULTED. xxiii 
 
 ENCYCLOPAEDIA BRITANNICA. 
 ENCYCLOPAEDIA METROPOLITANA. 
 
 ELLIS . . . /".--,. Bacon's Works (Spedding Edition). 
 EVANS . . . ' .1 . Ancient Stone Implements of Great 
 
 Britain. 
 
 FARADAY v .; . * -.?; <<-. Experimental Researches in Electricity. 
 
 Various Forces of Nature. 
 
 FAWCETT * . .A Manual of Political Economy. 
 
 FLOURENS .... Eloge de Cuvier. 
 
 FORBES .... Progress of Mathematical and Physical 
 
 Science. Transit of Venus. 
 
 FOSTER .... A Text-Book of Physiology. 
 
 FRANKLIN . ~v' " . . Experiments and Observations on Elec- 
 tricity. 
 
 GANOT . . /. . . , . ,. Physics. 
 
 GARNET . ... Heroes of Science. 
 
 GASSENDI . '\ ,; ; ; . Life of Copernicus. 
 
 GEIKIE . . . . Text-Book of Geology. 
 
 GEOFFROY ST. HILAIRE . Zoologie Ge'nerale. 
 
 GLADSTONE .... Juventus Mundi. 
 
 GOETHE .... CEuvres Scientifiques. 
 
 GRANT . . . ... History of Physical Astronomy. 
 
 GRAY, ASA . ., . . Botany. 
 
 GREVILLE WILLIAMS . . Manual of Chemical Manipulation. 
 
 GROTE . < . . History of Greece. 
 
 GUILLEMIN . . . The Heavens. 
 
 GUIZOT . . . .La Civilisation en Europe. 
 
 HAECKEL . , . . The History of Creation. 
 
 HALLAM , ' ' . . . The Middle Ages of Europe. 
 
 HAMILTON .... Lectures on Metaphysics and Logic. 
 
 HAMY . . , . . . Palaeontologie Humaine. 
 
 HELVETIUS . '. , ... De TEsprit. 
 
 HERBERT SPENCER . . Essays. First Principles. Principles of 
 
 Psychology. 
 
 HELMHOLTZ .... Tonempfindungen, als Theorie der Musik. 
 
 HERSCHEL, W. . . . Familiar Lectures on Scientific Subjects. 
 
 A Manual of Scientific Enquiry. 
 
 HERSCHEL, J. Outlines of Astronomy. Results of Obser- 
 
 vations at the Cape of Good Hope. 
 Study of Natural Philosophy. 
 
 HOEFER .... Histoire de la Physique et de la Chimie. 
 
 HOFMANN .... On Liebig and Faraday. Introduction to 
 
 Chemistry. 
 
 HOWES . . . -...;. Atlas of Practical Elementary Biology, 
 
 with Preface by PROF. HUXLEY. 
 
xxiv AUTHORS CONSULTED. 
 
 HUTCHINSON . . . Extinct Monsters. 
 
 HUMBOLDT .... Cosmos. 
 
 HUTTON .... Theory of the Earth. 
 
 HUXLEY . . . .On Priestley. Hume. Physiography. 
 
 Elementary Physiology. Physical Basis 
 of Life. On Von Baer. Lectures on 
 the Elements of Comparative Anatomy. 
 On the Classification of Animals. 
 
 JAMIN ..... Cours de Physique. 
 
 JARDINE .... Naturalists' Library. 
 
 JEVONS Principles of Science. 
 
 JONES Examples of Physics. 
 
 JOULE Mechanical Equivalent of Heat. 
 
 KEILL . . . . . Introduction to Natural Philosophy. 
 KELLAND AND TAIT . . Introduction to Quaternions. 
 KlRCHHOFF .... Researches on the Solar Spectrum 
 
 (Roscoe's Translation). 
 KNOX Permanence of Race Types. 
 
 LAING . Problems of Modern Science. Modern 
 
 Science and Modern Thought. Human 
 Origins. 
 
 LAMARCK .... Philosophic Zoologique. 
 
 LANKESTER .... The Advancement of Science. 
 
 LAPLACE .... Theorie Analytique des Probability's. 
 
 Systeme du Monde. Mecanique 
 Celeste. Essai Philosophique. 
 
 LARDNER .... Cyclopaedia. 
 
 LAVOISIER .... Elements of Chemistry. 
 
 LECKY ..... History of Rationalism in Europe. 
 
 LEWES Biographical History of Philosophy. Life 
 
 of Aristotle. 
 
 LEWIS, G. C. . . . Astronomy of the Ancients. 
 
 LEWIS, J. C. ... Heroes of Science. 
 
 LlEBlG . . . . . Letters on Chemistry. Introduction to 
 
 the Analysis of Organic Bodies. 
 
 LOCKE Essay Concerning Human Understanding. 
 
 LOCKYER, N. Lessons in Elementary Astronomy. Solar 
 
 Physics. The Chemistry of the Sun. 
 The Evolution of the Heavens and the 
 Earth. The Movements of the Earth. 
 Outlines of Physiography. The Me- 
 teoric Hypothesis. 
 
 LUBBOCK .... Prehistoric Times. Scientific Lectures. 
 
 Fifty Years of Science. Origin and 
 Metamorphosis of Insects. Ants, Bees, 
 and Wasps. 
 
AUTHORS CONSULTED. 
 
 XXV 
 
 LUCRETIUS . 
 LUPTON 
 
 LYELL 
 
 MACAULAY . 
 MARSH . 
 
 MAYER, A. M. . 
 MAURY . 
 
 MAXWELL, CLERK 
 MEYER, E. VON . 
 
 MILL, STUART . 
 MITCHELL . 
 MOHL, VON . 
 
 MOLLOY 
 MORLEY 
 
 MORTON 
 MONTUCLA . 
 Mum . 
 
 MULLER, MAX 
 MURCHISON . 
 
 De Rerum Natura. 
 
 Numerical Tables and Constants in 
 
 Elementary Science. 
 Principles of Geology. Student's Elements 
 
 of Geology. Antiquity of Man. 
 
 Essay on Bacon. 
 
 Dinocerata. Monographs. 
 
 Forces of Inorganic Nature. Sound. 
 
 Geography of the Sea. 
 
 Theory of Heat. 
 
 History of Chemistry (McGowan's Trans- 
 lation). 
 
 System of Logic. 
 
 Orbs of the Heavens. 
 
 Anatomy and Physiology of Plants. 
 Principles of Anatomy and Physiology 
 of Vegetable Cells. 
 
 Gleanings in Science. 
 
 Diderot and the Encyclopaedists. 
 
 Heroes of Science. 
 
 Histoire des Mathe'matiques. 
 
 Heroes of Science. 
 
 Lectures on the Science of Languages. 
 
 Siluria. 
 
 " NATURE." 
 NATURE (LA). 
 NEWTON 
 NICOLUCCI . 
 XIXTH C. REVIEW 
 NORMAN LOCKYER 
 
 OWEN . 
 
 PARKINSON . 
 PASCAL . 
 PEACOCK 
 PERRY . 
 PHILOSOPHICAL 
 PLAYFAIR 
 
 MAGAZINE. 
 
 PLINY . 
 PORPHYRY . 
 PORT ROYAL 
 POUCHET 
 
 Principia. 
 Skull of Etruria. 
 (Number for March, 1892.) 
 (See LOCKYER.) 
 
 Anatomy of the Great Apes. Lectures on 
 Comparative Anatomy. British Fossil 
 Reptiles. 
 
 A Treatise on Optics. 
 CEuvres Completes, 1865. 
 Life and Works of Young. 
 Steam. 
 
 Dissertation -prefixed to the Encyclopaedia 
 
 Britannica. 
 Natural History. 
 
 Introduction- to Aristotle's Categories. 
 Logic (Baynes' Translation). 
 Les Sciences au Moyen Age. 
 
xxvi AUTHORS CONSULTED. 
 
 POWELL, BADEN . . . History of Natural Philosophy. The 
 
 Unity of Worlds and of Nature. 
 
 PREECE .... On the Telephone. 
 
 PRESTON .... Treatise on the Theory of Light. 
 
 PREVOST-PARADOL . . Histoire Universelle. 
 
 PRICHARD .... Physical History of England. 
 
 PRIESTLEY .... History of Vision. On Different Kinds 
 
 of Air. 
 
 PROCTOR . . . . Essay on Astronomy. The Universe. 
 
 Other Worlds than Ours. Shooting 
 Stars and Meteors. The Sun. Transit 
 of Venus. 
 
 QUATREFAGES . . . Races Humaines. 
 
 REES Cyclopaedia. 
 
 REMSEN . . . . The Elements of Chemistry. 
 
 RENAN Averroes. 
 
 RODWELL, G. F. . . . Birth of Chemistry. Dictionary of Science. 
 
 ROMANES .... Scientific Evidences of Organic Evolution. 
 
 ROSCOE . . . . Spectrum Analysis. 
 
 ROSSITER . i . . Physics. 
 
 RUMFORD .... Essays. 
 
 ST. HILAIRE, GEOFFROY . Zoologie Generate. 
 
 SCROPE Volcanoes. 
 
 SENECA .... Quaestionum Naturalium Libri Septem. 
 
 SISMONDI .... History of Southern Literature. 
 
 SMILES Lives of Boulton and Watt. 
 
 SMITH, ADAM . . . The Wealth of Nations. 
 
 SMITH, PIAZZI . . . The Great Pyramid. 
 
 SPEDDING , . . . Bacon's Works. 
 
 SPENCER, HERBERT . . See HERBERT SPENCER. 
 
 SPRENGEL .... Histoire de la Mddecine. 
 
 STEWART, BALFOUR . . On Heat. Lessons in Elementary Physics. 
 
 STEWART AND GEE . . Lessons in Elementary Practical Physics. 
 
 STUART MILL . . See MILL. 
 
 TAIT Heat. 
 
 TAYLOR .... Sound and Music. 
 
 THOMSON, DR. . . . Outlines of the Necessary Laws of 
 
 Thought. 
 
 THOMSON, J. J. . . .A Treatise on the Motion of Vortex Rings. 
 THOMSON, SIR W. . . Electrostatics and Magnetism. Popular 
 
 Lectures and Addresses. 
 TODHUNTER .... A History of the Mathematical Theory of 
 
 Probability. 
 TYLOR Anthropology. 
 
AUTHORS CONSULTED. xxvii 
 
 TYNDALL . ; . : . . Natural Philosophy. On Light. On 
 
 Sound. Half-hours with Modern Scien- 
 tists. Heat a Mode of Motion. Faraday 
 as a Discoverer. The Glaciers of the 
 Alps. 
 
 VENTURI . . v . Ouvrages Physico - Mathe'matiques de 
 
 Leonardo da Vinci. 
 
 WRIGHT . . . . Ice Age in North America. 
 
 WALLACE . . v . Natural Selection. Darwinism. Island 
 
 Life. 
 
 WATTS . . . . . Dictionary of Chemistry. 
 
 WHEWELL . \ . ' " * . History of Inductive Sciences. 
 
 WILLIAMS, GREVILLE . . Manual of Chemical Manipulation. 
 
 WOLLASTON. . . .. On Dispersion. 
 
 XENOPHON . . , . . Economics. 
 
 YOUNG. . . VJVJH Lectures on Natural Philosophy. 
 
ERRATA. 
 
 Page 37, line 21, for auric chloride 
 
 (aqua regia, ^R) read auric chloride, aqua regia, /R. 
 
 38, 2, cupel cupels. 
 
 70, i, Canterbury Tales The Canterbury Tales. 
 
 22, If they 
 
 80, 24, give 
 
 129, 6, membrance 
 
 147, 21, points 
 
 If the alchemists. 
 
 gave. 
 
 membrane. 
 
 point. 
 
 to Socialism. 
 
 158, 7, of Socialism 
 
 J 76, 3> 3 > Manganese dioxide of Manganese. 
 
 metal 
 
 mineral. 
 
 6, Prussian 
 210, 9, 1,21279 
 
 Prussic. 
 
 1,21279 days. 
 
 215, 33, earth's surface earth's surface, at sea-level. 
 
 231, 6, polaroscope polariscope. 
 
 284, 17, no less in letters no less than in letters. 
 
 256, 29. Hydrogen. Note: In contradiction to the text-books 
 the liquefaction and solidification of Hydrogen has 
 not been confirmed by other experimenters. 
 
INTRODUCTION. 
 
 IMAGINE that you have been living in the depth of a narrow 
 valley; that your view has been limited for years by the 
 slopes of the surrounding hills; that you have never seen 
 anything but green fields. Imagine next that, having 
 climbed to the summit of the nearest slope, you suddenly 
 behold an extensive horizon all around ; after the monotonous 
 valley, you wonder with delight at the magnificent prospect 
 displayed far and wide ; you count forests, rivers, lakes, 
 villages, and cities. Charmed with the novelties afforded by 
 so short a journey, you next ascend an elevated peak whence 
 the prospect may be extended far away, and once there, you 
 are struck with a sight infinitely grander : you behold on the 
 one side ranges of mountains eternally covered with snow 
 and lost in the clouds, whilst on the other side you behold 
 the blue and boundless ocean, whose horizon melts with the 
 azure sky. At this undreamt-of display you are speechless 
 with emotion. You feel you are contemplating a divine 
 work. 
 
 The valley pictures the elementary knowledge acquired 
 during early youth. In that condition you can no more 
 
xxx INTRODUCTION. 
 
 guess the utility and beauty of study than the hardships of 
 existence. The next prospect pictures more advanced know- 
 ledge the knowledge acquired during the years of growth 
 up to manhood, and necessary to trace through various 
 paths your line of conduct in life. The third prospect pictures 
 the fathomless knowledge which science, art, and literature 
 strive to expound, and of which, in order to know the world 
 we live in, we all should try to get a glimpse, even if we are 
 not destined to become experts or discoverers. 
 
 And in the fanciful picture just sketched out you have 
 seen the terrestrial world only. If you now look up in the 
 heavens you see the sun ; night comes, you behold the moon 
 and the stars another world is revealed to you more in- 
 comprehensible and sublime, if possible, than the other, for 
 you are facing infinite space, and that is " powdered with 
 suns." This view has awakened deep thoughts. You wonder 
 how these orbs move, and light, and warm us ; and remember- 
 ing the storms you have witnessed before, you wonder how 
 the wind blows, the rain falls, the thunder roars, the lightning 
 kills, the river swells, the ocean rolls. The eyes have dis- 
 covered marvels to you, and now your mind wants to under- 
 stand them. Science then steps on the scene, and explains to 
 you the working of these wonders. And when science has un- 
 ravelled to you some of the secrets of nature, you want to know 
 by what process and by what men these secrets of nature 
 have become known. Such an inquiry is just as full of interest 
 as the history of humanity itself, of which it forms, in a sense, 
 the most vital element ; but it is more than interesting : it 
 leads to moral results you were far from conceiving. For 
 the more we realise the vastness of human knowledge, the 
 
INTRODUCTION. xxxi 
 
 better do we understand the insignificance of our persons. 
 Instead of being engrossed with our own importance, we 
 perceive our individual littleness, and are crushed by the 
 immensity of the Known, the Unknown, and the Unknowable. 
 We acquire modesty ; and if we extend our survey even 
 superficially all over the globe, and view the aggregate of 
 men's achievements, not only do we become modest, but we 
 plainly perceive that each civilised nation has a claim to our 
 admiration, and that our own, if great in one or several 
 branches, must nevertheless yield the palm of excellence to 
 other races on different grounds. Nor do we experience new 
 feelings of admiration and modesty simply, but our intellect, 
 also becoming widened, learns how to contemn deeds once 
 thought admirable, and heroes, so-called, who built their 
 fame on the woes of mankind. We henceforth reserve the 
 main portion of the tribute of praise and gratitude we are 
 capable of bestowing without, nevertheless, ceasing to 
 acknowledge the good legitimately done to progress by the 
 victors of Salamis, Zama, the Armada, or Waterloo for the 
 real benefactors of the human race, the men of science who 
 have, in a manner at once full of devotion, loftiness, 
 generosity, and nobleness, promoted civilisation in the field 
 of peace towards prosperity and happiness. 
 
PROGRESS OF SCIENCE. 
 
 CHAPTER I. 
 
 EARLY KNOWLEDGE METHOD OF RESEARCH. 
 
 If we imagine that into a gorgeously-decorated hall a rushlight is 
 brought, and, being held near to some part of the wall, makes visible the 
 pattern over a small area of it, while everything else remains in darkness ; 
 and if, instead of this, we imagine that electric lights turned on reveal 
 simultaneously the whole room with its varied contents, we may form some 
 idea of the different appearance under which Nature is contemplated by 
 the utterly-uncultured mind and by the highly-cultured mind. Whoever 
 duly appreciates this immense contrast will see that, rightly assimilated, 
 science brings exaltation of mental life. 
 
 HERBERT SPENCER. 
 
 No man visits a museum without being filled with deep 
 astonishment at the sight of the wonders of past ages. The 
 unsurpassable works of art of ancient Greece and Rome are 
 especially what strikes him most. His mind is at once 
 crowded with pregnant thoughts, and his bewilderment 
 deprives him of the power to express definite ideas, so varied, 
 so numerous, so beautiful are the objects presented to his 
 view. In the world of sensations he experiences, an 
 instinctive exclamation rushes to his lips : What people 
 those ancients were ! 
 
 But whoever has entered a universal exhibition and seen 
 the products of modern arts and industries goes away with 
 feelings of a much more absorbing order. It is not that his 
 admiration is aroused by the beauty of the works only, but the 
 undreamt-of ingenuity and countless diversity, the far-reaching 
 utility and absolute perfection of these works awaken in him 
 
2 PROGRESS OF SCIENCE. 
 
 endless impressions which for the first time, perhaps, make 
 him conscious of the strength and greatness of human energy. 
 Pure intellect, he feels, has conceived marvels, and unerring 
 hands have made them realities. Science, he feels, is in 
 possession of divine principles and laws to which human 
 labour has given a practical application in ways so unexpected 
 and multifarious, that imagination itself is powerless to 
 embrace them in their aggregate. From the gigantic 
 machinery of the factory to the delicate apparatus of the 
 physicist, from the resistless engine of destruction to the 
 minute instrument of surgery, every one of the ten thousand 
 things shown reveals the presence of an enchanter and that 
 enchanter, the man of science. And the admirer asks : Whence 
 comes he ? Who gave him birth ? Who trained him ? 
 
 To this three-fold query these pages supply the answer. 
 
 This, then, is a plain inquiry. It has nothing to do 
 with complicated theories. It deals with matter-of-fact all 
 through and goes straight to the point. The student may 
 read it without the fear of being led into paths unfamiliar to 
 him, despite the many-sided aspect of the subject, for common 
 sense puts a simple question, and common sense replies to 
 it in the simplest manner. 
 
 The growth of scientific knowledge will be made very 
 comprehensible and clear if we first briefly define science, and 
 show how it originally arose. For this purpose we cannot do 
 better than borrow the substance of what has been said on 
 this matter by a masterly philosopher.* 
 
 Science was, and is, an extension of common knowledge, 
 and can, by no possibility, be disconnected from it ; nor can 
 common knowledge and science be severed from the arts. 
 From the earliest times there was " a gradual advance from the 
 more to the less obvious phenomena. Science does not differ 
 from ordinary knowledge : the same faculties are employed in 
 both cases, their mode of operation is the same. Much 01 
 our common knowledge is, so far as it goes, rigorously 
 precise ; science is only an extension of the perceptions by 
 means of reasoning." Common knowledge then is the root 
 of the sciences and the arts, and the distinction between the 
 * Mr. Herbert Spencer's " Laws in General," and " Genesis of Science." 
 
EARLY KNOWLEDGE METHOD OF RESEARCH. 3 
 
 three is purely conventional. That science and the arts are 
 an outgrowth from the same root, Mr. Herbert Spencer 
 demonstrates by a masterly and almost exhaustive description 
 of man's advance. " From unmistakable evidence it is clear 
 that the earliest mode of conveying the idea of any number 
 of things, was by holding up the fingers as many fingers as 
 there were things." There are many tribes in which count- 
 ing does not exceed ten the limit of finger notation. The 
 word digit (finger) is significant ; likewise are the words cubit, 
 span, foot, palm, inch, hand, grain, carat, orgyia, pace. The 
 Roman numerals, one of the earliest systems of notation, 
 were meant to represent groups of fingers. " The idea of 
 equality arrived at by this and other means gave origin to 
 two series of relations those of magnitude and those of 
 number, from which arose geometry and arithmetic." The 
 simplest unit of time, the day, nature supplies ready-made. 
 The next simplest period, the moneth or month (measurer) 
 "was also thrown upon men's notice by the conspicuous 
 changes constituting a lunation/' etc. In this manner can 
 the advance made be shown, not only in these branches, but 
 in all. Such is the truth regarding the starting point of science. 
 
 A second point not less important is that the concrete led 
 to the abstract, that is, familiarity with concrete uniformities, 
 as Mr. Spencer so clearly puts it, has generated the abstract 
 conception of uniformity the conception of law. " Mental 
 advance is necessarily from the concrete to the abstract, from 
 the particular to the general, and, necessarily, the universal, 
 and therefore the most simple truths are last to be discovered. 
 When it is ascertained that the moon completes her cycle in 
 about thirty days, it is manifest that it becomes possible to 
 say in what number of days any specified phase of the moon 
 will recur ; and thus is quantitative prevision effected. And 
 following in the same wake came the first known astronomical 
 records which are those of the eclipses, etc." And the same 
 process obtains throughout the entire cycle of knowledge. 
 
 The third truth, which it is important to remember, is 
 that utility was the object of early inventions and science. 
 Humboldt was the first celebrated writer who clearly detected 
 this, but to Mr. Herbert Spencer chiefly we owe the weighty 
 
 B 2 
 
4 PROGRESS OF SCIENCE. 
 
 evidence which proves the fact to have been a universal one. 
 " The properties of the scales and of the lever, involving the 
 first principles in mechanics, were only generalised under the 
 stimulus of commercial and architectural needs. To fix the 
 times of religious festivals and agricultural operations were 
 the motives which led to the establishment of the simpler 
 astronomical periods, so that at first science was merely an 
 appliance of religion and industry." 
 
 A later, but not less conspicuous instance of the same fact, 
 we may add, is found in the reform of the Calendar (1581-2), 
 the main object of which was the fixing afresh of the Roman 
 Catholic feasts. " Such small knowledge of chemical relations 
 as was involved in ancient metallurgy, was manifestly ob- 
 tained in seeking how to improve tools and weapons. In the 
 Alchemy of the later times, the intense hope of private benefit 
 contributed to the disclosure of a certain class of uniformities." 
 " How to fix religious festivals, when to sow, how to weigh 
 commodities, how to measure ground, were purely practical 
 questions out of which arose astronomy, mechanics, geometry." 
 We need not do more than indicate these facts; for 
 further evidence we refer the reader to the works we have 
 mentioned ; but it is not unnecessary to remind the student 
 that throughout the Middle Ages also, utility was the main- 
 spring of activity among inventors and searchers. The wind- 
 mill, spectacles, stained glass, glazed pottery, mirrors, oil- 
 colours, clocks, fire-arms, the organ, paper, the compass, the 
 violin, printing, the suction-pump, the cross-staff, mathematical 
 symbols, the Rudolphine Tables, etc., were one and all 
 devised to serve a useful purpose, and " the useful and the 
 practical were the incentives " which led to them. The same 
 fact is observable in our times. And considering the inter- 
 action of the sciences upon one another, of the arts upon one 
 another and upon science ; considering also the natural 
 filiation of discoveries, their evolvement, that is, from one 
 another, we plainly see that science, after springing from 
 common knowledge and being promoted by utility, flows 
 from science itself, and can be promoted by nothing but 
 science, however much genius and chance may at times 
 assist it. It is then easy to perceive that books are 
 
EARLY KNOWLEDGE METHOD OF RESEARCH. 5 
 
 not, as many people imagine, powerful agents of scientific 
 growth ; their function and importance in that respect are 
 completely dwarfed by the smallest discovery ; their influence 
 is quite insignificant in comparison with the establishment of 
 the simplest scientific principle. Of this fact we shall have 
 ample evidence in the course of this record. 
 
 Science came into existence in the East. GEOMETRY, 
 so far as we know, seems to have originated in EGYPT to 
 measure each tiller's land after the yearly inundation of the 
 Nile ; ASTRONOMY originated possibly in CHALD^EA, but 
 more probably in Egypt to regulate the dates of religious 
 festivals. This last science appears to have been closely, nay 
 indissolubly, bound with Chaldaean and Egyptian mythology, 
 and seems to have been pushed very far in Egypt, since 
 numerous sculptures and inscriptions in reference to it are to 
 be found in every part of the Pharaohs' empire, some sym- 
 bolical only, others as plainly expressed as we could ex- 
 pect. But to speak of few things only, the Egyptians had 
 determined the ECLIPTIC that is the sun's apparent course 
 through the heavens ; they had divided this course into 
 twelve parts (corresponding to the months of the year), each 
 being a constellation, and called the whole circle of constella- 
 tions ZODIAC (i.e. circle of animals) because each bore the 
 name of an animal. These signs of the Zodiac are still 
 recognised and accepted among us, although, owing to the 
 precession of the Equinoxes, they do not agree at present 
 with the constellations which bear the same name. The 
 Egyptians had apparently a complete knowledge of the 
 SOLSTICES and the EQUINOXES, and the exact time of their 
 occurrence ; and more, they were acquainted, by centuries of 
 continuous daily and nightly OBSERVATIONS, for the purpose 
 of which most of the TEMPLES WERE BUILT, with the facts 
 brought about by the precession of the Equinoxes, and the 
 changes brought in the position of the stars by this phe- 
 nomenon, although they had not discovered the precession 
 itself. They only knew of its effects. But there is evidence 
 that all this was only a portion though undoubtedly the 
 chief portion of what they knew, as we may have occasion 
 to show. 
 
6 PROGRESS OF SCIENCE. 
 
 The Chaldaeans are justly also credited with the knowledge 
 of these facts, and this is precisely what we should expect 
 considering the antiquity of their civilisation. It is certain 
 that they made original observations and discoveries. They 
 so earnestly pursued the study of astronomy that they had 
 ZIGGURATS (temple-observatories) in almost every important 
 city, and from the time of Sargon I. (3800 B.C.) records of 
 eclipses were kept. They determined the SAROS, a cycle 
 of 223 lunations and an extremely successful attempt to 
 predict eclipses. By calculating the saros at 6,585^ days, 
 and trebling this period, they could predict eclipses to recur 
 in the same part of the heavenly sphere and at the same hour 
 of the day the total error of the three saros being only 
 58 minutes 6 seconds. They thought comets revolved in 
 periodic orbits a wonderful guess. They even knew oi 
 the PHASES OF VENUS ! as we learn from cuneiform tablets 
 nearly 5,000 years old. Callisthenes (330 B.C.) transmitted 
 to Aristotle Chaldsean observations made 2250 B.C. Want 
 of conclusive, or sufficient collateral, evidence outside cunei- 
 form tablets and Berosus, however, leaves us in doubt on 
 the subject of the priority of some of their discoveries. The 
 evidence, on the other hand, in favour of Egyptian priority 
 is so varied and weighty ; the civilisation of the Nile Valley 
 was so complete and homogeneous some 5000 B.C., that, 
 everything considered, Egypt seems on the whole to have 
 been the cradle of science. When we remember that 
 Diogenes Laertius, corroborating, no doubt, Manetho's 
 historical record, mentions that the Egyptians had observed 
 373 solar and 832 lunar eclipses, and that "the ratio between 
 these two numbers exactly represents that which would be 
 the true estimate of eclipses of some 1,200 or 1,300 years/' 
 it is difficult to resist the inference just stated. This view 
 is much strengthened by the position, orientation, measure- 
 ments, and structure of the Great Pyramid, which seem to 
 reveal extraordinary knowledge of geometry, geodesy, and 
 astronomy, since the Egyptians had apparently measured 
 with accuracy an arc of the terrestrial meridian, and inferred 
 that the earth was a sphere of given dimensions.* Chaldaean 
 * See Proctor's work on the subject, not to speak of Piazzi Smith's. 
 
EARLY KNOWLEDGE METHOD OF RESEARCH. 7 
 
 science was unborrowed, no doubt, but it was certainly in- 
 ferior to the Egyptian, for it does not seem to have included 
 much geometry, a branch which Egypt appears to have 
 originated and successfully applied to practical purposes. 
 
 After reaching, as early as 3000 B.C., an extension and 
 accuracy all but incomprehensible to us, considering the 
 scanty means of observation and paucity of instruments the 
 Egyptians and Chaldaeans possessed, these two sciences, 
 Geometry and Astronomy, remained stationary for ages and 
 ages until the Greeks became acquainted with them. A 
 Thales (600 B.C.), a Pythagoras (530), a Hippocrates (420) 
 would visit Egypt, and bring back to his own country the 
 knowledge of the Egyptians ; and once in the possession 
 of the rudiments, the Greeks extended these branches of 
 knowledge, and made them sciences worthy of the name, 
 concurrently with the other studies they pursued. We owe to 
 the Greeks whether or not they drew some of their notions 
 from the far- East, China or India, or from Egypt only all 
 the scientific elements which have enabled us to advance. 
 
 These elements cannot, strictly speaking, be said to have 
 existed before Aristotle otherwise than as common knowledge, 
 although some few phenomena were known with " rigorous 
 precision." With Aristotle, and after him, however, the know- 
 ledge of a whole series of phenomena developed into science 
 that is, qualitative prevision became quantitative prevision. 
 Yet, as the roots planted before Aristotle's time were vital 
 roots destined to grow, it behoves us to cast a cursory glance 
 upon the results of Greek inquiry at its earlier stage. 
 
 640548. Thales, one of the Seven Sages, to whom 
 we owe the famous precept, " Know Thyself? was a geometer 
 and an astronomer. He was the first among the Greeks 
 to determine the length of the year, to exhibit the nature 
 of the lunar and solar motions, to give an explanation for 
 the inequality of the days and nights in different seasons, 
 to distinguish the four distinct divisions of the year and 
 to discard the older division into two (solstitial) seasons only; 
 he marked out the equinoctial periods; he stated that the 
 moon reflects the sun's light to us; he foretold A SUN'S 
 ECLIPSE (May 28, 584 B.C.) Beyond this he formulated 
 
8 PROGRESS OF SCIENCE. 
 
 several of the geometrical propositions we have in Euclid ; 
 he also taught that WATER is the origin of everything that 
 exists a wrong doctrine, but one, nevertheless, which proves 
 him to have been an OBSERVER of nature. 
 
 It is probable that much of all this was Egyptian know- 
 ledge, for he is known to have visited the valley of the Nile. 
 
 610 547. Anaximander introduced the use of the 
 GNOMON into Greece (from Egypt possibly) which shows 
 that he was a practical observer; invented the SUN DIAL 
 teaching the Greeks how to measure the time of day by 
 the shadow of a rod cast by the sun ; he understood the 
 phases of the moon ; made a MAP of the known world, 
 being thereby the earliest practical geographer known to us. 
 
 566 470. Pythagoras, the famous philosopher, ex- 
 hibited the spherical shape of the earth, made the assertion 
 that the EARTH MOVES in the heavens, although he failed 
 to see that it moves round the sun ; he detected the evening 
 star and the morning star, to be one and the same planet. 
 He does not appear, as it is often asserted, to have enter- 
 tained the right theory regarding our solar system, although 
 some of his disciples (Philolaus amongst others) seem to 
 have suspected it.* He devised the square multiplication 
 table which bears his name ; he formulated and demonstrated 
 the famous XLVIIth proposition in Euclid, which proves 
 him to have been a good mathematician. He might be 
 called the FOUNDER OF GEOLOGY, for he stated that the 
 sea-shells we find on land and in rocks were deposited by 
 the sea, and he understood from what he had observed in 
 Egypt the process of formation of new lands by rivers 
 depositing mud at their mouths. As a physicist, he is said 
 to have made a MONOCHORD, and shown how musical sounds 
 are produced on a stretched string, in accordance with a 
 mathematical scale. 
 
 540 500. Xenophanes asserted that the fossil impres- 
 sions of animals and plants "were real remains of living 
 creatures, and that the mountains in whose rocks they were 
 found must at an earlier period have stood under water." 
 
 * Philolaus said : "The earth and planets move in oblique circles (or 
 ellipses) about fire, as the sun and moon do." 
 
EARLY KNOWLEDGE METHOD OF RESEARCH. 9 
 
 500 428. Anaxagoras, so celebrated as a religious 
 reformer and the precursor of Socrates teaching as he 
 did the existence of a supreme Intelligence was a practical 
 astronomer of no mean degree: he declared THE MOON to 
 be another earth like our own ; detected THE MOUNTAINS 
 and valleys of our satellite ; explained that an eclipse 
 of the sun is caused by the passage of the moon directly 
 between us and the sun, and an eclipse of the moon 
 by the earth's passage directly between the sun and the 
 moon and casting its shadow on the latter. He could 
 hardly have been the discoverer of this phenomenon, as 
 it is asserted of him, since Thales calculated the eclipses 
 of the sun, and the Egyptians (according to Diogenes 
 Laertius) had observed and detected the cause of the phe- 
 nomenon long since. Anaxagoras understood that the stars 
 do not move, but that the PLANETS Jupiter, Saturn, Mars, 
 Venus, Mercury, MOVE in the revolving heavens. He also 
 held that meteorites are of cosmical origin. 
 
 From this point, leaving what is rather legendary than 
 historical, or what is, in the main, Egyptian rather than 
 European knowledge, we pass into the Greek world proper, 
 whence we are enabled, from the reliable data in our pos- 
 session, to trace with certainty the rapid progress effected 
 in science. For, beholding, as we are able to do, the coming 
 into existence of the method of research, from its gestation 
 with Plato to its birth with Aristotle, we can follow the 
 stream of development in its unbroken course from the Vth 
 century before our era until the present day. Our scientific 
 survey then begins with the two great philosophers. 
 
 Every one knows what Plato's deductive method of 
 research was. 
 
 Plato (429347 B.C.), caring less for phenomena (matter, 
 objects, facts) than for his own conceptions, would arrive 
 after deep meditation at a certain doctrine which he deemed 
 a universal truth or law; and, in order to prove his pro- 
 position, he would seek round him, and bring forward, a 
 series of phenomena which would agree with it and ap- 
 parently establish it. But as he left out of his purview 
 many of the phenomena which would have upset his con- 
 
io PROGRESS OF SCIENCE. 
 
 elusions, His DEDUCTIVE PROCESS was necessarily defective. 
 By itself it could at best only become a means of meta- 
 physical inquiry, but used conjointly with inductive reason- 
 ing, it ultimately became, and remained, an indispensable 
 instrument of scientific logic. 
 
 Aristotle (384 322 B.C.) at once perceiving the in- 
 sufficiency of his master's method, which left so many 
 loopholes for error in physical inquiries, reversed Plato's 
 process, and thereby founded the scientific method of re- 
 search. This process is called the objective or INDUCTIVE 
 METHOD. The instrument by which Plato sought to arrive 
 at truth was Intellect, whereas Aristotle's was Experience. 
 
 In his Organon (Instrument), Aristotle expounds his 
 scientific method, and declares it to consist in observation, 
 experience, and induction.* These, he says, we should per- 
 sistently pursue. The great inductive philosopher would 
 examine facts, and from facts, duly ascertained, would be led 
 to sound conclusions, and thus establish a scientific law 
 from which other phenomena or truths could be deduced 
 by Plato's process. He would, let us say, inquire into 
 the nature of the sea ; he would find that the Atlantic, the 
 Mediterranean, the Adriatic, the Euxine, the Red Sea, the 
 Persian Gulf, the Indian Ocean, were all of them salt water, 
 and he would, after this examination, draw the conclusion 
 that "All seas are salt." If he found a sheet of water, 
 say in Switzerland, to be fresh water, he would conclude 
 that it was not a sea. His chain of reasoning he called 
 " Syllogism ".f 
 
 The dialectical section of the NYAYA SCHOOL had been 
 using the syllogism of GAUTAMA (died in 543 B.C.) for more 
 than two centuries before Aristotle's time. Whether the 
 Greek philosopher invented the syllogism afresh or borrowed 
 it from the Hindu school is unknown. The latter supposition 
 is quite possible, considering the intercourse between Persia 
 and India J on the one hand, and between Persia and Greece 
 
 * See Appendix I., II. f See Appendix III. 
 
 The Magi of Persia, whose extensive and profound knowledge of 
 philosophy was proverbial, were not likely to have been leit unacquainted 
 with the most striking features of Hindu philosophy. 
 
EARLY KNOWLEDGE METHOD OF RESEARCH, n 
 
 on the other. The expedition of Alexander to India, which 
 occurred in 327, would be sufficient even in the absence of 
 Callisthenes, who died early in that year, to account for the 
 similarity of the Greek and the HINDU SYLLOGISM, for 
 Alexander was accompanied by a whole set of learned men, 
 and his expedition did as much to reveal Eastern knowledge 
 as Bonaparte's Egyptian Campaign did to reveal the wonders 
 of the Nile Valley, until then unknown to modern Europe. 
 There is a difference between the two kinds of syllogism, 
 but this difference is only apparent, for the Greek syllogism 
 reduced to three the five terms of the Hindu the two 
 first terms of the latter being merely eliminated. The 
 NYAYAN SYLLOGISM runs thus : 
 
 I. The mountain burns, 
 II. Because it smokes ; 
 
 III. All that burns smokes ; 
 
 IV. The mountain smokes, 
 V. Therefore it burns. 
 
 Remove the two first terms, and you have the Aristotelian 
 form. 
 
 Be that as it may, Aristotle's chain of reasoning was the 
 one which we still use, and Induction was, and is, nothing 
 but the syllogism without a middle term. A syllogism : 
 All sheets of salt water are seas ; 
 The Baltic is salt ; 
 
 therefore, 
 
 The Baltic is a sea. 
 
 And suppressing the middle term you have an example 
 of induction* : 
 
 All sheets of salt water are seas ; 
 
 therefore, 
 
 The Baltic is a sea. 
 Another example of induction : 
 
 All sheets of salt water are seas ; 
 
 therefore, 
 
 The Swiss waters are not seas. 
 
 In all cases you arrive at truth, provided you have ascer- 
 tained the facts.f 
 
 * See Appendix II. I. t See Appendix I. 3. 
 
12 PROGRESS OF SCIENCE. 
 
 Such, briefly, is Aristotle's inductive method so that 
 Aristotle will ever be regarded as the FATHER OF INDUCTIVE 
 PHILOSOPHY. 
 
 And we must not think, as some writers do, that, having 
 propounded a method, Aristotle thought it sufficiently good 
 for his disciples' use, and did not put it into practice himself ; 
 on the contrary, he did practise it as much as it lay in his 
 power. The briefest outline is sufficient to show this : 
 
 Ancient writers record, for instance, that in Natural 
 History, he had specimens collected from every part of the 
 then known world, so as to deal with facts only. He had, 
 it is also said, menageries, collections of plants and minerals 
 of all kinds, in order to write his "Natural History" from 
 observation. " One cannot," says Cuvier, the founder of 
 Palaeontology, " turn a page of it without deep amazement." 
 And this statement is justified. 
 
 He classified nature into two classes : Organic and 
 Inorganic a classification retained to this day by many. 
 
 He was the founder of ZOOLOGY, and many of the divisions 
 which he determined are accepted even now such, for instance, 
 as the two which he called the oviparous and the viviparous. 
 
 He foresaw the great law of EVOLUTION " Animals/' 
 he said, " begin where plants end, for some forms are so 
 similar both to plants and to animals that it is impossible 
 to determine in which division they should be classed." 
 
 He pointed out that a continuous chain can be traced 
 from the lowest plant to the most developed animal each 
 being separated from the next "by almost imperceptible 
 differences." The idea of gradual growth and development 
 from low to high organisms, is, if not expressed in these 
 terms, at least implied in his pregnant exposition of natural 
 history. He based his classification of animals upon their 
 organs and the manner in which these organs are used. 
 
 In PHYSIOLOGY, few facts were left untouched by him, 
 and he frequently guessed the real process of nature, as our 
 own XlXth century scientists acknowledge. He discussed 
 and rejected the spontaneous generation theory, and believed 
 in that of Epigenesis (germs the spring of life), which he 
 defended with great power. 
 
EARLY KNOWLEDGEMETHOD OF RESEARCH. 13 
 
 In PSYCHOLOGY, he laid his finger on the secret of the 
 question regarding this science as a branch of Physiology 
 just what our most advanced men of science proclaim it to 
 be. He saw the law of association of ideas : " Ideas/' says 
 he, " by having been together acquire a power of recalling 
 one another; or every partial representation awakes the 
 total representation of which it had been a part." (De 
 Animal) 
 
 In ASTRONOMY he was so practical that he made 
 observations himself for he mentions an occultation of Mars 
 by the moon, and another of a star in Gemini by Jupiter. 
 (f From the rare occurrence of such phenomena, their observa- 
 tion shows that he paid considerable attention to the 
 planetary motions." He was the first plainly to intimate that 
 the earth is a round globe ; and he rectified and completed 
 the discoveries of Eudoxus an evidence of the importance 
 he attached to verification. 
 
 In PHYSICS he was the expounder of ancient knowledge. 
 The ancients had undoubtedly made great advances in 
 physics, since we find they used glass globes filled with 
 water " for concentrating the rays of the sun, and thus 
 producing fire." The refraction of heat was well known to 
 them, since Aristophanes, in the Clouds, alludes to the use 
 of a glass lens for obtaining fire. (Dialogue between Strep- 
 siades and Socrates, beginning with ^ Tmpa . . and ending 
 with TTJS >?/$ SIKTJS.) Aristotle's work on Physics is probably 
 much mutilated, but it contains sound facts as it stands. 
 If he was not always accurate in his explanations, he never- 
 theless argued with wisdom on Meteorology, Mechanics, 
 Mathematics, Astronomy, Chemistry, Geology, etc., if we 
 may, for brevity, place these branches under one heading. 
 Doubtless he is often weak by the light of Galileo and Newton, 
 but the world took twenty centuries to produce these two phy- 
 sicists, and although Aristotle's Physics may be considered 
 inferior to some of his other writings, yet it is a beautiful 
 work, and one which is justly regarded as fundamental. 
 
 He also wrote, and wrote with rare insight and force, 
 on Metaphysics, Ethics, Theology, Cosmogony, Art, Poetry, 
 and Politics. In this last branch he was not content, like 
 
i 4 PROGRESS OF SCIENCE. 
 
 Plato and Bacon, to build up a perfect State from his own 
 imagination, but he, on the contrary, made himself ac- 
 quainted with the history and institutions of the nations 
 which had come into contact with the Greeks up to 
 his time, and he was able thereby to sketch one hundred 
 and fifty-eight Constitutions a most practical work for 
 politicians and students far more serviceable than the 
 "Republic" of Plato or the " New Atlantis " of Bacon. 
 
 If Aristotle made many mistakes, and even failed to 
 apply his own method as rigorously as he might have 
 done, he none the less left gigantic work behind him ; and 
 whatever may be said of him, he is recognised, by all 
 lovers of truth, as the FOUNDER OF SCIENCE and Inductive 
 Philosophy. He left on the one hand a " Cyclopaedia of 
 Science," and on the other hand, an instrument of research 
 Induction. " He made men aware of the permanent 
 importance of fact, and he taught them to seek explanations 
 of phenomena by the objective method" It is men's business 
 to use that immortal creation induction rightly. 
 
CHAPTER II. 
 
 SCIENCE IN ANTIQUITY. 
 
 IN spite of Aristotle's stupendous intellect, science in 
 antiquity could not possibly develop and find applications 
 as it did in modern days. And without digressing, we may 
 take note of the important fact that notwithstanding the 
 immense and valuable discoveries of the XVIth century, 
 it is only within the last sixty or eighty years that science 
 has made such unexampled and rapid advance. Much of 
 the recent progress flows from the application of steam to 
 machinery, by means of which innumerable instruments have 
 been either invented or improved, and brought into common 
 use all, in their turn, assisting in further scientific develop- 
 ment. And this in the course of less than a lifetime. To 
 resume. 
 
 In antiquity there existed insuperable drawbacks to the 
 advance of science and industry, and amongst others : 
 
 I. WANT OF MATHEMATICS for despite great men 
 such as Euclid, Archimedes, Eratosthenes, and Hipparchus, 
 knowledge, in this branch of science, was limited : Dynamics 
 and Algebra in its higher application came into use after 
 Galileo only, and many new methods were invented in 
 modern times. 
 
 II. WANT OF INSTRUMENTS for apart from the gnomon, 
 the armillary spheres, the quadrant, the planetarium, the 
 dioptra, and the astrolabe, the few other ones which may 
 have existed were insignificant. 
 
 III. SLAVERY deprived the ancient world of the modern 
 
1 6 PROGRESS OF SCIENCE. 
 
 stimulus to industry viz., individual and independent 
 ambition and welfare ; for slaves had no end in view, not 
 even the bringing up of a family ; and they made machinery 
 unnecessary, because they were cheaper than machinery. 
 Slavery, therefore, limited the means of production, and 
 closed the road to competition and mechanical improve- 
 ments. 
 
 IV. On the other hand the universal CONTEMPT in which 
 slavery was held deterred free men from entering the indus- 
 trial and commercial career which was almost exclusively 
 the pursuit of slaves, and which alone could at one and the 
 same time conduce to the development of wealth, raise the 
 status of civilisation, and lead to that stimulation necessary 
 for the creation of new means of progress in the field of 
 applied science. So long as trade and industry, together 
 with manual labour, were considered as beneath the dignity 
 of free men, practical advancement was well-nigh impossible. 
 
 V. The mildness of the CLIMATE in which early civilisation 
 flourished restricted the necessaries of life and this was a 
 permanent cause of stagnation for utility was a much 
 weaker incentive of inventions and science than in northern 
 regions. 
 
 VI. PRECONCEIVED THEORIES constituted another draw- 
 back for science is very frequently the outcome of practical 
 and physical manual work, and there were relatively too few 
 trades and industries for them to induce scientific researches 
 and lead to many scientific results. Compare theory and 
 practice : Alchemy, for instance, sought the philosopher's 
 stone and the elixir of life and f ailed \ but on its way, 
 through and out of the processes of manipulation it neces- 
 sitated, it accidentally made many useful discoveries, and 
 finally paved the way to Chemistry. In antiquity the absence 
 of manipulation or the workshop was a bar to the disappear- 
 ance of the theoretical conceptions which stood in the way. 
 
 VII. MATERIAL SUBSTANCES naturally also play an 
 important part in the progress of scientific theories and 
 their application : without glass, for instance, we could have 
 no astronomical nor physiological instruments, hence neither 
 astronomy nor physiology; without coal and iron, the law 
 
SCIENCE IN ANTIQUITY. 17 
 
 of elasticity of gases would be a mere toy, instead of having 
 led to the construction of steam - engines, steamships, and 
 railways. Many of the substances familiar to us were 
 unknown to the ancients. 
 
 VIII. The POLITICAL ECONOMY of the old world was 
 limited to the development of agriculture (mostly by slave- 
 labour). The best and most practical minds, Xenophon and 
 Cato, discountenanced and despised industry and commerce. 
 Capital, where it existed, was either applied to usury, or 
 dissolved in the gratification of sensual enjoyment ; so that 
 industry, commerce, capital, the three greatest springs of 
 social progress, were practically non-existent. 
 
 When we bear in mind that tools are necessary to 
 construct machines, and machines are necessary to probe 
 the earth, and that in addition to the immense drawbacks 
 just enumerated, the ancients had no machinery to speak 
 of and scarcely any tools, we can at once understand what 
 little progress could be made, how slowly that little progress 
 could be effected, and how easily it was arrested arrested, 
 that is, in its infancy by the ruthless invasion of the Bar- 
 barians and the break-up of the Roman rule. 
 
 It is almost a truism to say that the underground re- 
 sources of the earth, the workshop, the Physicist's room, 
 and the Chemist's laboratory must of necessity be kept 
 in continual connection and INTERCOURSE with one another 
 in order that scientific progress may be effected. These 
 act and react upon one another just as much and in the 
 same manner as pure science and application of science 
 act and react upon each other. From those elements and 
 their reciprocal effects scientific evolution necessarily follows. 
 
 Furthermore, and this is of equal importance, in order 
 that improvements should be fruitful and durable, supply 
 a multitude of wants, give enjoyable affluence to peoples, 
 and thus conduce to the establishment of social order and 
 social welfare, and hence to that intellectual maturity which 
 breeds science, there must exist INTERCOMMUNICATION 
 among nations ; more, the means of communication are 
 equally indispensable to conquer, and act upon, Nature- 
 Nature having, for our good, unequally distributed that 
 
 c 
 
i8 PROGRESS OF SCIENCE. 
 
 which man requires to feed, to clothe, and to house himself, 
 and which TRADE, or Exchange in its broadest sense and 
 working, can alone distribute evenly. 
 
 EXCHANGE rests on foundations absolutely needful, such 
 as 
 
 I. MEANS OF TRANSPORT from the canoe and cart to 
 the steamship and railway. 
 
 II. DURATION or perpetuation OF IDEAS and their 
 spread which had, and still has, to be secured by writing, 
 the plastic arts, printing, the telegraph, and so forth. 
 
 III. The TRANSFORMATION OF THE EARTH to the 
 
 requirements of man such as the draining and drying 
 of marshy land, the clearing of a forest, the digging of 
 canals for irrigation, the cutting of roads, and so on which 
 can only be achieved by the labour, inventions, trades, 
 industries, and arts of generations. 
 
 IV. The PHYSICAL AND MORAL HEALTH of humanity 
 to be ensured by hygiene, medical science, education, and 
 practical morality. 
 
 V. The FREE AND ORDERLY INTERCOURSE of all classes 
 
 with one another in their own country, and of all nations 
 with one another throughout the globe an end obtained 
 by political development, international law, and social science. 
 
 It is clear that all these elements demanded ages upon 
 ages for their birth and growth, and, to make the ancients 
 responsible for their non-appearance in the Greek or Roman 
 world, is equivalent to making them responsible, and re- 
 proaching them, for having been our juniors by two thousand 
 years, or for having failed to find out what required two 
 thousand years to discover. 
 
 The ancients, far as they were from the point we have 
 now reached, have nevertheless achieved wonderful work, 
 even if we limit our estimate of it by the partial and frag- 
 mentary records of their knowledge in our possession. No 
 doubt but they knew vastly more than we give them credit 
 for ; but restricted to these limits, the advance they made 
 was so astonishing that we can never be tired of praising 
 them. To their ability, originality, and genius we can but 
 yield the amplest tribute of admiration. 
 
CHAPTER III. 
 
 PROGRESS IN ANTIQUITY. 
 
 THE first group of scientific facts to be recorded refers to 
 the Greeks after Aristotle's time, and will include only those 
 of primary importance. The briefest outline is imposed upon 
 us by the limits of our sketch. 
 
 After the fall of Athens from political greatness, Alexan- 
 dria, under the strong rule of the Ptolemies (323-43 B.C.), 
 became the centre of learning, and Greek philosophers 
 gathered there from all parts to enjoy the generous and 
 enlightened protection of those princes. For two hundred 
 years after the disappearance of their dynasty, the Alexandrian 
 Museum,* which they had erected, remained the seat of 
 science, so that the school of Alexandria flourished for more 
 than five hundred years as a scientific centre. No city was 
 ever so exclusively the seat of Intellect as the Egyptian 
 capital : for pure philosophy continued to be taught there 
 until 415 A.D. for two centuries, that is, after science had 
 come to be considered of secondary importance. Nor did 
 its influence stop when it ceased to be the abode of learned 
 men : its teachings remained for another thousand years the 
 paramount principles of intellectual growth in the world 
 hence historians justly mention Alexandria as the city which 
 has exercised the most lengthy and beneficial influence over 
 civilisation. 
 
 We have already seen that knowledge, before Aristotle's 
 time, was assuming a scientific aspect ; as we approach his 
 
 * This Museum was a group of palatial buildings four or five times as 
 extensive as Buckingham Palace. 
 
 C 2 
 
20 PROGRESS OF SCIENCE. 
 
 period we find this to be more decidedly the case than 
 before; but only when his powerful influence takes effect 
 upon his disciples and followers do we find science grounded 
 upon firm foundations. The reason of his influence lay, 
 as we have seen, in the imposing work he performed, and we 
 shall see in the course of the present survey that this vital 
 work of his was of a nature to evolve, necessarily, a long 
 series of fruitful results. The right method had at last come 
 into existence. 
 
 460 357. Democritus made two assertions, no doubt 
 due to profound observation and meditation, which modern 
 science has demonstrated to be well founded, viz. that the 
 MILKY WAY is an immense conglomeration of stars, and 
 that the Universe is built up by conglomerations of atoms. 
 The latter doctrine had been held in India by the Nyaya 
 school of philosophers founded by Canade. Whether Demo- 
 critus derived his notion from the Hindu ATOMIC SYSTEM is 
 quite possible, considering that the Persian empire stretched 
 as far as the Indus, and that glimpses of Hindu philosophy 
 may have reached the Greeks through Persia. The Magi were 
 likely to be well acquainted with neighbouring philosophies. 
 
 460 357. Hippocrates, the most famous physician of 
 antiquity, and the FATHER OF MEDICINE, destroyed the 
 theological theory of disease, which consisted in the doctrine 
 that every sickness was due to the anger of an offended God 
 a theory revived in our Middle Ages. He taught that disease 
 arises from natural causes. This was the great principle 
 which caused him to be considered as the founder of scientific 
 medicine. His Aphorisms, or Maxims, embody his immense 
 experience of pathology and therapeutics. They have been 
 a guide to generations of physicians, on account of their 
 profound wisdom and truth. 
 
 432 B.C. Meton having observed that 235 lunar months 
 correspond closely to 19 solar years, introduced (in 432) the 
 METONIC PERIOD* a cycle of 19 YEARS, by which he adjusted 
 the calendar with the course of the sun and moon. 
 
 * This cycle, intended to associate lunations with the year, was known 
 to the Chinese long before Meton. It is still in use in our almanacs; 
 the Golden Number (used to find Easter) is calculated in reference to it. 
 
PROGRESS IN ANTIQUITY. 21 
 
 406366. Eudoxus, who had built an observatory at 
 Cnidos, was the first to enunciate the REGULARITY OF 
 MOTION of the planets in the heavenly sphere, thereby 
 explaining their periodic reappearance in the same place, 
 and to make a map of the known stars. It is probable, 
 however, that this knowledge had been in the possession 
 of the Chaldaeans and the Egyptians for many centuries ; 
 but the fact that he had an observatory is full of significance. 
 
 362 287. Theophrastus composed a history of Stones 
 and a history of Plants ; another work, called " On the Cause 
 of Plants" on gardening and farming, is one of the most 
 practical ever written combining, as it does, pure science 
 with applied knowledge. It remained a text-book until 
 modern botany came into existence. Theophrastus must be 
 recognised as the FOUNDER OF BOTANY. His descriptions 
 embraced 500 different species of plants, which are grouped 
 or divided into herbs, shrubs, and trees a very misleading 
 CLASSIFICATION, but a most creditable attempt, nevertheless, 
 being based as it was upon direct observation. He was the 
 first to record the discovery of fossil bones and ivory this 
 being the earliest gleam of Palaeontology after Aristotle *, but 
 two thousand years will pass away before this science is 
 born. 
 
 330. Calippus corrected the Metonic cycle (which caused 
 an error of one day in 317 years) by establishing (in 330) 
 the CALIPPIC PERIOD of 940 lunations a cycle of 76 years 
 minus one day. These cycles were intended also to be 
 cycles of eclipses, but they were only approximate in this 
 respect. Calippus assisted Aristotle in correcting Eudoxus's 
 discoveries. This affords another proof of the practical 
 influence of Aristotle and of his method of verification. 
 
 330. Berosus invented the HEMISPHERE, one of the 
 most ancient instruments next to the gnomon and the dioptra. 
 
 323 285. Herophilus, a worthy successor of Hippo- 
 crates, ascribed the pulse to the CONTRACTION OF THE 
 HEART ; was the first to recognise the importance of care- 
 fully noting three things in the PULSE the strength, the 
 quickness, and the regularity of its beats. He was aware 
 of the existence of the lacteals, and their relation to the 
 
22 PROGRESS OF SCIENCE. 
 
 mesenteric glands ; traced the tendons, the ligaments, and 
 THE NERVES. Many of the names used by him and 
 Erasistratus are still accepted ; advanced anatomy and 
 physiology through his pursuit of dissection and vivisection 
 of animals and human bodies. ANATOMY, with and after 
 him, became the basis of medical teaching. The school of 
 medicine he and Erasistratus founded was famed for nearly 
 700 years. 
 
 323 283. Euclid compiled his book on GEOMETRY a 
 standard work to this day. He taught that light travels in 
 straight lines called " rays." 
 
 300260. Erasistratus, who, like Herophilus, was a 
 worthy follower of Hippocrates, was a great anatomist. 
 He described THE BRAIN and its division into two parts 
 the cerebrum and the cerebellum and pointed out its circum- 
 volutions. He described the STRUCTURE OF THE HEART, 
 and discovered it to be the fountain-head of arteries and 
 veins ; recognised TWO KINDS OF NERVES, those of motion 
 and those of sensation, and their connection with the brain, 
 apparently understanding the brain to be the thinking and 
 feeling apparatus. 
 
 287212. Archimedes, a mathematical and inventive 
 genius of the highest order, exceeded by none, possessing at 
 once marvellous originality of conception and immense 
 working power, discovered new provinces of inquiry. He 
 showed " how mathematical theory could be wedded to 
 physical experiments." His works are the application of 
 Aristotle's inductive process in a new field, if they do not 
 constitute by themselves the first true organum, as some 
 writers would have it. He measured the SPHERE, the 
 CYLINDER; discovered the LAW OF THE LEVER the 
 primary law of mechanics and the base of STATICS ; he 
 invented a planetarium representing the movements of 
 the heavenly bodies ; he invented, i, the SPIRAL-PUMP 
 (also called water-screw, screw of Archimedes, and cochlea) ; 
 2, CONCENTRIC MIRRORS ; 3, POWERFUL LIFTS ; 4, GIGANTIC 
 CATAPULTS. The three last inventions were, if we are to 
 believe Roman writers, used with tremendous effects against 
 the Romans who were besieging Syracuse. He founded 
 
PROGRESS IN ANTIQUITY. 23 
 
 HYDROSTATICS by the discovery of the principle which bears 
 his name: "A body immersed in a liquid loses a part of its 
 weight equal to the weight of the displaced liquid." This law 
 is the basis among other things of the calculations in ship- 
 building. And the same principle is true for bodies in air ; 
 so that Archimedes made the first successful attempt to 
 measure the SPECIFIC GRAVITY of different substances. 
 
 285 222. Hero (of Alexandria), one of the great 
 mathematicians of the time, made several mechanical in- 
 ventions, one of which was the pneumatic experiment called 
 HERO'S FOUNTAIN, in which a jet of water is maintained 
 by condensed air ; another, a STEAM-ENGINE the reaction 
 machine (the Eolipile), of which we have the description ; 
 also a double forcing pump used for a FIRE-ENGINE. 
 
 280 264. Aristarchus (of Samos) attempted to measure 
 the distance from the earth to the sun and to the moon 
 by a most ingenious method (dichotomy) ; measured the 
 magnitude of the sun's diameter ; calculated the year to be 
 365 days 6 hours ; held the HELIOCENTRIC DOCTRINE (also 
 ascribed to Pythagoras and Philolaus), teaching that it was 
 the earth, not the sun, which travelled round the ecliptic. 
 He understood that the position of the earth from pole to 
 pole is sloping, that is, oblique, to the ecliptic, and that this 
 OBLIQUITY causes the four seasons of the year. He appa- 
 rently was the first among the Greeks who dearly understood 
 that the change from day to night, and from night to day, 
 is due to the turning of the earth on its axis in 24 hours. 
 
 276 196. Eratosthenes made use of the solstitial 
 and equinoctial ARMILS (armillary spheres) which he invented, 
 or received from Ptolemy Euergetes, by means of which he 
 determined the distance between the tropics to be equivalent 
 to 47 42' 39", half of which gives 23 51' 19"'$ for the 
 OBLIQUITY OF THE ECLIPTIC. (In 1 870 it was calculated to 
 be 23 27' 22"'3 and is continually diminishing the rate of 
 decrease having been some twenty minutes per thousand 
 years.) We need hardly point out the great importance of this 
 discovery. Further, by his innovations, Eratosthenes may be 
 considered as the FATHER OF GEOGRAPHY. He constructed 
 a map of the known world ; described Libya, Asia, Europe ; 
 
24 PROGRESS OF SCIENCE. 
 
 and was the earliest to lay down the FIRST PARALLEL OF 
 LATITUDE (the 36th), after due observation of the identical 
 duration of daylight (14^ hours) on the longest day in the 
 year, from the Columns of Hercules (Gibraltar) to the Hindu 
 Kush. He attempted to measure the MAGNITUDE OF THE 
 EARTH by means of this parallel and the use of the gnomon ; 
 from Alexandria to Syene (now called Assouan), which lay 
 exactly south, he drew at right angles to his parallel a straight 
 line which would necessarily pass at the poles ; and having 
 ascertained the distance between the two cities (5,000 stadia 
 = 625 miles), and convinced himself (from the gnomon cast- 
 ing no shadow whatever at Syene on the summer solstice) 
 that Syene was exactly under the sun at noon on that day, 
 he measured the angle of the shadow cast by the gnomon at 
 Alexandria on the same day of the year at midday, and 
 finding it to be the fiftieth part of a circle, he easily found the 
 magnitude of the circumference (625 x 5o = 3i,25omiles). li 
 the result was incorrect, and such as a rough attempt could 
 be expected to give, the method was admirable and original. 
 He also studied other geographical problems, such as the 
 direction of mountain ranges, the shape of continents, and 
 the way in which the clouds carry rain. According to some 
 writers, he catalogued 675 fixed stars, and tried to ascertain 
 the distance from the sun and the moon to the earth. 
 
 250 220. Ctesibius invented the pump and other 
 hydraulic instruments ; perfected the CLEPSYDRA (water- 
 clock) by applying toothed-wheels to it. 
 
 250 220. Apollonius of Perga solved the problems of 
 the stations and retrogressions of the planets by means of 
 EPICYCLES and deferents, and next to Hipparchus formed 
 the alliance between Geometry and Astronomy. 
 
 160 145. Hipparchus, the REAL FOUNDER of astro- 
 nomical science, and the scientific genius of antiquity par 
 excellence, I, verified the determination of the OBLIQUITY 
 of the ecliptic of Eratosthenes the earliest attempt at an 
 exact determination of the " constants " of nature ; 2, found 
 the length of the TROPICAL YEAR within 12 seconds, making 
 it 365 days 5 hours 49 minutes ; 3, discovered the eccentricity 
 of the solar orbit ; 4, fixed the position of the line of the 
 
PROGRESS IN ANTIQUITY. 25 
 
 Apsides ; 5, formed the earliest Tables of the Sun, and 
 calculated with accuracy when lunar and solar eclipses would 
 occur; 6, determined the period of the moon's revolution, 
 relatively to the stars, to the sun, to her own nodes, and to her 
 apogee determinations which furnish one of the most delicate 
 tests of the truth of Newton's law of gravitation ; 7, determined 
 the eccentricity of the lunar orbit and its inclination to the 
 plane of the ecliptic ; formed Lunar Tables (and is therefore 
 the discoverer of the mode of constructing solar and lunar 
 tables) ; 8, approximated to the parallax of the moon ; 9, 
 catalogued 1,080 stars, and showed how they are situated 
 and grouped with relation to the ecliptic ; 10, invented the 
 planisphere or mode of representing the starry heavens upon 
 a plane, and of producing the solutions of problems of 
 spherical astronomy ; 11, devised the application of parallax 
 to determine the distances of celestial bodies ; 12, demon- 
 strated the methods of calculating triangles, whether recti- 
 lineal or spherical which may be considered as the beginning 
 of Trigonometry; 13, had the happy idea, for assisting 
 Geography, of fixing the positions of spots on the earth by 
 means of the latitudes and longitudes completing thereby 
 Eratosthenes's Geography ; 14, was the first who determined 
 the longitude by the eclipses of the moon; 15, constructed 
 a TABLE OF CHORDS, of which he made the same use as we 
 make of our sines ; 16, made use of the dioptra, and 
 invented the parallelic instrument and the ASTROLABE ; 17, 
 discovered the PRECESSION OF THE EQUINOXES a gradual 
 change in the position of the nodes (intersecting points) of 
 the earth's equator on the ecliptic. The nature of this 
 change is such that the nodes of the celestial equator on the 
 ecliptic in other words, " the first points of Aries and Libra 
 are continually travelling along the ecliptic in a direction 
 contrary to the order of the signs/' The intersection this 
 year, for instance, occurs at a point just before last year's 
 point (hence the name of precession), and occurs more to the 
 west every year by 5o"'2i ; so that the nodes shift retro- 
 gressively one degree in 71*6 years a complete revolution 
 of the nodes being accomplished in 25,866 years. This is one 
 of the most important discoveries in the world of science, and 
 
26 PROGRESS OF SCIENCE. 
 
 to our thinking the most marvellous feat of scientific genius 
 ever performed. It was reserved to Newton to show the 
 cause of this phenomenon. 18, Hipparchus is said by some 
 authors to have also understood and explained our SOLAR 
 SYSTEM i.e. the heliocentric theory, revived and demon- 
 strated by Copernicus. It is probable that he thought like 
 Aristarchus on the subject. 
 
 135 51. Posidonius measured a degree; and, having 
 observed the intervals between successive high TIDES to be 
 equal to the intervals between the moon's passage across the 
 meridian, correctly ascribed the Tides to be due to the 
 motions of the sun and the moon. Pliny, who came to the 
 same conclusion, and who stated it, only recorded or repeated 
 what Posidonius had observed. 
 
 100 45. Sosigenes, under the direction of Julius Caesar, 
 reformed the Roman Calendar, and devised the JULIAN 
 CALENDAR (45 B.C. 1581-2 A.D.) 
 
 B.C. 54 24 A.D. Strabo was a traveller and geographer; 
 he described all he saw with remarkable accuracy ; studied 
 VOLCANOES and earthquakes; pointed out that these phe- 
 nomena are caused by the hot vapour hidden within the earth ; 
 that when the vapour and lava can find a valve of escape as 
 they do in the Etna, the crust of the earth is not disturbed ; but 
 when they cannot escape they cause shocks and earthquakes. 
 
 B.C. 5 65 A.D. Seneca asserted that comets would be 
 found to revolve in PERIODIC ORBITS and return to sight 
 the Chaldaeans and the Pythagorians (if not Pythagoras 
 himself) entertained a like opinion. He knew that the tails 
 of comets are driven away from the sun ; and like Anaxagoras 
 thought Meteorites must be cosmical bodies. 
 
 100161 A.D. Ptolemy discovered the EVECTION OF THE 
 MOON ; determined the moon's parallax, and made several 
 other discoveries of secondary importance relating to the 
 motions of the moon and the planets ; invented the stereo- 
 graphic projection and the quadrant. His SYNTAXIS contains 
 the roots of most of the methods in use among us. He made 
 a regular system of astronomy based upon all the knowledge 
 the Greeks had acquired about the heavenly bodies, and this 
 system was accepted for 1,400 years until Copernicus. His 
 
PROGRESS IN ANTIQUITY. 27 
 
 Geography was also taught for fourteen centuries. He drew 
 maps of all the parts of the known world, including BRITAIN 
 (Albion), of which he traced the rivers and coast-lines, laying 
 on these maps the lines of latitude and longitude calculated 
 afresh by the rules of Eratosthenes ; but the longitudes are 
 very inaccurate, a defect due no doubt to the uncertainty 
 which existed as regards the shape and magnitude of the 
 earth. His catalogue of fixed stars does not exceed 1,022 
 fewer, that is, than the catalogue of Hipparchus. 
 
 130 200 A.D. Galen experimentally proved what Erasis- 
 tratus had already intimated viz., that the nerves and the 
 BRAIN are connected, and that the latter is the CENTRE OF 
 FEELING or sensation. This was the only discovery worth 
 mentioning he made. His pathology and therapeutics which 
 summed up the medical knowledge of antiquity, mixed with 
 much that was imaginary, were the guides from which 
 physicians until Paracelsus and Vesalius dared not deviate, 
 so great was his authority. Vesalius (1514 1564) proved 
 that Galen had not dissected the human body, and had 
 described it only from the dissection of animals. 
 
 We leave on one side mathematicians such as Pappus and 
 others, great masters though they were. 
 
 The Alexandrian Museum, founded by Ptolemy Philadel- 
 phus (285-247), included Collections, Menageries, Observa- 
 tories, besides its four Faculties of Literature, Mathematics, 
 Astronomy, and Medicine the last including the sub- 
 Faculty of Natural History. 
 
 The Temple of Serapis (called also the SERAPION) was 
 used as an hospital where the sick were tended, and the 
 persons studying Medicine became familiar with diseases and 
 their treatment. Surgery and Pharmacy received many im- 
 provements there.* 
 
 Such are in the main the achievements of the Greeks in 
 antiquity. The foregoing table enables us to appreciate the 
 value of the oft-repeated assertion that up to Harvey no 
 progress to speak of had been made in the arts and sciences 
 since Aristotle. 
 
 * For a more adequate presentment of Greek science, see Herbert 
 Spencer's " Genesis of Science," and WhewelFs " Physical Science." 
 
CHAPTER IV. 
 
 PROGRESS AMONG THE ARABS. 
 (From the IXth to the XVth Century^ 
 
 THE next group of scientific facts belongs to the Arabian 
 period. Science had migrated to Persia after 415 A.D., when 
 Bishop Cyril caused the destruction of the Alexandrian 
 Museum. The Greek men of science,, Nestorian and Jewish, 
 escaped death at the hands of the fanatical Christians by 
 flight, and carried away with them the sciences of which they 
 were the teachers. Protected by the Persian kings, science 
 survived the Alexandria catastrophe, and the Persians became 
 its custodians for two centuries until they were overcome by 
 the Moslem conquerors, the Arabs (641). The Arabs, their cycle 
 of conquest over, assimilated the Greek learning flourishing in 
 Persia, and in their turn became the representatives, guardians, 
 and teachers of ancient knowledge. Civilisation, or what was 
 of great value in the Greek world, was not dead ; it had 
 gyrated ; and the Arabs, having received science from the 
 ancients, gave to every branch of it an accuracy and enlarge- 
 ment at once unforeseen and substantial. The following 
 sketch will enable us to see that their triumphs in philosophy, 
 mathematics, astronomy, chemistry, and medicine were both 
 glorious and durable. 
 
 In order, however, fully to understand the part which the 
 Arabs have played in the progress of mankind, it is necessary 
 to see what sort of civilisation theirs was and this necessi- 
 tates a short description. A similar description was not 
 
PROGRESS AMONG THE ARABS. 29 
 
 needed in the case of the Greeks, because we all know by 
 what our training, books, museums bring every day to our 
 minds, that our civilisation is partly Greek. The monuments 
 of art, literature, and philosophy which we possess make the 
 Greek world familiar to us. It is not so with regard to the 
 Arabs. Very few people are aware of the grandeur and 
 beautyof their social state in the six centuries duringwhich they 
 stood in advance of the whole world. Our European historians, 
 actuated no doubt by national pride and religious prejudice, 
 have systematically kept out of sight both their magnificent 
 civilisation, and our immense obligations to them. A few 
 writers only, especially Sismondi, Pouchet, Draper, and 
 Renan, have done them justice. It is therefore needful to 
 sketch out what is unfamiliar to most readers. 
 
 The Arabian race is gifted with an INTELLECT which, 
 under proper direction and cultivation, yields the most 
 admirable effects. A general fact shows this very forcibly. 
 It took the Greeks six centuries, the Romans seven, ourselves 
 ten, to emerge from barbarism into civilisation ; the Arabs' 
 transition did not exceed one hundred years a phenomenon 
 which speaks volumes with respect to their natural gifts. 
 
 The POLICY of the Khalifs and Emirs of Islam was in- 
 spired by the two fine maxims of All, Mohammed's son-in- 
 law : (f Eminence in science is the highest of honours ; " " He 
 dies not who gives life to learning ; " and this liberal policy 
 prevailed for centuries from the Oxus to the Pyrenees. To 
 speak of one instance, AL MANSOR had no less than six 
 thousand learned men at his court. In contrast with this, and 
 during the best part of a thousand years, Christendom was 
 more or less overshadowed by monkish theology, and the 
 Church persecuted learning, regarding it as the work of 
 Satan. 
 
 The CITIES which flourished throughout Islam were towns 
 comparable in almost every point with our own in the present 
 day. Samarcand, BAGDAD, Ispahan, Damascus, Bassora, 
 Morocco, Fez, Seville, GRANADA, Toledo, CORDOVA, as well 
 as the towns in Sicily, were, outside the Arabian empire, un- 
 rivalled for beauty, luxury, and comfort. To every mosque 
 a school was attached, and in each town besides there were 
 
30 PROGRESS OF SCIENCE. 
 
 either academies, or colleges, or universities. Bagdad ex- 
 hibited every kind of magnificence. One of its palaces was 
 furnished with 38,500 pieces of carpet, 12,500 of which were 
 of gold brocade. Cordova, which almost rivalled Bagdad, 
 counted two hundred thousand houses, one million of in- 
 habitants, a hundred public baths, nearly as many HOSPITALS ; 
 a man could walk for ten miles of streets in a straight line ; 
 the streets were PAVED, AND LIGHTED throughout the night 
 by lamps. In Europe, there was not a city, properly so- 
 called, except Constantinople, which was not vastly inferior 
 in every respect ; towns were pestilential gatherings of hovels, 
 huts, and thatched houses, built of timber and mud. Paris 
 was left unpaved until Louis XI. (1461 1483) ; London had 
 not one public lamp until Henry VIII. (1509 1547). Our 
 colleges and universities were, only hundreds of years after- 
 wards, instituted in imitation of the Arabian, and to this day 
 our university practices, examinations, honours, and degrees 
 have descended from them. 
 
 The HOUSES of the great, and the palaces of the Emirs 
 especially, were enchanting abodes with which the Roman 
 emperors' palaces of previous ages could alone have been 
 compared. But the BEAUTY AND LUXURY of their interior 
 surpassed anything the world had as yet seen. They had 
 walls of alabaster and adorned with coloured designs fretted 
 with gold; halls supported by Spanish, African, Italian, 
 Greek marble columns, surrounded by balconies, and 
 ornamented with perfumed fountains ; towers for ventilation, 
 and caleducts for warm and scented air ; mosaic pavements 
 and ceilings of unique workmanship ; rooms with conservatories 
 and odorous cascades ; stained-glass windows of iridescent 
 hues; marble baths; furniture of citron and sandal-wood 
 incrusted with silver and mother-of-pearl ; Persian carpets 
 and rich tapestries ; Chinese porcelain and rock-crystal vases; 
 everything which industry and art, luxury and comfort could 
 devise to charm the mind and cheer the heart. Abderrahman 
 III.'s palace had no less than 1,200 COLUMNS. The Audience 
 Hall was incrusted with gold and precious stones. It con- 
 tained over 6,000 attendants. And this sovereign (912 961) 
 was not a mere sensual ruler, for, like most Khalifs, he ex- 
 
PROGRESS AMONG THE ARABS. 31 
 
 hibited that taste for statuary, paintings, and learning which 
 the popes of Rome showed only six hundred years later. When 
 the famous musician Zaryab came from Asia to superintend the 
 Cordova COLLEGE OF MUSIC, the Khalif rode forth to meet 
 him and do him honour. Those who now visit Spain may 
 bear witness to the richness and loveliness of Saracenic 
 architecture the ALHAMBRA and the CORDOVA CATHEDRAL 
 are specimens of its grandeur. In Europe the kings' palaces 
 were for centuries barbarous and unclean dwellings, chimney- 
 less, windowless, hardly better than stables, and " with a 
 hole in the roof for the smoke to escape ; " their furniture 
 consisted of rough wooden benches, stools, tables, and coffers, 
 rushes on the floor and straw mats against the walls. The 
 equipage of a travelling sovereign was an ox-cart. It was 
 only after returning from the Crusades that the kings and 
 barons, who had seen the luxury of the East, began to awake 
 from their coarse usages, and introduce slight improvements 
 in their customs. In this they were wholly indebted to the 
 Arabs ; it took them, however, another three hundred years 
 for realising anything like comfort and luxury. 
 
 The Arabs were of all peoples those who brought the 
 vastest improvements in the ARTS OF LIFE. They made 
 agriculture a science ; it was regulated by a code of laws ; 
 they improved it by irrigation, by means of flood-gates, wheels, 
 and pumps. They likewise made a science of the cultivation 
 of plants, of garden and orchard fruits ; to them we owe the 
 introduction of rice, cotton, silk, sugar, saffron, spinach, and 
 other vegetables, the Xeres and Malaga wines. They paid 
 great attention to the breeding of cattle, camels, sheep, and 
 HORSES, improving the breeds of those they possessed. From 
 them Europe inherited its love of the horse; likewise of 
 hunting and falconry. They preceded Europe in the practice 
 of true CHIVALRY. They also originated or improved many 
 branches of industry earthenware, iron, steel, leather, textile 
 fabrics, from the humblest to the most gorgeous. The 
 people's food was wholesome and most varied. The trade of 
 the world for centuries was in their hands and those of their 
 fast allies the JEWS OF SPAIN. Over a thousand merchant 
 ships trading between Barcelona and the Levant exchanged 
 
32 PROGRESS OF SCIENCE. 
 
 goods with Constantinople, the Black Sea, the ports of China, 
 India, and thence with the interior of Asia, also with Japan, 
 Madagascar, and the eastern coasts of Africa ; and last, not 
 least, books were written on the principles of TRADE. In the 
 high social state which the Arabs enjoyed, prosperity and 
 wealth increased to a prodigious extent a natural result of 
 industry and trade. The tales of the " Arabian Nights " throw 
 great light upon the thrifty customs of the people, who had 
 put aside warlike and predatory habits, to become peaceful 
 traders and merchants, cleanly, gentle, and sociable. The 
 revenue of the Spanish Khalif, Abderrahman III., was no less 
 than FIVE and a half MILLIONS STERLING a sum which 
 exceeded the entire revenue of all the sovereigns of Europe ; 
 and this enormous taxation was lightly borne owing to the 
 extension of trade and the increase of wealth in the com- 
 munity. (Drapers Intellectual Development^) 
 
 All these improvements gradually, though slowly, spread 
 from Spain and Sicily into the south of France, and next 
 into Italy the rest of Europe remaining in its uncivilised 
 condition for ages universal war and rapacity tearing it from 
 end to end. There, the people continued to live in huts, to 
 feed on roots, vetches, and beans, to clothe in untanned skins; 
 to vegetate in abject poverty and dirt, without industry and 
 commerce to speak of until the Crusades. Up to the XVIth 
 century the great ladies and princesses of Europe had gowns 
 which lasted for years, the uncleanliness and strong smell of 
 which were concealed by the use of penetrating perfumes. 
 
 The fact of capital importance to note here, is the RISE, 
 for the first time in the annals of the world, OF INDUSTRY 
 and commerce on a large scale, and these were not carried 
 on by slaves or slave-labour, but by free men. The in- 
 dustrial spirit which is destined to revolutionise the world 
 has already done so within the confines of Islam. It will 
 spread into Europe, and bring momentous changes. The 
 Saracens will lose the fruit of their progress, as the Romans 
 and the Greeks have lost theirs, by the invasion of a host of 
 irresistible barbarians, the Christians, whose fanaticism, as 
 ruthless in Spain as it had been at Alexandria at the bidding 
 of Cyril (415), and in Rome at the bidding of Gregory I. 
 
PROGRESS AMONG THE ARABS. 33 
 
 (59 604), and will be again in Mexico and Peru, will 
 sweep away wealth, industry, commerce, culture, schools, 
 palaces all that recalled the hated Saracen, and replace all 
 this by the DEADLY INQUISITION. But the hated Saracen 
 will have left his mark. For, happily, Europe, that part of 
 it at least which was not wholly under the baneful sway of 
 the monks and the popes, Europe we say has inherited 
 much from him, and it has enlarged that heritage for the 
 benefit of the whole of mankind. 
 
 We may now pro:eed to give a summary of the Arabian 
 achievements in the field of science, beginning it with the 
 mathematical and astronomical branches. 
 
 IXth c. Ben Musa, a famous teacher, and the earliest 
 author on ALGEBRA, substituted sines for chords thus 
 furthering the science of trigonometry and found the com- 
 mon method of solving quadratic equations. He brought 
 into use the INDIAN NUMERALS, i, 2, 3, 4, 5, etc. Algebra 
 is known to have originated in India. It had been used as 
 early as the Vth century A.D. by the Greek Diophantus of 
 Alexandria ; but the Arabs perfected it and brought it to us. 
 
 805 885. Albumazar drew up astronomical TABLES 
 calculated from his own observations of the stars. 
 
 813834. Al Mamun (in 830) directed two observations 
 on the obliquity of the ecliptic (to measure it afresh) to be 
 made by the astronomers and mathematicians around him 
 (the result being 23 35' 52") ; he also ordered the accurate 
 .measurement of the magnitude of the earth's circumference 
 by the measuring of a DEGREE (found to be 56! miles) ; 
 caused the works of Aristotle, Euclid, Ptolemy, and Hippo- 
 crates to be translated into Arabic. 
 
 823. Alfergani excelled in astronomical CALCULATIONS 
 based upon his direct observations. His works on astronomy 
 were translated, and studied in Europe for a long period. 
 
 850 900. Geber Al Batani (Albategnius) discovered 
 the motion of the sun's apogee showing Ptolemy's error 
 (of 17) ; calculated the length of the year more accurately 
 than Ptolemy, making it 365 days 5 hours 46 min. 24 sec. 
 within two minutes of the exact time. He corrected other 
 errors in the observations of Ptolemy ; established tables of 
 
34 PROGRESS OF SCIENCE. 
 
 the motions of the sun, moon, and planets, held in high 
 repute for centuries ; measured the obliquity of the ecliptic 
 in 879 the result being 23 35' o". 
 
 875. Thebit Ben Corrah found out the exact length of 
 the YEAR: 365 days 5 hours 48 min. n sec. As an 
 anatomist he described the ANATOMY OF BIRDS. 
 
 975. Aboul Wefa observed at Bagdad the third IN- 
 EQUALITY OF THE MOON (viz., the variation], by virtue of 
 which our satellite moves quickest when she is at new and 
 full ; but he failed to fix the law. This inequality was re- 
 discovered by Tycho Brahe. He also measured the obliquity 
 of the ecliptic in 987 (the result being 23 35' o"). 
 
 995. Aboul Rihau measured the obliquity of the ecliptic 
 with a QUADRANT of 25 feet radius in 995 (the result 
 2335'o"). 
 
 1008. Ebn Junis applied mathematics, using algebra 
 and the Arabic numerals in his calculations, in the solution 
 of physical and astronomical problems ; drew up the 
 HAKEMITE TABLES ; achieved the most valuable of chrono- 
 metric improvements by applying the PENDULUM to the 
 measure of time. The value of his work is proved by the 
 fact of Laplace making use of his astronomical observations 
 as an evidence of the diminution of the eccentricity of the 
 earth's orbit. 
 
 1080. Arzachael measured the OBLIQUITY OF THE 
 ECLIPTIC (the result being 23 34' o"). 
 
 Aboul Hassan used tubes for astronomical observations 
 to which ocular and object diopters were fixed and which 
 were a near approach to the invention of THE TELESCOPE. 
 
 Sufi (Abderrahman) improved the PHOTOMETRY of the 
 stars a feat which we should have expected to be reserved 
 only for modern science to accomplish. 
 
 1198. Geber of Seville constructed the OBSERVATORY of 
 that city the earliest in Europe and the most complete on 
 record. It was turned into a belfry after the expulsion of 
 the Moors, " the Spaniards not knowing what to do with it." 
 1259. Tasi (Nessar Eddin) drew up the ILKANIC TABLES 
 at the observatory of Meragha (near Tauris). 
 
 I 394 1449- Ulugh Begh (Prince) by means of a 
 
PROGRESS AMONG THE ARABS. 35 
 
 gnomon 180 feet high, determined the obliquity of the 
 ecliptic to be 23 30' 20" (?) ; the precession of the equinoxes 
 at 1 in seventy years (which gives 25,200 YEARS for the 
 entire cycle a marvellous approximation) ; drew up tables 
 scarcely inferior in accuracy to those of Tycho Brahe. 
 
 The preceding table enables us to see by how much the 
 Arabs extended Greek astronomy and mathematics. Their 
 originality and genius, however, are far more striking in 
 physics. The discoveries made by Alhazen alone, if made 
 amongst us at the present day, would make a profound 
 impression, and would be considered astounding additions to 
 modern science. It is difficult to understand how this great 
 man arrived at such results ; he was the scientific man par 
 excellence of the Arabian race, just as Hipparchus was 
 of the Greek, Galileo of the Italian, and Newton of the 
 English. 
 
 noo. Alhazen was at once a geometrician, a PHYSICIST, 
 and a physiologist. He was best known in Europe by his 
 Optics his works having been put into Latin comparatively 
 early. 
 
 a. By anatomical and geometrical investigations he 
 corrected the Greek mistake regarding the nature of vision, 
 showing that light-rays come from objects to the eye, and do 
 not issue forth from the organ ; 
 
 b. Determined the function of the retina, showing that 
 the impressions upon it are conveyed to the brain through 
 the optic nerve a discovery which implies dissection ; 
 
 c. Explained SINGLE VISION, by the fact that im- 
 pressions are made on symmetrical portions of the two 
 retinas. 
 
 d. He discovered REFRACTION, and showed the untrust- 
 worthiness of our sense of sight, and rightly ascribed illusion 
 to refraction and reflection a discovery of high order, by 
 which he was able to explain numerous phenomena, and 
 which ranks him among the greatest physicists of all times 
 and countries ; 
 
 e. Discovered that the DENSITY OF THE ATMOSPHERE 
 decreases with increase of height ; 
 
 /. Explained the curvilinear course of a ray of light 
 
 D 2 
 
36 PROGRESS OF SCIENCE. 
 
 through the air, and thereby discovered ATMOSPHERICAL 
 REFRACTION ; 
 
 g. Hence he explained the delusive appearance of the 
 sun, moon, stars before they have risen and after they have 
 set; 
 
 h. He justly ascribed increase of refraction to increase of 
 density ; 
 
 /'. He explained the phenomenon of TWILIGHT the effect 
 of which is to shorten the night ; 
 
 j. Was also the first to explain why a CONVEX LENS 
 will magnify objects if it be held at a proper distance 
 between them and the eye another effect of refraction, due 
 to the converging of light-rays. This was the first step 
 towards spectacles. 
 
 k. Determined the HEIGHT of the atmosphere 58 J miles 
 and its weight according to density the very discovery of 
 Torricelli five centuries later. Liais, in 1859, estimated the 
 height of the atmosphere to be 212 miles but beyond 50 
 miles it is so attenuated that it does not affect the duration 
 of twilight. 
 
 /.In hydrostatics, Alhazen discovered also that a body 
 will weigh differently in a dense or in a rare medium (air), 
 and that a body will LOSE WEIGHT in proportion as air 
 is denser. He therefore found that Archimedes's principle 
 holds good in air as well as in liquids. 
 
 m. Likewise, he explained the submergence of floating 
 bodies, as ships on the sea. 
 
 n. He understood the theory of the CENTRE OF GRAVITY 
 and the centre of suspension, and applied it to the investiga- 
 tion of balances and steelyards, showing the relations between 
 the centre of gravity and that of suspension ; 
 
 o. Recognised gravity as a force but a terrestrial force, 
 and asserted that it decreases with " the distance " a Newton 
 was required to demonstrate that it is a universal force, 
 and that its decrease is not as the distance but as its 
 square. 
 
 /. Discovered the relations between the VELOCITIES, 
 spaces, and times of falling bodies thus anticipating Galileo. 
 q. Discovered CAPILLARY ATTRACTION ; 
 
PROGRESS AMONG THE ARABS. 37 
 
 r. Improved the hydrometer, for determining the specific 
 gravities of liquids. 
 
 s. Drew up tables of SPECIFIC GRAVITIES (after Abur 
 Raihan, who was the first to construct them), and they 
 approach very closely to our own. In the case of mercury 
 he was more exact than we were last century. 
 
 t. In physiology, he upheld the doctrine of the PRO- 
 GRESSIVE DEVELOPMENT of animal forms thus anticipating 
 Diderot, Lamarck, and Darwin. 
 
 It is hardly necessary to point out that the great discovery 
 of ATMOSPHERIC REFRACTION increased the accuracy of 
 astronomical observations. 
 
 The Arabs originated scientific CHEMISTRY it was an 
 outgrowth of the medical science at first. The discovery of 
 strong acids laid its foundations. They had already defined 
 alchemy as the science of the balance, the science of the 
 weight, the science of combustion a definition wonderfully 
 accurate. 
 
 800. Giaber (also called Geber and Yeber), THE FOUNDER 
 OF CHEMISTRY, discovered nitric acid (aqua fortis, JE), 
 sulphuric acid, nitrate of silver, auric chloride (aqua regia, /R), 
 mercuric chloride (corrosive sublimate), mercuric oxide (red 
 oxide of mercury). His discovery of STRONG ACIDS was a 
 revolution, for most of our chemical experiments would be 
 impossible without them, and before Giaber no stronger acid 
 was known than concentrated vinegar. He set forth the 
 corrosive power of nitric acid, and how it dissolves gold 
 itself by adding a portion of sal-ammoniac thus solving 
 the problem of obtaining gold in a potable form. Giaber 
 proved that OXIDATION, or burning, INCREASES THE WEIGHT 
 OF METALS a fact over which Lavoisier will ponder nine 
 hundred years later, and by which he will be led (i.) to suspect 
 the phlogistic theory of combustion to be wrong, and (II.) to 
 establish the consistent theory of combustion the basis of 
 chemical progress in modern times. Giaber knew the nature 
 of ALCOHOL and GASES, and was thereby the Priestley or 
 Lavoisier of his time. He described the operations of 
 DISTILLATION, FILTRATION, SUBLIMATION (obtained mer- 
 cury by sublimation from cinnabar) ; he described also 
 
38 PROGRESS OF SCIENCE. 
 
 various CHEMICAL APPARATUS ; water-baths, sand-baths, 
 cupel of bone-earth, for the use of which he gives par- 
 ticularly precise directions ; many of the methods which 
 he prescribed are still used in our laboratories. 
 
 860 920. Rhazes, " the Observer/' discovered also 
 SULPHURIC ACID ; the preparation of pure alcohol by dis- 
 tilling spirit of wine with quick-lime. Improved the ART 
 OF DISTILLATION. 
 
 Xlth (?). Alchid Bechir, a famous manipulator of 
 chemicals, discovered Phosphorus (Hoefer). 
 
 VHIth to Xlth c, Marcus Graecus, in his " Liber Ignium," 
 described GUNPOWDER, the rocket, and the cracker in a very 
 precise manner. He also gave the prescription for making 
 the skin incombustible, so that we can handle fire without 
 being burnt hence the so-called miracle (in our Middle 
 Ages) of sitting on flaming straw. 
 
 Xlth (?). Kalid was one of the famous physicians often 
 mentioned, who brought about improvements in CHEMICAL 
 MANIPULATION. 
 
 In medical science, surgery, and pharmaceutics, the 
 Arabs made important additions to the knowledge left by 
 the Greeks. Medical men called to the assistance of the art 
 of healing both chemistry and botany. They brought in the 
 use of mild purgatives instead of violent drastics, of mild, 
 instead of violent remedies extracting them mainly from 
 plants. Only the most celebrated physicians need be 
 mentioned. 
 
 800. Masue, Al Mamun's physician, studied comparative 
 ANATOMY. His " Pharmacopoeia " was the guide of Europe 
 for ages. 
 
 9801037. Avicenna, "THE PRINCE OF PHYSICIANS," 
 found new medical remedies. The list of his many achieve- 
 ments is too long for enumeration here. He anticipated 
 Paracelsus in many respects, or more correctly, Paracelsus 
 took many hints from him. Avicenna's " Canon " (of 
 Medicine) in five books is a splendid work treating of 
 Physiology, Pathology, and Hygiene (Books L, II.) ; of 
 disease (III., IV.) ; of the composition and preparation of 
 remedies (V.). It was the one great work of authority for 
 
PROGRESS AMONG THE ARABS. 39 
 
 six centuries. He described small-pox, unknown to the 
 Greeks ; was the first to use coloured drawings to instruct 
 students. He is the author of an Encyclopaedia which 
 shows the vastness of his acquirements. He explained the 
 GEOLOGICAL FORMATION of mountain-ranges in a very lucid 
 manner; he likewise guessed the correct origin of fossils 
 a double feat which implies practical and personal observa- 
 tion of nature, thus anticipating the theories of uprisings, 
 alluvion, and erosion. " FOSSILS/' he says, "prove that the 
 rocks were deposited by water." He explained the nature 
 of petrifying waters ; mentioned meteorites, and made several 
 discoveries about minerals. He also contributed to the 
 knowledge of the plants of Bactria and Sogdiana, so fertile 
 in medical plants. He is, besides, the first philosopher who 
 started FREE INQUIRY, and thus inaugurated the age of 
 Reason. This philosophy was developed by Algazzali and 
 Averroes. 
 
 1106. Albucasis, a far-famed surgeon of Cordova, in- 
 vented and made use of excellent INSTRUMENTS, and did 
 not shrink from the performance of the most formidable 
 operations. Before him, the Arabs had already the lancet 
 (improved), the couching-needle, the probang, etc. He de- 
 scribed with great precision and detail complicated distilling 
 apparatus and their use. 
 
 1126 1198. Averroes, one of the most famous men in 
 the world, was also a physician of great renown, although in 
 this capacity he must yield the palm to Avicenna ; but his 
 medical work " Colliget" had great weight too. Outside his 
 professional sphere he discovered the SUN-SPOTS, and ascribed 
 a cause to them just as probable as that which Sir W. 
 Herschel explained a century ago. It is, however, by his 
 COMMENTARIES on Aristotle that he deserved the high 
 reputation in which he was held for centuries. It was by 
 this work that his influence on Europe was felt most this 
 influence being at once profound and decisive. These two 
 great men, Avicenna and Averroes, were conversant with 
 every branch of knowledge, and by their correctness of 
 thought and breadth of view, they gave immense impetus 
 to the learning of the Middle Ages. Their intellectual 
 
40 PROGRESS OF SCIENCE. 
 
 supremacy in Europe, undisputed until the XVIth century, 
 cannot be exaggerated, ranging as it did from matter of fact 
 to free thought. 
 
 1170 1262. Ebn Zoar (Avenzoar) enriched PHAR- 
 MACEUTICS by numerous additions. Discovered the acarus 
 of the ITCH, and the treatment of the disease (a discovery, 
 we might say, which should have saved the future Dukes 
 of Argyll the benevolent lavishness of timber for which they 
 have been proverbially blessed by grateful sufferers). 
 
 In connection with these branches, the services done to 
 science by the Jews and their schools in the East, in Spain, 
 France, and Italy, should not be forgotten, all of them fruits 
 of Arabian learning. Some of the most famous men were : 
 
 Xlth c. Rashi (Isaac Ben Soleiman), a physician who 
 swayed a deserved authority for a long period, made valuable 
 observations on pulse, fever, melancholia, and originated a 
 new system of DIETETICS AND REMEDIES. 
 
 Xlth c. Ebn Zohr (of Seville) wrote his treatises in 
 Arabic, Hebrew, Syriac a proof of his fame both in prose 
 and poetry : one was on the CURE OF DISEASES ; two on 
 fevers. He possessed a correct view of the morbific nature 
 of marsh miasm. 
 
 Xlth c. Ben Ezra (of Toledo), who was at once a poet, 
 critic, astronomer, mathematician, philosopher, and physician, 
 and had travelled in Asia (including India) and Europe, 
 wrote a famous work (Book of Proofs] on theoretical and 
 PRACTICAL MEDICINE, very extensively studied. 
 
 The universities of Salerno, Montpellier, Narbonne, 
 Tarentum, Bari, were either founded or directed by Arabian 
 Jews. Nor should we forget to mention 
 
 Xllth (?). Abba Mari (of Marseilles), who translated THE 
 ALMAGEST of Ptolemy, and Averroes's Commentaries of 
 Aristotle ; the latter was the first strong beam of light shot 
 across the whole of Europe. 
 
 But we must refer the reader to Draper's Intellectual 
 Development for further information. The number of Arabian 
 and Jewish physicians is legion we mean real medical men 
 and surgeons, and not empirical practitioners. 
 
 The Arabs showed their taste and aptitude for practical 
 
PROGRESS AMONG THE ARABS. 41 
 
 science in every direction. They undertook remote travels 
 and explorations with the view to enrich and diffuse the 
 knowledge of geography, botany, natural history, mineralogy. 
 For instance : 
 
 720. Assamsh, as early as 720, created scientific TOPO- 
 GRAPHY and statistics. 
 
 1130. Artefius, in his "Key to Wisdom," defined the 
 nature of MINERALS, plants, and animals with as much 
 lucidity and terseness as Linnaeus. " Minerals," he says, 
 " derive from the elements, plants from the minerals, animals 
 from plants." He described the preparation of soap. 
 
 116231. Abdallatif, the favourite of Saladin, described 
 the ANIMALS AND PLANTS OF EGYPT with an accuracy 
 unknown before him. The hippopotamus is described by 
 him better than by Hercdotus, Aristotle, and Pliny. He 
 rectified Galenus as to the human osteology. Had the Nile 
 mud dug to discover the antiquity of Egyptian civilisation 
 to a depth of 43 feet, counting 13,500 yearly mud layers, and 
 finding pottery at that depth. 
 
 Xllth (?). Abn Othman added new facts to the know- 
 ledge of ZOOLOGY, too numerous to describe in detail. 
 
 1248. Al Beithar did the same for BOTANY. After ex- 
 tensive travels, he composed a General History of Plants 
 alphabetically planned, in which he speaks of many species 
 unknown before, and also of their medical properties. 
 
 950. Al Farabi had nearly three hundred years before de- 
 tected the RESPIRATION OF PLANTS, in the leaves and bark. 
 
 Xllth (?). Alberuni extended the knowledge of mine- 
 ralogy, and of PRECIOUS STONES especially. 
 
 1130. Al Idrisi increased the knowledge of geography; 
 he made a silver GLOBE for King Roger II. of Sicily. 
 
 1283. Karwiny's "Wonders of Nature' 3 embraces as- 
 tronomy, geography, natural history ; treats of meteors and 
 other atmospheric phenomena. He ascribed EARTHQUAKES- 
 to vapours which act in the interior of the earth as in a vast 
 laboratory ; described two kinds of elementary vapours : 
 
 I. those above the earth which form clouds, rain, snow; 
 
 II. those under the earth which cause earthquakes. He also 
 speaks of the displacement of the sea. " A place," he says. 
 
42 PROGRESS OF SCIENCE. 
 
 "has been a town,'a plain, a sea, and land again." No wonder 
 he enjoyed a European reputation for hundreds of years. 
 
 Even philosophy had, as we have seen in the case of 
 Avicenna and Averroes, abandoned the metaphysical sphere, 
 and become as positive as it well could be before the 
 XlXth century. In this respect, 
 
 1058 mi. Algazzali is an exceedingly remarkable 
 instance of genius. He composed a work "On the CERTAINTY 
 OF KNOWLEDGE and Science," in which the deceptiveness of 
 the senses and of reason is argued with rare lucidity and 
 soundness a theory six centuries in advance of his time. 
 
 The practical spirit of the Arabs and their passion for 
 natural and experimental philosophy are further exemplified, 
 beyond chronometry, irrigation, agriculture, ceramics, metal- 
 lurgy, and the industrial arts already noticed, by their 
 application of hydraulics in the construction of waterworks, 
 reservoirs, canals, sluices, wells, in Spain, Africa, Egypt, 
 Syria, and Mesopotamia; by their invention and intro- 
 duction into Europe of the Semaphoric Telegraph ; their 
 study of numismatics and chronology. They invented several 
 kinds of 
 
 Clepsydras, particularly a balance clepsydra a new 
 principle altogether. They invented 
 
 Pendulum Clocks ; they improved the 
 
 Astrolabe ; they introduced the 
 
 Compass ; 
 
 Paper ; 
 
 Gunpowder and Artillery. These three things, the com- 
 pass, paper, and gunpowder, were mighty agents of progress, 
 and brought in innumerable results in the world, in Europe 
 especially: they assisted the evolution of society in every 
 direction. Gunpowder revolutionised the social system by 
 the destruction of the all-powerful feudalism ; the compass 
 revolutionised geography, commerce, theology ; paper spread 
 ideas, and assisted in the transformation of religious and 
 scientific views. The Arabs invented the 
 
 Aerometer; the addition of the 
 
 Cypher to the nine earlier INDIAN NUMERALS was a 
 stroke of genius entirely due to them. There is no doubt 
 
PROGRESS AMONG THE ARABS. 43 
 
 that we owe them these numerals, although they originated 
 in India. From Spain they quickly passed, together with 
 algebra, into Italy, where their advantage was at once re- 
 cognised in commercial computations. 
 
 The Arabs, to speak of another order of facts, cultivated 
 eloquence, taught grammar, rhetoric, and music. Their 
 immense poetical literature, to which celebrated poetesses 
 added a lovely portion, bears witness to the wealth of their 
 luxuriant imagination, just as their science shows the richness 
 of their intellectual faculties. To them we are indebted for the 
 introduction of song into Provence ; also for Rhyme, which 
 has enriched the poetry written in our modern languages. 
 
 The words nadir, zenith, algebra, cypher, carat, alchemy, 
 alembic, alkali, alcohol, syrup, julep, elixir together with the 
 words admiral, cotton, chemise, morocco, cordovan, which we 
 have adopted, throw a light upon the contribution of the 
 Arabs to progress in various paths. 
 
 All that could shorten or foster research was either in- 
 vented or instituted by them : 
 
 Libraries, 
 
 Observatories, 
 
 Laboratories, 
 
 Menageries and Aviaries of rare animals and birds, 
 
 Surgical Instruments, 
 
 Globes, and 
 
 Dictionaries. 
 
 They originated dictionaries, those most serviceable of all 
 books ; they had every kind biographical, historical, scien- 
 tific, written in Arabic, Hebrew, Greek, Latin some of them 
 in sixty volumes besides lexicons for the tuition of these 
 languages. They even had dictionaries of celebrated horses 
 and camels. 
 
 Their PUBLIC LIBRARIES were numerous, extensive, and 
 rich. There were as many as seventy in Spain alone. 
 Khalif Alhakem's private one was so large that its catalogue 
 filled forty volumes. It had no less than 600,000 works. 
 The Cairo library had 100,000 volumes. The Tripoli 
 library (burnt by the Crusaders!) also 100,000. Such 
 value was attached to books, and so earnest the love of 
 
44 PROGRESS OF SCIENCE. 
 
 learning, that after a successful war it was not rare to insert 
 stipulations in the treaty of peace for the cession of manu- 
 scripts originals or copies sometimes to the amount of 
 four hundred camel loads ! 
 
 To sum up, then, the Arabs extended 
 
 Geography, Arithmetic, 
 
 Botany, Algebra, 
 
 Pharmaceutics, Astronomy, 
 
 Surgery, Physics, 
 
 Medicine, Chemistry. 
 
 They improved upon mathematical and astronomical 
 knowledge ; gave us algebra (solving even cubic equations), 
 extended trigonometry, and thus met the needs of celestial 
 geometry. But they left their mark for all times equally in 
 Medicine, Physics, and Chemistry. 
 
 To Spain all those who had a taste for learning repaired, 
 from all parts of Europe : from Italy, from France, England, 
 Germany, and even Scandinavia. All the great men who 
 shone in Europe in the Middle Ages had acquired their 
 knowledge among or from the Arabs, and foremost among 
 them, between 1000 and 1350: 
 Stiorn Oddes, Roger Bacon, 
 
 Gerbert (Sylvester II.), Vincent de Beauvais, 
 
 Frederick II. of Germany, Duns Scotus, 
 Gaston Phcebus, Comte de Arnauld de Villeneuve, 
 
 Foix, Bonaventura, 
 
 Abelard, Albert of Saxony, 
 
 Albertus Magnus, Ramon Lulle, 
 
 all of whom were nurtured in Arabian learning and inoculated 
 by the' Arabs with the spirit of science, and with the habit of 
 thinking and reasoning. And if these early teachers, Albertus 
 Magnus and Roger Bacon, listened to the voice of experience, 
 silent for so many ages in Europe, and founded the EXPERI- 
 MENTAL SCHOOL amongst us, they were wholly indebted for 
 it to their Arabian teachers. 
 
 We may now contrast Islam with Christendom in a few 
 points which the preceding survey has not sufficiently 
 established : 
 
PROGRESS AMONG THE ARABS. 45 
 
 I. A comparison between the CREED of the Arabs 
 and that of Europe cannot be drawn here for many 
 reasons, but we may at least point out that with all its 
 inferiority, Mohammedanism has been the only creed, 
 with Protestantism, which has been wholly EXEMPT 
 
 FROM IDOLATRY ; 
 
 Whereas the Greek and Roman Christianity has been 
 polluted by Mariolatry, the WORSHfp OF SAINTS 
 and relics : certainly was this the case during the 
 Middle Ages. 
 
 II. The political system of Islam admitted and 
 practised a liberal religious TOLERATION. Provided the 
 subject races paid a trifling tribute to the Khalifs and 
 Emirs, they were allowed to live unmolested in the 
 worship of their fathers ; 
 
 Whereas INTOLERANCE of other creeds was one of 
 the principles of government throughout Christendom, 
 and that principle was enforced by extermination. 
 
 III. The Saracens and Jews originated the doctrine 
 of the SUPREMACY OF REASON over authority, and 
 this doctrine overthrew among them Supernaturalism 
 and its logic ; 
 
 Whereas AUTHORITY stifled reason and its supporters 
 until Luther in the North, and until the XVIIIth 
 century in the South of Europe. It was this difference 
 between the two systems which brought the Arabs' 
 influence into conflict with Christian Europe, and led 
 to the Xlllth century Crusade in South France. 
 
 IV. Luxury, the daughter of INDUSTRY and its 
 wealth, and the sign of a high civilisation, existed 
 throughout Islam. Its effects benefited all. Even- 
 small people, to speak of a significant detail only, 
 wore linen or cotton chemises, gay-coloured garments 
 of silk. Cleanliness was commanded by religion and 
 custom ; 
 
 Whereas industry and luxury were absent from one 
 end of Christian Europe to the other until after the 
 Crusades, and the GENERAL POVERTY was such that 
 people wore their skin-garments until they fell to 
 
46 PROGRESS OF SCIENCE. 
 
 pieces through dirt, vermin, and wear want of sani- 
 tation bringing in frequent plagues. 
 
 V. The people of Islam were lifting themselves up 
 by the unchecked cultivation of SCIENCE ; 
 
 Whereas Europe, then on a par with what Russia 
 was until Peter I., or what Abyssinia is now, was 
 withering in the science of MONK MIRACLES and 
 monkish philosophy. 
 
 VI. Particularly striking are the high acquirements 
 of the Saracens and Jews. They applied mathematics 
 to ASTRONOMY AND PHYSICS ; measured the obliquity 
 of the ecliptic, the length of a degree, the earth's radius 
 and circumference, corrected astronomical tables by 
 systematic observations, left Arabian names indelibly 
 written on the firmament, taught geography by the 
 use of globes, measured time by pendulum oscillations ; 
 
 Whereas the FLATNESS OF THE EARTH, the denial of 
 the antipodes, the solidity of the firmament, were 
 asserted in Europe, and those who doubted were dealt 
 with as heretics. 
 
 VII. DISEASES in Saracenic lands were considered 
 and treated as NATURAL EFFECTS of physical causes. 
 The patient sought the assistance of the physician and 
 the surgeon, who prescribed medicine or performed an 
 operation ; 
 
 Whereas Christian Europe was taught to consider 
 disease as a SUPERNATURAL VISITATION, which was 
 to be cured by miracle, exorcism, pilgrimage to the 
 nearest shrine, and trust to the efficacy, not of the 
 lancet of the leech or the bandage of the surgeon, 
 but of relics, charms, amulets, talismans, all more or 
 less in the keeping of the ecclesiastics who made their 
 administration a source of boundless profit, as they 
 did with the sale of indulgences later on. So in- 
 grained was the belief in supernaturalism that a 
 man like Francis Bacon believed in talismans and 
 witchery. 
 
 VIII. Men of intellect and LEARNING were honoured 
 throughout Islam ; 
 
PROGRESS AMONG THE ARABS. 47 
 
 Whereas they were accused of witchcraft in Europe 
 
 and PERSECUTED accordingly. 
 
 This comparison between Islam and Christendom presents 
 as striking a contrast as any that can be offered in the whole 
 of the historical period. It is, however, only bare justice 
 to state, that although it is absolutely true in the main, yet 
 Christendom during the mediaeval epoch was not wholly 
 wrapped in intellectual night. For Christianity, as a creed, 
 besides restraining violence to a considerable extent for 
 hundreds of years, was slowly elevating the European com- 
 munity, and preparing it for that evolution of new morals* 
 and new idealsf which must of necessity conduce to en- 
 lightenment. The Church, as an organised body, by pro- 
 tecting, as it did, the weak from the strong ; the Clergy, as 
 a teaching association, by keeping up the tradition of ancient 
 culture and a taste for letters in a certain measure even in 
 the Vlth and Vllth centuries, did an immense amount of 
 good work in the same direction. Furthermore, streaks of 
 light, harbingers of the dawn, were casting a more or less 
 visible glow all through the period, except perhaps two 
 centuries, and were bringing in a lasting and hopeful twilight. 
 Remarkable minds, from the midst of general barbarism and 
 want of knowledge, shed a sort of lustre over each century 
 after the seventh. In the lay world we find a CHARLEMAGNE 
 (742 814), and an ALFRED (849 901), who promote pro- 
 gress, and whose efforts are seconded by Paul Diaconus 
 (d. 796), Theodulf of Spain, Clement of Ireland, Peter of 
 Pisa, and still more by ALCUIN (d. 804), ANGILBERT (d. 814), 
 EGINHARD (d. 844), ERIGENAJ (d. 875), with a certain 
 degree of success. In the Church, also, notable intellects 
 appeared. Gregory I. (590604), Gregory II. (71631), 
 Gregory III. (73146), Leo III. (795816), Hincmar (806 
 882),GERBERT (9501003), Richer of St. Remi (fl. 9601000), 
 
 * Philippe Augustus was compelled to take back his wife Ingeburge 
 (1213) whom he had repudiated. 
 
 t In 1226 there were 200 hospitals and 2,000 leper-houses in France 
 
 alone. 
 
 J The only man who knew Greek in the whole West. Alter him, for 
 five centuries, that language was totally unknown. 
 
48 PROGRESS OF SCIENCE. 
 
 Abbon of St. Germain (fl. 9901010), HlLDEBRAND (1013 
 1085), Lanfranc (100589), Berenger (105088), Roscelin 
 (030 89), St. Anselm (10341109),* all of whom were, 
 and remain, imposing or interesting historical figures, con- 
 tributed somewhat, in one way or another, to the spread of 
 light. True it is that the multitude remained steeped in 
 profound ignorance, but so, relatively, it does to this day. 
 But as it is the degree of intellect in conspicuous men which 
 serves as a standard to gauge the stage of advance and 
 improvement of any time, we may be sure that a certain 
 momentum was given to progress by the great men just 
 mentioned. After them, and from St. Bernard (1090 1153), 
 the twilight broadens by degrees into daylight, (i.) by the 
 concurrence of momentous events,t fatal to millions it is true, 
 but auspicious of good for the immediate future; and (II.) by 
 the rapid appearance of numerous geniuses, as we shall 
 be able to see in the following chapter. 
 
 With this qualification to the contrast we have drawn, 
 the above sketch is the shortest account which can be given 
 of the Eastern contribution to the progress of mankind. 
 Most truly was Islam in the VAN OF CIVILISATION FOR 
 FIVE OR SIX CENTURIES, and we insist on this fact because 
 we moderns, in the legitimate pride we feel for our own 
 achievements, are prone to forget what is foreign to, and 
 remote from, us. The foregoing description will remind the 
 reader of what is due to the Arabs, and it is needless to say 
 that it leaves aside an immense amount of secondary work. 
 We clearly see that they were the connecting link between 
 the Greeks and ourselves, and that the assertion of a stand- 
 still for ages was as mistaken as it could possibly be. 
 
 Modern scientists, no doubt, have pointed out many 
 flaws in the science of the Arabs, as they have indeed in 
 that of the Greeks ; the vast extension of the field of know- 
 ledge among us, our numerous and admirable means of 
 verification have made it easy for us to detect inaccuracies 
 of facts and occasional errors in the conclusions drawn by 
 
 * John of Beverley (d. 722) and Bede (d. 735) might be added to those 
 names. 
 
 f See Chapter VI. 
 
PROGRESS AMONG THE ARABS. 49 
 
 the precursors of modern science ; but the bulk of their 
 original work nevertheless remains an inheritance which the 
 most captious critics find it impossible either to ignore or 
 despise. Even erroneous theories were steps towards 
 scientific truth, generating as they did a verification which 
 involved additional researches and acquisitions. Our own 
 modern science was often hasty in its conclusions too, as the 
 history of astronomy or of geology shows ; but although the 
 Plutonian and Neptunian hypotheses are untenable to-day, 
 yet Hutton and Werner will always be considered scientific 
 men, because, of their theories, part at least has proved true. 
 This applies to the Arabs, and no less to the Arabs than 
 to the Greeks and ourselves. 
 
CHAPTER V. 
 
 PROGRESS IN THE MIDDLE AGES AND DURING THE 
 REVIVAL. 
 
 CONTINUING our sketch we now arrive at the Medieval and 
 Revival periods in Europe the third and fourth eras of 
 scientific advancement during which science wholly passed 
 from the Saracenic to the European World. The gradual 
 advance during this period is far more astonishing than even 
 the brilliant achievements of the Arabs, considering the 
 formidable and terrifying obstacles which stood in the way. 
 The Saracen pursued his studies in the face of heaven and 
 in full freedom. Science was to him no forbidden fruit, and 
 if he made a discovery he was held in high honour for it 
 throughout Islam. Our mediaeval lover of science, on the 
 contrary, was obliged to pursue his researches underground, 
 so to speak, and hide his discoveries from all eyes. He was 
 for ever haunted by the maddening vision of the stake. 
 That science was cultivated at all under such circumstances, 
 in solitude, practically without books, without teachers, was 
 a proof of energy of intellect and will deserving all our 
 sympathy and admiration; but that science thus pursued 
 should have extended its roots and branches, and yielded 
 fresh fruit, is a fact which should make us revere our mediaeval 
 teachers as ideal heroes of the most exalted order, for they 
 were staking their lives every day, not as proud knights 
 seeking to win a holy relic or a lady's love with lance on 
 their hip and crest on their helm, but as devoted and 
 defenceless heralds facing the wakeful hydra armed with 
 
THE MIDDLE AGES AND DURING THE REVIVAL. 51 
 
 claws and flames, to deliver their fellow-men from unspeak- 
 able evils. Bearing this in our minds, the progress of the 
 later Middle Ages and the Revival has been absolutely 
 marvellous. 
 
 Those times witnessed : 
 
 I. most VALUABLE INVENTIONS ; 
 
 II. the appearance of some of the most important AGENTS 
 OF PROGRESS humanity can boast of ; 
 
 III. the discovery of scientific LAWS of the highest order. 
 Here again we have to be satisfied with brief records. 
 
 During this era there came into existence : 
 
 IXth c.* Watermills. The Romans were in possession of 
 them in an imperfect form as early as 500 A.D. 
 
 IXth c. The Organ, an orchestra in itself, the sublime 
 instrument par excellence. It gradually grew out of a hand 
 and bellows pipe known among the Romans. Nero had an 
 organ worked by water. 
 
 IXth to XlVth c. Clocks were improved in diverse ways, 
 -especially after Henry de Wyck (1364). Needless to speak 
 of the Hour-Glass, of which there was a variety. 
 
 Xth to Xllth. Music the creation of a new language 
 (musical notation and harmony) of which Hucbald (d. 930), 
 Guido d'Arezzo (1024), and Franco (1050-1083) were the 
 chief pioneers a gradual progress in the " use of the 
 phenomena of sound " until the XVIth century, accompanied 
 by the invention of various instruments (harpsichords and 
 clavichords). Bishop Ambrosius of Milan (340 397) and 
 Pope Gregory I. (544604) were associated with the earlier 
 .advance of Music. About 1400-20 DUNSTABLE invented 
 polyphony. 
 
 Xlth, Xllth. Windmills, whether invented in Europe or 
 introduced from the East during the Crusades, spread rapidly 
 during the Xllth century. 
 
 1115 1302. The Compass, which effected a fourfold 
 revolution revolution in theology, astronomy, geography, 
 commerce. The CHINESE (see Klaproth) were possessed of 
 it. They used it on land in the absence of roads as early as 
 the Xllth century before our era. From the Vllth to the 
 * All these dates are approximate only. 
 
 2 
 
52 PROGRESS OF SCIENCE. 
 
 IXth century (A.D.) the Chinese navigated as far as Ceylon 
 and the Persian Gulf with its assistance ; it was thus intro- 
 duced into India, whence the Arabs probably brought it to 
 us ; but it was amongst us that it was improved and ex- 
 tensively used in navigation. It certainly was due to neither 
 Marco Paolo (1256 1323) nor Gioja d'Amalfi (1302) a 
 myth that stands on the same footing as the tradition 
 regarding gunpowder. Mention of the compass is to be 
 found in books written long before Gioja's birth viz., La 
 Bible, written by Guyot de Provins in 1190 ; in " Treatise on 
 Things pertaining to Ships," by Alexander Neckam, of St. 
 Albans, born in 1157; and in James de Vitry's Chronicle,, 
 written in 1220. It was then called the sail-stone. Gioja r 
 who was a navigator, probably improved what was used in 
 his time. He is said to have made a rude compass by means 
 of a round cardboard with a magnetised needle fixed on it,, 
 which he laid on the surface of a basin full of water. The 
 card thus rendered sensitive to magnetic action would easily 
 revolve under its influence and point to the north. But the 
 compass was used in a different way long before Gioja's time. 
 
 Xlllth c. Paper, one of the greatest elements of civilisa- 
 tion. Paper seems to have originated in China, and to 
 have been brought to us by the Arabs. These lay a claim 
 to the invention. It was made of rags in Europe during the 
 Xlllth century. 
 
 Xlllth c. Gunpowder, the destroyer of Feudalism, the 
 instrument of freedom and political progress, and for blasting 
 purposes in engineering work one of our most useful agents. 
 It was doubtless invented in the East, just as the Greek fire 
 was ; the Arabs may justly lay a claim to its discovery their 
 chemical manipulation led them to it and they employed it 
 with cannon as early as iiiS*; but it was Europe which 
 perfected its fabrication, and made an extensive use of it in 
 war. We must reject as a myth the ascription of the invention 
 to the Swiss monk Schwartz, or Roger Bacon. These two 
 merely transcribed the description of gunpowder found in 
 
 * The Moors employed artillery against Saragossa in 1118, the 
 Spaniards used it against Cordova in 1280 and against Gibraltar in 1306, 
 the King of Granada at the Siege of Baza in 1325. 
 
THE MIDDLE AGES AND DURING THE REVIVAL. 53 
 
 older authors. Gunpowder was the result of gradual modifi- 
 cations of several explosive substances known from time 
 immemorial ; there was really no single inventor. 
 
 1 220. Algebra, which powerfully developed mathematics. 
 The Hindus, as we now know from Sanskrit writings, 
 originated it. It was introduced into Europe by the Arabs, 
 who extended it. But it was greatly improved by our 
 mediaeval mathematicians. 
 
 1300. Spectacles, which restored the sense of sight to 
 millions and millions, were invented in Italy, by either 
 Alessandra da Spina of Pisa, or Salvinus Armatus of 
 Florence. The Assyrians were already in possession of 
 the magnifying glass one (now in the British Museum) 
 having been found in Sennacherib's library. The CHINESE, 
 too, seem to have invented spectacles as early as the Vlth 
 century of our era. Alhazen had pointed out the mag- 
 nifying property of lenses ; but our spectacles appear to 
 have been invented independently of these sources. 
 
 1310. Watches, a natural outgrowth of the clock, were 
 invented as early as the XlVth century (1310). 
 
 1320. Cannon, known to the Arabs of Spain before 1200, 
 but much improved in Europe. 
 
 1364. Muskets, a clever modification of the cannon. 
 
 1500. Pistols, a most serviceable modification of the 
 musket. These three weapons prove the practical ingenuity 
 of mediaeval Europe. 
 
 Xth to Xlllth c. Stained Glass, immensely improved ; 
 
 1 300. Mirrors, made of glass ; Enamelling, and 
 
 XVth c. Glazed Pottery, imitated from the Arabian and 
 Greek, but perfected ; 
 
 XVth, XVIth c. Majolica, all of which demanded so 
 much practical knowledge, originated in Italy. DELLA 
 ROBBIA (1415) and PALISSY (1580) were the masters of the 
 ceramic art. 
 
 1415. Oil Painting was invented about 1400 by Van 
 EYCK BROTHERS. This proves the progress made in practical 
 -chemistry. Great strides in art since then. 
 
 1440. Engraving, the medium of illustration in art and 
 science. 
 
54 PROGRESS OF SCIENCE. 
 
 1 200 1600. The Violin family of instruments, the basis 
 of modern orchestration. It sprung from the ancient string 
 instrument crwth, which was transformed into the viol about 
 or after the Xlth c., and this was improved until the violin 
 form was reached. Fetis traces the use of the bow to India. 
 
 XVIth c. The Cross-Staff, and Sea-quadrant the latter 
 probably of early origin the Greeks, as we have seen, had 
 a quadrant. 
 
 1453. Printing, which rendered the pulpit secondary, and 
 was the propagator of learning, free inquiry, the Reforma- 
 tion the great civilising agent of Europe. The CHINESE,, 
 as early as the VI th c., and probably before, had invented 
 block-printing ; but the alphabetical printing was due to 
 European genius to Guttenberg especially. The assistance 
 which Printing gave science may be estimated by the fact 
 that Vitellio's Optics, Euclid's Geometry, were published as 
 early as 1533, Rhseticus's Trigonomical Tables soon after, 
 and so forth. 
 
 1560. The Suction Pump, which led Galileo and 
 Torricelli to the discovery of atmospheric pressure. 
 
 Then came great men : 
 
 1394 1460. Prince Henry, the Navigator, initiated the 
 explorations which led to the discovery of half the world, 
 by the incessant labour, direction, solicitude, and protection 
 he bestowed on navigation. He may be said to have 
 opened Africa and Asia. His scientific claim lies in his 
 having created modern navigation and geography, and 
 applied to both the assistance of mathematics, cartography, 
 astronomical instruments and observations, thereby ensuring 
 the steady development of the two sister sciences, each of 
 which was full of promise for civilisation. 
 
 1394 1482. Toscanelli constructed a GNOMON on the 
 Cathedral of Florence in 1468. 
 
 1423 1461. Peurbach invented the decimal division, 
 and composed Tables of the Eclipses, and also EPHEMERIDES; 
 re-invented the tangents, and calculated the Tables of 
 Tangents for each degree a new step in the advancement 
 of mathematics; was the first European who composed a 
 treatise on trigonometry. 
 
THE MIDDLE AGES AND DURING THE REVIVAL. 55 
 
 14501506. Columbus discovered AMERICA (Oct. 12, 
 1492) ; observed the magnetic declination. 
 
 1436 1476. Regiomontanus computed the earliest 
 EPHEMERIDES ever composed. 
 
 1451 1504. Waltherus was the first in Europe to USE 
 CLOCKS to measure time during astronomical observations. 
 
 14521519. Leonardo da Vinci advanced MECHANICS 
 before Stevinus and Galileo ; also chemistry ; traced the 
 origin of fossils ; strongly advocated experiments.* He left 
 fourteen valuable books on Natural Philosophy. 
 
 1469 1524. Vasco de Gama rounded the CAPE OF 
 GOOD HOPE (discovered by DlAS in 1486), and found the 
 sea-route to the East Indies (Nov. 22, 1497). 
 
 14701521. Magellan circumnavigated the globe (1519 
 1522), discovering Cape Horn, the Magellan Straits, the 
 Pacific Ocean, and numerous groups of islands. Magellan, 
 killed in the Ladrone Islands, had not the happiness to 
 complete the voyage ; his lieutenant, Sebastian del Cano > 
 reaped the glory of sailing round the earth first. 
 
 1473 1543. Copernicus demonstrated the planetary 
 system, " founding his reasonings upon rigid induction. " 
 The ancient Greek astronomers seem to have guessed the 
 truth, but failed to demonstrate it. Copernicus's conviction 
 was so thorough that he predicted that we should see the 
 phases of Mercury and Venus. The Copernican system was 
 not generally accepted until Galileo. 
 
 1486 1567. Stiefel found the germs of logarithms, the 
 shorthand of Arithmetic a discovery perfected and made 
 effectual by Napier ; invented the use of letters for unknown 
 quantities, and the sign + for plus and - for minus. 
 
 1423 1541. Paracelsus transferred the medical science 
 from books to observation and nature, and by his public 
 lectures on medicine and chemistry, " rid Europe of humor- 
 alism, Galenism, and polypharmacy thus giving the heaviest 
 blow to the old pathology." Many of his ideas are borrowed 
 from the Arabs. He applied himself to reforming therapeutics^ 
 and based the medical art partly upon a knowledge of 
 chemistry. He was the first to lay down the problem of Life 
 * See pages 99, 104107, and Appendix IV. 
 
56 PROGRESS OF SCIENCE. 
 
 which was to become the ultimate object of future research. 
 As a chemist, he separated gold from silver (in a mixture of 
 the two metals) by means of nitric acid ; pointed out that 
 air feeds a flame. As a physician, he applied new remedies 
 (laudanum and antimony amongst others), and discovered the 
 general law of nutrition. His follower Libavius (1550 1616) 
 continued his chemical work, and discovered the process of 
 making red glass by the oxide of gold. His Alchymia 
 Recognita contains valuable descriptions of old, and new, 
 processes. 
 
 1494 1555. Agricola was the founder of modern metal- 
 lurgy, removing it from the alchemist's laboratory to the 
 foundry an immense stride in practical chemistry. He was 
 also the discoverer of bismuth (1529). 
 
 14971558. Fernel measured a DEGREE by the revolu- 
 tion of a wheel in 1527, ascertaining thereby the earth's 
 circumference to be 24,480 Italian miles nearly the same 
 result as Al Mamun's. 
 
 1500 155- Tartaglia caused mechanics to progress in 
 several ways ; may be called the father of ballistics, having 
 been the first to explain the laws governing the flight of 
 projectiles, which Leonardo had understood sixty years 
 before, but without fully explaining them. 
 
 15011576. Cardan, the inventor of "the CARDAN 
 RULE/' also advanced theoretical and practical mechanics. 
 
 1510 1590. Palissy explained the origin of springs and 
 of FOSSILS, and improved the ceramic art. Glazed pottery 
 for domestic use is due to him. 
 
 1512 1594. Mercator, after Prince Henry, contributed 
 most to revive GEOGRAPHY on scientific principles (Tabulae 
 Geographic), constructing marine Charts on what is called 
 Mercator's Projection representing latitudes and longitudes 
 by lines; he also revived astronomical chronology, and 
 restored hydromechanics, at least partially. 
 
 1522 1565. Ferrari greatly improved ALGEBRA, and 
 resolved algebraic equations of the third and fourth degrees. 
 
 1526 1594. Palestrina made music AN ART as well as 
 A SCIENCE. His compositions have remained unsurpassed. 
 
 1537 1619. Aquapendente (Fabricius ab), tutor of 
 
THE MIDDLE AGES AND DURING THE REVIVAL. 57 
 
 Harvey, discovered the VALVES OF THE VEINS a great 
 step towards Harvey's own discovery. As an astronomer 
 discovered (Aug. 1596) the variable star Mira (also called 
 o Ceti). 
 
 1540 1 60 1. Ubaldi developed the LAWS OF THE LEVER 
 and the point of gravity his elucidation an important 
 forward step. 
 
 1540 1603. Viete invented the mathematical SYMBOLS 
 an ingenious and most serviceable creation ; he also ap- 
 plied algebra to geometry; may be said to have preceded 
 Descartes and Newton on the road of mathematical analysis. 
 
 1540 1603. Gilbert showed that a great many sub- 
 stances have the magnetic power of attraction when rubbed, 
 and that this attraction is stronger when the atmosphere is 
 cold and dry ; he found out the main principles of electricity 
 after countless experiments an evidence that experiments 
 were made in earnest. He should be remembered as the 
 FOUNDER of the science OF ELECTRICITY ; but he was also 
 one of the masters of the Inductive Method.* 
 
 15451615. Porta invented the CAMERA OBSCURA, used 
 in astronomy and photography; invented also the MAGIC 
 LANTERN, which was perfected by the German Kircher, 
 some time later ; showed vision to emanate, not from the 
 eye, but from the light which comes to it comparing the 
 eye to the camera obscura. Delia Porta had also a good 
 notion of the use of two magnifying glasses, but does not 
 appear to have either made or improved telescopes, as it is 
 asserted. 
 
 1546 1 60 1. Tycho Brahe built a magnificent observatory 
 on the island of Huen, given him by Frederick II. of 
 Denmark, where he observed the heavens night after night 
 for more than twenty-five years; he mapped 777 stars 
 (1,000 according to Brewster), and drew up the celebrated 
 RUDOLPHINE TABLES (in honour of the Emperor Rudolphus 
 II.) a work of twenty-five years' observations, the basis of 
 Kepler's labours, and one of the grandest works ever 
 composed. Tycho rediscovered the third inequality of the 
 moon the variation discovered before by Aboul Wefa; 
 * Set Appendix V. 
 
58 PROGRESS OF SCIENCE. 
 
 determined that comets are beyond the moon, and cut the 
 firmament in all directions; made numerous beautiful physical 
 and astronomical instruments. He earnestly advocated 
 experiments, and took nothing for granted without rigid 
 verification.* He was the reformer of the astronomical 
 science beyond all question. 
 
 15481620. Stevinus elucidated some of the LAWS OF 
 PRESSURE, motion, THE LEVER, and the equilibrium of 
 liquids. 
 
 Ab. 1546. Lelio reformed the CALENDAR in 1581 a 
 proof that " observations " were pursued everywhere. 
 
 1550 1617. Napier developed and perfected LOGA- 
 RITHMS there were several reprints of his works in a 
 few years. This new mode of calculation was a discovery 
 which has multiplied perhaps " hundredfold the working 
 process of every computer, and has rendered easy calculations 
 which were before impracticable." 
 
 1550 1600. Bruno (Giordano) lectured on and popu- 
 larised the COPERNICAN SYSTEM ; asserted that other worlds 
 might be inhabited besides ours, entertaining the opinion, as 
 early as 1591, that the stars may be suns attended by planets 
 like our earth. He attempted to establish the mechanical 
 conception of the universe (Democritus's view) . He denounced 
 Aristotle and authority as early as 1580 (in Oxford in 1583). 
 For his fourfold offence he was burnt alive in 1600. He must 
 be remembered as one of the great martyrs of science. 
 
 1560 1621. Harriot explained the origin of colours in the 
 RAINBOW, more fully than Roger Bacon and Vitellio had done, 
 
 1564 1642. Galileo, the greatest man of science, together 
 with Archimedes, Hipparchus, and Alhazen, the world pro- 
 duced before Newton, invented the THERMOMETER, one 
 of the most important agents in our possession, in I597 
 and from that time the phenomena of heat could be studied,, 
 and these of course include a vast number of chemical 
 phenomena. He improved Lippershey's or Janssen's 
 TELESCOPE and microscope the starting point of modern 
 astronomy and physiology, and with the assistance of the 
 telescope made great discoveries. He created DYNAMICS- 
 * See Appendix V. 
 
THE MIDDLE AGES AND DURING THE REVIVAL. 59 
 
 the great science of the moderns after his experiments on 
 the fall of bodies, and the PENDULUM. " The pendulum," says 
 one of our best authorities on scientific researches,* " is the 
 most perfect (certainly one of the most perfect) of all instru- 
 ments, chiefly because it admits of almost endless repetitions. 
 Since the force of gravity never ceases, one swing of the 
 pendulum is no sooner ended than the other is begun, so that 
 the juxtaposition of successive units is absolutely perfect. 
 Provided that the oscillations be equal, 1,000 oscillations 
 will occupy 1,000 times as great an interval of time as one 
 oscillation. The excessive value of this instrument arises 
 from two circumstances : (i) the method of repetition which 
 is invaluable in science is eminently applicable to it ; (2) 
 unlike other instruments, it connects together three different 
 quantities, those of space, time, and force. (A) A pen- 
 dulum of invariable length, suspended at the same place 
 where the force of gravity may be considered constant, 
 furnishes a measure of time, (B) The same pendulum, 
 made to vibrate at different parts of the earth's surface, 
 and the times of vibration being astronomically determined, 
 the force of gravity becomes accurately known, (c) With 
 a known force of gravity, and time of vibration ascertained, 
 by reference to the stars, the length is determinate." We 
 have quoted this passage in full a liberty the author will be 
 the first to forgive us for knowledge' sake because of the 
 important part the pendulum has played in the science of the 
 last three centuries. We leave Galileo for the present, as we 
 shall again have occasion to speak of him and his scientific 
 discoveries. 
 
 1566 1624. Antonio de Dominis explained the true 
 theory of the RAINBOW, in 1591, which Harriot still more 
 perfectly elucidated about the same time or shortly after. 
 
 1566 1627. Ghetaldi published the earliest determina- 
 tions of SPECIFIC GRAVITIES of metals "in 1603 a subject 
 which Archimedes and the two great Arabian physicists Abur 
 Raihan and Alhazen had partly treated. 
 
 15 d. 1600. Cavaliere created the ORATORIO, which, 
 with the Opera, constitutes dramatic music. 
 
 * Jevons. 
 
60 PROGRESS OF SCIENCE. 
 
 1567 1643. Peri and Monteverde created the OPERA, 
 after attempts at reconstructing the melopeia of the Greeks. 
 
 1571 1630. Kepler formulated the three LAWS OF 
 MOTION, together with Galileo's, the basis of Newton's 
 labours ; explained the tides, but it was reserved to Newton 
 to formulate the law which regulates them. 
 
 1577 1643. Guldinus determined the CENTRE OF 
 GRAVITY a solution necessary for the progress of 
 mechanics. 
 
 1577 1644. Castelli created HYDRAULICS, showing how 
 to measure running water. 
 
 1577 1644. Van Helmont recognised numerous kinds of 
 GAS being the first of all writers to use the word ; called 
 carbonic acid " wood-gas" the gas rising from fermenting beer, 
 " gas sylvestre." His lectures on chemistry popularised that 
 science. 
 
 15781657. Harvey discovered the CIRCULATION OF 
 THE BLOOD, the starting point of modern physiology ; 
 discovered also that the blood during its passage through the 
 lungs meets the air drawn in at each breath. 
 
 As a biologist he made valuable discoveries about 
 generation : he observed the very beginnings of life in the in- 
 cubated egg of the fowl and in the embryos of mammalian 
 animals the result of which was the demonstration of the 
 famous dictum, " Omne vivum ex ovo " (all life comes from 
 an egg), which is true of all higher animals if not applicable 
 to plants. 
 
 1591 1626. Snell measured the length of a DEGREE by 
 means of trigonometry the result confirming Kernel's calcu- 
 lations ; he also discovered the LAW OF REFRACTION (1621) 
 determining the index of refraction. Snell's law, as it is called, 
 is stated thus : TIu ratio between thz sines of the incident and 
 refracted rays is always the same for the same substance 
 the index of refraction for water being three-fourths. The 
 importance of this law may be conceived when it is re- 
 membered that the power of telescopes could not have been 
 regulated without it. 
 
 16001610. Scarpi, Drebbel, Santorio invented an air 
 THERMOMETER each in 1600, 1609, J 6io respectively. They 
 
THE MIDDLE AGES AND DURING THE REVIVAL. 61 
 
 also improved hygrometers (for determining the amount of 
 moisture in the air) ; and as a proof that instruments were 
 made on scientific principles, it may be stated that the spirit 
 of wine and the mercury thermometers were made, the first 
 by the Academy del Cimento in 1655, the second by Halley 
 about 1680, on the principle of relative dilatation. 
 
 Nearly every branch had been seated, at the end of the 
 XVIth century and the beginning of the X Vllth, on a scientific 
 basis viz. : 
 
 Astronomy, Hydrostatics, 
 
 Physics, Optics, 
 
 Mechanics, Electricity, 
 
 Hydraulics, Dynamics. 
 
 Furthermore, great strides had been made in other 
 branches, and if the advance in these was less extraordinary, 
 it sufficed nevertheless to place them also on scientific 
 foundations. 
 
 Zoology was advanced by 
 
 1516 1565. Gesner, who continued the work of Aristotle 
 and the Arabs by his countless observations, and published 
 a celebrated work on ANIMALS, in which he described every 
 known animal, its habitat, habits, food, etc. ; he travelled 
 over a large area of Europe to study fresh-water and marine 
 fish, and collect numerous minerals and plants ; founded the 
 earliest ZOOLOGICAL CABINET in Europe. His book on 
 mineralogy describes the forms of crystals of different 
 minerals, besides fossil shells. 
 
 i^iy 64. Belon studied BIRDS AND FISHES, adding 
 much to the stock of previous knowledge. 
 
 Botany was advanced by 
 
 1498 1554. Tragus, Cassalpinus, and Lobel. 
 
 iSiq 1603. Caesalpinus made valuable additions to 
 this branch ; knew some 1,500 species, 700 of which had 
 been collected by himself. He distributed them into sixteen 
 classes according to their seeds ; was the first to point out 
 the reproductive action of stamens. His CLASSIFICATION 
 was the first attempt of the kind in modern Europe. In 
 other fields he discovered the constant form of CRYSTALLI- 
 SATION in metals, and the increase of weight of metals by 
 
62 PROGRESS OF SCIENCE. 
 
 oxidation ; in physiology, he observed the swelling of veins 
 below ligatures, and inferred from it the refluent MOTION OF 
 THE BLOOD in those vessels. 
 
 1538 1616. Lobel discovered the two GREAT GROUPS 
 of the vegetable kingdom the monocotyledons and the 
 dicotyledons. 
 
 Physiology had its foundations strengthened by 
 1561 1638. Santorio, who introduced the THERMO- 
 METER, HYGROMETER, and the BALANCE into the study of 
 life ; discovered the process of cutaneous perspiration. 
 Anatomy received a powerful impulse from 
 1405 1464. Piccolomini, who gave a scientific basis to 
 general anatomy by his description of the CELLULAR 
 TISSUE. 
 
 1463 1512. Achillini observed the course of the cerebral 
 cavities into the inferior cornua ; knew of the ileo-caecal 
 valve and other facts unknown before him ; described the 
 malleus and incus two TYMPANAL BONES ; showed the 
 tarsus to consist of seven bones; rediscovered the fornix 
 a triangular brain lamina, and the infundibulum brain- 
 tunnel. 
 
 1483 1553. Fracastoro made valuable observations on 
 
 CONTAGION. 
 
 15091553. Servetus nearly detected the course of the 
 circulation by his persevering DISSECTIONS. 
 
 1 5 14 1 564. Vesalius, who deserved the title of FOUNDER 
 OF MODERN ANATOMY, showed the discrepancies between 
 the results of dissection and Galen, who had never dissected 
 the human body and had given a wrong description of it. 
 To Vesalius mainly we owe the transformation of anatomy 
 into an exact science, and by that fact a solid foundation 
 was given to medicine. Vesalius's book was illustrated 
 by the best artists of Italy a great help to students. 
 
 1523 1552. Fallopius studied the general anatomy of 
 the BONES ; described the EAR with great accuracy, and 
 made assiduous researches into the organs of reproduction. 
 
 1527? 1574. Eustachius discovered the EUSTACHIAN 
 TUBE, leading from the ear-drum to the throat. 
 
 1530 1589. Arantus was the first to describe the inferior 
 
THE MIDDLE AGES AND DURING THE REVIVAL. 63 
 
 CORNUA of the ventricles of the cerebrum ; speaks of the 
 choroid plexus. 
 
 1581 1626. Asellius discovered the LACTEALS (1622), 
 which carry from the intestines the nourishing matter of the 
 food to make fresh blood a discovery made more complete 
 in 1647 by PECQUET, who determined the function of the 
 thoracic duct (which conveys blood-making fluid into the 
 large veins, and then to the heart); and in 1649 still 
 more so by RuDBECK, who detected the lymphatics, which 
 play the same part as the lacteals in other parts of the 
 body. These three anatomists thus supplemented and 
 crowned the labours of Harvey, by finding and tracing the 
 vessels which carry nourishment to the blood. 
 
 Medicine and Surgery meanwhile were advancing 
 through 
 
 1517 1590. Pare, who created modern surgery, and was 
 the first to understand the nature and treatment of FIRE-ARM 
 WOUNDS ; replaced red-hot iron cauterisation by the binding 
 of arteries after amputation a reform which saved thousands 
 of lives. 
 
 1553 1617. Alpinus created DIAGNOSIS. 
 
 (Fl. 1534.) Goiter created PATHOLOGICAL ANATOMY; 
 he studied the influence of the brain and the action of the 
 heart, and distinguished himself by his researches on the 
 nerves, the bones, and the cartilages. 
 
 (Fl. 1540.) Plater set forth the CLASSIFICATION of 
 disease. 
 
 All these learned men and many more could be men- 
 tioned contributed in one way or another work done for 
 all times. They did more. By them, men were taught one 
 great lesson : that Aristotle, Ptolemy, Galen, had been far 
 from settling everything for ever as it had been asserted 
 for centuries ; that there were whole groups of phenomena 
 they had not suspected, let alone their mistakes ; that 
 NATURE, THE SUBLIME TEACHER, must be examined and 
 consulted ; and that it exercises more sway over truth than 
 human authorities, however revered for their antiquity, their 
 station, their number, and their unanimity. The Church, the 
 interpretation of Scripture, the science of ages, the testimony 
 
64 PROGRESS OF SCIENCE. 
 
 of the senses of hundreds of generations, the weight attached 
 to fifty centuries of unanimous belief among kings, princes, 
 legislators, thinkers in all countries, the wisdom of humanity 
 may be dead against a theory held by a daring solitary man 
 and, yet, that one man, armed with a single physical fact, 
 is enough by himself to overthrow for ever the consensus of 
 mankind and the revered opinions of mighty men. ONE 
 FACT PROVES STRONGER THAN HUMAN WISDOM. A 
 Galileo or a Magellan outweighs a thousand generations. 
 
 This lesson was the result of the wonderful development 
 of scientific activity and enlightenment in every direction. 
 This scientific activity was made still more evident by the 
 foundation of 
 
 Learned Societies : 
 
 The Natural Academy of Naples, created by Porta 
 in 1560; 
 
 The Lyncean Academy of Rome, created by Prince 
 Cesi in 1603, soon followed by the creation of 
 The Accademia del Cimento at Florence (1637), 
 The Royal Society in London (1645), 
 The Royal Society of Sciences in Paris (1666). 
 The Practical Arts, by the side of all this, had advanced 
 immensely, witness Distillation, Glass Making, the Ceramic 
 Art, the application of Chemistry to Art, Medicine, Industry. 
 The Plastic Arts, besides Architecture, Sculpture, 
 Painting had reached incomparable perfection through 
 BRAMANTE (H49 1 S I 4)> 
 
 LEONARDO DA VINCI ( J 45 2 1 $ 1 9)> 
 
 MICHAEL ANGELO (14741564), 
 
 TITIAN (i477 15/6), 
 
 GIORGIONE ( J 477 l $ ll )> 
 
 RAPHAEL (14831520), 
 
 CORREGGIO (14941534), 
 
 CELLINI (15001570). 
 
 The logic of these facts is irresistible; they cannot be 
 explained away by any sophistry. It is in the face of this 
 surging progress that it has been asserted and repeated 
 again and again, that nothing worth mentioning had ad- 
 vanced since Aristotle until Francis Bacon's time. 
 
 How the name of " Dark Ages " was ever given to the 
 
THE MIDDLE AGES AND DURING THE REVIVAL. 65 
 
 centuries which are illumined by so many marvels passes 
 all comprehension. If, owing to the deluge of Germanic 
 barbarism, it can justly be applied to the centuries which 
 immediately followed the break-up of the Roman empire, 
 it is wholly inapplicable to those ages which preceded the 
 Revival. And, as we have already hinted, it is a rather 
 misleading appellation even if applied to the earlier period. 
 The wretched social conditions of the times, the anarchy 
 prevailing in the political arena, the sway of a powerful 
 Church dominated by ambition and superstition, made the 
 mediaeval era as unlike ours as possible ; but these defects, 
 arising from the dislocation of the ancient world, did not 
 necessarily involve the whole of the mediaeval era in darkness. 
 Why, the lay world and the Church itself were hardly ever 
 without great and brilliant intellects. The defects lay in 
 the general situation. The world had a new civilisation 
 to elaborate, and its various elements the sacerdotal, the 
 monarchical, the aristocratic, and the democratic trying 
 each in turn to be completely dominant, and never suc- 
 ceeding, made the process of gestation very fitful and slow. 
 The conflict was unavoidable and beneficial, leading as it 
 did to two results unattainable any other way, and which 
 no other civilisation had as yet effected : it endowed Europe 
 with immense and durable mental and physical energy ; it 
 brought in the live-and-let-live principle of government 
 that is, it conduced either to the welding of the elements 
 just mentioned to form a new society, or to the conciliation 
 of these elements so as to permit them to exist side by side 
 in the same society. 
 
 Now, whether a period which produced men like 
 Urban II., d. 1099, Thomas Aquinas, d. 1274, 
 
 Henry IV. of Germany, noi, Albertus Magnus, 1280, 
 Abelard, 1 142, Roger Bacon, 1292, 
 
 Barbarossa, 1190, Duns Scotus, 1308, 
 
 Innocent III., 1216, Dante, 1321, 
 
 Frederick II. of Germany, 1250, Petrarca, 1374, 
 
 Innocent IV., 1254, Boccaccio, 1375, 
 
 Clement IV,, 1268, Wiclif, 1387, 
 
 Louis IX., 1270, Chaucer, 1400, 
 
66 PROGRESS OF SCIENCE. 
 
 and some others,* deserves the epithet of dark, because 
 serfdom, violence, and superstition existed, is more than 
 questionable, considering that slavery still existed in America 
 thirty years ago, and that violence and superstition were 
 almost as prevalent in the XVI Ith century witness the 
 Thirty Years' War and the religious persecutions as they 
 were five hundred years before. And if we look at the 
 society of the times, we come to the same conclusion. The 
 social conditions described by Boccaccio and Chaucer, which 
 are so striking in many ways, and which reveal so much 
 sense, politeness, wit, and elegance, could not have come 
 into existence in one day. They could only be the results 
 of a lengthy and steady course of moral and mental training. 
 The beautiful correspondence and exquisitely refined poems 
 of Petrarch would, by themselves, suffice us to arrive at 
 the same verdict. Had we such pictures and such works 
 alone before us, we never could apply, if we look at them 
 rightly, the term " dark age " to that in which the society 
 they represent existed. In Art also architecture and music 
 especially the progress effected before the Xlllth century 
 set in would lead us to a similar conclusion. But when, in 
 addition to the rulers, thinkers, and writers just mentioned, 
 and to the social state and artistic work we are alluding to, 
 we find a host of great men exploring every field of human 
 knowledge, and making countless beautiful discoveries, it 
 then becomes absolutely impossible to apply the words 
 Dark Ages to the times in which they lived certainly not, 
 at all events, to the centuries which preceded the Revival 
 and gave birth to the progress in the scientific arena of 
 which we have presented a noble roll. It is therefore as 
 well that we should protest against the indiscriminate use 
 of them, if we wish to see those times under their true 
 
 * Damiano of Ravenna (d. 1072), Gaunilon of Marmoutier (d. iioo), 
 Anselm of Laon (d. 1117), Hildebert of Tours (d. 1133) all Realists ; 
 Champeaux (d. 1121), Hugh de St. Victor (d. 1140), Robert Pulleyn 
 (d. 1150), Lombardus of Novara (d. 1164), John of Salsbury (d. 1180), 
 Simon of Tournay (d. 1200), David of Dinant (d. 1200), Alain de Lille 
 (or de Ryssel), (d. 1203) all famous Nominalists ; and after them for a 
 century, a number of Aristotelians, Averroists, Thomists, Scotists, and 
 Lullists. 
 
THE MIDDLE AGES AND DURING THE REVIVAL. 67 
 
 colour and aspect. After the first Crusade, say after THE 
 YEAR noo to draw a precise line, and conscious that in 
 so doing we are understating the case, as the next chapter 
 will convince us light dawns rapidly, and the appellation 
 can apply intellectually no longer in any way. The XHIth 
 century was so fruitful that it would have witnessed a 
 complete revival had it not been for the great wars which 
 slackened the intellectual movement. 
 
 F 2 
 
CHAPTER VI. 
 
 NUMEROUS CAUSES OF SCIENTIFIC PROGRESS. 
 
 Now, in order more fully to account for the immense 
 development of science during the Mediaeval and Revival 
 Periods, we must not omit to mention other concurrent 
 causes of progress, at once numerous and powerful, besides 
 those upon which we have already laid particular stress, 
 The roots of that development were both ancient and deep,, 
 and they were of a nature to grow vigorously, if slowly. 
 
 By the side of the influence exercised by the Arabs, 
 and through them by antiquity, the social and political 
 changes which took place in Europe, between the time of 
 the Crusades and that of the Revival, constituted a revolu- 
 tion probably unique in magnitude in the annals of the 
 human race since the other revolutions, such as the 
 Revival itself and the Reformation, were, in part, offshoots 
 of it and that revolution, as we will proceed to show, was 
 exceedingly favourable to the scientific advance. 
 
 The Crusades caused the birth and rapid growth of 
 European industry, and the latter necessarily led to the 
 individual emancipation from serfdom, and to the communal 
 and political enfranchisement of millions of men, many of 
 whom formed a wealthy Burgess class remarkable for thrift, 
 ambition, and energy. Soon, many of the drawbacks which 
 existed in antiquity began to disappear, while new elements 
 of advancement, all of them irresistible, came into being.* 
 
 * See Hallam's "State of Europe in the Middle Ages," Vol. II.,. 
 chapter ix., part 2. 
 
NUMEROUS CAUSES OF SCIENTIFIC PROGRESS. 69 
 
 The sea, by the fresh rise of navigation, became the main 
 highway of transit, even before the Compass made its 
 appearance, and intercourse between East and West revived. 
 Old barriers, social as well as geographical, were by degrees 
 weakened in every direction. Associations and co-operation 
 gave collective strength to trade. Commercial wealth, now 
 created, widened " Economy/' until then agricultural only, 
 and vied with land-wealth in devising novel sources of 
 material welfare. Capital, a new factor, centred in many 
 points, faced vast enterprises. The bill of exchange sup- 
 pressed the distance of money markets. Mining supplied 
 raw material hitherto limited. The abolition of slavery and 
 serfdom meanwhile gradually induced mechanical con- 
 trivances to replace and multiply hand labour. The practical 
 skill and the operations involved in industry and art had 
 natural consequences of a high order : they stimulated com- 
 petition unknown till then ; they raised, by several degrees, 
 the intellectual power of the artisan and burgess multitude ; 
 they conduced to improved processes of production, that is, 
 to a vast number of inventions,* many of which were as 
 favourable to the scientific movement, such as it was, as 
 to industry. Warfare itself became scientific from the use 
 of fire-arms. Simultaneously, the practice of art, together 
 with the growth of the aesthetic faculty, and of the activity 
 consequent upon it, was likewise beneficial to practical 
 science, which in its turn no less beneficially reacted upon 
 art and industry. Marvellous cathedrals in every country 
 afford splendid and irrefutable evidence of that fact. In 
 France alone 1128 great churches were built in the Xlth 
 and Xllth centuries, besides 989 new monasteries (most 
 of which opened schools) during the Xllth and Xlllth 
 centuries. The creative power which could give birth to 
 such architectural wonders is also to be found in sculpture, 
 in painting, in music; it is evidenced with equal variety in 
 
 * As early as the Xth century the mathematical science and me- 
 chanical inventions of Gerbert (better known as Pope Sylvester II.), 
 d. 1003, were sufficient to give him a great reputation (Hallam). He 
 had studied at Cordova. The Indian numerals, algebra, the pendulum 
 clock were introduced into Europe by him. 
 
7o PROGRESS OF SCIENCE. 
 
 literature, from the "Divine Comedy" to " Canterbury Tales" 
 as from the " Decamprone " to " Gargantua" or from the 
 " Song of the Niebelung" to "Reynard the Fox"; it is also 
 displayed in mechanical art, from the organ and clocks to 
 fire-arms and the violin. \The taste for learning led to the 
 creation of universities in every land,* and soon to that of 
 public libraries.f How could originality at once so exuberant 
 and inexhaustible draw a line at science ? It did not. The 
 intellectual evolution was manifold and universal : it varied 
 only in degree. It is undeniable that, under these new 
 circumstances, successive multitudes of students J were at- 
 tracted to the universities by Natural Philosophy, just as 
 much as by Jurisprudence and Theology, although natural 
 philosophy was taught in an attenuated form, and under the 
 fiery and watchful eye of jealous and dogmatic churchmen. 
 That natural philosophy was in the air, so to speak, is 
 proved by the numerous adepts in ALCHEMY who, at their 
 peril, were at work everywhere during the Middle Ages. 
 This was the most attractive of the scientific studies then 
 pursued, because it was understood, however vaguely, to be 
 the link between organic and inorganic science, and hence 
 pregnant with potentialities. If they conspicuously failed 
 in the transmutation of metals, they achieved "very con- 
 siderable success in the department of synthesis" and the 
 formation of new combinations one of the main pursuits 
 of the chemists of the present day ; for, " to decompose 
 
 * At Salerno, Bologna, Paris, Oxford, Cambridge, Padua, Naples,. 
 Toulouse, Montpellier, Salamanca, Orleans, Bourges, Angers, Prague, 
 Leipsic, and many others in Germany. Most of these had in time the 
 four Faculties of Theology, Canon-Law, Medicine, and Arts and the 
 Faculty of Arts gave instruction in the Trivium (Grammar, Logic, and 
 Rhetoric), and in, the Quadrivium (Arithmetic, Geometry, Music, As- 
 tronomy). The universities were essentially lay centres of learning, 
 and that was an all-important change : Salerno and Montpellier were 
 schools of medicine, Bologna and Orleans great schools of Roman law, 
 Paris the great theological school ; but if such was in the main their 
 respective strength, they also afforded instruction in all the other 
 channels of learning. 
 
 f Paris, Oxford, Glastonbury Abbey (400 volumes), St. Albans,. 
 Heidelberg, etc. 
 
 J There were as many as 10,000 at Bologna, 5,000 at Oxford, over 
 25,000 at Paris, etc. 
 
NUMEROUS CAUSES OF SCIENTIFIC PROGRESS. 71 
 
 metals, to re-form them, to change them from one to another, 
 and to realise the once absurd notion of transmutation, are 
 the problems now given to the chemist for solution." This 
 from Faraday, and to show the reader that the alchemists 
 were far from being poor dreamers whose researches were 
 founded on total ignorance. A further evidence of the taste 
 for scientific research is to be found in the ENCYCLOPAEDIC 
 WORKS composed during that time,* large portions of which 
 were, notwithstanding the prevalence of theology and scho- 
 lastic metaphysics, devoted to the exposition and teaching of 
 the various branches of natural philosophy then in existence. 
 Besides, a vast number of books dealt with each branch 
 in a separate form a fact which implies the existence of 
 many teachers and countless pupils. So great and ubiquitous 
 was the scientific bent, that numerous didactic poems were 
 composed everywhere, on natural history, mineralogy, geo- 
 graphy, astronomy a fact which speaks volumes about the 
 growing taste. Why, even chroniclers, so meagre and dry 
 before the XHIth century, became remarkably learned and 
 shrewd. Not only did they show a rare comprehension of 
 important events, of their causes, of their effects, but they 
 inquired into questions of morals, geography, ethnology, 
 natural history. This is particularly the case with William 
 of Tyre and James de Vitry (1200), amongst others and the 
 fact constitutes a conspicuous sign of the times. Religious 
 ideas no longer despotically swayed the human mind to the 
 exclusion of all else; the Crusades had freed it from that 
 sway,t and one of the main consequences of that eman- 
 
 * We need here only mention the work of Albertus Magnus, Roger 
 Bacon, Albert of Saxony, Vincent de Beauvais, Ramon Lulle, Basil 
 Valentine, and later on, Ringelbert of Basel (1541), Alsted (1620). The 
 authors of separate works are to be counted by hundreds. (See Hallam, 
 
 499-) 
 
 t The Crusaders had seen their own inferiority to the Greeks and to 
 the Moslems in matters of refinement, art, literature, science ; they had 
 seen the Church " at home," in Rome, and had quickly perceived the 
 laxity of morality among the high clergy, detected the selfish policy of 
 the papacy, and the part played by earthly interests in the so-called 
 religious questions ; they had seen and understood worldly ambition to 
 have been the spring of action of the nobility which rushed to the East ; 
 they had travelled, seen many peoples, monumental cities, two distinct 
 
72 PROGRESS OF SCIENCE. 
 
 cipation was the growth of the scientific spirit in all direc- 
 tions throughout Europe. Roger Bacon was undoubtedly 
 the boldest and most original innovator of the mediaeval era; 
 in him the Experimental School had an earnest inquirer and 
 an enthusiastic master; but, had he never existed, the 
 scientific method must nevertheless have resulted, later 
 possibly, from the pursuit for generations of two great 
 series of labours, viz., astrology and alchemy, which, in their 
 higher flight, must not be confounded with the occult 
 sciences, survivals of fetichism more or less, such as magic, 
 necromancy, chiromancy, sorcery, cabalism. 
 
 Astrology and alchemy were immensely beneficial to 
 progress. They afforded for a lengthy period the strongest 
 stimulus to scientific investigation. In the absence of scien- 
 tific analysis, which alone could assign their true position in 
 general physics to astronomical phenomena, " there existed 
 no doctrine, no principle that could restrain the ideal ex- 
 aggeration ascribed to celestial influences " ; astrology was 
 such an exaggeration ; but, it rested upon the subjection of all 
 phenomena to immutable natural laws. Astrology, therefore, 
 was in the highest degree serviceable in sowing and pro- 
 pagating a notion (i.) of the unchangeableness of the laws 
 of nature, and (n.) of the subjection of phenomena to those 
 laws, "by which a rational prevision became possible." 
 Alchemy rendered the very same service in that respect ; so 
 that these two pursuits contributed largely to the develop- 
 ment of human reason on the one hand, and of science on 
 the other: the first (astrology), among other benefits, en- 
 gendering a " high idea of human wisdom from its power of 
 foresight under natural laws"; the second (alchemy) rousing 
 a noble sense of human power, by "inspiring bold hopes 
 from our intervention in those phenomena which were sus- 
 ceptible of modification." Science, thus, was the outcome 
 evolved from simultaneous causes. It was not, mushroom-like, 
 of sudden, unexpected, unsuspected growth ; it was not due 
 
 civilisations superior to their own in many ways, and their intellect was 
 enlarged in proportion. Narrow ideas had died out ; the sphere of 
 activity had ceased to be solely theological it had become political, 
 commercial, industrial, literary, artistic, and scientific. 
 
NUMEROUS CAUSES OF SCIENTIFIC PROGRESS. 73 
 
 to one man ; it was not the result of a method alone : it owed 
 its birth to concurrent energies, practical in the main ; but 
 its final parturition was the work, as we have said, of the 
 great men who preceded Kepler, Galileo, and Harvey, just 
 as its culture and immense advancement after Kepler, 
 Galileo, and Harvey were the work of the great men whom 
 we shall mention the earlier and the later movements 
 being connected from beginning to end by an unmistakable 
 filiation of discoveries. The concatenation presents a series 
 of powerful links without a single break.* It is obvious at 
 a glance, especially in its main points. The discovery of 
 Copernicus, and the labours of Tycho Brahe consequent 
 upon it, prepared the way for the investigation of Kepler, 
 which constituted the true system of celestial geometry and 
 gave birth to celestial mechanics; Galileo's mathematical 
 theory of motion, and his discovery of the laws of falling 
 bodies, together with Descartes's mathematical revolution, 
 necessarily followed by Huygens's discovery of the law of 
 centrifugal force, led to Newton's final discovery. 
 
 This brief summary suffices to demonstrate how unbroken 
 the evolvement of science was without the intervention of 
 an outside agent. The evolutionary law, in fact, worked 
 throughout the Mediaeval and Revival Periods with irresistible 
 force, and without any deviation from its natural and 
 necessary course. 
 
 * Comte. 
 
CHAPTER VII. 
 
 ROGER BACON. 
 
 IN the preceding chapters the immense scientific progress 
 effected until the 'end of the Revival Period has been briefly 
 described. In the present chapter the special work of Roger 
 Bacon will be considered ; and, as that work is important 
 as a fact of scientific history, whether it be viewed for its 
 intrinsic value, or as a connecting link between the Arabs 
 and the Revival Period since like the hand of a clock it 
 indicates the height of the flowing tide at the time it will 
 be interesting to establish a comparison between Roger 
 Bacon and Francis Bacon, which will enable the reader to 
 form a judgment upon their respective originality, worth, 
 and influence. It is acknowledged by his greatest admirers 
 that Francis Bacon was, in scientific acquirements, vastly 
 inferior to his immediate predecessors ; but it is not a little 
 surprising to see that men who lived three hundred years 
 before him were also in possession of knowledge far superior 
 to his own. This was particularly the case with regard to 
 Albertus Magnus and Roger Bacon. 
 
 Albertus Magnus (1193 1280). This great man might 
 take whales for fishes and bats for birds an error shared 
 until more recent times by many writers but his classi- 
 fication of the Animal Kingdom is admirable, and his work 
 on Natural History is rich in botanical descriptions. He 
 described the principal forms of flowers ; he detected the 
 embryo of seeds ; he also detected the sleep of plants 
 hits which are suggestive of the use of the lens. He planted 
 
ROGER BACON. 75 
 
 the germs of cerebral physiology. He studied in a special 
 manner, besides zoology and botany, both physics and 
 mineralogy adding, now and then, his own observations 
 to those on record before his time. His mineralogy proves 
 the accuracy of his observations: on the question of aerolites, 
 he gave the different theories still held only fifty or sixty 
 years ago. He explained the origin of thermal springs as 
 a modern observer would have done. It is notorious that 
 Francis Bacon cannot show credentials like these, light as 
 they may seem to us when weighed by the standard of 
 modern knowledge. 
 
 It is, however, when we come to 
 
 Roger Bacon (1214 1292) and his work that the in- 
 ference is forced upon us that Francis drew all his inspiration 
 for his own labours from his namesake, for all the sound 
 notions found in the Novum Organum, De Augmentis, etc., 
 can be traced back to Roger's. The parallelism as to plan 
 and ideas is a revelation full of surprises. 
 
 The two Bacons take the same direction and have the 
 same goal in view ; but the earlier Bacon, it strikes one 
 upon the most superficial examination, is the original 
 thinker, unites theory and practice, seriously labours towards 
 the great object, whereas the Elizabethan Bacon stands in 
 the light of a borrower content to theorise, shamming prac- 
 tice some would say, and working to a great extent from 
 ostentation. 
 
 The parallelism between them presents three very striking 
 points. First, we have errors which both men shared alike ; 
 second, we have errors which Roger discarded, but which 
 were persisted in by Francis ; lastly, we have sound notions 
 shared in common by both. 
 
 I. Taking first the errors the two Bacons cherished, we 
 find that (a) Roger believes in the transmutation of metals 
 and the making of gold ; so does Francis both taking their 
 notions chiefly from the Byzantine alchemist Psellus (Xlth 
 century), (b) Roger believes in the means of prolonging life; 
 so does Francis both endorsing one of the most delusive 
 hopes of the alchemists. (<:) Roger thinks his method 
 capable of equalising men's minds, and making science easily 
 
76 PROGRESS OF SCIENCE. 
 
 accessible to all in an equal degree ; so does Francis both 
 ignoring the great part played in the history of discovery by 
 native genius, by chance, and by analogy. 
 
 II. Taking in the next place the errors which Roger 
 discarded, but of which Francis was a believer, we find that 
 {a) Roger disbelieves in magic ; Francis, on the contrary, 
 believes in it. (b) Roger disbelieves in astrology ; Francis, 
 on the other hand, believes in that art. (c) Roger, again, 
 -disbelieves in talismans, whereas Francis believes in their 
 power, and what is more, strongly believes in witchcraft and 
 spirits besides. This divergence of views, on subjects of such 
 capital importance, between two men who appeared at three 
 hundred years' distance from each other, and who are popularly 
 thought to have been representative characters the early 
 one of the Middle Ages, the other of the Revival is a 
 startling fact, since we find here the very reverse of what 
 we should expect. The modern Bacon entertained doctrines 
 which had died out three centuries before among many of 
 the educated class ; the earlier Bacon the man of the 
 Xlllth century entertained the very views which the 
 present world entertains with regard to these subjects.* 
 
 III. Coming lastly to the third series in the parallelism 
 we are drawing, that is, the sound notions which the two 
 Bacons held in common, we find that both (a) projected a 
 dictionary of the Arts and Sciences ; (b) both treated of optics, 
 and called that branch "Perspective " ; both also used the ex- 
 pression "prerogatives of experiment" This double coincidence 
 is very remarkable, (c) Both denounced Scholasticism with 
 vehemence, as a school moving in a circle of abstractions, 
 foreign to the sense of reality and the contemplation of 
 nature a school at once artificial, subtle, disputatious, and 
 pedantic, shutting up the mind within its sphere, and remov- 
 ing it from natural phenomena. Both Bacons therefore 
 denounced Authority, (d) And denouncing Authority, they 
 
 * In justice to Francis Bacon, we must not think that he was the only 
 eminent man of his time who believed in magic, astrology, talismans, and 
 spirits. No ; many men of science Kepler among them shared these 
 delusions. What is significant, however, is that instead of being in the 
 van of progress in these matters, Francis Bacon was less emancipated by 
 knowledge than some great minds of earlier ages. 
 
ROGER BACON. jj 
 
 declared war against the ancients as well as against the 
 Schoolmen. Roger protests against the yoke of Aristotle and 
 
 the ancients in words which it is impossible not to admire 
 
 words spoken then for the first time, and which the echo of 
 centuries has repeated as an undeniable truth. "Scarcely 
 half a century ago/ 5 says Roger,* " Aristotle was suspected of 
 impiety and proscribed from the schools. And now he is 
 presented as a sovereign master ! What is his right to it ? 
 He is learned, they say; granted; but he does not know 
 everything. He has done in his time what was possible then - r 
 but he did not reach the utmost boundary of wisdom. 
 Avicenna has made grave mistakes, and Averroes might 
 be criticised upon more than one point. The very saints 
 are not infallible; they were often mistaken, and were 
 obliged to retract, witness St. Augustine, St. Jerome, and 
 Origen. But, says the School, the ancients must be respected. 
 Eh ! doubtless, the ancients are venerable, and we must show 
 ourselves grateful to them for having traced the way to us ; 
 but we should not forget that these ancients were men, and 
 have erred more than once ; they have even committed the 
 more errors in proportion as they were older, for the youngest 
 are in reality the oldest; modern generations must surpass- 
 those of former times in enlightenment, since they inherit all 
 the labours of past ages." A page of wisdom this ! Francis 
 Bacon's famous " Juventus Mundi" (the youth of the world), 
 which has been so often quoted, and for which he has been so 
 often praised, is the very embodiment of the idea expressed 
 by Roger, at the end of the passage just cited. But to 
 continue : (e) the two Bacons declared that art, borrowing 
 nature's own forces, must enable men to domineer over 
 nature itself. Roger was the first to expoundf this grand 
 idea which would ensure the omnipotence of man's genius* 
 (f) Both great men treated of the general causes of ignorance, 
 the chief of which was the influence of Authority in every 
 shape both detecting four obstacles to science which differ 
 very little except in name : the four offendiada of Roger 
 I. Influence of unworthy authority ; II. Custom; III. Imper- 
 
 * Compendium Philosophise, Cap. II. 
 f De Mirabili Po testate Artis et Natures. 
 
78 PROGRESS OF SCIENCE. 
 
 fection of undisciplined senses ; IV. Concealment of our own 
 ignorance, become with Francis the Idols of the Theatre, the 
 Idols of the Forum, the Idols of the Tribes, the Idols of the 
 Den. (g) Both men, again, proclaimed Experience to be the 
 sole guide of the scientific pioneer that is, they advocated 
 the study of the physical sciences, subjecting it to reason. 
 " Experimental science," says Roger, " is the mistress of the 
 speculative sciences, and has three prerogatives. First, she 
 tests and verifies the conclusions of the other sciences ; 
 secondly, she discourses on the notions which other sciences 
 deal with magnificent results to which these sciences are in- 
 competent. Thirdly, she investigates the secrets of nature by 
 her own powers." " I call experimental science/'* says he 
 again, " that one which neglects (puts aside) arguing; for the 
 strongest arguments prove nothing so long as conclusions are 
 not verified by experience." " Experimental science does not 
 receive truth from the hand of the superior sciences ; for it is 
 she which is the mistress, and the other sciences are her 
 servants. She has the right to command all the sciences, since 
 alone she certifies and consecrates their results. Experimental 
 science therefore is the queen of sciences and the bound of 
 all speculation." " In all researches," he goes on, " we must 
 use the best possible method. Now this method consists in 
 studying in their necessary order the diverse parts of science, 
 placing in the first rank what should really be found at the 
 beginning : the easiest before the most difficult, the simple 
 before the composite, the general before the particular. We 
 must also choose as a study the most useful objects on account 
 of the brevity of life.f Science must be exhibited with clear- 
 ness and certainty, without mixture of doubt and obscurity. 
 Now all this is impossible without experiment, for we have, 
 indeed, various means of knowing authority, reasoning, 
 experiment; but authority has no value unless it is accounted 
 for (Non sapit nisi detur ejus ratio] ; it does not enable one 
 to understand, it only makes one believe; it imposes itself 
 upon the mind without enlightening it. As to reasoning, 
 sophistry cannot be distinguished from demonstration, except 
 
 * Opus Tertium. 
 
 t Francis Bacon advocated science on utilitarian grounds. 
 
ROGER BACON. 79 
 
 only by verifying the conclusion by experiment and practice." 
 Again : " There are two modes of investigation, viz., through 
 argument and through experiment. Argument concludes, 
 and makes us conclude the question; but it does not certify, 
 and cannot remove doubt in such a manner that the mind 
 may remain in sight of truth, unless it finds it through 
 experience ; because many use arguments towards the know- 
 able, but because they use not experiment they neglect 
 (pass by) attainable things, and neither avoid injurious 
 things, nor strive after good ones. For, if any man who 
 has never seen fire has made it credible through sufficient 
 arguments that fire burns and harms, and even destroys 
 things, the mind of the hearer would never on this account 
 be still, and would not avoid fire before he has put his hand 
 or anything combustible into fire, so that he would prove 
 through experience what argument taught, but by the 
 additional experience of combustion the mind is made 
 certain, and finds rest in the brightness of truth whence 
 argument does not suffice, but experience does." This 
 pregnant and luminous passage shows what a clear idea 
 of verification Roger Bacon entertained, and what capital 
 importance he attached to experiment. It is impossible 
 to find in any scientific author a clearer explanation and 
 a sounder injunction. 
 
 The doctrines of Roger Bacon, we see, are not the 
 germs only, but also the backbone and sinews of Francis 
 Bacon's Novum Organum. 
 
 After thus marching side by side the two Bacons part 
 company, the one in pursuit of knowledge, the other in 
 pursuit of shadows ; for, over and beyond the objects we 
 have enumerated Francis Bacon does not proceed, whereas 
 Roger performs work at once extensive and significant, 
 which leaves the would-be Instaurator nowhere in the race 
 of progress. 
 
 The history of science is at rare intervals summed up, 
 and personified, so to speak, by great encyclopaedic minds. 
 Twenty-two centuries have produced but few such ones 
 Aristotle first, Humboldt last, and between them Avicenna, 
 Averroes, Albertus Magnus, and Roger Bacon ; for Pliny 
 
8o PROGRESS OF SCIENCE. 
 
 and Diderot to name the most famous "devoted their 
 labours to researches of erudition only," and were not, like 
 the first, earnest practical inquirers, observers, manipulators, 
 and experimentalists ; so that Roger Bacon belongs to the 
 same genus as Humboldt. 
 
 Roger Bacon was not only familiar with the science of 
 the ancients and that of the Arabs, but he knew Arabic, 
 Hebrew, Latin, Greek, and was able to compose works in 
 the three last tongues on mathematics, physics, chemistry, 
 astronomy, medicine, geography, physiology, and theology. 
 His equipment in point of scholarship alone was of a far 
 more weighty kind than Francis Bacon's, it is clear. Then 
 he spent his fortune in travels, books, instruments, and 
 experiments, in all of which Francis (books excepted) did 
 not spend half-a- crown. That speaks volumes as regards 
 earnestness ; but what is more to the purpose and far more 
 significant, Roger devoted all his time, energy, and mind 
 to scientific pursuits, and suffered years and years of im- 
 prisonment for his science ; the other devoted his time and 
 faculties to worldly ends, and dabbled in science only for 
 worldly purposes. If he, too, went to prison, it was for debt 
 incurred for diamond rings. 
 
 What now were the achievements of Roger Bacon in 
 natural philosophy which give him a unique place in the 
 history of the Middle Ages, and made him the precursor of 
 modern science to the exclusion of his great namesake ? 
 
 A. In the first place, Roger's clear insight, as G. H. 
 Lewes has pointed out, is displayed in the recognition of 
 the essential connection of all the sciences. " All sciences," 
 says he, " are connected together, and mutually assist one 
 another, like members of the same body, each one of which 
 performs its own function, not only for itself, but for all the 
 others."* Here we have the interaction of the sciences on 
 one another noticed with a force which Francis failed to 
 express when he faintly reproduced the same idea (Nov. 
 Org. I. 107). 
 
 * " Omnes sciential sunt connexae et mutuis se fovent auxiliis, sicut 
 partes ejusdem totius, quarum quaelibet opus suum peragit, non solum 
 propter se, sed pro aliis." (Opt4s Tertium, iv.) 
 
ROGER BACON. 81 
 
 B. Next, we find Roger intimating that there are two 
 sorts of observations the one passive and vulgar, the other 
 active and learned. The latter alone deserves the name of 
 experiment : 
 
 " There is," says he, " a natural and imperfect experiment 
 which is unconscious of its own power, which does not under- 
 stand its proceedings, and is in use among artisans, and not 
 among the learned. Over and above it, above all speculative 
 sciences and all arts, there is the art of making experiments 
 that are neither weak nor incomplete." But how will ex- 
 periments arrive at precise results ? By calculation, for 
 " Physicists must understand," says he, " that their science 
 is powerless, if they do not apply to it the power of mathe- 
 matics, without which observation languishes and is incapable 
 of certainty."* In Francis Bacon, again, we see the intimation 
 of the fact that observations are of two kinds; but he com- 
 pletely failed to grasp that which lies at the root of this 
 injunction the importance of calculation in scientific re- 
 searches and the absence of this requirement would by itself 
 suffice to vitiate his method and instruction even if these 
 were right in all other respects. The unfortunate fact that 
 he puts mathematics aside as an unworthy and deceptive 
 instrument proves his want of perception of the means and 
 ends of science. Roger, with masterful knowledge, sets forth 
 the foremost importance of mathematics with unerring force; 
 so that it is clear, as Lewes justly observes, that "after 
 having denounced the incompetence of the syllogistic method 
 of the schools, he endeavoured to substitute for it the 
 scientific method and its two handmaidens, mathematics and 
 experiment," thereby founding the Experimental School. 
 And Roger, lest he should seem faint-hearted, fears not to 
 reiterate his injunctions : " The exposition must be demon- 
 stration. That is impossible without experiment. We have 
 three means of knowledge authority, reasoning, experiment. 
 Authority has no value unless its reason be shown : it does 
 not teach ; it only calls for assent." 
 
 At a time when authority was supreme and was accepted 
 as an article of faith, he had the courage to write in this 
 * Opus Majus, p. 199 (J ebb's Edition). 
 
 G 
 
82 PROGRESS OF SCIENCE. 
 
 strain the courage, that is, to defy authority, and to advise 
 men to shake off its yoke, and examine all and everything 
 for themselves ! No wonder he spent twenty-four years in 
 confinement. " In reasoning," he continues, "we commonly 
 distinguish a sophism from a demonstration by verifying the 
 conclusions through experiment," and we find him constantly 
 insisting upon the necessity of " verification " and the " futility 
 of argument." * 
 
 C. Furthermore, " Armed," says he, " with experiment 
 and calculation, science must not be content with facts, 
 though these may have their utility ; it seeks truth ; it 
 wants to find out the laws, the causes canones, liniversales 
 regulce" f 
 
 D. Roger was not an advocate of calculation only; he 
 was a skilful practical MATHEMATICIAN himself. He rightly 
 considered mathematics as the key of several other branches, 
 and he resolved problems of mechanics, optics, astronomy, 
 by the use of geometry. 
 
 E. Roger was a real CHEMIST, for the way he speaks of 
 the properties of metals alone shows that he handled the 
 things he mentions. He knew that there are different kinds 
 of air (gases), and that one of them extinguishes a flame; he 
 invented the experiment of burning a candle under a bell- 
 glass to prove that the candle goes out when the air is 
 exhausted. But his most astonishing conception, perhaps, 
 was his anticipating the suggestion of our greatest modern 
 chemists, that the elements, as we know them, are evolved 
 from a primal matter (whether this be helium or protyle). He 
 says : " The elements are made out of v\y (the stuff of which 
 things are made], and every element is converted into the 
 nature of another element" (De Arte Chymia) as if indeed 
 he had a correct knowledge of the simple chemical elements, 
 and, at the same time, understood them to have been built 
 up of an earlier and simpler primordial kind of matter 
 endowed with potentialities capable of developing such 
 characters and energies, as the changeable conditions of 
 heat and pressure forced them to assume. It is of all things 
 
 * Opus Majus, p. 336-7 ; Opus Tertium^ Cap. xin. 
 t De CahstibuS) Cap. I. 
 
ROGER BACON. 83 
 
 the most unlikely that he should have known as much about 
 the elements as all this, but the fact remains that the idea of 
 chemical evolution is implied in the words we have quoted. 
 The only explanation we can suggest to account for such a 
 pregnant idea is that, as the alchemists sought to effect 
 transformations of all kinds and often succeeded, Roger was 
 led to the conception that nature could transform everything, 
 and at the beginning of things had compounded various 
 elements out of one a wonderful conception ! Need we 
 mention that Francis was unable to appreciate chemistry and 
 its founders ? his knowledge in this respect stopped at 
 boiling sandstone soft ! a comical experiment which no 
 chemist in the world ever accomplished before or since. 
 
 F. Roger was also a true PHYSICIST of high order too. 
 Before we see his more important work as such, we may note 
 in passing that he mentions a phenomenon which seems to 
 have been observed and recorded for the first time by him, 
 viz. the warm temperature of mines (a fact denied by Francis 
 Bacon), and the constancy of that warmth.* " In mineralium 
 vero locis invenitur calidas semper constans." We state 
 this detail for the mere purpose of showing the varied range 
 of his researches. It was in optics, however, that he proved 
 his competence. He treats of this branch in several works. In 
 >u Perspectives " he describes the eye and the sense of sight ; 
 explains the anatomy and physiology of the eye ; expounds 
 the laws of refraction and reflection ; and evidence is also 
 found in that work that he reconstructed the concentric 
 mirrors of Archimedes. In " M. irabili Potestate Artis et 
 Natures" he again treats of refraction of luminous rays, and 
 explains by it the mirage so frequent in the East. In Opus 
 Majus he deals (page 337) with magnifying glasses in a 
 superior manner. After describing concave and convex 
 glasses and the difference of their respective effects, he says : 
 " It is easy to conclude from the laws just spoken of that the 
 largest things may appear small, and vice verscl ; that remote 
 objects may appear quite close, and reciprocally ; for we can 
 cut glasses in such a manner, and adjust them in such a way 
 as regards our eyesight and exterior objects, that the beams 
 * Speculum Alchemiae, Cap. v. 
 
 G fl 
 
84 PROGRESS OF SCIENCE. 
 
 are broken and refracted in the direction we choose ; so that 
 we shall see a close or a remote object under whatever angle 
 we please ; and thus at an incredible distance we should read 
 the most minute letters, we could count the grains of sand 
 and of dust, on account of the great width of the angle under 
 which we should see them, for the distance by itself has no 
 direct importance, but the size of the angle has. And so, a 
 child would look like a giant, a man appear a mountain. 
 And likewise for distance ; so that a small army would seem 
 very large, and placed very far would appear very near, and 
 reciprocally. In this manner we could make the sun, the 
 moon, and the stars descend to us so to speak by bringing 
 their figure close to the earth." 
 
 From such a description to the telescope the distance is 
 not very great, and it is quite possible, as some writers have 
 thought,* that he constructed a telescope for his own use. 
 For we must remember that the Egyptians, and the Greeks 
 after them, made some of their astronomical observations by 
 the means of a long narrow tube, called dioptra, which 
 permitted them to isolate a star, and so prevent in a certain 
 degree the reflection and refraction that made accuracy of 
 observation well-nigh impossible for the naked eye. This 
 tube passed from the Greeks on to the Arabs, and Roger 
 Bacon must have known and used it. He does not describe 
 it particularly, but neither does he describe particularly any 
 of the instruments and apparatus in common use which he 
 mentions in Opus Tertium. And as he was on the one hand 
 fully aware of the properties of magnifying glasses, a man of 
 his rare ingenuity might very well have tried to adjust 
 magnifying glasses to the dioptra, and thereby have made 
 some rough kind of telescope. He would soon probably be 
 led to improve it and make it a more serviceable instrument 
 by the insertion into it of a smaller and narrower dioptra, 
 which would slide up and down so as to give a right focus. 
 His recommendation of the reform of the Calendar would 
 not, taken by itself, warrant the belief that he invented the 
 telescope, since ordinary visual observation and mathe- 
 
 * S. Jebb, Wood, Cuvier. Cuvier thought he could even recog- 
 nise in one of Roger Bacon's descriptions, that of the plain microscope. 
 
ROGER BACON. 85 
 
 matical calculation would suffice for advocating such a 
 reform; but when, together with that recommendation of his, 
 we consider his knowledge, his practical bent, his creative 
 mind, his probable acquaintance with the dioptra, and when we 
 read the foregoing description, we find it difficult to resist 
 the inference that he had a telescope. Whether he had 
 or not, however, the hints he gave were in themselves 
 almost certain to lead to the invention of that instrument. 
 
 Be that as it may, there is no doubt that in Optics he 
 stands as one of the pioneers of modern science. Not only 
 did he know the labours of Alhazen in that respect, but he 
 first had the eminent merit of describing the complicated 
 mechanism of the eye " with rare precision/' and even 
 suspected the action of the retina. And not only this, but 
 he maintained, against the authority of Aristotle, that the 
 propagation of light is not instantaneous. " Authors/' he 
 says, " Aristotle included, teach that the propagation of light 
 is instantaneous ; whereas the truth is that it takes time to 
 be effected a time very short, but indeed measurable."* 
 He also held that the light of stars belongs to themselves, 
 and is not reflected solar light. He tried, besides, to account 
 for stellar scintillation, and to explain the curious phenomenon 
 of shooting stars. These bodies, according to him, are not 
 real stars, but bodies relatively small (Corpora parvcs quan- 
 titatis] which traverse our atmosphere and are ignited by the 
 very rapidity of their motion ! This, indeed, shows his 
 marvellous scientific intuition. With the same rare power 
 of reading natural phenomena aright, he also explained the 
 rainbow by pointing out that the sun's rays are refracted by 
 the falling drops of rain, for he had noticed the " analogy of 
 the rainbow colours with those produced by drops of water 
 and by crystal " ; he desires us to consider " the objects 
 which present the same phenomenon/' and he mentions "the 
 hexagonal crystals from Ireland and India, though we are 
 not to suppose the hexagonal form is essential, since similar 
 colours may be detected in many transparent substances." 
 The Polish physicist Vitellio, who lived later on, also 
 ascribed the colours of the rainbow to the same cause. 
 * Opus Majus, 300, 398. 
 
86 PROGRESS OF SCIENCE. 
 
 G. But Roger Bacon was not a Mathematician, a Chemist, 
 a Physicist only, he was also an ASTRONOMER, for we have 
 an uncontested proof of his knowledge in astronomy, and that 
 is the reform of the Calendar to which allusion has already 
 been made. In " Specula Mathematical he devotes a whole 
 chapter to this important subject. 
 
 The Calendar. " The defects of the Calendar/' says he, 
 " have become intolerable to the sage and are in horror to 
 the astronomer. Since Julius Caesar's time, and in spite of 
 the corrections which have been tried by the Council of 
 Nicaia, Eusebius, Victorinus, Cyrillus, Bede, the errors have 
 become only more aggravated ; they have their origin in 
 the evaluation of the year, which Caesar believed to be 
 365 J- days, which every four years brings in the intercalation 
 of an entire day ; but this evaluation is exaggerated, and 
 astronomy enables us to know that the length of the solar 
 year is less by T^th of a day (about 1 1 minutes) ; thence it 
 happens that at the end of 130 years,* one day in excess 
 has been reckoned, and this error would be corrected if one 
 day was cut off after that period. 
 
 "The Church had at first fixed the Spring Equinox on 
 the 25th of March, and now on the 2ist; but the Equinox 
 does not arrive at that date. This year (1267), the Equinox 
 has come on the I3th of March, and every 125 years or 
 thereabouts it will come sooner by one day. The Church 
 was mistaken from the first : 140 years after the Incarnation 
 Ptolemy found that the Equinox came on the 22nd of 
 March; that was 1127 years ago. It now comes on the 
 I3th, that is 9 days sooner, and by dividing 1127 by 9,, 
 we obtain 125, which is the number of years at the end of 
 which the Equinoxes are advanced one day. The Church 
 pretends that the Winter Solstice fell on the day of the 
 Nativity of Jesus Christ, the 25th of December. That is 
 a mistake the verification of Ptolemy having fixed it on 
 the 22nd, in the year 140, it could not, in the year one, 
 be more than a little over one day later that is to say,, 
 between the 23rd and the 24th. 
 
 " Nor could the Spring Equinox in the year one be on 
 * Jn reality, 128 years. 
 
ROGER BACON. 87 
 
 the 25th of March, since Ptolemy for the year 140 fixed 
 it on the 22nd of that month ; still less can it be as it is 
 reckoned to-day on the 2 1st according to Church usage; in 
 reality it comes about the I3th, since it advances by one day 
 in 124 years. The Equinoxes then are not fixed occurrences 
 in the first place, and in the second place they do not come 
 on the days indicated by the Church." 
 
 We see that Roger Bacon indicated both the necessity 
 and the nature of the reform with perfect clearness and 
 precision. The Arabs, before him, had determined, it is 
 true, the length of the year to be 365 days 5 hours 48 
 minutes 1 1 seconds ; but the fact remains that Roger Bacon 
 had acquainted himself with all the elements of the problem, 
 and by dint of observation and calculation, solved it with 
 remarkable sagacity. Nor was he less exact and sagacious 
 in correcting errors in reference to lunations : . 
 
 " The present Calendar," says he, " wrongly indicates new 
 moons ; in 76 years the new moon anticipates the period 
 fixed by the Calendar by 6 hours 40 minutes ;* so that at the 
 end of 356 years the error will amount to one entire day/' 
 And adding other errors to that one, he shows that after 4,266 
 years there will be full moon in the heavens, and new moon 
 in the Calendar. His petition to the Pope to reform the 
 Calendar ends by the following appeal : " A reform is 
 necessary; men trained in calculation and astronomy are 
 aware of it, and rail at the ignorance of the prelates who 
 maintain the present conditions. Unbelieving philosophers, 
 Arabian and Hebrew, the Greeks who live among Christians, 
 as in Spain, Egypt, and eastern countries, and elsewhere too, 
 have in horror the stupidity which the Christians exhibit in 
 their chronology and the celebration of their feasts. And yet 
 the Christians have at present enough of astronomical 
 knowledge to rely upon a safe basis. Let Your Reverence 
 command it, and you will find men who will be able to 
 remedy these defects those I have spoken of, and others 
 besides there are thirteen in all without counting their 
 infinite ramifications. If this glorious work were to be 
 accomplished in the time of Your Holiness, men would see 
 * More precisely, 6 hours 8 minutes. 
 
88 PROGRESS OF SCIENCE. 
 
 one of the greatest, best, and most beautiful achievements 
 ever attempted by the Church of God." 
 
 This is not all. Roger Bacon had the daring to question 
 the Ptolemaic System on every point, and he attacked it 
 precisely on the point which, later, attracted the attention a*nd 
 labour of Copernicus. Space prevents us from going fully 
 into this matter. 
 
 In all this, then, Roger proved that he was an astronomical 
 observer and mathematician of high order. 
 
 H. There is another thing which he seems to have 
 studied, or at least deeply pondered over, and the outcome 
 of his meditation on that subject is not the least astonishing 
 evidence of his universality. Alchemy, which he practised 
 with perseverance, led him almost to anticipate the doctrine of 
 animal magnetism. " The soul," says he, "acts upon the 
 body, and its chief act is speech. Now speech, actuated by 
 profound thought, by direct will, by strong desire and a 
 powerful conscience, keeps in itself the power which the soul 
 has communicated to it, and carries that power outside ; it is 
 the soul which through speech acts both upon physical forces 
 and upon other souls, which bend to the will of the 
 operator.* Nature obeys thought, and the acts of men have 
 an irresistible energy. Therein are explained characters, 
 charms, and sortileges ; therein also lies the explanation of 
 miracles and prophecies, which are only natural phenomena. 
 A soul which is pure and sinless can thereby command 
 elements and change the order of the world ; this is why the 
 Saints have wrought so many prodigies/' 
 
 When we bear in mind all these proofs of scientific 
 genius, we cannot wonder that Humboldt should have 
 considered Roger Bacon as " the greatest apparition of 
 the Middle Ages/'f and should have endorsed the eulogium 
 of Leland : " He went round and into the whole of philo- 
 sophy in such a manner that he left no part of it unexplored." 
 
 I. There is still another aspect in which Roger Bacon 
 ought to be considered his practical prescience, or his 
 faculty of conceiving practical applications. For, when 
 
 * Opus Majus, p. 251 ; Opus Tertium, Cap. XXVI I. 
 f Cosmos, Vol. II., p. 398. 
 
ROGER BACON. 89 
 
 once the laws of nature have been discovered, speculation 
 has ended, and application commences. No force is so 
 hidden in nature but man's mind can reach it; none so 
 tremendous but his will can master it. If here, on the 
 subject -of the possibilities of science, Roger Bacon gives 
 a free rein to his imagination (as he does in a measure 
 when speaking of the power of magnifying glasses see 
 page 84), it must be owned, nevertheless, that his expec- 
 tations were not altogether extravagant, since we have now 
 suspension bridges, submarine boats, diving-bells, balloons, 
 steamers, railways that is, marvels not unlike those which 
 he predicted were possible achievements. 
 
 " Instruments will be made," he says,* t( to navigate 
 without the assistance of rowers, and float and direct the 
 largest ships, with one man to conduct them, and more 
 quickly than if they were full of sailors ; vehicles (carriages) 
 which will roll along with inimaginable speed without any 
 team ; instruments to fly aloft, in the middle of which 
 a man will move some spring which will put in motion 
 artificial wings beating the air like those of birds ; a small 
 instrument three fingers in length and the same size in height 
 capable of raising and lowering incredible weights without 
 fatigue. With its assistance it will be possible for one to fly 
 with his friends from the depth of a dungeon, and come down 
 on the earth at will. Another instrument will be used to drag 
 any resisting object on an even ground, and will enable one 
 man to carry a thousand persons against their will ; there will 
 be an apparatus to walk on the bottom of the sea and of rivers 
 without any danger ; instruments to swim and remain under 
 water; bridges over rivers without any piles or columns; in 
 fact, all kinds of marvellous machines and apparatus." 
 
 Out of the wonderful variety of his achievements, we have 
 steadily to remember that Roger's pre-eminent work, and 
 therefore paramount claim on us, was the introduction of the 
 EXPERIMENTAL METHOD the starting-point of modern pro- 
 gress in Europe. To him, then, belongs the glory of having 
 pointed out, and traced, the sole road of science, of having 
 " created both the law and the practice of experimentation." 
 
 * De Mirabili. 
 
9o PROGRESS OF SCIENCE. 
 
 It will not appear unfair if we now ask what Francis 
 Bacon has done which can possibly be compared with the 
 wondrous work of Roger ? 
 
 True it is that Roger Bacon's work was " the continuation 
 of that of the Arabs," as some writers have said with ludicrous 
 assumption of authority by way of depreciation ; but if his 
 was to be truly scientific work, it must of necessity have 
 been a continuation of that science which existed before 
 him. That filiation was the only possible one, and what 
 is more, the only one worth anything. By tradition, 
 training, erudition, originality, practical work, discoveries, 
 the Arabs, as we have seen, had for four centuries been at 
 the head of civilisation. The passion for natural science, 
 which by degrees brought in the conception of a universe 
 ruled by immutable laws, sprang among, and was derived 
 from, the Arabs and chiefly from Avicenna and Averroes 
 who were the real ushers of the scientific Revival. They 
 were the sole custodians of knowledge from India to Spain, 
 whilst Europe was intellectually benumbed by anarchy; 
 and the fact that Roger Bacon was their pupil and their con- 
 tinuator constitutes his most invaluable merit, and one of 
 his chief claims to remembrance ; for, although he came 
 after such masterly teachers, he left his mark for all times 
 by his daring innovations, and the impetus he cannot fail 
 to have given far and wide in his and subsequent times 
 until the Revival. Francis Bacon, sad to say, with his wont 
 presumption, despised both the Arabs and their pupil one 
 of the five most admirable geniuses of ten centuries.* 
 
 No comment is necessary. The contrast we have drawn 
 between the two Bacons is so strong, that once perceived, 
 it can never be forgotten. The splendid work of the first 
 Bacon enables us to determine the shadowy work of the 
 second ; we can measure the distance that separates them ; 
 we can distinguish the man of science from the pretender. 
 And if the distance is so great, how much greater is that 
 which separates Francis Bacon from such men as the princes 
 of science, who, before and around him, are the true repre- 
 sentatives of the Revival ! 
 * Hildebrand, Thomas Aquinas, Albertus Magnus, Dante, Roger Bacon. 
 
CHAPTER VIII. 
 
 CHARACTER OF THE REVIVAL. 
 
 THUS far we have seen the advance in science made among- 
 the Greeks, the Arabs, and during the Middle Ages of Europe. 
 We have now to give special attention to the era called 
 the Revival, the general character of which it is important 
 to briefly indicate. One hundred and seventy- five years 
 roughly (1450 1625) may be estimated as the time con- 
 stituting this period. The intellectual movement of the 
 previous half-century tended to bring it about ; it certainly 
 prepared the Western world for it. We see this exhibited 
 in the development of modern languages, and the reviving 
 of the Greek language as early as 1395. Five years later 
 AURISPA brought to Italy two hundred and thirty-eight 
 Greek manuscripts including Plato and Pindar. The 
 imminent capture of Constantinople by the Turks induced,, 
 thus early too, numerous learned Greeks to leave that capital 
 and seek a safe asylum in Italy. The rapid advance of art 
 and science were other unmistakable indications of the bent 
 taken by the European mind. The Pope NICHOLAS V. 
 (1447 55) an d COSMO DE' MEDICI (142964), the first 
 by the foundation of the Vatican Library, the second by 
 his protection of artists, poets, scholars, and scientists, 
 represented the tendency of the age. But the Revival was 
 especially inaugurated by two decisive events, dissimilar 
 in kind but uniting their effects into one stream. The first 
 was the SEIZURE OF CONSTANTINOPLE by the Turks 
 (1453, May 29th) which caused a general flight of culti- 
 
92 PROGRESS OF SCIENCE. 
 
 vated Greeks to Italy. The refugees brought over the 
 only kind of wealth they could carry Greek books the 
 works of the dramatists, the works of poetry, history, juris- 
 prudence, philosophy, and science of the ancient Greeks,* 
 which, together with the discovery of numerous specimens 
 of statuary and architecture, revealed the whole civilisation 
 of the ancient world. The second event was the invention 
 of PRINTING (1453), the weighty and momentous conse- 
 quences of which were probably never equalled by any other 
 single event in the records of mankind. Its two immediate 
 effects were, first, the cheapening of books and their multi- 
 plying to infinity; and, second, the substitution of reading 
 for pulpit teaching. The priest ceased to be the sole 
 instructor of the people. All men could now imbibe infor- 
 mation and learning from their authentic sources. Printing 
 propagated the works of antiquity throughout the West. 
 The study and imitation of those precious monuments, as 
 -eminent writers have pointed out, were to precede original 
 inspiration. But the universal resurrection of ancient litera- 
 ture, received everywhere with enthusiasm, at once exercised 
 a paramount influence upon the genius of Europe. For 
 gradually, Roman jurisprudence replaced feudal law, Greek 
 and Latin poetry replaced sacred poetry, the philosophers 
 replaced the Fathers of the Church, free inquiry shared with 
 religious ideas imperial authority over the mind, the ideas 
 of political government of the ancient world replaced theo- 
 cratical and feudal notions. The work of the age is to 
 have created general interests and general notions which 
 affected nations and governments alike. The Revival era 
 hastened the dawn of great monarchies in the political 
 world, and hastened the immense expansion of commerce 
 and industry in the social world, whilst in the religious 
 sphere it caused the growth of freedom of conscience which 
 brought in the REFORMATION, and in the moral sphere it 
 caused that growth of literature, rationalism, and science 
 which resulted in the CLASSIC SCHOOL. This school was 
 
 * The Greek refugees did not bring books only, they brought over 
 their own culture as well, and they became teachers and expounders, thus 
 giving momentum to the strength of progress. 
 
CHARACTER OF THE REVIVAL. 93 
 
 not a literary movement only that was its outer form 
 but a much deeper movement which obtained vital sway 
 over the West : " the learned were lost in admiration, not 
 alone for the ancient writers, but for the entire fabric of 
 the society of antiquity," for its manners, for its opinions, 
 its institutions, its arts, its philosophy, its science. No- 
 period in history was ever so encouraging-, so brilliant, so 
 lofty, so beneficent, and so commanding as that age which 
 spread enlightenment in every direction. Such was the 
 work of the Revival. One of the most direct results bearing 
 on science, which the capture of Constantinople and the 
 invention of the printing-press brought about, was the study 
 of PLATO AND ARISTOTLE. For the first time in Europe 
 both these philosophers were seen in their own works, and 
 both were at last understood. The effect of this study was 
 that the unadulterated Plato overcame the Platonism of the 
 Alexandrians, whilst the unadulterated Aristotle extinguished 
 the " base Aristotelian doctrines of the schools/' so that 
 their real philosophy and science, speaking for themselves, 
 gave a strong impetus to the sciences which were already 
 taking deep root at the time. 
 
 Before completing the outline of the scientific advance 
 made during this eventful era, it will not be inappropriate 
 to clear up a perplexing point of history. 
 
 In viewing the universal progress accelerated in Western 
 Europe by the migration of the learned men of Constanti- 
 nople to Italy, it may seem a mystery that accession to- 
 Greek knowledge should not have been gained at a far 
 earlier period than the XVth century. If Greek learning 
 was to be so beneficial, what reason was there for its being 
 confined in the East for so many ages ? Were the Greeks 
 averse to sharing a part of the treasure they possessed with 
 any of the nations of the West ? It could not be so, since 
 they flocked to Italy as early as the XlVth century bringing 
 ancient manuscripts. Was the West so shrouded in igno- 
 rance as to be unaware of the existence of an intellectual 
 world at Constantinople ? Or, was it so blinded by barbaric 
 pride as to despise that mental culture ? Neither alternative 
 could have been the case after the Crusades, since the 
 
94 PROGRESS OF SCIENCE. 
 
 Crusaders themselves had been struck by the civilisation of 
 the Greek Empire, had admired it as vastly superior to their 
 own, and had brought back therefrom improving notions and 
 novel ideas. Was the want of communications so great as 
 to prove an insuperable difficulty ? No ; for the renascence 
 of industry, commerce, and navigation had gradually broken 
 down that obstacle as early as the Xlth century. On the 
 other hand, how was it left to the hated Saracens in the first 
 instance to teach Europe science and philosophy, and prepare 
 its mind for a further evolutionary step ? 
 
 All these questions are satisfactorily answered by a fact 
 which, though it has not escaped attention, has not as yet 
 had one of its consequences pointed out by historians with 
 due force. There were, for nearly a thousand years, roundly 
 speaking, until the XVth century, two Europes in reality a 
 Greek and a Latin and they were completely severed 
 intellectually by the GREAT SCHISM, begun with the quarrel 
 of Leo, the Isaurian, with Pope Gregory II. on the question 
 of image-worship (726), and irrevocably established by 
 ritualistic differences, in 1043, m Hildebrandt's time. The 
 severance of Christendom into two unyielding Churches the 
 Greek and the Roman consummated that separation of the 
 East from the West, which the removal of the capital of the 
 Empire from Rome to Byzantium by Constantine (330), and 
 the subsequent barbarian invasion of the West, had politically 
 already brought about. The Great Schism proved, between 
 the two sections of Europe, an effective Chinese Wall. The 
 Roman Church forbade the West, under the penalty of ex- 
 communication, to have any intercourse with the " heretical " 
 Greeks in matters theological and the interdict practically 
 extended to Greek learning : any Greek teaching aroused 
 suspicion. The Saracens, on the other side, imposed their 
 presence upon Western Europe by the force of conquest. If 
 their vicinity could not be helped, their learning and teaching 
 at least could be checked by repression, and were, wherever 
 that course could be adopted. This learning, however, 
 slowly filtered through the boundaries of Islam, and, in time, 
 made itself felt in Europe as we have seen. But as it was 
 scientific in the main, and as science could at best attract 
 
CHARACTER OF THE REVIVAL. 95 
 
 but a small minority, it could not command that general 
 interest or exercise that general influence over the Western 
 mind which the Revival of Greek learning secured after 1453. 
 Varied as the Revival was in its nature, yet it was by its 
 literary element especially that its force powerfully operated. 
 It was on account of its being literary that it was 
 supremely and universally decisive. It may be said that had 
 the Greek world been accessible to the Western mind long 
 before it actually was, the intellectual benefits derived from 
 it would in the same way have been literary the Greeks, 
 as Christians, devoting but little attention to science and 
 being engrossed by theology and letters. In any case, 
 then, the action of the Arabs upon us would have 
 been just as necessary, and would have affected mediaeval 
 Europe in the same manner and degree as it did. Western 
 Europe was irrigated by the scientific stream of the Arabs 
 first, and by the literary and artistic stream of the Greeks 
 at a later period at a time, that is, when the Arabian plant, 
 dried up in Islam itself but growing up healthily in Christen- 
 dom, showed that the European soil had been duly 
 fertilised for the reception and cultivation of universal 
 knowledge. 
 
 That the Revival was delayed so long was not an unmixed 
 evil, since its postponement permitted Europe to undergo 
 a lengthy period of preparatory training which secured its 
 certain and rapid success, for learning, when it at last came, 
 was propagated like wildfire ; that it came so late was mainly 
 due to the Great Schism an evil, therefore, not altogether 
 without compensation, since it gave Europe the time necessary 
 for its maturation. 
 
 Now that the general character of the Revival has been 
 indicated, and the tardiness of its birth accounted for, we 
 may proceed to complete the sketch of its eminent scientists 
 begun in Chapter V., by presenting the aggregate of their 
 work. 
 
CHAPTER IX. 
 
 THE SCIENTISTS OF THE XVTH AND XVITH CENTURIES. 
 
 IN the table of the mediaeval and Revival periods, given 
 in that chapter, we set forth two groups of facts the first 
 embraces the large number of inventions up to the year 1625; 
 the second, the large number of men of science over half a 
 hundred who appeared before or about the end of the XVIth 
 century. In order now to enable the reader to perceive the 
 aggregate achievements made in the various branches of 
 research, we shall set forth a rapid summary of the 
 same period presenting it under a somewhat different 
 aspect. 
 
 First, then, we have a cluster of Mathematicians, such 
 as Stiefel, Fernel, Tarlaglia, Cardan, Ferrari (1522 1565), 
 VlETEj Napier, and SNELL, whose services to pure mathe- 
 matics, or mechanics, or physics, made rapid progress in 
 these branches a matter of absolute certainty in the near 
 future. Each of these men left sterling work behind him 
 which became in one way or another a new point of 
 departure. 
 
 In the Natural Sciences and Medicine we find the labours 
 of Gesner and Belon as regards Zoology ; of Tragus, C^ESAL- 
 PINUS, and Lobel as regards Botany ; of PARACELSUS, Pare, 
 Coiter, as regards Medicine, which base these branches on solid 
 foundations. Nay, more, Anatomy had been studied ever since 
 Mondini (1315), and its rise a radical accession to natural 
 philosophy may be said to have completed the nascent 
 system of modern science. Achillini, Fabricius, Caesalpinus, 
 
SCIENTISTS OF XVTH AND XVlTH CENTURIES. 97 
 
 Servetus, Solomon Albert! (1540 1600), VESALIUS, Fallopius, 
 Eustachius, Arantus, Santorio, and Asellius had been worthy 
 precursors of Harvey, not by their excellent descriptions of 
 the human frame only, but by their physiological discoveries. 
 They had studied the brain, the nerves, the cartilages, and 
 the bones with success ; they had discovered cellular tissue, 
 the lacteal vessels, the choroid plexus, the tube from the 
 throat to the ear-drum, the refluent course of the blood in 
 the veins, the valves in these vessels, the function of the skin, 
 thus laying the foundations of the science, and preparing the 
 way for Harvey. 
 
 And all round we find the same tidal advance : some 
 particular facts threw great light upon the practical and 
 intellectual course men were taking and pursuing. A few 
 typical instances will suffice to show this. A Waltherus, in 
 the XVth century, made use of clocks in his astronomical 
 observations to avoid haphazard conclusions ; a Roman 
 Churchman, Cardinal Cusa (1401 1464), some time before the 
 appearance of Copernicus, believed in the solar system which 
 science has proved to be correct a fact, this, proving 
 that authority was gradually losing its hold upon men, and 
 that observations were becoming the first principle of re- 
 search. Within another hundred years or so, this system was 
 all but universally accepted by sound minds, since we find 
 GIORDANO BRUNO actually daring to ventilate that system at 
 Oxford, one of the strongholds of orthodoxy (1580 1583) 
 a forcible evidence of the rapid progress ideas had been 
 making. Such was the tendency of the times. 
 
 Further examination of the field shows how extensive 
 and varied it was. In the sphere of Observation, Toscanelli 
 and his gnomon^ one hundred and fifty years before Harvey's 
 time, Peurbach and his Ephemerides,Z>/z0 and his reform of the 
 Calendar, Caesalpinus and his double discovery as regards 
 crystallisation and oxidation, Alpinus and his diagnosis, 
 Plater and his classification of disease, Palissy and his dis- 
 covery of the origin of springs, Tycho Brake and his minute 
 description of the "new star" of 1572 74, and Kepler's of 
 the "new star" of 1604, to speak of a few only, stand 
 out in strong relief when opposed to the fanciful records 
 
 H 
 
98 PROGRESS OF SCIENCE. 
 
 of the Schoolmen, and show that Roger Bacon had regal 
 successors. 
 
 In Practical and Theoretical Science, in metallurgy, 
 chemistry, geology, astronomy, physics, the XVth and XVIth 
 centuries were equally fruitful of results. AGRICOLA had 
 created modern METALLURGY ; Antonio de Dominis had ex- 
 plained the correct theory of the rainbow, which Harriot made 
 clearer still ; MERCATOR had created modern GEOGRAPHY ; 
 Santorio, with true scientific insight, had shown the use, not 
 only of the thermometer, but also of the hygrometer, and 
 even of the scales in physiological research ; Ubaldt had 
 developed mechanical laws ; STEVINUS had published his 
 book on the principles of equilibrium, determined the funda- 
 mental property of the inclined plane, and solved the general 
 problem of forces acting obliquely elucidating all along some 
 of the LAWS OF PRESSURE, motion, THE LEVER, and the 
 equilibrium of liquids ; PORTA had invented the CAMERA. 
 OBSCURA, the magic lantern, and demonstrated light to be the 
 cause of vision ; Tycho Brahe had constructed several in- 
 struments of great precision, catalogued nearly 800 fixed 
 stars, and drawn up the RUDOLPHINE TABLES after twenty- 
 five years' incessant observations an immortal work ; he- 
 had determined the COURSE OF COMETS, and shown the third 
 inequality of the moon ; CASTELLI had founded hydraulics;. 
 SNELL had discovered the LAW OF REFRACTION, one of the 
 most important in optics ; GILBERT, one of the great masters 
 of the inductive method, had determined the principles of 
 MAGNETISM and ELECTRICITY after years of experiments one 
 of the best proofs that the experimental method was used in 
 earnest ; he had determined the poles of the magnet, described 
 the DIFFERENCE BETWEEN THE MAGNETIC and the ASTRO- 
 NOMICAL meridian, demonstrated the POLARISATION OF IRON 
 BARS by being placed in the direction of the magnetic meridian 
 teaching that the EARTH IS A MAGNET, which accounted, 
 according to him, for the inclination and declination of the 
 compass. Harvey had explained the CIRCULATION OF THE 
 BLOOD a discovery of supreme importance in physiology, 
 due to deductive and inductive reasoning in an equal degree. 
 
 Leonardo da Vinci, " whose knowledge/' as Hallam 
 
SCIENTISTS OF XVTH AND XVlTH CENTURIES. 99 
 
 justly says, "was almost preternatural," had advanced 
 several branches of science. He had cultivated the MATHE- 
 MATICAL AND PHYSICAL SCIENCES, NATURAL HISTORY, 
 chemistry, ENGINEERING, and MECHANICS. In this last 
 branch, he had anticipated by more than a century Stevinus 
 and Galileo with regard to the laws of the lever and the fall 
 of bodies, and even written on the equilibrium of water. 
 " The progress of the science of mechanics was necessary 
 before the Copernican system could be developed," and it 
 was Leonardo who improved this science. He understood 
 the law regulating the flight of projectiles. He gave a clear 
 exposition of the theory of forces obliquely applied on a 
 lever*; was well acquainted with the earth's yearly 'motion ; 
 understood the LAWS OF FRICTION, and likewise the principle 
 of VIRTUAL VELOCITIES the golden rule of mechanics ; aerial 
 perspective, the nature of coloured shadows, the use of the 
 iris, the effects of the duration of visible impressions on the 
 eye; he INVENTED water-mills, water-engines, canal and 
 river locks, A WATER PUMP, and anticipated Castelli in 
 HYDRAULICS ; he invented a spinning machine, a planing 
 machine, an automatic walking lion ; designed a STEAM 
 CANNON; described the CAMERA OBSCURA before Porta's 
 invention ; he studied the flight of birds ; attempted to make 
 an apparatus for flying ; occupied himself with the " FALL OF 
 BODIES on the hypothesis of the EARTH'S ROTATION on 
 its axis ; " he treated of the TIMES OF DESCENT along in- 
 clined planes and circular arcs, and of the nature of machines. 
 He "considered with singular clearness respiration and 
 combustion, and foreshadowed one of the great hypotheses of 
 geology the UPRISING OF CONTINENTS " after tracing the 
 origin of Fossils. t He also studied chemistry and anatomy : 
 his anatomical designs are the finest in existence. 
 
 * Appendix IV. 
 
 f "The sea," says Leonardo, "alters the equilibrium of the earth ; the 
 shells which are found heaped up in the different layers of soil have 
 necessarily lived in the same place, which was occupied by the sea. The 
 great rivers carry into the ocean the sediment which they roll along in 
 their course. The banks, formed by these deposits, have been covered 
 over by other and later clay layers of various thickness, and what was the 
 bottom of the sea has become the summit of mour. tains." 
 
 H 2 
 
ioo PROGRESS OF SCIENCE. 
 
 His labours were pursued with unsurpassed success by one 
 who may be called the greatest representative of modern 
 science with Newton, viz. Galileo. 
 
 Galileo invented the earliest (air) THERMOMETER, and 
 improved Janssen's useless TELESCOPE and MICROSCOPE. By 
 the invention of these three instruments, he ensured the rapid 
 development of THERMOLOGY, ASTRONOMY, and PHYSIOLOGY. 
 By means of his telescope, which magnified only eight times, 
 he discovered the SUN'S SPOTS and the revolution of the sun 
 on its axis in 28 days ; discovered the four MOONS OF 
 JUPITER (1610)* demonstrating the Jupiter system to be a 
 miniature of the solar system ; discovered Venus to be a 
 planet of our system, and the phases of that body a discovery 
 which was another solid support of the Copernican doctrine, 
 and caused its general acceptance ; explained the revolutions 
 of the planets to be in the same direction as that of the sun 
 on its axis ; discovered the mountains and valleys of the 
 moon, also the reflection of the earth-light on its dark disk, 
 and determined the true nature of our satellite ; he also 
 determined the true nature of the nebulae resolving some 
 into stars; discovered innumerable fixed stars which had 
 never been seen or suspected by man forty in the 
 PLEIADES alonef a death-blow to the doctrine of the 
 human destiny of the universe, since these bodies could 
 not have been created for the purpose of illuminating the 
 night for human beings. So far the ASTRONOMER. As a 
 MATHEMATICIAN and PHYSICIST, his discoveries were not 
 less important and decisive. 
 
 DYNAMICAL MECHANICS are under great obligation 
 to him. He discovered the LAWS OF FALLING BODIES in 
 which the descent is due to the influence of a permanently 
 acting force (attraction), the velocity increasing (at the rate 
 of 32 feet per second) in consequence thereof; saw that a 
 
 * A fifth moon was discovered (September 9th, 1892) by Professor 
 Barnard (of the Lick Observatory). This is the smallest of Jupiter's 
 satellites ; it is close to the planet (112,000 miles from the centre), makes 
 two revolutions in one day, and is the fastest satellite known to us with 
 the exception of Mars' minor moon, discovered in 1877. 
 
 t There are no less than 2,600 in that system. 
 
SCIENTISTS OF XVTH AND XVlTH CENTURIES. 101 
 
 body moving slowly or swiftly is equally affected by gravity 
 irrespective of its weight thus eradicating the old Aris- 
 totelian error that a light body falls less rapidly than a heavy 
 one; showed also that a body projected horizontally must 
 have a horizontal motion and also an accelerated motion 
 downward determining, that is, the trajectory described by 
 a body not falling vertically ; he determined (before Newton 
 came, as we see) the connection between the spaces of descent 
 and the times and illustrated facts experimentally by the 
 use of inclined planes ; he demonstrated that the earth's 
 ATTRACTION ACTS EQUALLY on all bodies, proving it by 
 the use of hollow spheres in which various substances of 
 different weight suspended by strings of equal length oscil- 
 lated in equal times ; and from the Pisa Tower proved that 
 the velocity of falling bodies is independent of their weight ; 
 so that he disclosed the law of falling bodies and that of the 
 composition of forces two great generalisations of terrestrial 
 physics, being thereby the founder of terrestrial dynamics. 
 But collaterally with these great discoveries he had established 
 the THREE LAWS OF MOTION : I. A body remains at rest 
 or perseveres in uniform motion in a straight line unless 
 disturbed by another force; II. The change of motion is 
 proportional to the motive force impressed and in the 
 direction of the line in which the force is impressed ; III. To 
 every action is ever opposed an equal reaction ; or, the 
 mutual actions of two bodies upon each other are ever 
 equal and opposite. To Galileo, therefore, we owe the 
 discovery of the law of the uniformity and perpetuity of 
 motion indeed, he ESTABLISHED the doctrine of the PER- 
 MANENT GOVERNMENT OF THE WORLD BY LAW a doctrine 
 only strengthened by the discoveries of Kepler and Newton. 
 Further, Galileo, concurrently with Cavalieri (1598 1647), 
 found the CALCULUS OF THE INDIVISIBLE, and concurrently 
 with Stevinus, placed HYDROSTATICS AND HYDRODYNAMICS 
 on exact foundations, by his discovery of the laws (known 
 by the Alexandrian school) respecting the mechanical 
 properties of water i.e. the laws of the EQUILIBRIUM OF 
 FLUIDS. He was the first to discover that water raised by 
 the suction pump cannot ascend higher than 34 feet, but it 
 
102 PROGRESS OF SCIENCE. 
 
 was Torr'celli who discovered the reason to be due to the 
 pressure of the atmosphere. Galileo also established another 
 LAW OF MECHANICS of great importance in determining 
 the balance of machines, that any force that will lift a weight 
 of two pounds up one foot, will lift a weight of one pound 
 up two feet the first step towards Joule's great determina- 
 tion. He made excellent observations on sound and MUSICAL 
 NOTES viz. that the greater the number of vibrations the 
 higher the note will be. He also found the law of the 
 PENDULUM by observing that the vibrations (swings), long 
 or short, of the chandelier of the Pisa Cathedral were made 
 in equal times hence the invention of the pendulum clock 
 (by Huygens). He also found one of the laws of RADIANT 
 HEAT ; endeavoured to determine the weight of air ; observed 
 numerous phenomena regarding magnetism, gravitation, and 
 acoustics. On the last subject, he taught, like Pythagoras, 
 that SOUND IS A VIBRATION OF THE AIR " which we feel 
 when it reaches the drum of the ear." (See Newton, 
 page 219.) 
 
 The importance of Galileo's creative works on Barology 
 cannot be exaggerated : they substantially extended natural 
 philosophy being nothing less than the opening of a whole 
 department of physics, and the creation of a new class of 
 inquiries, a valuable function of which was to develop the 
 resources of experimentation.* 
 
 Galileo by these numerous achievements proved himself a 
 masterly MATHEMATICIAN and ASTRONOMER and a supreme 
 PHYSICIST. But, we repeat, the highest philosophical import 
 of all his discoveries was the pre-eminent fact of the per- 
 manency of natural laws. 
 
 Closing this glorious list of great men comes Kepler, 
 the contemporary of Galileo, and in some respect his rival. 
 Kepler improved the telescope using two CONVEX LENSES 
 (instead of a concave and a convex lens as Galileo had 
 done), by which improvement the instrument was made 
 more powerful, and covered a wider span of the heavens at 
 one time. He explained the TIDES to be an effect of the 
 moon's attraction a view entertained in antiquity by 
 
 * Comte. 
 
SCIENTISTS OF XVTH AND XVlTH CENTURIES. 103 
 
 Fosidonius ; was one of the first to notice the rotation of the 
 SUN ON ITS AXIS, "like an orator in the midst of a crowd/' 
 he says, "who can face all his auditors simply by turning 
 upon himself" ; he indicated for the first time the UNDU- 
 .LATORY THEORY OF LIGHT; determined the refraction of 
 light to be nil at the zenith; expressed his belief in the 
 WEIGHT OF AIR ; in the sun being a magnet ; put forward 
 the empirical law, known as BODE'S LAW, by which the 
 distances of the planets seem to follow an arithmetical pro- 
 gression (see Piazzi, further on); he correctly foretold the 
 dates of the transits of Mercury and Venus ; he also explained 
 the correct use of the different PARTS OF THE EYE ; lastly, 
 he formulated the three laws of movement known as 
 KEPLER'S LAWS, which, constituting as they do one of 
 the great triumphs of mathematics, made the discovery of 
 Newton's law of gravitation a possibility. This, Kepler 
 accomplished after perseveringly observing the motions of 
 Mars and the laws, meant to apply to Mars only, he found 
 to apply to all planets. The result was obtained only after 
 years and years of labour but they are laws found for all 
 times ! Kepler's laws are : i. Orbits, of which the sun 
 occupies a focus, are elliptical (1609) > n - The areas de- 
 scribed by a line drawn from the planet to the sun are 
 proportional to the times, or, planets describe equal areas 
 about the sun in equal times (1609) ; in. The squares of 
 the period of complete revolution, or periodic times of any 
 two planets, are proportional to the cubes of their mean 
 distances from the sun or, the squares of the periodic times 
 of the planets are proportional to the cubes of their distances 
 {1618) a law which, in 1622, he proved to hold good for 
 the satellites of Jupiter as regards their primary. The third 
 law contains the principle of Newton's laws.* It is not too 
 much to say that the modern system of astronomy deserves 
 far better to be called the Keplerian system than the Coper- 
 nican. Kepler, speaking of attraction and gravitation, says : 
 " Everything is simple in the variety of nature. Thus, in a 
 river, the simple motion is the tendency of water to repair to 
 the centre of the earth, but as the way is not direct, the 
 
 * See page 201. 
 
104 PROGRESS OF SCIENCE. 
 
 water follows all the sinuosities of the ground, and the motion? 
 is complicated, to all appearances, by foreign causes." And 
 from chapter xxxii. to xlii. (of his great work) every passage,, 
 almost, alludes to attraction and gravitation. If Kepler was- 
 a MATHEMATICIAN chiefly he should also be remembered as 
 an astronomer, A PHYSICIST, an optician of a high order. 
 
 We may suitably complete this brief chronicle of the 
 advance made in the Experimental School during the Revival, 
 by quoting what Leonardo da Vinci said about experi- 
 ment, verification, and the Inductive Process, to show 
 what a powerful and precise instructor and advocate he was- 
 of those very principles which Roger Bacon had already 
 proclaimed as the indispensable requirement of scientific 
 progress. He says 
 
 " Theory is the general and practice the soldiers. 
 
 " Experiment is the interpreter of the artifices of nature. 
 It never deceives us; it is our judgment itself which some- 
 times leads us astray, because we expect from it effects 
 which are contrary to experiment. We must consult experi- 
 ment by varying the circumstances till we have deduced 
 from it general laws ; for it is it which furnishes true laws. 
 
 " In the study of the sciences which depend on mathe- 
 matics, those who do not consult nature, but authors, are 
 not the children of nature ; they are only her grandchildren. 
 Nature alone is the master of true genius. 
 
 " In treating any particular subject, I would first of all 
 make some experiment, because my design is first to refer to- 
 experiment, and then to demonstrate why bodies are con- 
 strained to act in such a manner. This is the method which 
 we ought to follow in investigating the phenomena of nature. 
 It is very true that nature begins by reasoning and ends with 
 experiment; but it matters not; we must take the opposite 
 course ; as I have said, we must begin by experiment, and en- 
 deavour by its means to discover general principles. 
 
 "Experience has been the mistress of those who have 
 written sensibly, and I shall in any case proclaim her my 
 mistress. Truth is the daughter of time alone, as wisdom is 
 the daughter of experience. 
 
 " Sound judgment is derived from sound understanding; 
 
SCIENTISTS OF XVrn AND XVlTH CENTURIES. 105 
 
 (del bene intendere], and sound understanding from reason 
 (ragione}) itself born from sound experience, the common 
 mother of all the sciences and all the arts. 
 
 "The rules of experience are sufficient means (cagioni) 
 for us to discern the true from the false. 
 
 " Before laying down a general rule, experiment two or 
 three times, and see whether the experiments produce the 
 same effects." 
 
 This was thought, said, written, and acted upon more than 
 a hundred years before the Novum Organum saw the light. 
 In the face of this plain and direct language it is rather 
 strange that Dr. Whewell should have dared to convey the 
 idea that the writings of those who preceded Francis Bacon 
 were "too abstruse" to be understood for the unvarnished 
 truth is that the cases are reversed. This misleading state- 
 ment has been quoted so often that it is only right we should 
 protest against it by showing its complete inaccuracy. 
 
 Leonardo despises the Alchemists who seek the trans- 
 mutation of metals, but recognises them as fruitful inquirers 
 within certain limits that is as founders of chemistry. He 
 condemns without restriction " the searchers of perpetual 
 motion, necromancers, magicians, who beget nothing but 
 lies/' And being a real man of science he does not forget 
 the great part played by mathematics and deduction, 
 without which induction would be inefficacious. He says : 
 
 " He who blames the supreme certainty of mathematics 
 feeds on confusion, and will never put a stop to the contra- 
 dictions of the sophistical science which produces nothing but 
 an eternal clamour (un eterno gridore). 
 
 " Wherever there is relation and proportion, there is room 
 for calculation ; the proportion is not found in numbers 
 and measures only, but likewise in sound, gravity, time, 
 place (space), and in any force whatever." This aphorism,, 
 worthy of Newton himself, reveals a masterly insight and 
 grasp of science in its most important bearings. 
 
 "True science," he goes on, "is not nourished by the 
 dreams of its investigators; but from the first true and 
 ascertained principles it advances progressively and with true 
 consequences to the very end. This is what we see in the 
 
io6 PROGRESS OF SCIENCE. 
 
 first mathematics, whose object, number and measure 
 arithmetic and geometry treat with sovereign truth of the 
 discontinuous and continuous quantity. 
 
 " No human investigation can ba called true science if it 
 does not pass through mathematical demonstrations. 
 
 " Those who are infatuated by practice without science 
 are like the navigator who sails a ship without helm and 
 compass ; he never knows with certainty whither he goes. 
 Practice must always be built upon theory. Study science 
 first, then follow the practice which is born from science. 
 Hence the treatise of the mechanical sciences must precede 
 the treatise of useful inventions. 
 
 " We call science a sequence of reasonings (quale discorso 
 mentale) which takes for its starting-point the last principles out- 
 side which in nature nothing can be found but is a part of that 
 science." That is experience as a point of departure, and the 
 mathematical form as a point of conclusion ; such is his con- 
 ception of science a conception endorsed by modern science. 
 
 Leonardo respects the ancients,andwithdiscrimination even 
 protects them against the commentators who distort them : 
 
 " Some commentators," he says, " blame ancient inventors 
 who gave birth to grammar and to the sciences, and stand 
 forth like errant-knights (e fansi cavalier?) against dead 
 inventors ; and because they are incapable to become inventors 
 themselves, they are through sloth and the convenience of 
 books, carelessly occupied to cavil at their masters by false 
 arguments." . . . And then we find him consulting the 
 ancients with care and admiring them : with true scientific 
 sense he admired Archimedes beyond any. And respecting 
 the ancients he does not fail to assail the Schoolmen together 
 with authority : 
 
 " Many will think they can reasonably blame me, alleging 
 that my proofs go counter to the authority of some great 
 men held in high reverence through their uncontrolled 
 judgments (inespertf) t not considering that my ideas are born 
 from pure and simple experiment which is my true mistress. 
 If I do not, like them, quote authors, I shall invoke a thing 
 much higher and more worthy viz. experiment which is 
 their master's mistress. 
 
SCIENTISTS OF XVTH AND XVlTH CENTURIES. 107 
 
 " If we believe them (the Schoolmen), that knowledge is 
 mechanical which is born from experiment, and science that 
 which is born from, and ends in, the mind ; semi-mechanical 
 that which is born from science and ends in manual operation. 
 But it appears to me that those sciences are vain and full of 
 error which are not born from experiment (experience), mother 
 of all certainty, and which do not end in a definite experiment 
 (che non terminano in nota experimentia) , that is, the principle, 
 the middle or the end of which does not pass through one of 
 the five senses. 
 
 " If we are told that the eyesight prevents true and 
 attentive mental knowledge by which one penetrates into 
 the divine science, and that such an obstacle led a philosopher 
 to put his own eyes out, I reply to this that such an eye, as 
 lord of the senses, does its duty to put an obstacle to those 
 confused and lying reasonings (discorsi) about which men, with 
 loud shouts and agitation of hands, for ever go on disputing. 
 
 "Avoid the precepts of those speculators who do not 
 confirm their reasonings by experiment." 
 
 " Do not trust to those authors/' says he again, " who 
 have sought by their sole imagination to become the in- 
 terpreters between nature and man, but to those only who, 
 by the results of their experiments, have exercised their 
 minds to recognise how experiments deceive him who does 
 not know their nature, because those experiments which 
 often appear identical are very different." This about writers 
 who declared that being given a motor which shoots a weight 
 a given distance off, one may multiply the distance to infinity 
 by dividing the weight to infinity. 
 
 The preceding injunction is another evidence of the value 
 which Leonardo da Vinci attached to verification. In fact, 
 in true scientific spirit, he used to write " false " (false) 
 under a proposition which he had enunciated, after experi- 
 ments had shown him its unsoundness.* 
 
 All this had been done during the Revival when Francis 
 
 Bacon entered the lists, and stood up as the herald and sole 
 
 champion of science. " Our only hope," said Francis Bacon, 
 
 "is in the regeneration of the sciences by regularly raising 
 
 * For further evidence of Leonardo's science, see Appendix IV. 
 
io8 PROGRESS OF SCIENCE. 
 
 them on the foundation of experience, and building them 
 anew, which I think none can venture to affirm to have been 
 already done or even thought of." (Nov. Org. I. 97.) And 
 his first proof of qualification as a leader was his denunciation 
 of the progress effected, and his second the display of his own 
 work as a contrast to that of other men. And it is gravely 
 declared urbi et orbi by Ellis, Spedding, Abbott, Buckley, 
 Church, and others, that " he was the first to insist upon the 
 importance of collecting facts and making experiments, and 
 that in doing so he rendered a great service to science/' 
 
 It is, after our survey, needless to dwell upon the incom- 
 petency of Francis Bacon to stand up as a judge. He was so 
 little conversant with science, that he not only denied that 
 any advance had been made since Aristotle, but he was un- 
 aware that the objective method, or the inductive process, or 
 inductive philosophy, by whatever name we may call it, had 
 been both promulgated and practised by a host of men. For 
 a hundred and fifty years at least, to speak of the Revival 
 period only, a multitude of facts had been collected ; valuable 
 instruments had been made ; experiments without end had 
 been carried on ; countless observations had engrossed inves- 
 tigators ; sterling discoveries had been arrived at ; and yet 
 he remained in the delusion that the world had stood still. 
 He thought that he alone was moving, whereas he was alto- 
 gether behind his age. And what attitude was his, in the face 
 of great facts, when these stirred up mankind ? His attitude 
 was still one of sceptical impassiveness. He called for instru- 
 ments, and slighted the telescope. He advocated observations, 
 and disparaged those of Galileo. He ignored Tycho Brahe's 
 and Kepler's. He recommended experiments, arid disdained 
 those of Gilbert. He advised inquiries into the laws of the 
 Cosmos, and, after Copernicus and Kepler, fought against the 
 heliocentric doctrine and gloried in believing the earth was the 
 centre of the universe. Nothing could shake him out of his 
 presumption. How then was he qualified ? How was he the 
 Instaurator ? the leader of a new era ? the initiator of modern 
 progress, as we are so often told he was ? We leave the 
 answer to the judgment of the reader. 
 
CHAPTER X. 
 
 MODERN SCIENCE. 
 
 In the family of studies, science is the Cinderella who hides unknown 
 perfections in obscurity. The whole work of the house has been given to 
 her to do. It is through her skill, intellect, devotion, that we have attained 
 all the commodities and pleasant things of life, and, while she serves others 
 and keeps modestly aloof, her proud sisters display their tinsel beauty to 
 the eyes of the world. 
 
 HERBERT SPENCER. 
 
 IN the preceding chapters a review has been given of the 
 science of the Greek, the Arabian, the Mediaeval, and the 
 Revival periods, which has enabled us to appreciate to its 
 full value the work done in those times. It now behoves us 
 to proceed with the sketch of science in the modern period. 
 This is so vast a subject that no apology need be made for 
 presenting it in an altogether inadequate manner. Insufficient 
 as the presentment of it will prove, it has nevertheless not 
 been undertaken without difficulty, or without a deep feeling 
 of diffidence. Not only does the author acknowledge that he 
 has taken a purview of each branch too restricted in extent 
 fully to satisfy the inquirer, much less the scientific critic, but 
 he is also well aware that he has left out of the list of the 
 masters which follows, many men who stand high in the 
 annals of science. Out of the host of those who have 
 gloriously tilled the field of knowledge, to make a satisfactory 
 selection is scarcely possible. So many have equal claims 
 that to mention them all would be the only way out of the 
 difficulty ; but this being impracticable in a sketch, the choice 
 must be determined by what appears typical originality in the 
 
no PROGRESS OF SCIENCE. 
 
 work accomplished rather than by what is imposing in extent 
 and weight. And this has been the guiding principle in the 
 main here. It will explain why the author has credited the 
 great men he mentions with little more than a fraction of 
 their labours a deficiency inherent to the nature of the 
 present work of which he is conscious, and upon which he 
 lays particular stress ; but he trusts he has fairly succeeded in 
 giving at least the main achievements of the scientists he has 
 brought within his survey. In some instances, he has pre- 
 ferred to enunciate a scientific fact in that plain speech which 
 the ordinary reader is likely to apprehend best, rather than in 
 that technical diction which a thorough adept in this or that 
 branch would have adopted. In so wide a scope, in any case, 
 the author confidently relies upon meeting with the indulgence 
 of the experts. These will consider the exiguity of the limits 
 imposed by the plan and object of his book, and they will no 
 doubt own that within those limits he has carried his scheme 
 out in as accurate and conscientious a manner as the matter 
 permitted. 
 
 The progress of modern science, it need hardly be said, 
 necessarily proceeds from the labours carried on and the 
 results obtained before : it is the natural continuation 
 without a break of the work of the XVth and XVIth 
 centuries. 
 
 At this point, the threshold, so to speak, of modern science, 
 it is needful to give the student a short classification of the 
 sciences a matter attended with some difficulty, because 
 every science can be exhibited under two very distinct 
 methods, the historical and the dogmatic ; any other method 
 being nothing but a combination of the two, and whatever the 
 procedure, the classification must always be somewhat artificial, 
 it being impossible to present, with entire exactness, the 
 sciences in their natural connection and according to their 
 mutual dependence. By the historical method knowledge is 
 presented in the order in which it was obtained ; by the dog- 
 matic, knowledge is presented as it may be conceived by an 
 expert who would begin to reconstitute science as a whole. 
 
 Of the many classifications proposed, we shall give 
 COMTE's historical CLASSIFICATION, which is the best of the 
 
MODERN SCIENCE. 
 
 in 
 
 NATURAL SCIENCES (OR NATURAL PHILOSOPHY). 
 
 MATHE- 
 MATICS. 
 
 ORGANIC BODIES. 
 
 INORGANIC BODIES. 
 
 ^ 
 Scciology. 
 The 
 Science of 
 Social Or- 
 ganisation. 
 
 -N 
 
 Biologj'. 
 The Science 
 of Organised 
 Matter (of 
 
 Chemistry. 
 
 The 
 Science of 
 Molecules. 
 
 Physics. 
 
 The Science of the Laws regulating 
 the Central Properties of Bodies 
 (regarded in the mass). 
 
 Astronomy. 
 The 
 Science cf 
 Celestial 
 Bodies. 
 
 The Science of 
 Magnitudes. 
 
 
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112 
 
 PROGRESS OF SCIENCE. 
 
 "kind, though in a degree arbitrary, and Mr. Herbert Spencer's 
 dogmatic classification, the only objection to which is that it 
 does not show how science was obtained unless we bear in 
 mind the process of evolution and interaction which the 
 author has not failed satisfactorily to elucidate with his usual 
 grasp and clearness. 
 
 Comte classifies the fundamental sciences, which he 
 reduces to six and groups into two classes, according to their 
 natural dependence the most general phenomena going on 
 successively to the more particular. 
 
 " Each of the sciences," says Comte, " presents some in- 
 dication appropriate to itself, which ought to be studied at 
 its source to be duly appreciated. Mathematical science 
 exhibits the elementary conditions of positivity ; astronomy 
 determines the true study of Nature ; physics teaches us the 
 theory of experimentation ; chemistry offers us the art of 
 nomenclature ; and physiology discloses the theory of classi- 
 fication." 
 
 Mr. HERBERT SPENCER has proposed another CLASSIFI- 
 CATION which, though dogmatic in the sense indicated above, 
 is nevertheless strictly based upon the principle of evolution. 
 
 ^Science is 
 
 that which treats 
 
 of the 
 phenomena 
 themselves 
 
 I. Abstract Science treats of 
 
 II. Abstract-Concrete Science treats 
 
 1.1. Concrete Science treats of .. 
 
 in their true 
 elements ; 
 
 in their 
 totalities. 
 
 } I. Abstract Science .. - - { Sema'tic, 
 
 > II. Abstract-Concrete Science 
 
 ( Mechanics, 
 Physics, 
 ( Chemistry, etc. 
 
 Mil. Concrete Science .. 
 
 (Astronomy, 
 Geology, 
 Biology, 
 Psychology, 
 Sociology, etc. 
 
 j I. The universal law of relation I Mostlyexdusively 
 ( 1 1. The laws of relations . . j Mathematics. 
 
 / I. The universal laws offerees') 
 
 f Mostly Statics and 
 
 \ II. The laws of forces as mani- f Dynamics, 
 fested by matter . . . . ) 
 
 r 
 
 I. The universal laws of distri- 
 bution of ending matter 
 and motion.. 
 
 The universal laws of distri- 
 bution continuing matter 
 and motion 
 
 From Astronomy 
 to Sociology. 
 
 Each of these two classifications has its distinct merits 
 Comte's has the merit of simplicity, Spencer's the merit of 
 
MODERN SCIENCE. 113 
 
 rigid exactness but its synthetical character makes it difficult 
 of comprehension for those who are unfamiliar with the 
 philosophy of science. 
 
 In the following table of modern science, consulting solely 
 the general reader's convenience, we have been guided by 
 what appears to us a simpler, though less scientific, plan, viz. 
 that of grouping the branches of science in the order of their 
 practical importance, without special regard to their filiation 
 or their logical sequence, observing, however, the chronological 
 succession in which they advanced. 
 
 GROUP I. Taking first Biology that is, the organic group 
 we shall successively survey its sub-branches Botany, 
 Anatomy, Zoology, Palaeontology, Physiology, Biology 
 proper, Anthropology, Philology, and Sociology.* 
 
 BOTANY. 
 
 16281694. Malpighi applied the microscope as an aid 
 to botany, thereby immensely extending the stock of previous 
 knowledge ; revealed the minute germs, fibres, and vessels in 
 the structure of plants (1661), becoming thus the FOUNDER 
 OF VEGETABLE ANATOMY. Among the numerous discoveries 
 he made in the texture of plants, arrived at by constant 
 watching and observation, he detected the cellular tissue, the 
 ducts, the whole process of growth of seeds, describing the 
 different stages of the germ and pointing out the develop- 
 ment to be similar in many respects to the growth of the chick 
 in the egg. GREW (1628 1711) was pursuing the same 
 investigations at the same time, and made several discoveries. 
 It was Grew who discovered the stomates, and their function. 
 These little mouths open and shut to receive and give out air 
 and moisture. But it was Dr. HALES (1677 1761) who clearly 
 discovered the way in which plants breathe through the sto- 
 mates, showing these to be the organs of respiration though 
 he did not find out that plants decompose the air, and absorb 
 carbon and reject oxygen a discovery which was made later. 
 
 1628 1704. Ray, after lengthy travels over Europe with 
 * Appendix AA contains a definition of each branch. 
 
 I 
 
ii4 PROGRESS OF SCIENCE. 
 
 his friend and associate WiLLUGHBY, made a CLASSIFICATION 
 of the known plants more perfect than Csesalpinus's, grouping 
 them into three divisions the IMPERFECT PLANTS (flowerless 
 ferns, mosses), and the PERFECT PLANTS (flowering), them- 
 selves divided into two classes : I, the dicotyledons , the seeds 
 of which "open into two seed-leaves/' some having simple 
 flowers (like the pink), and some having compound flowers 
 (like the daisy) ; 2, the monocotyledons form the other class, 
 " the seeds of which have only one seed-leaf" (like a grain of 
 wheat). This system was made more perfect by Tournefort ; 
 but some of Ray's divisions were adopted by Linnaeus. Ray 
 was also an excellent zoologist Willughby's work being 
 partly due to his knowledge and assistance. Ray's History 
 of Insects exhibits a clever classification, based upon either 
 stability of form, or metamorphosis, and then again upon 
 organic characters wings, feet, habits, food, etc. Ray and 
 Willughby are two names which can hardly be separated. 
 With them botany and natural history take a new departure, 
 after them each step forward is a long stride into rich regions 
 of knowledge. 
 
 1656 1708. Tournefort founded the science of geo- 
 graphical DISTRIBUTION of plants after extensive travels in 
 the East and in Europe ; described ten thousand plants, 
 and arranged them with great discrimination, establishing 
 the orders and genera in the Vegetable Kingdom according 
 to the general character of species. His classification was an 
 improvement upon Ray's. Of his genera, 130 were pre- 
 served by Linnaeus. As a descriptor he is regarded as a 
 model, and his work on botany established his reputation all 
 over Europe. 
 
 1707 1778. Linnaeus pointed out the phenomena of 
 fecundation in plants ; classified the Flora according to the 
 organs of reproduction (stamens and pistils) the most 
 famous ARTIFICIAL CLASSIFICATION. It is artificial because 
 it grouped species without regard to their fundamental like- 
 nesses of organisation and structure. He created a scientific 
 language by originating a mnemonic instrument at once 
 ingenious and useful giving to every plant and animal a 
 second (or specific) name which conveys a description of 
 
MODERN SCIENCE. 115 
 
 their special character. The Animal Kingdom is indebted 
 to him for its complete classification according to the organs 
 of mastication and of digestion. His nomenclature of genera 
 has been introduced into every branch of science. His 
 definition of the inorganic and organic world is as famous for 
 its truth as for its terseness " stones grow, plants grow and 
 live, animals grow, live, and feel" The artificial system of 
 classification of plants is now superseded by the natural 
 system, but it retains much of its useful value by the facility 
 it affords of finding the name of a plant or an animal. 
 
 1748 1836. Jussieu (Antoine Laurent), continuing the 
 original work of his uncle Bernard (1699 1767), created the 
 NATURAL SYSTEM, i.e. the method of natural classification 
 founded upon the subordination of characters, structure, 
 organisation, and relations the structure of the EMBRYO 
 serving as a chief basis. He divided the whole Vegetable 
 Kingdom into three great branches the acotyledon, the 
 monocotyledon, the dicotyledon which led to the constitu- 
 tion of the Families, or Natural Orders, as now accepted. 
 This system has been extended and improved by DE 
 CANDOLLE (17781841), Robert BROWN (17731858), 
 ENDLICHER (1804 49), LINDLEY (17991865), Sir 
 William HOOKER (1785 1865), the founder of the 
 Kew Garden Museum and Herbarium, and his son, Sir 
 Joseph, both of whom advanced the knowledge of the Flora 
 of the British Empire in a manner never attempted before. 
 Sir Joseph, besides his important contributions to the progress 
 of systematic botany (Genera Plantarum, Flora Indica), was 
 intimately associated with Darwin in the studies preliminary 
 to the publication of the " Origin of Species." 
 
 !^4Q 1832. Goethe made valuable observations upon 
 the growth of plants ; pointed out their process of transfor- 
 mation, from primitive stems or leaves into all kinds of 
 varieties according to the work Nature has intended them to 
 do. Among other things, he showed that the stamens and 
 pistil are nothing but the flower-leaves metamorphosed into 
 a particular form so that they may serve to produce seeds. 
 Goethe's theory of METAMORPHOSIS OF PLANTS has proved a 
 /great discovery, and the study, once started (1790), led to the 
 
 I 2 
 
u6 PROGRESS OF SCIENCE. 
 
 production of fine artificial flower varieties in colour and shape. 
 His facts are in perfect harmony with the process of evolution 
 elucidated by Darwin. The great German philosopher also- 
 speculated on the more engrossing problems of life. As a 
 follower of Buffon, he held that "the more perfect organic 
 natures from fishes to mammals, and man at their head, were 
 formed on one original type which still daily changes its form 
 by propagation ; " so that, like Lamarck, G. St. Hilaire, E. 
 Darwin, and others, he was an evolutionist. He tried to 
 prove the tendency of Inheritance and of Adaptation in 
 organisms two laws of development. His study of com- 
 parative anatomy led him to the discovery of the mid-jawbone 
 in man a fact of import, for it argues for man's descent from 
 lower types. 
 
 1750 1816. Sprengel was the first (1789) to point out 
 the close connection which exists between plants and insects, 
 and to discover how the FERTILISATION OF PLANTS BY INSECTS 
 is carried on a subject fully investigated later on by Darwin 
 and others. Sprengel showed that the shape, the colours of a 
 flower, and the honey it secretes are intended by nature to 
 attract insects to it, so that they may carry the pollen-dust 
 which clings to them (while they suck the honey) to other 
 flowers, and so fertilise the ovules in the seed-vessels which 
 would otherwise remain barren. Flowers, he also found, 
 which are neglected by insects are insignificant as a rule, but 
 their variety does not perish because they have a large 
 quantity of pollen-dust, and the wind carries it in every 
 direction to fertilise. It was not until Charles Darwin had 
 pointed out the splendid work done by Sprengel that the 
 worthy German inquirer was appreciated. 
 
 ANATOMY, ZOOLOGY, and PALAEONTOLOGY. 
 
 16211675. Willis studied the BRAIN, traced the course 
 of the NERVES, classified them, and introduced the doctrine of 
 LOCALISATION OF FUNCTIONS in the brain a branch which,, 
 later on, developed into phrenology, a new study unrecog- 
 nised as yet as a science. 
 
 16311687. Steno revealed the existence of the OVARIES 
 
MODERN SCIENCE. 117 
 
 in viviparous animals and woman an observation which 
 brought about new ideas regarding the theory of fecun- 
 dation. He was the first to explain more extensively than 
 Pythagoras, Leonardo, and Palissy the origin of fossils (1669); 
 his observations regarding the PETRIFACTION of rocks are 
 remarkable, but less so than his pointing out the system of 
 STRATIFICATION AND UPRISING which is now admitted so 
 that he was a real geologist as well as a naturalist. SciLLA, 
 in 1670, carried this study further by his observations of the 
 rocks and fossils of Calabria. 
 
 1635 1672. Willughby, the earliest great naturalist 
 England may be proud of, studied fishes, birds, and quad- 
 rupeds ; collected with his friend Ray, who took a share in 
 all his labours, a great number of specimens. His book on 
 quadrupeds is an excellent instance of CLASSIFICATION, 
 dividing the whole sub-kingdom into oviparous and vivi- 
 parous, and subdividing the species according to the kind 
 of feet and teeth they exhibit. The birds he divided into 
 land birds and water birds, and then subdivided them again 
 according to their beak and claws and food. The fishes 
 were classed into groups not very different from those now 
 adopted. 
 
 1707 88. Buffon, by his comprehensive work on natural 
 history, popularised a vast amount of useful knowledge. 
 Animals, their structure, instincts, habits, are so beautifully 
 described ; he showed the power and majesty of Nature in 
 a manner so novel and striking that he exercised immense 
 influence. The general interest in scientific researches which 
 he created entitles him to be considered as one of the great 
 promoters of knowledge in the XVII Ith century. The 
 scientific value of his labours is twofold. First and foremost 
 it lies in the fact that he was the earliest writer who clearly 
 formulated the suggestion derived from practical obser- 
 vation that all species of plants and animals probably 
 descend from a common origin, and are due to a gradual 
 divergence from the parental type ; so that he planted THE 
 SEED OF THE ORGANIC EVOLUTIONARY DOCTRINE organic 
 development by law. He intimated that man himself forms 
 no exception, and may be considered as a branch of the 
 
n8 PROGRESS OF SCIENCE. 
 
 same tree. These views were rapidly propagated, and even 
 enlarged upon by Diderot. By the end of the XVII Ith 
 century, the origin of species had become an important sub- 
 ject of speculation in most parts of Europe. Secondly, the 
 value of Buffon's work lies in his tracing the DISTRIBUTION 
 OF ANIMALS all over the globe, as well as the geographical 
 and climatic causes of such distribution. The anatomical 
 portion of his natural history is the work of Daubenton. 
 
 1716 1800. Daubenton gave additional value to Buffon's 
 work in the manner just mentioned. He also supplied 
 Buffon with fine ANATOMICAL DESIGNS. He besides holds 
 a special place in science by his having been the first to 
 apply COMPARATIVE ANATOMY to the determination of 
 FOSSIL BODIES, thus opening the only road to the study of 
 the Fauna of geological epochs. 
 
 1722 89. Camper discovered (in 1761) the auditory organs 
 of fishes, and (in 17/1) discovered that air penetrates into 
 the bones of birds by the process of breathing, to make them 
 more buoyant in flying ; was the first to dissect the orang- 
 outang, and to show the anatomical difference between 
 anthropoid apes and man ; determined the FACIAL ANGLE 
 (the profile line of the human face) and made it a criterion 
 of race though too exclusively becoming thereby one of 
 the founders of anthropology. His analogy between the 
 human body and that of the quadruped, bird, and fish, is 
 equally serviceable to the naturalist and to the artist. 
 
 1758 1828. Gall, the founder of CRANIOLOGY, is entitled 
 to fame for his marvellous DISSECTION OF THE BRAIN, the 
 anatomy of which had been unsatisfactory his work was a, 
 revelation to anatomists, despite the fact that his conclusions 
 (phrenology) were far too hasty to find general acceptance. 
 
 1769 1832. Cuvier was the most eminent founder of 
 COMPARATIVE ANATOMY. He embraced the entire Animal 
 Kingdom. He divided it according to organisation into the 
 VERTEBRATA, MOLLUSCA, ARTICULATA, RADIATA the three 
 last of which had been neglected. Then he divided the four 
 sub-kingdoms into Classes, Orders, Families, Genera, and 
 Species, arriving at a much more satisfactory and complete 
 classification than Linnaeus, because he based it upon the 
 
MODERN SCIENCE. 119 
 
 INTERNAL STRUCTURE and organs. He showed the nature 
 of reptiles. He founded PALEONTOLOGY, too, and had the 
 genius to reconstruct the antediluvian world (so-called) from 
 fossil bones so that he connected past and present animals by 
 comparative anatomy, and, through this, Zoology had a solid 
 basis of classification, and Physiology extensive elements for 
 the explanation of phenomena. He held the doctrine of the 
 fixity or IMMUTABILITY OF SPECIES a doctrine combated by 
 Geoffrey St. Hilaire, and completely overthrown by Darwin's 
 investigations, although it is admitted that some of Cuvier' s 
 views were to a certain extent reconcilable with those of his 
 opponents. Cuvier founded the PARIS MUSEUM, which 
 stood as a model of classification and arrangement. La- 
 marck, Geoffrey St. Hilaire, and Cuvier formed a sort of 
 scientific Triumvirate which swayed immense influence, and 
 gave a powerful impulse to the study of several branches of 
 Biology. Cuvier's colossal working power enabled him to 
 accomplish the labour of several naturalists. He was such 
 a master of comparative anatomy that from seeing the frag- 
 ment of an animal, a bone, or only part of a bone, he could 
 reconstruct the whole : " None of the parts" says he, ' ' can 
 alter without an alteration of the others also. Thus, if the 
 stomach of an animal is made so as only to digest fresh 
 flesh, his jaws must be formed to devour the prey, his claws 
 to seize it and tear it, his teeth to masticate the flesh, and 
 the whole system of his organs of motion to follow and 
 overtake it ; ... so that, not only the class, but the order, 
 the genus, and even the species of an animal are revealed by 
 each part of it." It was by this masterful knowledge that 
 he was able to put together the skeletons of EXTINCT 
 ANIMALS being the first to reveal to astonished naturalists 
 that past geological eras had produced animals differing 
 from ours in some particulars. And this revelation at once 
 set men pondering over the antiquity of the world. He 
 threw light upon the newly discovered Ichthyosaur, Plesio- 
 saur, Iguanodon, Pterodactyl ; on the Mosasaur ; on Tertiary 
 animals, on the Megatherium, the Mammoth, the Mastodon 
 types which had puzzled and confounded naturalists until 
 he demonstrated their nature. 
 
i2o PROGRESS OF SCIENCE. 
 
 1802 57. D'Orbigny studied and classified the FORA- 
 MINIFERA a most important class, since the accumulation 
 of its remains constitutes geological strata. 
 
 1804 92. Owen is the highest authority in many im- 
 portant branches of comparative anatomy through his studies 
 of the GREAT APES, the KANGAROOS, the giant New Zealand 
 Wingless Birds (the DiNORNis), the CEPHALOPODS, the 
 BRACHIOPODS, etc. ; his anatomical labours are so numerous 
 and important that he may be called the greatest comparative 
 anatomist of his time. He introduced the study of palaeon- 
 tology in England, and no scientist since Cuvier, whose pupil 
 he was for a time, has enriched palaeontology to a greater 
 extent than he has. He contributed a vast series of papers 
 on extinct animals and their living representatives, making 
 discoveries which filled up the gaps in past and present 
 species. He was the first fully to describe the GREAT SLOTHS 
 (the Megatherium 18 feet long, the Mylodon n feet), 
 armadilloes, and SAURIANS of South America, the flying 
 reptiles, the swimming lizards and tortoises of the Secondary 
 and Tertiary periods, and to bring into notice countless 
 reptiles, birds, and mammals in British strata. But his 
 investigations of the saurians (so-called antediluvian reptiles), 
 first of those known to Cuvier, and next, of the Cetiosaur, 
 the Megalosaur, the Scelidosaur, and then the Mylodon, and 
 then the Dinornis, may be pronounced his most original and 
 fascinating work. He carried our knowledge about these (so- 
 called) antediluvian animals very far indeed, and by his 
 luminous views left very few anatomical problems concerning 
 them to be solved, though it was reserved to the next generation, 
 as our next notice will show, to give an extension to the science 
 of life in early geological periods undreamt-of in Owen's 
 prime time. Like Cuvier, he applied the law of correlation 
 of structure, and could, with a bone, a vertebra, or a tooth, 
 reconstruct the extinct animal of which it had been a part. 
 By his palaeontological researches and discoveries, he caused 
 geology to obtain still greater popular favour than it had 
 obtained before thereby powerfully assisting the work of 
 William Smith, Sedgwick, Murchison, Lyell, and Agassiz. 
 He believed, with Sedgwick, in the separate origin of distinct 
 
MODERN SCIENCE. 121 
 
 types, and, with this reservation, he followed Geoffrey St. 
 Hilaire as regards unity of organic composition. Likewise, 
 he believed in the variability of species, rejecting, however, 
 the idea of volition on the part of the lower types an 
 objection which implies haphazard selection ; so that he was 
 an opponent of the Darwinian law of evolution, though he 
 recognised it as a factor in the plan of Creation. But his 
 views regarding Darwinism are rather confused and difficult 
 to reconcile with one another. He discovered the type of 
 the vertebrate skeleton. He founded the MICROSCOPIC 
 SOCIETY, and organised the NATURAL HISTORY MUSEUM 
 (London) the finest in the world by far ; and thus was the 
 continuator of Cuvier and of Hunter. As a guide to 
 classification he took the brain for some orders, the teeth 
 for others. His " Odontography," on the teeth of different 
 types, is the finest work of its kind. 
 
 Since Prof. Owen practically finished his work, 
 palaeontology, as we have hinted, has been enriched by 
 numerous and magnificent specimens of extinct species, 
 supplying new links, found chiefly in America. 
 
 b. 1831. Marsh (Prof. O. C), the most eminent living 
 palaeontologist, has probably rendered as much service to 
 science as any of his predecessors taken singly. Some 
 would say that he has surpassed them all, so numerous, 
 varied, important, weighty, and startling are the discoveries 
 that we owe to his indefatigable and intelligent enthusiasm. 
 In estimating the respective work of great men we have, 
 however, to remember that the founders the Lamarcks, the 
 Cuviers, the Owens must ever command undivided admi- 
 ration, for their demonstrations and applications of principles 
 serve as chart and compass to scientific men. Apart from 
 that consideration Prof. Marsh's work is so imposing that 
 it is difficult to set forth all his claims to fame. It might 
 almost be said that before he came into the field, the 
 masters, immense and fruitful as their labours were, had 
 only deciphered the alphabet, interpreted the language, 
 and constructed the grammar of palaeontology, whereas 
 Marsh composed the extensive poem describing its un- 
 suspected wonders. He unearthed from every part of 
 
122 PROGRESS OF SCIENCE. 
 
 America, but especially from the rich sepulchre of Colorado, 
 hundreds and hundreds of extinct animals, so that where, in 
 some instances, only one bone, one tooth, one vertebra of a 
 skeleton was known, we now have entire specimens, and speci- 
 mens not of one species, but of twenty, fifty, eighty species. 
 Just as Lamarck investigated and explained fossil shells, or 
 Cuvier the fossils of quadrupeds, so Prof. Marsh has laid 
 bare before us the Dinosaurian world of the Secondary Period 
 the world, that is, of the huge monsters which were then 
 the lords of creation. The specimens he discovered are so 
 very numerous that he has divided the Dinosaurs (four- 
 footed reptiles or lizards some herbivorous, some carni- 
 vorous) into five sub-orders, and these into genera, the 
 animals ranging in size from 2 feet in length to 60. Of the 
 nine great orders of Reptilia which existed then, the snakes, 
 tortoises, crocodiles, and lizards alone survive. The Cera- 
 tosaur was 17 feet, the Megalosaur and the Apatosaur 40, 
 the Diphodocus and the Cetiosaur 50, the Brontosaur 60. 
 The Atlantosaur was 30 feet high and 80 feet long; his 
 thigh-bone was over 6 feet ! The Triceratops had a skull 
 6 feet long. The Scelidosaur was covered with spines all 
 over his back. The Stegosaur was armed from his head 
 to his tail with a ridge of erect plates on his back, almost 
 triangular in form and some 2 or 3 feet in diameter, and 
 the end of his tail was bristling with four pairs of powerful 
 spines from I to 2 feet long. He had two brains a small 
 one in the skull, and another, ten times as large, in the 
 sacrum close to the haunches. When we bear in mind 
 that some of these monsters, as large as or larger than ele- 
 phants, could walk on their hind legs and could have 
 looked in our houses through a window on the second 
 storey, we can imagine what a stupendous spectacle they 
 presented. Prof. Marsh, likewise, found as many as 60 
 species of Mosasaurs sea-serpents ranging from 10 to 80 
 feet in length. He made out four species of Pterosaurs or 
 Pterodactyls flying reptiles the largest of these measuring 
 25 feet across the wings. The Dinocerata huge mammals 
 not unlike the rhinoceros were found to have formed no 
 less than thirty species. Marsh discovered, in the Eocene 
 
MODERN SCIENCE. 123 
 
 lake- basin \vhere he found the Dinocerata, the series of 
 fossil horses which enabled him to prove the present horse 
 to be descended from the small five-toed Eohippus (see 
 Darwin), one of the most beautiful and conclusive examples 
 of the law of animal evolution (1870). By the side of the 
 animals above-mentioned innumerable snakes, crocodiles, 
 tortoises, fishes, marsupials, rodents, insectivorous and carni- 
 vorous types, were also found, the species of which were for 
 the most part unknown before. Prof. Marsh, it is hardly 
 necessary to add, has enriched the Yale College Museum, 
 which he has to a great extent reorganised, by countless 
 specimens of all kinds the Pterodactyls alone are repre- 
 sented by more than 600 individuals, the Mosasaurs by 
 1,400! Marsh handsomely acknowledges the earnest help 
 he received in his labours from Mr. T. B. Hatcher, his 
 assistant, without whose energy and skill some of his ex- 
 plorations would have proved fruitless. To the whole of 
 the work we just attempted to describe, Prof. E. D. COPE, 
 of the Pennsylvania University, and Prof. Joseph Leidy, both 
 American scientists of distinction and learning, have con- 
 tributed their share, especially as regards the Vertebrates 
 of the Cretaceous and Tertiary formations. 
 
 Such is the glorious record of American science within 
 the last twenty or twenty-five years. 
 
 PHYSIOLOGY. 
 
 1628 1694. Malpighi, by means of the MICROSCOPE, im- 
 mensely extended the scope of anatomy and physiology, 
 revealing minute structures hitherto unsuspected ; discovered 
 the CAPILLARIES microscopic tubes connecting the arteries 
 with the veins an additional evidence of Harvey's theory ; 
 also the AIR-CELLS and their membranes in the lungs, from 
 which the blood derives its oxygen and rejects carbonic acid, 
 thereby explaining what was so mysterious even after 
 Harvey. Malpighi studied the tongue and carefully described 
 its vessels, nerves, and coverings ; also the SKIN, discovering 
 its several parts the epidermis, the MALPIGHIAN LAYER, 
 which contains the pigment which colours the skin, the 
 
124 PROGRESS OF SCIENCE. 
 
 dermis or true skin, and the perspiration ducts (1665). He 
 was really the earliest investigator of the lungs, the skin, and 
 the mucous membrane. He also investigated the formation 
 of the chicken in the egg. He was the first anatomist, too, 
 who studied the ANATOMY OF INSECTS and revealed their 
 marvellous structure : his description of the silk-worm (1669) 
 in particular made a deep impression, giving as it did an idea 
 of the breathing, circulation, secretion, growth, and metamor- 
 phosis of the insect ; so that Malpighi started THREE im- 
 portant biological BRANCHES the physiology of plants, insects, 
 and animals. 
 
 1632 1723. Leuwenhoeck, by means of microscopes 
 made by himself, studied the Infusoria, and discovered 
 the Rotifers and other animalcules of the infusorial group 
 living either in water or in the body of other animals 
 showing that a speck, no larger than a grain of sand, 
 may be made up of eight or ten thousand living crea- 
 tures. He was a worthy rival of Malpighi. His " Epistolae 
 Physiologicae " were much in advance of his time. The study 
 of Infusoria, of which he was the chief pioneer, has been 
 immensely enlarged by Ehrenberg (1795 1868?), who has 
 demonstrated that these minute creatures have internal 
 structures similar to those of higher animals. He has 
 described over five hundred species, some of which he dis- 
 covered in fog, rain, and snow. 
 
 1637 80. Swammerdam improved the art of dissecting, 
 applying it to the general history of INSECTS ; determined 
 the degree of blood-heat in animals by means of a new ther- 
 mometer; described the rise of lymphatic vessels, lately 
 discovered by Riidbeck ; compared the history of bloodless 
 animals with that of plants ; composed the history of blood- 
 less animalcula a work unsurpassed in anatomical accuracy. 
 
 1668 1738. Boerhaave made the medical school of 
 Leyden famous by his successful labours, which attracted to 
 Holland numerous students, several of whom became cele- 
 brated physicians. Besides the beneficial impulse he gave to 
 Medicine, he founded ORGANIC CHEMISTRY the pursuit, 
 that is, of chemical analysis of the substances composing plants 
 and animals. Anatomists had described the structure and 
 
MODERN SCIENCE. 125 
 
 functions of organs Boerhaave studied the very materials of 
 those organs, thus extending the area of chemistry, which 
 since Giaber had remained inorganic. He did more ; for after 
 discovering the components of plants, he also found the 
 source out of which plants derived their materials, viz. the 
 chemical substanceswhich made them up out of the soil through 
 the roots, and out of the air and sunshine through the leaves. 
 Likewise, by analysing milk, blood, bile, chyle, lymph, he 
 showed animals to derive their materials from plants, or 
 altered vegetable matter. His determinations were neither 
 perfect nor complete, owing to the ignorance as yet prevailing 
 as regards the constitution of plants, since chemists had not 
 yet discovered the four gases (carbonic acid, hydrogen, nitro- 
 gen, and oxygen) which enter into their composition ; but he 
 nevertheless opened a new branch the chemistry of life and 
 was therefore one of the chief instructors of the age. Among 
 the numerous facts he elucidated, he demonstrated the 
 phenomena of animal structure to be in accordance with the 
 
 LAWS OF MECHANICS. 
 
 1708 77. Haller, a pupil of Boerhaave just as famous as 
 his master, made the Gottingen university a centre of 
 physiological science. Leaving aside the 180 volumes on 
 science he published with the help of his pupils, and the 
 masterly drawings which illustrate most of them, we owe to 
 him the discovery of the POWER OF MUSCLES TO CONTRACT; 
 he found the cause of their contraction to be due, not to the 
 nerves only, but also to independent irritation. He studied 
 the physiology of the human body in a masterly manner. 
 His services to COMPARATIVE ANATOMY were very extensive 
 and important : he was the first to make this branch a 
 separate science. He also collected material for the complete 
 description of the FLORA OF SWITZERLAND. 
 
 1720 93. Bonnet added a great deal to the knowledge 
 of the GROWTH of plants and animals ; made a vast number 
 of observations and experiments, and discovered vegetables 
 to have the power of seeking and finding that which is 
 indispensable to their development moisture, air, and 
 sunlight a department which Darwin will investigate fully, 
 and a fact which is accounted for by law. Bonnet also 
 
126 PROGRESS OF SCIENCE. 
 
 discovered that lower animals (worms, lobsters, polypes, for 
 instance) have the property of growing afresh limbs and 
 organs lost by fracture, maybe such as heads, tails, legs, 
 e tc. a study pursued concurrently and carried further by 
 Spallanzani. Some animals (the aquatic salamander, for 
 example) were shown by these two physiologists to grow the 
 same limb eight times in succession. Bonnet in his Contem- 
 plation of Nature threw out the first suggestion of PROGRESSIVE 
 EVOLUTION from the lowest organism to the highest a 
 subject developed later by Lamarck and fully analysed by 
 Darwin. 
 
 1729 99. Spallanzani made decisive experiments upon 
 microscopic ANIMALCULA ; determined the FORCE OF THE 
 HEART upon the arteries, and the relative speed of the blood 
 through the different channels ; showed Infusoria to be 
 oviparous, viviparous, and hermaphrodite; pointed out the 
 principle of DIGESTION IN INSECTS. Like Bonnet, he ex- 
 perimented upon the power of regrowth possessed by lower 
 animals, such as snails, water-salamanders although some, 
 like the last-mentioned animal, have, as he showed, a heart, 
 red blood, lungs, bones, muscles. Spallanzani also studied 
 the vegetable kingdom, and pointed out numerous phenomena. 
 In the course of the XVIIIth century, biology may be said 
 to have made great strides through the labours of Haller, 
 Bonnet, Spallanzani, and Hunter, independently of the 
 immense work of Linnaeus, Buffon, and Lamarck. 
 
 17481794. Vicq d' Azir studied the NERVOUS SYSTEM 
 with a thoroughness never surpassed in his time; and he 
 established the LAW OF HOMOLOGY, which will become later 
 the subject of a great scientific battle. 
 
 17491823. Jenner originated VACCINATION, one of the 
 greatest benefits for which humanity is indebted to science 
 and an innovation in meeting disease which will bear rich 
 fruit in the XlXth century inoculation becoming then a 
 subject of deep researches and experiments. 
 
 1773 1858. Brown (Robert), concurrently with MOL- 
 DENHAUER (17661827) and MIRBEL (1776 1854), studied 
 the physiology of plants and greatly extended our knowledge 
 of the formation of the seeds, the structure of the cells and 
 
MODERN SCIENCE. 127 
 
 tissues, and the growth of stems. Robert Brown, in par- 
 ticular, established the existence of the embryo-sac, the 
 function of the funicle (nourishing duct), and the micropyle 
 (fertilising duct) in fact the whole economy of the SEED- 
 VESSEL a determining feature in the modern classification 
 of plants. These discoveries are allied to those of Sprengel. 
 
 b. 1787. Serres studied the brain, and showed the de- 
 velopment of bones to proceed from the PERIOSTEUM 
 (outward envelope). 
 
 1801 1858. Muller (Johann) made the physiology of 
 the senses of SIGHT AND HEARING a special study, even in 
 lower animals; pointed out the anatomical type of glands, 
 the components of blood, and other phenomena; but his 
 capital feat in science lies in his originating COMPARATIVE 
 PHYSIOLOGY. He had an equal influence in the scientific 
 world as a physician, a chemist, a zoologist, and a physicist. 
 
 1811 72. Simpson (Sir James Y.) introduced the use 
 of CHLOROFORM as an anaesthetic, an innovation in the 
 treatment of disease and surgical operations which has 
 relieved humanity from immense suffering. 
 
 18131878. Bernard (Claude) discovered the FUNCTION 
 OF THE LIVER, the pancreas, the salivary gland, and the 
 spinal chord four capital determinations. 
 
 BIOLOGY (proper). 
 
 1683 1757. Reaumur was the first to recognise the 
 nature of coral and CORAL FORMATIONS, and to make a 
 special study of insects and carry investigations over a much 
 more extensive field than his predecessors. As a physicist, 
 he invented the THERMOMETER which bears his name and 
 is divided into 80 degrees from the freezing to the boiling 
 points of water. 
 
 1728 94. Hunter, as one of the founders of modern 
 biology and pathological physiology, pointed out, after going 
 through an immense range of important observations and 
 experiments in the vegetable and animal kingdoms, the 
 necessity of embracing and connecting all the studies relating 
 to life, instead of limiting the science of biology to the study 
 
128 PROGRESS OF SCIENCE. 
 
 of simple species through anatomy and physiology only. 
 The influence of his teaching that is, of a body of physio- 
 logical doctrines was equally extensive and durable. He 
 also raised surgery from a poor empirical art to a noble 
 science by initiating striking improvements. He discovered 
 the electric nature of the Torpedo's commotions ; showed the 
 electric nature of the Gymnotus ; explained the respiration 
 of birds fully; studied the cetacea; and one of his main 
 claims upon our gratitude founded the Hunterian Museum, 
 one of the most beautifully classified collections in existence 
 each organ being displayed throughout its stages of 
 development from its lowest to its most complicated form. 
 Hunter was the most famous successor of Harvey as a 
 physiologist. It should be mentioned that the Italian 
 Morgagni (1682 1771) preceded Hunter in the field of 
 pathological anatomy and left invaluable contributions to 
 science, although he did not formulate the broad generalisa- 
 tions which make Hunter famous. 
 
 1731 1802. Darwin (Erasmus), adopting Buffon's theory 
 of the origin of species by evolution, assigned the main cause 
 of animal development to the actions, wants, and habits of 
 the animals. This is the germ of the theory of organic 
 development; it only wanted the doctrine of natural selection 
 to anticipate Charles Darwin in all points. "As the earth 
 and ocean," says Erasmus Darwin, " were probably peopled 
 with vegetable productions long before the existence of 
 animals, and many families of these animals long before 
 other families of them ; shall we conjecture that one and the 
 same kind of living filament is and has been the cause of 
 all organic life ? " In " Zoonomia/' we read : 
 
 First, forms minute, unseen by spheric glass, 
 Move on the mud, or pierce the watery mass ; 
 These, as successive generations bloom, 
 New powers acquire, and larger limbs assume ; 
 Whence countless groups of vegetation spring, 
 And breathing realms of fin, and feet, and wing. 
 
 " When we revolve in our minds," says Erasmus Darwin, 
 "the great similarity of structure which obtains in all the 
 warm-blooded animals, mankind included, one is led to 
 
MODERN SCIENCE. 129 
 
 conclude that they have alike been produced from a similar 
 living filament. In some this filament in its advance to 
 maturity has acquired hands and fingers with a fine sense 
 of touch, as in mankind. In others it has acquired claws 
 and talons, as in tigers and eagles. In others, toes with 
 an intervening web or membrance, as in seals and geese. 
 In others, it has acquired cloven hoofs, as in cows and swine, 
 and whole hoofs in others, as in the horse ; while in the bird 
 kind this original living filament has put forth wings instead 
 of arms or legs, and feathers instead of hair." 
 
 These passages might have been written by his grandson 
 Charles Darwin so thoroughly do they agree with the 
 latter's teaching. But we must at the same time recognise 
 that they expressed suggestions only, and, profound as these 
 suggestions were, they lacked the authority of that evidence 
 and demonstration which it was the glory of his grandson 
 to furnish, and which alone could carry conviction. They 
 nevertheless gave a strong impetus to the movement of 
 inquiry which was already agitating the European mind. 
 
 1744 1829. Lamarck, who may be called the founder 
 of PHILOSOPHICAL ZOOLOGY, divided the animal kingdom 
 into two divisions the Vertebrata, and the Invertebrata 
 terms which have been retained. He investigated fossil shells 
 {as Cuvier did fossils of quadrupeds) opening thus a new 
 palaeontological area shells holding a vast place in the 
 classification of geological strata. He studied invertebrate 
 animals worms, snails, insects, shell-fish, sea-anemones, and 
 sponges ; showed for the first time their infinite variety of 
 forms and organisation, together with the important part 
 they perform in nature. Science is also indebted to him for 
 the separation of the Crustacea (lobsters, crabs, shrimps) from 
 insects, the introduction of the tribes of the arachnida 
 (spiders), the determination of the class which he called 
 annelida (worms, centipeds), the distinction of the micro- 
 scopic infusoria from the polypes (radiate animals) ; he 
 further determined the genera of the mollusca (snails, oysters), 
 many genera and species of coral, and finally described and 
 explained the fossil shells of the Paris chalk in a masterly 
 manner. He crowned his studies of the lower animals by 
 
130 PROGRESS OF SCIENCE. 
 
 classifying them in accordance with their anatomy, and 
 divided them into classes, orders, and genera being the first 
 naturalist to begin a classification with the simplest and least 
 highly organised animals. The great work of his life, how- 
 ever, had by far more importance than all this series of 
 laborious researches, and was certain to exert paramount 
 influence over scientific philosophy for all times. His process 
 of classification seems logically to have convinced him (1801) 
 that, acting by law, nature commenced with the simplest 
 types, and that from these types had sprung an ever in- 
 creasing variety of species branching off from one another, 
 so that the present plants and animals are the outcome of 
 those of past geological eras. Therein lay the whole subject 
 of evolution versus creation a momentous subject which was 
 destined, after Charles Darwin, to force human thought into 
 new regions. From this brief statement it is easy to see 
 that none could have more influence than Lamarck over the 
 modern school of evolutionists. His work, " Philosophic 
 Zoologique," which Robert Chambers popularised in " Vestiges 
 of Creation" (1844), has shaped evolutionary thought and 
 produced a decisive impression upon scientific men. The 
 last thirty years of his life were devoted to the elucidation 
 of the problem of origin of species. The core of his teaching 
 lies in the formulation of the idea that gradual modification 
 from one primordial type has produced them all, and he 
 extended this doctrine to the inorganic world alterations 
 being in all cases and in every sphere the result of law. 
 Anticipating Lyell, he even held that the ordinary process 
 of natural laws was sufficient to account for all the phe- 
 nomena presented by the earth's crust. He held the means 
 of animal modification to have been, and to be due, not to 
 differences and changes of habitat only, as is often said of 
 him, but (i) to the direct environment or physical conditions 
 of life., of which climatic and geographical changes form only 
 a part ; (2) to the blending, or separating, or crossing of 
 formerly existing types ; (3) to the effects of habits, and 
 hence to the use and disuse of certain organs and limbs. 
 The "use and disuse" theory has been considered as of 
 paramount importance by C. Darwin and Herbert Spencer. 
 
MODERN SCIENCE. 131 
 
 Thus, proceeding further than Buffon, Erasmus Darwin, 
 Goethe, who had only asserted the principle, Lamarck 
 systematically and scientifically laid down the great problem 
 of the variability of species for the first time, and thereby laid 
 the foundation of the LAW OF BIOLOGICAL EVOLUTION, by 
 demonstrating the alteration of types man included, for he 
 also enunciated the doctrine, first amongst biologists, that 
 man is the descendant of an ape-like ancestor. The essen- 
 tially original element he brought into science was, let it be 
 remembered, not the evolutionary idea, but the idea that law 
 presides over every process of nature, and hence obtains in 
 biology as in all else. 
 
 17721844. Geoffrey St. Hilaire (Etienne), believing 
 like Lamarck in the MUTABILITY OF SPECIES, demonstrated 
 the unity of plan of the animal kingdom, and pointed 
 out its branching off into innumerable divisions from a 
 central stream. As a matter of fact, he believed all species 
 to be derived by modification from one or several primitive 
 types (1795). He was, like Buffon, Lamarck, and others, an 
 evolutionist. Cuvier held a contrary view. He thought that 
 each species and variety had been separately created and 
 gifted with special organs to meet its wants. And as creation 
 had left them, so they were now. St. Hilaire held that 
 " Nature has formed all living beings on one plan, essentially 
 the same in principle, but varied in a thousand ways in all 
 the minor parts all the differences are only a complication 
 and modification of the same organs." And this HOMOLOGY 
 (similarity of structure) runs through all animals, so that the 
 leg of a horse, a lion, an ox, the wing of the bat, the paddle 
 of a porpoise, the hand of man are the same organs made up 
 of the same bones these being merely altered to meet different 
 purposes. This great principle was demonstrated by St. 
 Hilaire, but it has been fully worked out since by Darwin, 
 Wallace, Haeckel, and others. The divergence of conclusions 
 between Cuvier and Geoffrey St. Hilaire was one which in- 
 terested and stirred up the whole scientific world for a whole 
 generation. His son (Isidore) was a great authority on 
 variability and correlation. 
 
 1779 i SS 1 - Oken was the first to suggest the theory of 
 
 K 2 
 
132 PROGRESS OF SCIENCE. 
 
 UNITY OF ORGANIC COMPOSITION the life-matter being 
 " original slime." He also suggested that the development of 
 animal forms proceeds from " mile " cell-growth a profound 
 idea which SCHLEIDEN (1838) and SCHWANN (1839) worked 
 out and fully demonstrated the first tracing the plant embryo 
 to a single nucleus-enclosing cell ; the second tracing the 
 animal embryo to a similar primordial form the cell, there- 
 fore, being the fundamental unit of which every organism, 
 whether plant or animal, is built up. To Schwann may 
 therefore be ascribed the demonstration of the unity of the 
 composition of animal organism. 
 
 1792 1876. Von Baer founded EMBRYOLOGY a very 
 important branch of biology tracing as it does all the stages 
 of development of an animal from its first appearance in the 
 egg to its birth (1828). Von Baer, next, showed a very 
 striking phenomenon, viz. : that the embryos of a fish, a 
 lizard, a bird, an ox are not distinguishable from one another 
 and they continue growing so until a certain stage, and at 
 that stage the fish begins to differ from the three others, and 
 goes on growing into a certain variety of fish ; of the three 
 embryos that remain alike still for a time, one, the lizard, 
 begins to branch off from the common appearance ; then of 
 the two remaining, alike still for a little time, the bird branches 
 off; and lastly the ox embryo takes a decided turn, but only 
 some time after. This great fact offered a new basis for 
 classification, for animals could now be differentiated accord- 
 ing to the special characters they assumed from the beginning, 
 and some defects of classification were rectified. This dis- 
 covery had a philosophical importance besides, for it went far 
 to prove that unity of plan upon which G. St. Hilaire had 
 insisted the embryo showing the same parts developing 
 differently in different animals out of identical beginnings. 
 Von Baer, like Von Buch, anticipated Charles Darwin in 
 believing that a variety may slowly be altered into a per- 
 manent type a doctrine taught long since, as we have seen. 
 In close connection with Von Baer's observations, one of the 
 most instructive additions made to this branch of physiology is 
 due to Mr. Romanes, who, by the use of the microscope again, 
 recognised in the lower class of invertebrates, the jelly-fish 
 
MODERN SCIENCE. 133 
 
 (medusa), rudimentary indications of organs similar to those 
 we possess : traces of a nervous system, rudiments of eyes, and 
 (f sacs of mineral particles " supposed to be a rude hearing 
 apparatus. From such beginnings has the law of evolution 
 brought about all the alterations and complications which can 
 be seen in the organic world. 
 
 180072. Pouchet enunciated the fundamental LAW OF 
 FECUNDATION in mammals ; endeavoured to prove the theory 
 of spontaneous generation but counter experiments carried 
 on by other biologists showed that what might be taken for 
 spontaneous generation was nothing but the hatching of 
 microscopic germs. 
 
 1801 1872. Von Mohl (Hugo) by his study of the 
 anatomy and physiology of plants, especially in relation to the 
 pores of their tissue and the existence of vegetal cells, became 
 next to Oken the originator of the theory of PROTOPLASM a 
 new area of research. We are entirely indebted to the micro- 
 scope for this very important addition to knowledge. Much, 
 as regards the structure of cells, tissues, fibres of plants, was 
 already known as we have seen, when Von Mohl discovered, 
 in 1853, th e primitive form of living matter in other words, 
 life in its most elementary condition and this matter, he 
 showed, enters into the composition of a cell, and circulates 
 therein with marvellous activity. It is also present in the 
 embryo-sac. And being the simplest form of life known the 
 clay out of which bodies are formed the discoverer called it 
 protoplasm (first formative material). Chemically it is a 
 compound of carbon, hydrogen, oxygen, and nitrogen, which 
 is manufactured by the plant out of the soil, air, water, sun- 
 heat and light. Thus plants draw directly from chemicals 
 both food and life ; some animals feed on plants that is, on 
 the same chemicals prepared for them by the plants as other 
 animals, ourselves included, partly feed on vegetable-feeders 
 that is, on the same chemicals again, further assimilated and 
 prepared as suitable nourishment. Reversing the description 
 roughly, we might say: Man feeds on chemicals turned first 
 into plants, then into ox-flesh. Protoplasm is therefore the 
 most primitive form of life on the one hand, and the material 
 out of which all living bodies are principally supported on the 
 
134 PROGRESS OF SCIENCE. 
 
 other hand. Whether, under the different conditions of pres- 
 sure, heat, magnetism, electricity, which existed at an earlier 
 stage of the earth's existence, chemical combinations spon- 
 taneously occurred which produced this living compound in the 
 first instance, is so far one of the unsolved problems which has 
 exercised the minds of many. We can produce no protoplasm 
 in our laboratories with any of the powers at our disposal, that is 
 certain. What we just stated as a hypothesis is considered by 
 some one of the possible processes of creation for the spark of 
 life, the seed, once produced, evolved millions of ever-growing 
 varieties. Spontaneous generation may have obtained once. 
 
 1809 1882. Darwin (Charles) established the LAW OF 
 BIOLOGICAL EVOLUTION, one of the grandest generalisations 
 on record, after devoting forty years to the close obser- 
 vation and study of plants, insects, worms, birds, animals, 
 and man, finally demonstrating more than the principle 
 laid down by Lamarck, for he proved the variability of 
 Species BY NATURAL SELECTION AND THEREFORE THE 
 SURVIVAL OF THE FITTEST (1859). Two strongly-winged 
 pigeons pairing together instead of pairing at haphazard 
 with weaker pigeons (this is sexual selection), their descen- 
 dants, able to fly more swiftly than most pigeons to escape 
 danger, and to a greater distance to find food, will survive 
 weak pigeon varieties, because, being the fittest, they come 
 off victorious in the struggle for life. Such, in the main, 
 is the theory in a nutshell. The theory of evolution, as 
 the reader is aware, had been repeatedly broached, but 
 the proof that evolution obtained in biology, the way how 
 biological evolution worked itself out, this was the great 
 work of Darwin, and the one which settled the matter 
 for all times. Darwin has supplied us with a prodigious 
 mass of facts a vast number of evidences showing that 
 the plants and animals now existing are all descended from 
 common ancestors, whose structure and organisation were 
 less complicated than they are at present. To prove this 
 proposition, which at first offended our prejudices and 
 pride, he has shown us innumerable instances of the gra- 
 dation of species into one another, so that from the present 
 forms of plants and animals, it has become possible to 
 
MODERN SCIENCE. 135 
 
 ascend to remote ancestors, and establish the genealogy of 
 many species. Up to the present day, " We have attained," 
 says Prof. Cope, one of our highest authorities on the 
 subject, " the long since extinct ancestor of the lowest ver- 
 tebrates; we have the ancestors of all the reptiles, of the 
 birds, and of the mammals. And if we consider mammals 
 separately, we have traced up a great many lines to their 
 points of departure from very primitive types. Thus we 
 have obtained the GENEALOGICAL TREE of 
 
 the deer, camel, musk, 
 
 horse, tapir, rhinoceros, 
 
 cats, dogs, lemurs, 
 
 monkeys, and have important evidence as to 
 the origin of man." And the significance of this fact is 
 much increased by the details of the FILIATION in the 
 course of development. Taking, for instance, THE HORSE 
 as we have it at present, we find that its earliest family 
 ancestor (in America) was : 
 
 In the Early Eocene (Tertiary Period), the EOHIPPUS, the 
 size of a fox, with four toes and the remnant of one fifth toe ; 
 
 Then in the Upper Eocene, the OROHIPPUS, whose rudimen- 
 tary first toe was gone and the fifth toe was reduced to a splint ; 
 
 Then in the Lower Miocene, the MISOHIPPUS, the size of 
 a sheep, with a rudimentary splint on the foreleg and only 
 three toes ; 
 
 In the Upper Miocene came the MIOHIPPUS, who comes 
 near the Anchitherium of Europe the tips of whose outer 
 toes just touched the ground ; * 
 
 In the Lower Pliocene, the PROTOHIPPUS, the size of an 
 ass, nearly similar to the Hipparion of Europe three toes 
 only, the middle of which only touched the ground ; 
 
 In the Middle Pliocene, the PLIOHIPPUS, who has lost 
 the small hooflets on the rudimentary toes in all aspects 
 resembling the horse ; 
 
 In the Upper Pliocene finally came the HORSE, with one 
 solid toe covered with a single solid nail (the hoof). 
 
 In Europe, the earliest ancestor of the horse as yet found 
 was the PAL^EOTHERIUM, with three toes, the middle one 
 being the largest ; 
 
136 PROGRESS OF SCIENCE. 
 
 Then came the ANCHITHERIUM, with the two outer toes 
 just touching the ground and the middle toe being the main- 
 support ; 
 
 Then came the HIPPARION, the immediate ancestor of the 
 horse, with the two side toes so rudimentary as to be useless ; 
 
 Then came the HORSE, without the side toes. 
 
 This genealogy of the horse was elaborately traced out 
 by Prof. O. C. Marsh, the great American palaeontologist. 
 
 We may remark in passing that the Miohippus of America 
 and the Anchitherium of Europe were first cousins ; we may 
 further remark that America was the home of the horse's 
 ancestors ; that one of the family, possibly the Misohippus, 
 may have migrated to Europe, when the two continents were 
 joined, and there developed a collateral branch independently, 
 whose descendants were first the Palaeotherium, then the An- 
 chitherium, then the Hipparion,then the Horse. The family, 
 which died out in America after the Upper Pliocene epoch, 
 was perpetuated in the European branch until the present 
 day. We find the horse in Europe throughout the Quaternary 
 Period. By tracing a multitude of facts similar to those, 
 Darwin was able to establish his biological evolutionary law, 
 and Herbert Spencer has since shown the law of evolution to 
 be one which applies universally to all orders of facts ; that 
 if changes of structure, brought about by new conditions, enable 
 the Flora and Fauna to live on and on, under new forms, 
 despite the successive alterations of the globe, changes of 
 conditions modify with equal energy and variety the whole of 
 the Universe for, whether we view the organisation of society 
 only, or the construction of the earth or that of the stars, we 
 detect the same adaptation of things to new necessities : 
 geology and astronomy, barring ft natural selection " and its 
 mode, teach us the same lesson as biology. Well might Mr. 
 Jevons say "that it is questionable whether any scientific 
 works which have appeared since the Principia of Newton are 
 comparable in importance with those of Darwin and Spencer." 
 
 Darwinism, which at first shocked many minds, has now 
 been accepted even by divines of the Church. " It seems/' 
 says Bishop Temple, "more majestic, more fitting of Him 
 to whom a thousand years are as one day, thus to impress 
 
MODERN SCIENCE. 137 
 
 His will once for all on His creation, and provide for all its 
 countless varieties by this one original impress, than by special 
 acts of creation, to be perpetually modifying what He had 
 previously made." 
 
 By Darwin's explanation it is easy to reconcile the 
 divergent views entertained by Cuvier and Geoffrey St. Hilaire. 
 Truth being one, and these two great men being possessed 
 of sound knowledge, it was likely that it would be found that 
 they were both right, and that they were both in the possession 
 of truth in the main was shown by another truth the one 
 Darwin brought to light. For the law of the survival of the 
 fittest made it imperative that each part of an animal should 
 be exactly fitted to meet its wants and should work har- 
 moniously with the rest of the body, as Cuvier demonstrated 
 it to be the case; whilst the law of natural selection made it 
 equally imperative that if animals have been gradually 
 altered from one another, by the instinct to pair with those 
 exactly like themselves though they might slightly differ 
 from the rest of their species, they should be made on one 
 plan as St. Hilaire showed they were. Cuvier's doctrine of 
 immutability, however, was totally destroyed by the same 
 stroke. Darwinism goes much further : it accounts for the 
 fact that existing animals in one continent are of the same 
 nature as those found in the same area in a fossil state, though 
 slightly differing from them ; and finally it accounts for the 
 fact that " lower forms of life are (necessarily) found in the 
 most ancient geological formations." 
 
 It is fitting here, in order to prevent misconception, that 
 the place which Darwin holds in the history of evolutionism 
 should be clearly determined. The doctrine of evolution,* as 
 we have repeatedly seen, originated long before Darwin. 
 Buffon had foreshadowed it in the middle of last century; 
 Geoffroy St. Hilaire (1795) thought species derived by 
 modification from one another, and Goethe endorsed that 
 view. At the same time Erasmus Darwin, Charles Darwin's 
 grandfather, adopting the same theory, went further still 
 by enunciating some of the causes of animal development. 
 Lamarck (1801), besides holding that all species were 
 * The doctrine can be traced to India. 
 
138 PROGRESS OF SCIENCE. 
 
 descended by gradual modification from one primal form, 
 commanded greater influence still, because he systematised 
 a large number of facts, and brought in the idea that law 
 governed the living world as it governed all else. Later, 
 William Smith pointed out that rocks were deposited in 
 successive order, and thus carried the doctrine of evolution 
 into the domain of geology ; and, subsequently, Lyell sub- 
 stantiated the theory as regards the main problems involved in 
 the formation of the earth. In astronomy, as early as 1744 
 and 1/99, tne same lesson was taught by Kant and Laplace, 
 regarding the origin, constitution, order, and gradual formation 
 of the heavenly bodies. Thus far, we see that the evolutionary 
 law was demonstrated as having obtained in astronomy and 
 geology, and that it had been all but demonstrated in 
 biology. To this last determination without speaking of 
 Von Buch, Lecoq, Von Baer, and Dean Herbert, each of 
 whom did valuable work three men, Malthus, Dr. Wells, 
 Patrick Matthew, contributed an important share. Malthus 
 (1798) pointed out the struggle for existence which keeps 
 human reproduction to the same limit as food-supply; Dr. 
 Wells (1813) actually hit upon the notion of " natural 
 selection " as regards the races of mankind ; Patrick Matthew 
 (1831) went even further: he not only intimated the same 
 idea, but he applied it to the whole of nature. We thus see 
 that the staircase of biological evolution had been gradually 
 ascended before Charles Darwin reached its upper platform. 
 This is not all. Herbert Spencer, as early as 1852, had 
 published his " Development Hypothesis/' which embraced 
 the main arguments, features, and facts of the whole evolu- 
 tionary doctrine, and enunciated, with luminous force, the 
 doctrine of descent with modification. 
 
 It seems, after such a recapitulation, as if there remained 
 nothing for Darwin to do : the evolutionary theory had been 
 strongly established in several branches, and had been fairly 
 sketched even in biology. Yet, for all that, there was a 
 vacant place left, and that vacant place was the most im- 
 portant of all. It was absolutely imperative, before biological 
 evolution could be accepted, that it should be demonstrated 
 beyond doubt by a vast array of proofs of all kinds. This 
 
MODERN SCIENCE. 139 
 
 was absolutely necessary because the question touched not 
 heavenly bodies, not the earth's history, about which ordinary 
 mortals feel only secondary interest if they feel any at all 
 but touched mankind itself, its origin, its history, its feelings, 
 its creed, its destiny; and each individual, attacked so to 
 speak directly by the doctrine, was sure to reject it loftily 
 unless irresistible and overwhelming evidence brought con- 
 viction to him, and left him no room for the shadow of 
 a doubt. This was the work left for Darwin to do, and he 
 did it. His contribution to evolutionism was, as we know, 
 not the idea itself; nor was it the idea of descent with 
 modification ; it was the idea of " natural selection " by 
 which he was able to prove plants and animals to have 
 been slowly evolved from simpler forms, "with definite 
 adaptations to the particular circumstances by which they 
 were surrounded." Where an inquirer had seen the law 
 obtaining in flowers only, another inquirer in timber only, 
 a third in mankind only, Darwin showed the law to have 
 held good universally for the whole of organic nature that 
 is, where some had seen the particular he saw the universal ; 
 and he showed this by such a multitude of facts, proofs, 
 instances in so many different species of plants, and so many 
 more of animals, that the conclusion was irresistible. Again, 
 where all the aforesaid philosophers and inquirers had 
 asserted even plausibly, but asserted only, he brought forward 
 innumerable examples of every kind, and silenced dissent 
 by irrefragable proof. Again, where only one line of argu- 
 ment in favour of organic evolution was set forth, Darwin 
 accumulated the argument from palseontological succession, 
 the argument from geographical distribution, the argument 
 from embryological development, the argument from classi- 
 ficatory relationships i.e. 9 the genealogical tree. Where one 
 had seen " descent with modification," he saw descent with 
 modification by "natural selection " which is the key of the 
 mystery. Where Malthus, and even Wallace, had expressed 
 suggestive hints, he constructed a vast inductive system. 
 Finally, where Erasmus Darwin, or Chambers, or Lyell saw 
 the working of a final cause, he saw that of an efficient cause 
 a fundamental distinction, as we shall have again occasion 
 
140 PROGRESS OF SCIENCE. 
 
 to point out. Darwin sums up the chief features of his theory 
 as follows: "(i) Growth with reproduction; (2) inheritance; 
 (3) variability from the indirect and direct action of the 
 conditions of life and (4) from use and disuse; (5) a ratio 
 of increase (reproduction) so high as to lead to (6) a struggle 
 for life, and as a consequence (7) to natural selection, en- 
 tailing (8) divergence of character and (9) the extinction of 
 the less improved forms. Thus from the war of nature, 
 from famine and death, the most exalted objects which we 
 are capable of conceiving, namely, the production of the 
 higher animals, directly follows." If the belief of an efficient 
 cause, instead of a final cause, should offend our moral 
 sense, we should aptly remember the words of Bishop 
 Temple already quoted, supplemented by what a distin- 
 guished evolutionist says on the subject. " To the careless 
 and hasty eye," says Crookes, " design and evolution seem 
 antagonistic ; the more careful inquirer sees that evolution 
 steadily proceeding along an ascending scale of excellence, 
 is the strongest argument in favour of a preconceived plan." 
 This beautiful thought does not meet the argument of the 
 existence of evil ; but it is well calculated, nevertheless, to 
 comfort those who may be disposed to look upon evil, not 
 as a permanent feature in organic nature, but as a transitory 
 process towards the ultimate attainment of good. 
 
 For all the reasons we just indicated, Darwin converted 
 the whole world where Lamarck had only aroused interest 
 among the learned. He made evolution comprehensible, 
 and having made it comprehensible in biology, which stirred 
 up an interest in every man, he by the same stroke caused 
 also cosmic evolution to be understood at last, and to be 
 accepted as a universal law, with the same readiness as gra- 
 vitation is accepted ; so that, although he neither originated 
 the idea of evolution, and although general evolutionary 
 law had been demonstrated ; yet, Darwin holds the highest 
 place amongst evolutionists ; because, whereas evolution was 
 only a vague and insignificant notion to most before him, 
 he attracted the attention of the world to it, and brought it 
 home to all men, high and low, learned and ignorant, with 
 equal force. 
 
MODERN SCIENCE. 141 
 
 Having said this much, we have to add that Darwin had 
 exceptional advantages in fulfilling the task he undertook. 
 A five years' cruise round the world (1831-6) as naturalist 
 on board the Beagle a Government vessel bound on a 
 voyage of exploration enabled him to acquire a unique 
 training as an observer, a unique experience as an analyst, as 
 well as a unique collection of specimens for the solution of 
 biological problems. With the study of Erasmus Darwin, 
 Lamarck, Malthus, and their successors ; with the uniformi- 
 tarianism of Lyell ; with the general evolution of Herbert 
 Spencer, he was fully equipped, and had actually the whole 
 subject-matter of his "Origin of Species/ 7 If he was 
 vehemently attacked at first a fact which drew universal 
 attention on him and militated for him thereby in the end 
 he also had the good-will, and even the assistance of men 
 enjoying European reputation Lyell, Wallace, Haeckel, 
 Hooker, Herbert Spencer. To Herbert Spencer, Darwin is 
 indebted for the expression of "survival of the fittest/' which 
 describes more tersely and clearly than " natural selection " 
 the great Darwinian principle. To the organising and 
 systematising mind of Herbert Spencer, too, devolved the 
 task of working out the metaphysical and psychological 
 aspects of evolution, and of adding to Darwinism the force of 
 his application of the evolutionary method to sociology, to 
 the origin of societies, to the origin and growth of languages, 
 of worship, of customs, manners, institutions, industry, 
 religious polity, political government. Herbert Spencer will 
 always be considered as the greatest philosopher of evolu- 
 tionism, but Darwin will remain its central pillar, because 
 what other people suspected, suggested, intimated, discussed, 
 and argued, he was the first to prove by observing, experi- 
 menting, demonstrating so that " popular instinct which 
 regards Darwinism and Evolution as somewhat synonymous, 
 is in a certain degree justified." Darwin's work forms the 
 keystone of the evolutionary system, and " supports it by the 
 mass of evidence it has accumulated." His task was to bring 
 evolution from the clouds to our door-step. But to Herbert 
 Spencer alone we owe the entire philosophical conception and 
 fabric of evolution as a " cosmical process," one and con- 
 
142 PROGRESS OF SCIENCE. 
 
 tinuous " from nebula to man, from star to soul, from atom 
 to society." He is the high-priest of the evolutionary 
 creed. (Grant Allen's Darwin?) 
 
 To understand the full import of evolution, we must 
 read the crystalline exposition of the system in Spencer's 
 " First Principles " ; but to apprehend its outline we need 
 only recollect its simplest definition. Evolution means a 
 constant and everlasting process of infinite transformation 
 working itself out in regular order, and spontaneously 
 producing new divergences in obedience to, and in harmony 
 with, definite natural laws. In other words, the evolutionists 
 see in evolution " a vast aggregate of original elements per- 
 petually working out their own redistribution in accordance 
 with their own inherent energies." This process applied to 
 the development of plants and animals is very clearly appre- 
 hended too, as soon as we admit, as we must, the " struggle 
 for existence " to which all organised things are subjected by 
 the circumstances which surround them ; for, in that struggle, 
 " variations, however slight, if in any degree profitable to the 
 individual which presents them, will tend to the preservation 
 of that particular individual ; and, being on the average 
 inherited by its offspring, will similarly tend to the increase 
 and multiplication of its species in the world at large." This 
 is the principle of natural selection or survival of the fittest 
 the great principle which Darwin added to the evolutionism 
 of Lamarck and his followers, and which has revolutionised 
 human thought. Of the cause of variation we know little as 
 yet or nothing, unless Weismann has hit upon it in his theory 
 of the persistence of germ-plasm. That would explain the 
 problem ; but the germ-plasm doctrine is far from being as 
 yet an established fact. 
 
 Of all the works of Darwin, besides his "Origin of 
 Species" (1859), the "Fertilisation of Orchids" (1862) and 
 the "Descent of Man" (1871) are the most famous: the 
 first, because it opens the loveliest fairyland of nature ; the 
 second, because it contains all the evidence and arguments 
 which science can furnish of the relationship of man with the 
 rest of the animal kingdom. His u Variation of Animals and 
 Plants under Domestication" (1876) is a storehouse of daily 
 
MODERN SCIENCE. 143 
 
 verifiable facts, whilst his treatise on " Sexual Selection," 
 which expounds the celebrated " Theory of Courtship," 
 explains a very important element of organic evolutionism. 
 We may mention also that his " Effects of Cross and Self- 
 Fertilisation in the Vegetable World" (1876) called 
 attention to the now well-known Knight's law " Cross- 
 fertilisation produces finer and healthier offspring, while 
 continuous self-fertilisation tends to final extinction " ; and 
 to Sprengel's beautiful work, " Fertilisation in Flowers," 
 which had been lying in the dust of libraries ever since 1789, 
 despite its intense interest and worth. That more than eight 
 hundred works on the same subject should have appeared 
 since Darwin drew attention to Sprengel may give an idea 
 of the germinal force that lay in his labours. 
 
 It is bare justice to state that Mr. Alfred R. WALLACE was 
 working independently in the same direction as Darwin 
 himself, and that he arrived at similar conclusions about 
 the same time, after four years' work in Brazilian forests, and 
 eight years' explorations in the Malay Archipelago. The 
 writings of this fervent servant of science* are worthy of 
 Darwin himself. 
 
 Since Darwin's death, Darwinism may be said to present 
 three groups of inquirers : I. the Wallace-Haeckel group, who 
 are orthodox Darwinians ; II. the Herbert Spencer group, 
 who are rather inclined to Lamarckianism ; III. the Weismann- 
 Romanes group, who explain variation as due to external 
 influences, and among these to sexual reproduction mainly. 
 Weismann thinks his theory of the continuity of the germ- 
 plasm is the key to the problem. For, the egg-cell (if we 
 may use the common term) will be affected by the sperm- 
 cell which unites with it, and the offspring receiving the 
 variation inherent in the sperm-cell, is itself different from 
 both parents, and will carry its own variation, by the trans- 
 mission of its germ-plasm, to its immediate descendant, whose 
 nature will in like manner be affected by the process just in- 
 dicated and repeated by its progenitor. This theory would 
 clear up the mystery of the cause of variation. Before it is 
 
 * " Travels on the Amazons and the Rio Negro," " Tropical Nature," 
 "Geographical Distribution of Animals." 
 
144 PROGRESS OF SCIENCE. 
 
 accepted, the existence of the germ-plasm has to be con- 
 clusively confirmed. 
 
 b. 1821. Virchow is justly regarded as one of the leading 
 physiologists and biologists of modern times. His researches 
 into CELLULAR PATHOLOGY particularly, deep and thorough 
 in an equal degree, make him one of the great masters of 
 science, for he may be considered as the founder of that 
 branch. He proved the soundness of his own doctrine, 
 " Omnis cellula a cellula " (every cell comes from another 
 cell), by tracing the origin of disease to hereditary cells. 
 This is the fundamental principle of cellular pathology. 
 He discovered new aspects of ulceration and inflammation 
 in berculosis and other affections. His investigations in 
 prehistoric archaeology are almost as much prized as those 
 he made in pathological anatomy. Strange to say, he 
 fought for the doctrine of fixity of species against the 
 Darwinian theory resembling in this Owen and Agassiz, 
 not to speak of Lyell, who accepted Darwinism only after 
 it had conquered the scientific world. It is only fair, both 
 to Darwinism and to its opponents few nowadays to state 
 that opposition is grounded on religious belief rather than 
 on scientific considerations. It is a conflict between a 
 sentimental inclination and a powerful fact, in which the 
 latter must of necessity prove victorious in this as in so 
 many cases before. 
 
 b. 1822. Pasteur studied organised ferments in beer, 
 vinegar, and wine, analysing meanwhile bacilli and bacteria 
 (microbes) with such success that he was able to discover (?) 
 the bacillus of rabies (HYDROPHOBIA), and further, introduce 
 inoculation against this terrible disorder the effect of which 
 is prevention and cure. His discoveries, which unveiled 
 the mysterious sources of infectious disease, have caused a 
 revolution in medicine and surgery, and led to vast progress 
 in them, making them at once more scientific and efficacious. 
 He may be considered as one of the greatest benefactors 
 of humanity certainly the greatest of our time to be 
 remembered in all ages as Pare, Jenner, and Simpson, all 
 of whom have contributed to the decrease of human suffering. 
 
 1825 92. Bates, with whom Alfred Russell WALLACE 
 
MODERN SCIENCE. 145 
 
 was at first associated, went to Brazil in order to study 
 tropical life in its richest region. It was these two genuine 
 inquirers who opened an almost virgin soil and made it 
 known to the scientific world. In the depths of Brazilian 
 forests where he wandered for years, Bates, after collecting 
 endless varieties of tropical butterflies, unravelled the history 
 of evolution on the gauze-like wings of these insects. He 
 also expounded the fine and striking theory of mimicry a 
 crucial instance of animal development. The phenomena he 
 thus disclosed were precious to biological science : for the 
 strange disguises which insects and birds frequently assume 
 are facts that afforded a new principle to Charles Darwin, 
 "which enabled him with ease to reduce a great number of 
 points to order and symmetry," and supplied him with addi- 
 tional evidences of natural selection. " The Naturalist on the 
 Amazons " was the work which made Bates famous. 
 
 b. 1825. Huxley, equally great as a writer, a philosopher, 
 and a man of science, is probably the greatest biologist 
 living. He originated researches in oceanic HYDROZOA 
 during a voyage around the world ; showed the existence 
 of extensive masses of monera at the bottom of deep oceans, 
 "where they form a sort of live slime" (1868); carefully 
 investigated the development of invertebrates ; pursued 
 investigations in PROTOPLASM and advanced this branch 
 rapidly, thereby becoming the highest authority on the 
 origins of life so far as they can be determined by man. 
 In numerous branches of biology, Huxley has contributed 
 facts and conclusions which corroborate with unanswerable 
 force the evolutionary process elucidated by Darwin, so 
 that he is justly regarded as one of the most powerful 
 demonstrators of the law. With keen scientific perception, 
 for instance, he demonstrated birds to be descended from 
 reptiles from the Dinosaurs the immense gap between 
 them being filled up by the discovery of intermediate bird- 
 like reptiles and reptilian birds the linking ancestors of 
 the bird being the Compsognathus and Archaeopteryx of the 
 Old World and the Ichthyornis and Hesperornis of the 
 New World the last two brought out by Prof. Marsh. 
 This genealogy of the bird supplies one of the most 
 
 L 
 
146 PROGRESS OF SCIENCE. 
 
 striking evidences of the evolutionary doctrine. As regards 
 man, to us the most engrossing of all subjects, Huxley 
 showed anatomically that man must be classed in the order 
 of Primates, as one of the many divergent types which 
 that order embraces within its extensive limits. In his 
 work, " Man's Place in Nature," published about the same 
 time as Lyell's "Antiquity of Man" (1863), Huxley arrived 
 at the conclusion that man must necessarily be the descen- 
 dant, like other mammals, from some common vertebrate 
 ancestor, and that the prevalent view of his origin and of 
 his destiny "must be modified by the evolutionary principle." 
 His " Lectures on Comparative Anatomy," " Introduction 
 to the Classification of Animals," "Address on the Coming 
 of Age of the Origin of Species" (1880), are deservedly 
 held in universal esteem. 
 
 b. 1834. Haeckel, one of the most brilliant followers of 
 Darwin, might be called the Huxley of Germany, but for his 
 tendency to venture upon speculations at times unsupported 
 by strict scientific inquiry. Apart from this consideration he 
 has rendered sterling services to science. In the first place 
 he, more than all others, contributed to the spread of 
 the evolutionary idea throughout Germany, despite his 
 troublesome terminology. Among other matters finely 
 treated he discussed with unique boldness the successive 
 stages of man's genealogy. In corroboration of Darwinism 
 he undertook a vast inquiry in order to determine the laws 
 governing the form of structure and mutual relations of living 
 things, so as to establish the general principles of biological 
 science. The first part of this labour he expounded in 
 " Generelle Morphologic " (1866). This work was an attempt 
 to found a " natural system " on the basis of genealogy ; 
 in other words, to construct hypothetical pedigrees of the 
 various species, including man. To this end he investigated 
 and pointed out several aspects of organic evolution, notably 
 those relating to the metamorphosis of organs, taking care to 
 strengthen his views by working out with remarkable cogency 
 and mastery the Darwinian theory of sexual selection. His 
 " History of Creation " (1868) a popular work contains an 
 application of the Darwinian theory to the chief groups of 
 
MODERN SCIENCE. 147 
 
 animals, and a determination of their mutual relations and 
 lines of descent. His "Anthropogenic" is an elaboration of 
 the same principles to the special problem of the evolution of 
 man. It includes subjects which have been exercising 
 biologists' minds of late years such as the Gastraea theory, 
 the Ccelum theory, and the nature and origin of segmentation 
 into which our limits do not allow us to enter. He 
 vigorously defends what he calls the " fundamental law of 
 biogenesis/' known in England as the recapitulation theory, 
 according to which the actual development of an animal is a 
 repetition of the ancestral development of the species ; or, 
 as it has been put, animals in their development climb up to 
 their own genealogical trees a theory generally accepted by 
 biologists. (See Von Baer.) He was amongst the first who 
 realised and taught that doctrine. He strongly dissents from 
 Weismann's teaching with regard to heredity pointing out 
 that the existence of germ-plasm is as yet a mere conjecture, 
 and maintaining that acquired characters are transmitted. He 
 holds that the ancestors of the Vertebrates must be looked for 
 amongst the segmented Turbellarian worms. The weak 
 points of Haeckel's teaching lies in human embryology, " the 
 difficulties of the problem of which he lays aside " a great 
 deal, mainly due to the labours of the celebrated Leipzig 
 Prof. His amongst others, and known for certain, he entirely 
 ignores. Haeckel's works contain genealogical tables, one of 
 his usual modes of exposition, which, strongly suggestive as 
 they are, are not always accepted by naturalists. Yet, his 
 zoological classification is on the whole considered as one of 
 the most perfect ever devised. Haeckel, it should also be 
 remembered, has made sponges a particular study, and is held 
 as one of the few authorities on that special branch of 
 organisms which yields strong evidence of evolution. 
 
 Haeckel was not alone in Germany in working out the 
 problems of life initiated by Darwin. To speak of a few 
 only, the two Mullers (Fritz and Hermann) till the same 
 field with earnest conviction and intelligence : the first 
 collected his fine " Facts for Darwin/' which abound in 
 instances and evidences of organic development ; the second 
 observed with German patience and thoroughness the action 
 
 L 2 
 
148 PROGRESS OF SCIENCE. 
 
 of butterflies and bees on the fertilisation of flowers ; while 
 Riitimeyer explained with keen perception mammalian re- 
 lationships in accordance with the Darwinian theory. These 
 contributions to scientific knowledge, it is hardly necessary to 
 say, were only a small percentage of the mass which laborious 
 Germany has accumulated within the last twenty years. 
 
 b. 1834. Lubbock (Sir John) added valuable information 
 to that furnished by Malpighi, Leuwenhoeck, Swammerdam, 
 Spallanzani, Reaumur, and Lamarck, who had paid much 
 attention to insects. Sir John has supplemented our know- 
 ledge of BEES AND ANTS by wonderful details. Nothing in 
 nature is more beautiful than the instinct, the habits, the 
 order, the intelligence of these insects, and nothing in science 
 is more admirable than the love, the patience and cleverness Sir 
 John has displayed in this study. To say that he watched 
 one individual insect queen for fourteen years is to give an 
 idea of the thoroughness of his work. His books are de- 
 lightful reading. Anthropology is also much indebted to 
 Sir John Lubbock for his extensive investigations. His 
 persevering researches resulted in valuable works, the pur- 
 port of which is accurately described by their titles : (f Pre- 
 historic Times," which came out about the same time as 
 Tylor's "Early History of Mankind" (1865); "Origin of 
 Civilisation " (1870), and " Primitive Condition of Man." In 
 those books the author has accumulated conclusive evidences 
 of the remote antiquity of man and man's slow evolution from 
 the lowest state of brutishness to his civilised condition. 
 
 ANTHROPOLOGY. 
 
 1752 1840. Blumenbach founded this new science was 
 the first who gave a serious attention to the natural history of 
 man, neglected until then. His "Skulls of All Nations" 
 opened the road to the STUDY OF MANKIND in all parts of 
 the globe the configuration of the. skull, stature, colouration, 
 of the skin, eyes, hair, ethnology, philology, worship becoming 
 so many subjects of serious investigation, and so much 
 material to establish a basis for the divisions of the human 
 races. 
 
MODERN SCIENCE. 149 
 
 1788 1868. Boucher de Perthes discovered flint im- 
 plements and a HUMAN JAW in the drift of the river Somme 
 {1847), thereby causing a revolution in the views held hitherto 
 regarding the antiquity of man. He shattered at one blow 
 the erroneous ideas of mankind as regards the origin of man, 
 his place in creation, and his course of development. His 
 discovery was supplemented in 1853 by antiquarians rinding 
 the Swiss Lake dwellings, which are comparatively recent, 
 but which nevertheless added another evidence to the antiquity 
 of man. Other countless discoveries have extended our 
 knowledge on that point (see Broca and Agassiz). 
 
 1791 1862. Knox (Robert) showed in his work, "The 
 Races of Man/' the PERSISTENCE of the Jewish, Celtic, and 
 German TYPES, and endeavoured to prove that distinctions 
 were immutable a theory which, though apparently sup- 
 ported by the evidence yielded by atavism (heredity), can 
 no longer be held in the face of the law of evolution. Knox's 
 facts are of much value, nevertheless, for they add another 
 set of proofs of the remote antiquity of man. For if man has 
 undergone no visible change within such a lengthy period as 
 the whole of the historical epoch, hundreds, perhaps thousands 
 of such periods must have been necessary for the production 
 of the many existing human varieties. 
 
 17961850. Retzius gave a theory of CRANIOLOGY ac- 
 cording to which the whole human race would be divided 
 into two fundamental groups, founded upon the relation 
 between the antero-posterior diameter (length) and the 
 transverse diameter (breadth) of the skull the autochthons of 
 Europe (natives, aborigines), the stone-man being broad- 
 headed (brachycephalic), and the foreign population, the 
 bronze-man, being long-headed (dolichocephalic) ; but later 
 researches and discoveries have proved this easy method to 
 be insufficient for a correct classification of races. 
 
 b. 1808. Pruner-Bey, after visiting Italy, Greece, Egypt, 
 Syria, Arabia, believed in the persistence of types in his- 
 torical times so long as there is no change of habitat ; founded 
 the differential characters of the human races upon their 
 physiological development; originated the ESTHONIAN 
 THEORY, according to which the Esthonians (who are brachy- 
 
150 PROGRESS OF SCIENCE. 
 
 cephalic) would be the only remnants or survivors of the 
 autochthons of Europe other anthropologists, however, con- 
 tending that the Finns, the Lapps, the Basques are also 
 direct descendants from the primitive population of Europe, 
 although they differ in the configuration of their skulls. 
 
 b. 1 8 10. Quatrefages de Breau believed that the Quater- 
 nary man presented TWO TYPES in Europe : viz., a tall and 
 dolichocephalic man (the Cro-Magnon cave man), and a 
 short and brachy cephalic man (the Esthonian, or the Loess 
 Valley man), both of which have persisted to this day not- 
 withstanding the invasion of Europe by the so-called Aryan 
 races. 
 
 b. 1817. Vogt pointed out the difference between man and 
 the anthropoid apes, in popular lectures, and contributed to 
 promote the study by numerous observations. His injunction 
 to study the whole race as it lies buried in the strata of the 
 earth, and not as a living genus only, was not the least of his 
 services. 
 
 1824 80. Broca, the founder of the earliest Anthropo- 
 logical Society (Paris), proved the Cro-Magnon (and the 
 Eyzies) man, analysed by him, to be different from other 
 known races a fact which demonstrates the unsoundness of 
 previous anthropologists' belief with regard to the unity 
 or duality of race of the primitive inhabitants of Europe. 
 Broca insisted upon the presence of THREE TYPES, which we 
 may differentiate as the Constadt type, very dolichocephalic 
 (long-headed) and prognathic (with projecting jaw) of 
 which the Neanderthal is an extreme instance ; the Cro- 
 Magnon (Vezere Valley) type, rather brachycephalic (broad- 
 headed) with good cranial development, tall, not unlike the 
 modern race ; the Furfooz type, a dwarfish race with a round 
 head, resembling the modern Laplander all of them different 
 from the races of Africa, Asia, and America ! The discovery 
 of numerous caves, ancient human dwellings, both in Europe 
 and America, has thrown much light upon the antiquity of 
 man and the variety of races and habits, notably, besides those 
 already alluded to, the Brixham cave (Devon), Kent's Cavern 
 (near Torquay), Gower Cave (South Wales), Victoria Cave 
 (Yorkshire), Woking Cave (Somersetshire), King Arthur's 
 
MODERN SCIENCE. 151 
 
 Cave (Herefordshire), the Chaleux cave (Belgium), the 
 Vezere cliffs (Dordogne), the Danish Kitchen-Middens and 
 Danish Mosses, the Swiss and Italian lake-dwellings, and 
 hundreds of other sites. Innumerable palseontological im- 
 plements and many human remains discovered everywhere 
 prove the antiquity of man by unmistakable evidence, and 
 reveal the fact that his presence on the earth must have pre- 
 ceded the Glacial period. 
 
 The Anthropological Society of London (now Institute), 
 founded by Dr. James Hunt (1863), had not been long in 
 existence before it contributed a wide range of information 
 towards the natural history of man. 
 
 PHILOLOGY. 
 
 1765 1837. Colebrooke encouraged the study of Oriental 
 languages by composing a SANSKRIT GRAMMAR and Dictionary 
 bringing to the notice of Europe the Grammar of Panini, one 
 of the most profound books produced in any language. 
 
 17671835. Humboldt (C. W.) founded COMPARATIVE 
 PHILOLOGY, which was destined to throw so much light 
 upon the growth of civilisation ; his " Studies on the Basque 
 Language," and his " Kawi Language in the Isle of Java," 
 constitute valuable documents on the history of speech. 
 
 1786 1859. Grimm (Wilhelm Carl) discovered and 
 elucidated the law of the transmutation of .consonants, called 
 GRIMM'S LAW, between (i.) Indo-European languages (San- 
 skrit, Greek, Latin), (n.) the Low German languages, and 
 (ill.) Old High German a feat which has assisted the study 
 of our race in a remarkable degree. 
 
 1790 1832. Champollion, following the ingenious hint 
 supplied by Thomas Young, deciphered the HIEROGLYPHIC 
 LANGUAGE of the Egyptians a thing vainly attempted for 
 two centuries, and the most marvellous feat of the kind ever 
 performed. And not only did Champollion accomplish the 
 solution of a problem which had baffled investigation for 
 ages, but he actually constructed a hieroglyphic grammar and 
 a hieroglyphic dictionary two performances of genius. The 
 key once found, subsequent scholars followed, and now 
 
152 PROGRESS OF SCIENCE. 
 
 hieroglyphic texts can be as easily read as Greek. This 
 great work has caused a revolution in history, revealing as it 
 does an antiquity undreamt of, and a civilisation seven thou- 
 sand years ago which was in many ways more astonishing 
 than ours. Not one of its least important results is the new 
 light it throws upon the antiquity of our race. 
 
 1791 1 8 . Bopp investigated the growth of speech, and 
 traced up the connection existing between a certain group of 
 Oriental languages and those of Europe (Sanskrit, Slavonic, 
 Celtic. German, Greek, and Latin), and their common descent 
 from one original language of which there remains no literary 
 trace. This demonstration is almost conclusive as regards 
 the kindred of all the nations of Europe (the Turks, Hun- 
 garians, Finns, Laps, Esthonians, and Basques excepted), and 
 their descent from one extinct stock conventionally called 
 Aryan. Bopp's COMPARATIVE GRAMMAR, a monument of 
 research and learning, may be called the basis of modern 
 philology; but its value is considerably enhanced by the 
 flood of light it throws on the history of races, coming as it 
 did after ANQUETIL DUPERRON (1731 1805) by his dis- 
 covery and translation of the Vendidad (fourth book of the 
 ZEND AVESTA), and after BURNOUF (1775 1844) and Sir 
 Henry RAWLINSON (1816 ) by their discovery of the 
 key to CUNEIFORM LANGUAGES the lost languages of the 
 Semites, Persians, and Assyrians had furnished documentary 
 evidence of the Aryan theory. 
 
 b. 1823. Max Miiller elucidated in a much further degree 
 the science of philology by a series of works unsurpassed for 
 learning and depth, among which his translation of the 
 Hitopadesa and of THE VEDAS, the HISTORY OF THE SAN- 
 SKRIT LANGUAGE, Lectures on the Science of Language, 
 stand foremost. By these labours and their purport the 
 author has established his title to be considered the champion 
 of the Aryan theory a theory which seems undisputable as 
 regards language, but which is disputed as regards race : 
 identity of speech by no means necessarily implying identity 
 of race. 
 
 Closely connected with anthropology comes : 
 
MODERN SCIENCE. 153 
 
 SOCIOLOGY. 
 
 1619 83. Colbert patronised science as well as art and 
 literature; was the earliest and greatest representative of 
 the progressive tendency of the industrial movement; made 
 MANUFACTURES, until then so despised by statesmen 
 generally, the permanent form of European industry; en- 
 couraged their growth by every means in his power, but 
 chiefly by removing many of the taxes and impositions under 
 which they languished, and protecting their interests wher- 
 ever they were threatened : was one of the precursors of the 
 Economists. It may not be out of place to mention that this 
 enlightened Minister suppressed execution for witchcraft and 
 accusation for sorcery in France. This act of common sense 
 and justice was the earliest of the kind in Europe. 
 
 16941774. Quesnay, one of the founders of political 
 economy, advocated COMPLETE LIBERTY of agriculture, 
 commerce, industry, the abolition of customs in the provinces, 
 free circulation of corn. His motto was "Laissez faire et 
 laissez passer" The weak point of his school lies in the 
 doctrine that agriculture alone is capable of accumulating 
 wealth. Adam Smith and his followers rightly showed 
 that exchangeable products constitute real social wealth, and 
 that society benefits in proportion as labour increases their 
 value. 
 
 17121778. Rousseau has commanded just as wide an 
 influence in another sphere of the social organism by his 
 scheme of SECULAR EDUCATION, which has been adopted by 
 the lay world in all civilised countries through the advocacy 
 of those whom he inspired Jean Paul Richter, Herder, 
 Basedow, Lavater, Pestalozzi, Jacobi, Schiller, Gothe. The 
 teaching introduced by Rousseau's educational reform in- 
 volved individual and public freedom, abolition of prejudices 
 and servitude, a new doctrine of happiness consisting in 
 limitation of desire, self-reliance, manhood, patriotism, work 
 as a duty for all (rich or poor), respect for truth, and craving 
 for justice. The system meant no less than the restoration 
 of naturalism. It need hardly be pointed out that, as 
 
154 PROGRESS OF SCIENCE. 
 
 education and government are the two agencies which 
 surround internal and external character, Rousseau, by his 
 action on political organisation on the one hand, and educa- 
 tional organisation on the other hand, has to a vast extent 
 shaped some of the features of modern civilisation, especially 
 when it is remembered that association and collective action 
 are derived from his scheme. 
 
 1715 1771. Helvetius, whose views on government and 
 belief seemed offensive to so many and aroused so much 
 indignation once, deserves a place amongst great sociologists, 
 not because he devoted his life to philosophy and DUTY, but 
 because he assailed the social ordering of the ancient regime, 
 and expounded the idea of general UTILITY as the foundation 
 of social morality, which Bentham, in England, carried out 
 in legislation. " T/ze laws'' says Helvetius, "should be 
 referred to a single principle such as that of utility of the 
 public" a principle that contains all the seeds of European 
 legislation in our times. His influence, therefore, is likely 
 to last as long as civilisation. 
 
 1723 1790. Adam Smith caused a revolution in trade 
 by his " Inquiry on the Nature and the Wealth of Nations/* 
 The principle of WEALTH IS LABOUR, not in commerce and 
 agriculture only, but in every branch of human activity. 
 The yearly labour of a nation is the source from which it 
 derives all the necessaries of life which consist either in the 
 product of the work of one nation or in what she can pur- 
 chase from other nations. Another principle is complete 
 LIBERTY OF ACTION hence FREE TRADE. Adam Smith 
 also showed the great results of division of labour. Of all 
 economists he had the greatest influence. It is not too much 
 to say that he transformed the social system. 
 
 1727 1781. Turgot, one of the earliest practical econo- 
 mists in Europe; his "Valeurs et Monnaies," and his 
 " Reflexions upon the Formation and Distribution of Wealth/' 
 together with his economical and commercial policy as a 
 Prime Minister, inspired Adam Smith. He wanted the 
 emancipation of labour at home and freedom of trade 
 abroad. He established FREEDOM IN THE CORN TRADE in 
 J774 a reform already tried in 1749 and in 1763 by 
 
MODERN SCIENCE. 155 
 
 Machault and Laverdy, He also advocated a system of 
 general education. 
 
 1738 1794. Beccaria caused the institution of the Jury 
 to be introduced on the Continent ; caused the ABOLITION 
 OF TORTURE ; denounced the harshness of the penal code ; 
 advocated that punishments should be proportionate to the 
 offence so that he was a beneficent legislator, although his 
 work on Crimes and Punishments is only a philosophical 
 treatise. 
 
 1747 1832. Bentham, inspired by Beccaria, introduced 
 the principle of IDEAL JUSTICE into legislation and juris- 
 prudence many reforms due to his action, but the softening 
 of the harsh penal code which existed until then (1830) was 
 the greatest one which he initiated. After him no man could 
 be hanged for forgery or sheep stealing. Practical sociology 
 is indebted to him for two maxims : " Men cannot be happy 
 by making the misfortune of others " ; " Legislation should 
 give the greatest happiness to the greatest number" His 
 theory of government, derived from Helvetius, was essentially 
 UTILITARIAN, and has guided legislators to a great extent 
 since the 1832 Reform. 
 
 1753 1814, Rumford was the first to suppress MEN- 
 DICITY (in Munich, 1790) and to show this evil to be one of 
 the worst forms of social vice. 
 
 1766 1834. Malthus was the first (1798) to draw the 
 attention of economists to the tendency of population to 
 multiply to the last limits of food supply, and to the irre- 
 sistible influence of competition and starvation in restraining 
 its further growth beyond those limits. It was obvious ta 
 many thinkers that although he dealt with the subject of 
 human communities only, numerous analogies could be found 
 in other domains of animal and vegetable life, and, as a 
 matter of fact, it was not long before the same principle was 
 seen to apply to all species. " Reproduction is everywhere 
 and in all species for ever outrunning means of subsistence ; 
 and starvation and competition are for ever keeping down the 
 number of the offspring to the level average or normal supply 
 of raw material. Animals are all perpetually battling with 
 one another for the food supply of the moment ; plants are 
 
156 PROGRESS OF SCIENCE. 
 
 perpetually battling with one another for their share of the soil, 
 the rainfall, and the sunshine. . . . And the struggle is chiefly 
 between members of the same species. ... It is not the 
 soldier, or the sailor, or the ploughman that kills the artisan, 
 but the number of artisans who undersell him and crowd him 
 to fill up every vacant position." Malthus's work, which 
 aroused debate everywhere, exercised enormous influence as 
 a " germinal factor " upon the whole subsequent course of 
 sociological and economical thought. Its influence on the 
 current of biological and speculative opinion was just as far- 
 reaching; for Charles Darwin candidly states that he hit upon 
 the idea which made him famous upon reading Malthus. 
 " With my mind prepared (as you know)," says he, " I 
 fortunately happened to read Malthus's Essay on Population, 
 and the idea of natural selection through the struggle for 
 existence at once occurred to me." Hence it has aptly been 
 observed that Darwinism is Malthusianism on a large scale ; 
 it is " the application of the calculus of population to the 
 wide facts of universal life."* Given Malthus on the one 
 hand, and Lamarckian evolution on the other, a Darwin 
 must have combined the two and have arrived at the theory 
 of natural selection. Malthus, therefore, by his original 
 Essay, assisted three scientific branches sociology, anthro- 
 pology, and biology in an equal degree. His influence over 
 sociology bore naturally on political economy rather than 
 social questions. 
 
 1769 1859. Humboldt, who was a stranger to no 
 science, deserves a place among scciologists, for the light he 
 throws, in his " Essay on the Kingdom of New Spain," on 
 commerce, industry, agriculture, mineral wealth, etc., thereby 
 assisting political economists. 
 
 1798 1857. Comte founded sociology scientifically in 
 his " POSITIVE PHILOSOPHY " by analysing the growth of 
 society, the course of its evolution through its theological, 
 metaphysical, and positive stages ; by showing its defects 
 and the remedies likely to remove them. The cause of our 
 political and moral anarchy, according to him, lies in our 
 intellectual anarchy, itself due to metaphysical aberrations. 
 
 * Grant Allen. 
 
MODERN SCIENCE. 157 
 
 The remedy can be found in a new system of education 
 only, based upon positive science. He was one of the first 
 systematic exponents of the law of evolution as applied to 
 society. 
 
 b. 1820. Herbert Spencer, the great PHILOSOPHER OF 
 EVOLUTION, and at the same time greatest of all modern 
 expositors and philosophers, scientifically co-ordinated all the 
 elements of progress, and expounded the Evolutionary Hy- 
 pothesis in all its multitudinous aspects cosmic and astro- 
 nomical, geological and biological, psychological and social, 
 ethical and religious, etc. in a series of works unsurpassable 
 alike for grasp, depth, and lucidity, notably those bearing upon 
 the development of the human species, from the human unit 
 to the most complex social system. His views were in the 
 first instance inspired by the doctrines of earlier evolutionists,. 
 BufTon, Diderot, Kant, Laplace, Erasmus Darwin, Geoffroy 
 St. Hilaire, Gothe, Lamarck, Malthus, Comte, Von Baer ; 
 and then fully corroborated by Lyell's and Charles Darwin's 
 results. But his system of philosophy extends far beyond 
 the limits of his predecessors', and forms a complete 
 SYNTHESIS of positive philosophy and social physics. His 
 working power was on a par with the sterling knowledge 
 he displays, for he seems to have felt at home in every 
 science, and to have, so to speak, " practised " all branches 
 in an equal degree of thoroughness. His mind stands on 
 the same level as those of the very few universal men who 
 have enlightened humanity most in the course of twenty- 
 four centuries. His masterly originality shines in the 
 number and vastness of the inquiries and elucidations he 
 independently pursued and worked out, just as much as 
 his powerful genius shines in the conception and elaboration 
 of a system which, embracing the physical world as well 
 as the spiritual, satisfactorily solves the profoundest problems 
 which lie within the boundaries of our intellectual sphere; 
 for, with unerring sense and in this he will remain a guide 
 to all future philosophers he excludes what lies beyond the 
 veil that for ever conceals ultimates from human ken. To 
 descend from heaven to earth from the Cosmos to Man 
 the remedy he advocates for the curing of many of our 
 
158 PROGRESS OF SCIENCE. 
 
 social evils lies also in positive and scientific education. 
 It is hardly necessary to point out that our better know- 
 ledge of man's nature will modify our present principles 
 of government and legislation, for obviously legislation and 
 government should be in harmony with the nature and 
 requirements of each race. INDIVIDUALISM, in contra- 
 distinction of SOCIALISM, is the principle of progress which 
 Mr. Herbert Spencer strongly endorses, the neglect of which 
 inevitably dooms society to cruel disappointments. 
 
 Such is the record of the organic group in its briefest 
 form. We see how the results of the previous period fade 
 into insignificance; how far they have been left behind by 
 the achievements accomplished in the modern era. Not 
 only do we perceive the great advance made by the very 
 first modern pioneers in the field, such as Malpighi, Willis, 
 Steno, Leuwenhoeck, Reaumur, but we also see each branch 
 rapidly expanding its area, each phenomenon casting new 
 light for deeper and more extensive explorations, each con- 
 clusion becoming the point of departure for new inquiries. 
 And although the fresh problems daily arising prove far 
 more complicated than older ones ; although they are of 
 such deep import and vast proportions, and offer such 
 difficulties as to appear absolutely insoluble; yet, by un- 
 exampled perseverance, hard work, profound thought, they 
 are almost invariably solved, until the veil which hid the 
 prospect is lifted, and the most mysterious aspects of nature 
 yield their secrets one after another. W T e see how paltry 
 and commonplace the original ideas of the men who were 
 once reputed thinkers are in reality, in the face of the 
 magnitude of those which have exercised the minds of our 
 modern philosophers. For the set of facts embraced by 
 the branches just surveyed would have astonished schoolmen 
 and unpractical thinkers of former ages in no small degree, 
 and aroused their scorn to the utmost. They would have 
 pointed out more suo the worthlessness of the " few observa- 
 tions" biologists, physiologists, palaeontologists, and botanists 
 have made, for they left unexplained the reason why the 
 plesiosaurus had no wings as well as the pterodactyl, or, if 
 
MODERN SCIENCE. 159 
 
 species were variable, why were not the genera, the orders, 
 the classes, likewise variable and interchangeable at will ? 
 Vaccination would have been ridiculed by them, because 
 it could prevent one disease only, and not all diseases. 
 Botany would have been declared useless so long as it did 
 not teach us how to grow Brussels sprouts on rose-trees ; 
 besides which, modern classifications have a suspicious look 
 of Aristotelian nonsense about them which makes science 
 too ancient to be worthy of attention. 
 
 These, or arguments of the same kind, were used against 
 real science at as late a period as the end of the Revival even 
 by men of talent and fame. We mention them for the pur- 
 pose of showing the gulf which then separated prejudice from 
 science, and which now separates those times from ours. 
 
 It is not unnecessary to lay a stress on the fact 
 that many of the immense results enumerated in the last 
 twenty or thirty pages flow with unmistakable directness from 
 Harvey's splendid discoveries and principles. 
 
 GROUP II. GEOLOGY. 
 
 Passing now to Geology, we find : 
 
 1665 1728. Woodward collected (1695) numerous SPECI- 
 MENS of coal, gravel, marble, chalk, sandstone and other 
 rocks. Besides the early students of this branch of science 
 already mentioned Pythagoras, Leonardo, Palissy, Steno, 
 and Scilla Ray and Hooke had also paid much attention 
 to it, both offering suggestions regarding the causes of the 
 earth's crust being made up of successive strata. Ray also 
 pointed out that a mere flood could not deposit fossil remains 
 in extensive beds in the regions where they were found, and 
 that there was evidence that the animals must have lived on 
 the different areas for many successive generations. But with 
 Woodward begins a new departure. He was not content 
 to speculate, he made collections of rocks exhibiting fossils 
 with a view to investigate more deeply. Still, his action 
 going no further, there was no certainty as regards the 
 process of geological formation until Moro and Vallisneri 
 (both Italians) began a series of steady observations. 
 
160 PROGRESS OF SCIENCE. 
 
 1687 1750. Moro was the first to point out that ROCKS 
 must have been DEPOSITED as soft mud, some by the sea, for 
 they contain marine fossils, others by rivers, for they contain 
 fresh-water plants and animals, and that they were subse- 
 quently upraised by earthquakes from time to time. After 
 him comes 
 
 1726 97. Hutton, who may be called the FIRST GREAT 
 GEOLOGIST in point of time and importance. He travelled 
 and made many scientific explorations in order to collect 
 facts, and from these he was able to ascribe the changes on 
 the earth's surface to volcanic action and subterranean heat, 
 thereby originating the PLUTONIAN (or Vulcanian) THEORY, 
 the exclusiveness of which, entertained by Plutonists gene- 
 rally, though not by Hutton himself, is now discarded. 
 Hutton also indicated the processes of denudation, erosion, 
 formation of valleys, river channels, and the action of running 
 water, which levels mountains, carries their materials to the 
 ocean, and thus helps to prepare the sea-floor to become new 
 continents, when in the course of time it is uplifted by under- 
 ground forces all of which modes of action modern geologists 
 have proved to be well founded in fact. He also explained 
 the theory of rain, and threw great light on the study of 
 meteorology. The most important lesson he taught, how- 
 ever, and the one for which he will always be remembered, is 
 that the history of the past must be studied by the changes 
 going on at present, and that THE LAWS which regulated the 
 economy of the globe in past ages were the same as those 
 NOW IN OPERATION (1788); so that he was the precursor of 
 Lyell in teaching the PERMANENCY OF LA.W. These theories, 
 owing to the influence of the Wernerian school, and the want 
 of elegance and lucidity of style of Hutton's Theory of the 
 Earth, were held in little repute for some time. 
 
 1743 1822. Hauy enunciated the theory of CRYSTAL- 
 LISATION that it takes place in accordance with geo- 
 metrical laws and classified minerals in accordance with 
 their crystallisation. 
 
 1748 1819. Playfair (John) studied the geological system 
 of THE ALPS, and threw additional light upon geological 
 laws. It is, however, by his popularising the views of 
 
MODERN SCIENCE. 161 
 
 .Hutton, his master, that he is chiefly to be remembered, for 
 being an excellent expositor he had much influence in 
 advancing the study of the earth. 
 
 1748 1 8 . Keferstein, in his Geognostic Remarks upon 
 the basalt formations of Western Germany, demonstrated the 
 volcanic FORMATION OF BASALT against the Neptunian 
 .school of Werner. 
 
 1750 1817. Werner, by observing, like Hutton, the crust 
 of the earth instead of guessing natural processes, power- 
 fully helped to make geology an experimental study, and 
 ground that science on firm foundations. He originated the 
 NEPTUNIAN THEORY, which consisted in believing water to 
 .have been the almost exclusive cause of new formations, and in 
 .leaving aside other concurrent causes. His sweeping theory 
 Is now recognised to be correct only as regards sedimentary 
 rocks, but his fine lectures promoted the advance of the 
 science, for Hutton himself received much profit from Werner's 
 teaching and theories. 
 
 1760 1832. Hall (Sir James) founded EXPERIMENTAL 
 GEOLOGY by devising experiments in illustration of the 
 structure and origin of rocks ; and this constitutes another 
 service done by Hutton's school to the progress of science. For 
 owing to the influence of the Wernerian school, and Hutton's 
 want of style, Huttonian theories were little known. His 
 friend Hall showed their soundness ; he demonstrated basalt 
 to have been once in a molten condition, by fusing some, and 
 pointing that it exhibits a stony texture by slow cooling. 
 He carried out similar experiments upon limestone convert- 
 ing it into marble under great pressure, and showing it to 
 act on other rocks. Hutton's theories began from that time 
 to command the attention they deserved ; but it was only 
 after Playfair's exposition of them that Hutton was at last 
 recognised as a great authority, and appreciated as an earnest 
 and unerring investigator. 
 
 17691832. Cuvie'r threw great light on geology by his 
 almost exhaustive study of FOSSILS, but wrongly ascribed 
 changes in the stratification to sudden cataclysms. Lyell, 
 since then, has demonstrated the transformation to be due to 
 .slowly-acting laws. 
 
1 62 PROGRESS OF SCIENCE. 
 
 Smith (William), the father of BRITISH 
 GEOLOGY, formulated the generalisation already foreshadowed 
 by his predecessors as we have seen, that each stratum 
 has been successively the bed of the sea, and contains the 
 fossilised monuments of the races of organic beings then in 
 existence ; that each stratum contains organised fossils peculiar 
 to itself, and may be recognised by examination of them ; he 
 distinguished between diluvial and stratified deposits, and laid 
 down that the same strata are always in the same order of 
 superposition, and contain the same fossils. He was the first, 
 in fact, to teach the identification of strata and to determine 
 the succession by means of their embedded fossils. He showed 
 that a fixed order of sequence could be traced among the dif- 
 ferent superincumbent strata. Scientific geology took its rise 
 from this striking discovery. The doctrine of geological evo- 
 lution was necessarily implied by his teaching. His geological 
 maps of England and Wales, constructed in 1815, after 
 twenty-five years' personal observations and surveyings, made 
 over every part of Britain,, is a lasting monument of practical 
 scientific industry. 
 
 1769 1859. Humboldt (Alexander Von) gave great im- 
 pulse to the progress of science by his extensive researches in 
 America and Central Asia, in geography, ethnology (human 
 races and -customs), botany, natural history, climatology, 
 mineralogy, and geology ; was one of the founders of 
 METEOROLOGY and the physical geography of the sea. His 
 Cosmos (or Universe), the result of sixty-six years' labour, is a 
 general view of the world, which sums up the knowledge 
 reached in every branch of science up to his time (1859). 
 The want of absolute accuracy in some details which the 
 work exhibits occasionally is compensated for by the enor- 
 mous amount of information accumulated in it, a large 
 portion of which was original and due to direct ob- 
 servation on his part. In a work of such proportions in- 
 accuracy was inevitable at times, but the Cosmos will remain 
 a cyclopaedical monument worthy of its author, who may be 
 called the modern Aristotle. CLIMATOLOGY is the one 
 branch of science most indebted to him. He carried out the 
 immense undertaking of determining, and tracing across the 
 
MODERN SCIENCE. 163 
 
 chart of the earth, ISOTHERMAL LINES (lines of equal heat), 
 which indicate for all places a given mean temperature for 
 the year. Isothermal lines for the year are called annual 
 isotherms : the isotherms for July and January are respectively 
 called isotherals (summer) and isocheimenals (winter). 
 These charts are most important aids to the study of 
 climatology, " indicating as they do those general laws which 
 apart from latitude and altitude affect the climate of a 
 country. The winter isotherms which cross the British 
 Isles offer a striking feature : they run nearly North and 
 South across Britain instead of lying along parallels of lati- 
 tude; so that a high temperature is to be sought by travelling 
 from East to West instead of North to South." Since 
 Humboldt's time this branch of science has rapidly advanced. 
 One of the chief facts ascertained which affects the economy 
 of a country is the action of aqueous vapour in checking 
 (I.) the radiation (loss of heat) of the earth's heat into space, 
 and (n.) the fierceness of the sun's heat on the earth, owing 
 to the power of aqueous vapour to absorb and retain heat. 
 Says Tyndall on the subject : " Aqueous vapour is a blanket 
 more necessary to the vegetable life of England than clothing 
 is to man. Remove for a single summer night the aqueous 
 vapour from the air which overspreads the country, and you 
 would destroy every plant capable of being destroyed by a 
 freezing temperature." And conversely, if the aqueous vapour 
 did not absorb and retain a great portion of the sun's heat 
 in summer, the vegetation would be parched up, and animals 
 would die from the effects of heat. Climate is affected also 
 by altitude, by proximity of large masses of water, evaporation, 
 and sea and wind currehts. 
 
 1774 1853. Buch (L. Von) demonstrated the great 
 mountain ranges to have been covered by the sea, but to have 
 been formed by gradual upheavals ; discovered the slow and 
 gradual elevation of Sweden, but failed to detect volcanic 
 agency in new formations. As a naturalist he observed the 
 Fauna of the Canaries, and he pointed out that varieties may 
 be slowly changed into permanent species, thereby antici- 
 pating Darwin in one point. 
 
 < Ritter (Carl) created COMPARATIVE GEOLOGY 
 
 M 2 
 
164 PROGRESS OF SCIENCE. 
 
 by demonstrating the relationship which exists between the 
 different parts of our planet, and the influence of the earth's 
 surface upon the development of humanity. 
 
 1785 1873. Sedgwick was the first to notice the sepa- 
 rate nature of the CAMBRIAN ROCKS underlying the Lower 
 Silurian, and in a comprehensive survey tried to co-ordinate 
 the whole range of geological facts known in his time. He 
 mapped the geology of Wales ; described the PALAEOZOIC 
 (ancient life) DEPOSITS in detail, strongly opposing the 
 theories of derivation. 
 
 17871856. Prevost established the theory of the 
 geological strata being formed by alternate FLUVIAL AND 
 MARINE DEPOSITS in the same basin by the meeting of 
 sea and river currents. 
 
 1790 1852. Mantell, in the midst of a busy professional 
 life, carried on almost continuous geological explorations, in 
 the course of which he elucidated several interesting points 
 of the earth's history especially studying, with Buckland, 
 the Carboniferous, Wealden, and Tertiary deposits ; discovered 
 the bones of four out of the five great DlNOSAURlANS known 
 up to 1870, and among them the Iguanodon and the Hylaeo- 
 saurus thereby rendering signal service to palaeontology as 
 well as to geology. It may be said of him that if he left 
 scientific interpretations to Cuvier and Owen, he supplied the 
 two great masters with facts to work upon. He should also 
 be remembered as a popular expositor ; his " Medals of 
 Creation," " Wonders of Geology," " Petrifactions and their 
 Teaching," exercised great influence and aroused keen interest 
 in science. 
 
 1792 1871. Murchison found the primitive rocks of 
 Wales to belong to a unique system THE SILURIAN ; 
 assimilated the stratified rocks of Devon and Cornwall to the 
 red sandstone of Scotland,* calling them the DEVONIAN 
 
 * In his classification of rocks in the Scotch Highlands, Murchison, it 
 should be stated, made a serious mistake, which remained unnoticed for 
 a whole generation until it was overthrown by the observations of Pro- 
 fessors Nicol, Bonney, Drs. Charles Callaway, Henry Hicks, Mr. Hudle- 
 ston, and by the patient investigations of Mr. Charles Lapworth, a private 
 
MODERN SCIENCE. 165 
 
 SYSTEM ; made an immense survey of the geological features 
 of RUSSIA (where he traced the history of the Permian rocks), 
 the Ural mountains, THE HIMALAYAS, THE CAPE, Spain, 
 Brittany, Chili, and some Pacific groups. A few details may 
 show the practical nature of his work. In Italy and Sicily he 
 studied the action of the Vesuvius and the Etna, and showed 
 the rocks these volcanoes had been building. He accounted 
 for the vast masses of lava and basalt, found in all parts of 
 the earth, by recalling to his readers' mind that the eruption 
 of the Skaptar (Iceland), in 1783, had produced a stream of 
 lava 90 miles long, 8, 10, 15 miles broad, and 500 or 600 feet 
 thick the mass poured out on that occasion equalling the 
 bulk of Mont Blanc. He studied also the present formation 
 of limestone beds in the Mediterranean, their enormous 
 thickness, and their uprise of some 3,000 feet above the 
 sea level ; he pointed out the subsidence of part of the 
 English coast-line and the gradual crumbling of the cliffs far 
 beyond the old site of towns which have been moved further 
 inland. All these facts and many others were the materials out 
 of which Lyell was able to demonstrate his geological laws. 
 
 1797 1858. Scrope made a special study of VOLCANOES ; 
 showed their multifarious action in all parts of the globe ; ex- 
 haustively surveyed the Auvergne volcano system, one of the 
 most instructive areas in the world : his work done for all time, 
 so beautifully is it carried out. His two chief books are mines 
 of geological knowledge. 
 
 1797 1875. Lyell classified the stratification of the crust, 
 and established some of the GEOLOGICAL LAWS, especially that 
 of uniform, continuous, and permanent action of forces the 
 one great discovery which made him the master of the science. 
 William Smith had already taught that strata were laid 
 successively; but it was Lyell who formally introduced 
 
 geologist who definitively demonstrated the fact (1883). He proved the 
 Upper Gneisses which overtop the sandstones, conglomerates, and Durness 
 limestones to be identical with the Lower Gneisses the primeval crust 
 of the earth and that the Upper Gneisses, therefore, were not of recent 
 formation as Murchison had taught, but as ancient as the earliest stage of 
 the earth's crust \ so that the order of succession of rocks in the Highlands 
 is apparent only, and not real. 
 
i66 PROGRESS OF SCIENCE. 
 
 the evolutionary principle into geology, instead of the sudden 
 cataclysms and new creations of former geologists, and at 
 their head Cuvier an immense stride forward. The 
 evolutionism of Lyell, however, was not that of the Spencer- 
 Darwin school for, where thorough evolutionists see an 
 efficient cause, Lyell, influenced by religious considerations, 
 saw a final cause; and the difference is, not important only, 
 but fundamental. For in the former case (in Lyell's 
 evolutionism), a supernatural power would be restraining a 
 warring chaos by a beneficent omnipresent and ubiquitous 
 interference ; whereas in the latter case, matter swayed by 
 natural laws is for ever effecting a new redistribution of its 
 elements, in harmony with its own inherent energy. The 
 evolutionary hypothesis explains the existence of evil, from 
 the presence of microbes which destroy life wholesale, to the 
 recurrence of earthquakes which destroy cities otherwise evil 
 would necessarily be prevented by the superior power. 
 METAMORPHISM, the name Lyell gave to his system of 
 gradual transformation, he based on entirely scientific ground. 
 He holds that nature has formed the crust of the earth, and 
 wrought all the successive changes, renovations, destructions 
 which it has undergone by the working of certain constant 
 and uniform laws, which are now what they ever were that 
 is, attraction, degradation, denudation, deposition, radiation, 
 evaporation, and contraction have done it all by their per- 
 manent action. This great principle of uniformitarianism, for 
 which Lyell stoutly fought, has been accepted by scientific 
 men, but, at present, with the reservation, however, that 
 variations in the energy and in the rate of activity may 
 have occurred, which played an important part in the 
 terrestrial history otherwise, how are we to account for the 
 Glacial period, which was comparatively sudden ? Physicists, 
 too, have sobered the minds of those geologists who claimed 
 a sort of "perpetual motion in the machinery of nature," to 
 use the words of Sir A. Geikie, by pointing out that the 
 gradual loss of solar heat must necessarily modify the laws 
 in future ages, and must likewise have done so in the past. 
 By a striking anomaly, Lyell, who recognised the modification 
 of the globe to be due to natural laws in fact to evolutionary 
 
MODERN SCIENCE. 167 
 
 development refused to accept some of the most obvious 
 evolutionary doctrines, rejecting, for instance, and fighting 
 against the theory of gradual animal development for a long 
 time. It was towards the end of his career only (at sixty-six 
 years of age), and when Darwinism had proved universally 
 triumphant, that Lyell abandoned this attitude at last, and 
 acknowledged the soundness of its doctrines. He even en- 
 dorsed them completely (if reluctantly) in his famous book 
 the Antiquity of Man the first work in which evidences of 
 man's antiquity were collected and clearly presented to man- 
 kind (1863). 
 
 !7Qg 187 . Elie de Beaumont drew up the geological 
 MAP OF FRANCE (in collaboration with Dufrenoy). His 
 " Revolutions of the Globe " contain the celebrated theory 
 of the uprising and of the direction of mountains. 
 
 1303 1879. Dove, in his " Isothermal Lines " (1848 64), 
 enunciated and explained the law of Storms, or the law of 
 ROTATION OF WINDS, by virtue of which the wind veers 
 round according to the sun's motion i.e., passes from North 
 to North-east, then to East, then South-east, then South, and so 
 on a course most regularly observed in winter. For a station 
 in south latitude a contrary law of rotation prevails. 
 
 1806 1873. Maury assisted geology by his fine studies 
 and demonstrations of the action of the ocean and rivers in 
 the formation and transformation of the crust; his investiga- 
 tions on the wind and sea-currents much advanced the study of 
 meteorology. To his action and work the establishment of 
 innumerable meteorological stations all over the globe is 
 due. His famous work (THE GEOGRAPHY OF THE SEA) 
 was the result of no less than twelve hundred thousand 
 observations gathered from all parts a fact which speaks 
 volumes for his earnestness and thoroughness. 
 
 1807 74. Agassiz opened a new field in science. He 
 discovered one of the grandest phenomena of geology by 
 his investigation of a feature of the earth's surface which 
 had escaped the attention of geologists, with the exception 
 of DE SAUSSURE viz., the formation of glaciers, and the 
 part they played at a certain period of the history of the 
 globe. De Saussure, exploring the Alpine glaciers, had 
 
168 PROGRESS OF SCIENCE. 
 
 noticed the accumulation of deposits in the valleys, due ta 
 their action ; Agassiz, following up this study, detected 
 other phenomena which revealed the nature of the climate 
 of the earth during a long series of ages which are now 
 called GLACIAL PERIOD. He discovered that the whole 
 of the Northern American and European continents had 
 been once covered with a field of ice, and therefore with 
 immense glaciers in every valley, which extended as far as 
 the south of Germany and France, and in America as far 
 south as the Scth, 48th, and even 45th degree of latitude 
 the present glaciers being the remnants as yet unmelted 
 of the cap of ice. This cap of ice, as far as it reached, 
 extinguished vegetation and life in the Northern hemi- 
 sphere. It accounts for several important facts : (i) for the 
 presence of huge boulders or boulder- clay foreign to the 
 region in which they are found, for both boulders and mud 
 must have been brought where found by glaciers ; (2) for 
 the presence, too, of drift (glacial debris) in valleys of different 
 formation ; (3) it accounts also for the polished and grooved 
 surface of rocks (striae) ; and (4) finally it accounts for the 
 striking difference between the kind of Flora and Fauna 
 which existed over the same area before the Glacial age, 
 and those which exist now in the same habitat. Before 
 the Glacial era, tropical plants and animals flourished all 
 over England and countries of the same latitude; the intense 
 cold, frost, ice, killed these or drove them southward, and 
 their place was taken by Arctic flora and fauna mosses,, 
 lichens, firs ; reindeer and Polar bears. And when the ice- 
 fields retired, the plants and animals which invaded the free 
 area were different from those of the pre-Glacial epoch and 
 from those of the Glacial epoch. Subsequent researches 
 have revealed the same changes at the same period to have 
 occurred also in Asia. The causes of this great catastrophe 
 which overtook the earth are as yet unascertained. It was 
 possibly due to the greater inclination of the earth's axis ; 
 or to the periodic elongation of the earth's orbit and the 
 concurrent effects of precession; or again, to an alteration 
 in the shape of the continents which would have diverted 
 the warm sea-currents from their present and pre-Glacial 
 
MODERN SCIENCE. 169 
 
 course. The first view is entertained by French geologists, 
 the second by James Croll and Sir R. Ball, the third by 
 Lyell ; but it is possible that this wonderful phenomenon 
 may have been brought about by the concurrence of the 
 three causes obtaining at the same time, otherwise a glacial 
 era would recur periodically. Another hypothesis is that 
 our siderial system moving towards Hercules as it does- 
 at the rate of 150 millions of miles per annum, passed 
 through intensely cold regions of space a supposition of 
 which we have no experience. The phenomenon, whatever 
 the cause, and whether it occurred once or several times 
 within a certain range of time for there are traces of two 
 Glacial periods in the Carboniferous and Permian Ages, 
 and undoubted evidences of inter-Glacial period within the 
 time-limits of the Ice Age teaches us one thing, viz., that 
 the uniformity of geological laws is not absolute. For here 
 we see, at an advanced stage of the terrestrial history 
 that is, during the Quaternary period, to speak of one 
 period only a phenomenon overwhelming the earth with 
 comparative suddenness, and this suddenness, so far, baffles 
 every explanation. The knowledge of this great Ice Age 
 is the work of Agassiz. 
 
 We may point out that careful computation has enabled 
 us to approximately assign the time of the Glacial period : 
 reckoning backwards, the present or post-Glacial epoch 
 cannot be estimated to have covered less than 6o,coo years; 
 the retreat of ice-fields cannot have covered less than. 
 80,000 years ; the duration of the Glacial noontide in- 
 cluding in it the inter-Glacial eras may have covered any 
 number of ages, for we have no evidence for stating whether 
 it declined as soon as it reached its maximum, or whether 
 it remained stationary for ages and ages ; but as there is 
 evidence of several partial advances and retreats, and of 
 prolonged inter-Glacial periods, the total duration of this 
 stage cannot have covered less than 80,000 years, taking 
 the very lowest possible estimate. Before that noontide, 
 the advance of ice southward may have covered from 5,000- 
 to 80,000 years. All these estimates are far below those 
 given by some geologists, and especially by Lyell, who has 
 
170 PROGRESS OF SCIENCE. 
 
 computed that for the deposit of the Rhine Valley loess 
 alone, 320,000 years must have been necessary ; but taking 
 the minimum estimate, we may boldly say that the Glacial 
 era cannot have begun less than 300,000 years ago. The 
 point is of importance because it bears upon the antiquity, 
 not of the earth only, since the Glacial epoch is a mere 
 fraction of the earth's life, but upon the antiquity of the 
 human race, for there is evidence that man existed through- 
 out the Ice Age, and probably long before, that is, in the 
 Tertiary period ; many of the palseontological implements 
 in our possession are clearly the handicraft of pre-Glacial 
 man, for they were found in pre-Glacial deposits. 
 
 The brief survey of geology enables us to measure the 
 work performed by modern inquirers in a new field. Two 
 centuries ago mankind was in total ignorance of the earth's 
 history. A few valuable hints had been given by Avicenna, 
 by Leonardo, by Palissy, but they were too slight on the 
 whole to awaken anything beyond curiosity or doubt. The 
 modern era opens a new expanse, where guesses are taken as 
 of no account, and are replaced by ceaseless observation 
 which conduces to substantial knowledge. The first tentative 
 steps are in the right direction and lead at once to creditable 
 results, but the march, gradual and somewhat wayward in 
 the beginning, in time becomes steady, then becomes rapid, 
 and conducts the stout explorers, despite strong barriers and 
 frequent obscurity, to victorious achievements. Patient 
 labour has disclosed the history of the world we live in. 
 Vast regions are as yet virgin soil to the geologist; large 
 tracts in Asia, in Africa, are yet unexplored ; but the areas 
 which have been visited and probed are so varied, so nume- 
 rous, and so distant from, or so close to, one another, that we 
 may proclaim geology a triumphant science all along the 
 line, for it has now accomplished its work the facts as yet 
 unravelled are relatively mere details. Murchison's labours 
 alone would enable us to describe the growth and the con- 
 stitution of the earth with almost absolute certainty, so widely 
 did they extend, and so conscientiously were they carried 
 out. But geology does not show us the structure of the 
 earth only ; it also teaches us great truths that were not so 
 
MODERN SCIENCE. 17* 
 
 much as suspected three hundred years ago, namely : (l.) the 
 vast antiquity of creation ; (n.) the process of the earth's 
 formation ; (ill.) the remote antiquity of man ; (IV.) the 
 confirmation of the permanency of law in the inorganic 
 world, as it is found to exist in the organic world a fact 
 made plain before, by Galileo, Kepler, Newton, and Laplace, 
 but corroborated here by such plain evidence that it can 
 be verified daily by any plain man. This makes geology 
 a complete and fascinating science. But it is so far removed 
 from the ideas entertained three centuries ago, that we may 
 be sure it would have found powerful opponents then as 
 astronomy did. For instance, we may easily imagine how 
 schoolmen would have exercised their power of raillery at 
 the expense of the benighted geologists for their researches 
 and work ; fancy a Humboldt, a Murchison, a Scrope actually 
 exploring the whole globe, to find, what ? just the facts we 
 have mentioned ; whereas it was sufficient for them (the school- 
 men) to think in order to know all about it. And the geologist, 
 they would have said, shows us only the process of formation of 
 rocks, the composition of those rocks, the order of their super- 
 position, and so forth but he does not tell us why basalt 
 is not bright yellow, or why the sea fails to produce it as 
 well as volcanoes. The geologist would reply that its 
 constituents being chiefly felspar and augite, it could not be 
 bright yellow, and that being volcanic and the sea not being a 
 volcano (!) the sea could not produce it, a reason which 
 they would have thought very unscientific, and therefore 
 very poor. This remark is no overdrawn analogy of their 
 logic, for they have actually made use of this very kind 
 of reasoning (we could quote instances) in face of natural 
 phenomena. They would have scouted the idea of consider- 
 ing what the geologist teaches us as being worth knowing. 
 What he ought to have sought and done, they would contend, 
 was to transform basalt into schist, and schist into con- 
 glomerate, and that into quartz, and that into a jelly-fish, and 
 the jelly-fish into a gooseberry-bush or a turnip at the very 
 least which he cannot do therefore he is not a man of 
 science, but only an empirical idler like Gilbert or Galileo, for 
 no doubt they would have called his labours " experiments." 
 
i/2 PROGRESS OF SCIENCE. 
 
 Once again we repeat that this kind of logic was typical 
 of former ages ; new doctrines and new principles of thought 
 were so distasteful to those who considered themselves as 
 "the directors" of opinion, that the most inane pieces 
 of sophistry were put forward as valid arguments in support 
 of extravagant opposition, as if mankind, senseless and 
 ignorant, could be crammed with anything. Brazen as- 
 surance seemed the only essential wanted to ensure authority. 
 
 GROUP III. CHEMISTRY. 
 
 1626 91. Boyle proved by experiments air to be neces- 
 sary for COMBUSTION ; that a candle cannot burn nor animals 
 live without air ; he pointed out that the globe contains other 
 substances than those recognised in his times earth, water, 
 air, and fire; discovered (1661) the LAW that bears his name, 
 and which is also called Mariotte's law, of the COMPRESSI- 
 BILITY OF GASES the law, that is, of elasticity of air, the 
 formula of which is, " The temperature remaining the same, the 
 volume of a given quantity of gas is inversely as the pressure 
 which it bears )} in other words, the volume of a gas 
 decreases in proportion as the weight upon it increases 
 if you double the pressure, you halve the volume. We shall 
 see the vast importance of this great discovery, one of the 
 most serviceable in our possession, our modern industry and 
 wealth being largely dependent upon it. Boyle also improved 
 Guericke's air-pump. 
 
 1645 79. Mayow, the best chemist of the XVIIth, 
 pursuing Boyle's experiments on COMBUSTION and respira- 
 tion, discovered air to be composed of two gases one, which 
 he called FIRE-AIR (oxygen), and which is heavy, supports 
 a flame and life, and is consumed by combustion and 
 breathing ; another, which is lighter, and is useless for 
 breathing and burning the nitrogen of Lavoisier thus going 
 further than Harvey in showing air to be the chief agent 
 in respiration, and going half-way towards the discovery of 
 Priestley and Lavoisier in showing air to be a compound 
 gas. He discovered also that " air exists in salpetre and in 
 many acids." 
 
MODERN SCIENCE. 173 
 
 ^ r 1660 1734. Stahl pointed out numerous chemical phe- 
 nomena, and showed the way in which many different 
 substances combine together to form new compounds. 
 Ignoring or disregarding Mayow's experiments, he formu- 
 lated the PHLOGISTIC THEORY of combustion, by which he 
 assumed that all combustible bodies contained a substance 
 (Phlogiston) which dispersed into air during the process of 
 burning. This theory explained some chemical facts so 
 plausibly that chemists accepted it at once whereas serious 
 verification would have upset it. The very fact that bodies 
 grow heavier by burning, as Geber had shown nine hundred 
 years before, should have confuted it, for if bodies lost 
 something (their phlogiston, so called) by burning they 
 would become lighter instead of heavier. As it was left 
 unverified, the phlogistic theory held the field for nearly 
 a century, and retarded the progress of chemistry all the 
 time. Even when Lavoisier exploded it, men like Priestley 
 adhered to it still. This baneful effect of a preconceived idea 
 was the last serious delusion which misled science. But the 
 lesson bore fruit : after that very few theories were accepted 
 without repeated verification. 
 
 1728 99. Black (Joseph) found the causticity (burning 
 property) of quicklime (1756), and detected its loss of weight 
 after it was burnt. From this fact he was led to the discovery 
 of FIXED AIR (carbonic acid gas*), failing, however, to 
 discover that it was an acid. He was further led by a series 
 of clever experiments to see that a flame would not burn nor 
 animals live in it ; also that our breath contains fixed air ; at 
 the same time he showed air to be necessary for combustion, 
 thus corroborating Mayow's demonstration from end to end. 
 The discovery of fixed air was an important stride in 
 chemistry. Another capital service rendered to science by 
 Black was his discovery of LATENT HEAT the heat that 
 is hidden in water and steam (1760) the latent heat of water 
 at o (Cent.) being 79-25 C, and the heat of steam at 100 C. 
 being 537*2 C. ; so that we have to remember that water 
 
 * In one million gallons of London air carbonic acid gas exists to the 
 extent of 380 gallons ; over one square mile in the country the carbonic 
 acid gas present weighs 371,875 tons. 
 
174 PROGRESS OF SCIENCE. 
 
 is a solid (ice) plus heat, because the heat used to melt ice 
 is absorbed in the water ; whilst a gas is a liquid (say water) 
 plus heat, because the heat used to turn water at boiling point 
 into gas (steam) is absorbed in the steam. By this discovery 
 Black found a law which together with the known law of 
 elasticity of gases (Boyle's law) enabled James Watt, under 
 the guidance of Black himself, to invent practical steam 
 machinery the new power of the modern world. Black 
 demonstrated also that certain chemical substances are 
 possessed of definite and invariable composition and pro- 
 perties thereby PARTLY establishing THE LAW (which 
 Lavoisier defined) of the FIXITY OF COMPOSITION of chemical 
 compounds. Black's " Lectures on the Elements of 
 Chemistry " contain a large amount of practical knowledge 
 his researches on alkalis and fixed air (carbonic acid gas) are 
 excellent examples of the scientific process and manipulation. 
 It may be mentioned in honour to him that he was one of the 
 first to abandon the phlogistic theory after Lavoisier had 
 shown its imaginary character. 
 
 1731 1810. Cavendish found the accurate composition 
 of nitric acid, discovered HYDROGEN (water producer, 1766), 
 which he called INFLAMMABLE AIR an effect of which was 
 to make aerostation safer ; formed WATER by sending an 
 electric spark through a mixture of oxygen and hydrogen 
 (1784), which showed water to be a compound of these two 
 g ases another important discovery, also made by Lavoisier. 
 Cavendish invented the EUDIOMETER, for testing the purity 
 of air by ascertaining the quantity of oxygen it contains 
 now used for examining the composition of gases ; he 
 calculated the weight of the earth by means of the Torsion 
 Balance a wonderful determination.* Cavendish has been 
 called, prematurely we think, the Newton of Chemistry a 
 title better deserved by Dalton, who came later and made 
 a discovery which is absolutely fundamental. In the absence 
 of Dalton, Lavoisier would no doubt deserve the title of 
 honour. 
 
 1733 1804. Priestley discovered f oxygen (1774) from 
 
 * Modern computation gives the round number of six thousand 
 trillion tons. t Discovered also laughing gas. 
 
MODERN SCIENCE. 175 
 
 oxide of mercury, by means of a burning glass. He called it 
 " DEPHLOGISTICATED AIR " the name of oxygen being 
 given to it by Lavoisier, who understood its property and 
 character. The sterility of this great discovery in Priestley's 
 hands is due partly to his blind adherence to StahPs phlogistic 
 theory, and partly to the carelessness of his experiments. 
 Priestley did great service to science, nevertheless. He 
 determined the properties of NITROUS AIR (nitric acid), 
 vitriolic acid air (sulphuric dioxide), muriatic acid air (hydro- 
 chloric acid), and alkaline air (ammonia). His experiments 
 on inflammable air (hydrogen) drew the attention of chemists 
 to this gas, and led them to numerous results. He discovered 
 that PLANTS INHALE the vitiating part (say fixed air) which 
 the atmosphere may contain, and thereby restore air to its 
 purity. This was one more step, after Grew and Hales,, 
 towards the explanation of the breathing of plants, but he 
 failed to see the reason why. It is now known that plants 
 absorb carbonic acid, decompose it in order to live on the 
 carbon, which they retain, whilst they reject the oxygen. 
 Priestley assisted MANIPULATION by several inventions the 
 most serviceable of which is the pneumatic trough. 
 
 1735 84. Bergmann studied the theory of elective or 
 CHEMICAL AFFINITIES. Newton had shown the powerful 
 attraction of some substances with one another, thus taking 
 the first step in the study which Bergmann pursued. This 
 great chemist drew up a table of those substances which show 
 affinity with one another (called Table of Elective Affinities). 
 The French chemist Geoffroy had drawn up Tables of 
 Affinity (the term is his own) as early as 1718, indicating the 
 order in which bodies displace each other, and thus marking 
 to some extent the force of affinity. The word as used in 
 chemistry means " a disposition to unite." Bergmann's 
 work extended much further than this study. During his 
 experiments to establish his tables, he found out Black's fixed 
 air to be an acid which he called air acid or AERIAL ACID ; 
 but he failed to find out that it is a compound of two elements. 
 It was Lavoisier who discovered it to be made of carbon and 
 oxygen, and gave it the name of carbonic acid which de- 
 scribes its character at once. Next to this, Bergmann founded 
 
j;6 PROGRESS OF SCIENCE. 
 
 CRYSTALLOGRAPHY, and made a chemical classification of 
 minerals a very valuable performance. 
 
 1742 86. Scheele published a famous paper on Man- 
 ganese, showing the peculiar characters of this metal (1774) ; 
 found tartaric acid, barytes, fluor-spar and its acid, chlorine, 
 glycerine (the sweet principle of oils), sugar of milk, Prussian 
 acid (while studying Prussian blue) ; but his great discovery, 
 made in 1775 concurrently with Priestley and Lavoisier, was 
 that of OXYGEN which was to open a new era in chemistry : 
 so that Scheele should be remembered as one of the greatest 
 chemists of the XVIIIth century, although unfortunately for 
 science he was still imbued with phlogistic views. 
 
 J 743 94- Lavoisier, the FOUNDER OF MODERN 
 CHEMISTRY, gave the death-blow to StahPs phlogistic 
 philosophy by his DISCOVERY OF OXYGEN (1778), the 
 mysterious character of which he unravelled after it had 
 puzzled generations of chemists. This discovery, made some 
 time after Priestley's and Scheele's, did not remain a fruitless 
 one in his hands ; for by it he thoroughly explained the 
 PHENOMENON OF COMBUSTION a fact of supreme im- 
 portance in chemistry. He showed that a rusty or heated 
 metal gains the exact weight which air loses by the process 
 thus demonstrating the process to be the reverse of that 
 imagined by Stahl, since air, instead of receiving something 
 additional by the burning of a substance, loses, on the con- 
 trary, a part of its constituents, namely, its fixed air (oxygen). 
 The law may be formulated thus : "All burning and breathing 
 and the change in metals are caused by a gas (oxygen} being 
 taken up out of air, and joined to other substances" Lavoisier 
 next showed oxygen to be the most abundant* and the most 
 useful of all substances in the economy of our earth ; and for 
 this reason he made this gas the basis of chemical nomen- 
 clature, giving to acids the termination of ic when they con- 
 tain much oxygen ; the termination of ous when they contain 
 less ; he designated bases by the name of oxides ; and affixed 
 ate or zte, according to the degree of oxygenation of the acid, 
 
 * It constitutes more than one-half of the earth's crust, and is 
 present in water to the extent of eight-ninths of the total weight, and in 
 air to the extent of one-fifth of the bulk. 
 
MODERN SCIENCE. 177 
 
 to salts (i.e., the compounds of acids with their bases). He 
 divided matter into THREE FORMS (solid, liquid, gaseous) 
 according to the degree of heat ; established the principle of 
 the "conservation of mass that in no process of change is 
 there any alteration in the total mass of matter taking part in 
 that change " ; discovered phosphoric acid, and described 
 some of the substances formed by combining it with various 
 bases; foresaw the existence of the metals potassium and 
 sodium ; discovered also the exact composition of water ; 
 established the distinction between COMPOUNDS and 
 ELEMENTS, and laid down the definition of the latter; 
 established the law of fixity of composition of chemical com- 
 pounds; determined the properties of oxygen, calling it 
 " acid-producer," believing it to enter into the composition of 
 all acids a generalisation which admits of exceptions (see 
 Davy). By his immense work Lavoisier gave a new impulse 
 to the advance of chemistry, so long arrested by Stahl's 
 hypothesis. He showed that there is no such thing in nature 
 as " transmutation " in the alchemical sense of the word. He 
 applied CHEMISTRY to PHYSIOLOGY, and explained the two 
 hypotheses of respiration one of which, that respiration is 
 a process chemically similar to that of calcination, modern 
 science has confirmed. 
 
 We may point out that the successive discovery of the 
 four gases carbonic acid, hydrogen, nitrogen (found by 
 Rutherford in 1772), and oxygen revolutionised chemistry 
 in a manner the importance of which cannot be exaggerated. 
 These four gases play the main part in the maintenance of 
 vegetable and animal life. " Out of the raw material," says 
 Dr. Crum-Brown, " gathered by Black, Scheele, Priestley, and 
 Cavendish, Lavoisier constructed a consistent and compre- 
 hensive theory upon which the subsequent progress is firmly 
 grounded." Chemistry with him and his school became 
 once more a quantitative science (that is, components of a 
 substance were now carefully weighed) instead of being 
 merely qualitative. Another remark to be made is that 
 Lavoisier's nomenclature aids science by its simplicity and 
 clearness instead of fixed air we have carbonic acid, which 
 is thoroughly descriptive of the nature of this gas ; instead 
 
 N 
 
178 PROGRESS OF SCIENCE. 
 
 of inflammable air, we have hydrogen (water-producer) ; 
 instead of fire-air, we have oxygen (acid-producer), and so 
 forth. It was Lavoisier, too, who discovered the fixed air 
 of Black, or the air-acid of Bergmann, to be an acid made 
 up of 72 parts of oxygen and 28 parts of carbon, for which 
 reason he called it carbonic acid. 
 
 As a physicist, Lavoisier formulated the principle of 
 equilibrium between the effect of heat on the one hand, and 
 that of universal gravitation on the other heat tending to 
 dilate or separate matter, gravitation tending to keep it to- 
 gether and enunciated the hypothesis that HEAT rs MOTION 
 in his " Principles of Heat." He also invented, with Laplace, 
 the ice CALORIMETER. 
 
 1743 1817. Klaproth was the first to publish all the 
 numerical and analytical details of scientific investigations ; 
 discovered the elements CERIUM, URANIUM, ZIRCONIUM, and 
 analysed many minerals little known until then. 
 
 1748 1822. Berthollet ascertained nitrogen to be one 
 of the essentials to the composition of animal substances; 
 his investigations into the combination of carbon and hydro- 
 gen received an application in gas light ; the art of dyeing is 
 much indebted to him ; discovered the LAWS which govern 
 THE MIXTURE OF GASES. 
 
 1762 1807. Richter discovered (1792) THE LAW which 
 rules the proportions of chemical elements : " Elements in 
 compound bodies are mixed in fixed and definite propor- 
 tions" a corollary of Lavoisier's law of fixity; but not 
 until Dalton was the significance and truth of this law 
 recognised, although Proust (17541826), Wenzel (1777),. 
 and Higgins had intimated its importance. Richter's pro- 
 cess of investigation largely accelerated the progress of 
 electricity. 
 
 1763 1829. Vauquelin discovered CHROMIUM AND- 
 GLUCINUM ; made the first accurate analysis of beryls and 
 emeralds. 
 
 1766 1828. Wollaston discovered PALLADIUM AND- 
 RHODIUM ; found the process of rendering platinum malle- 
 able ; invented a sliding scale of chemical equivalents; was 
 one of the most skilful analysts of his time. Wollaston did, 
 besides, good service to biology. While in Madeira he 
 
MODERN SCIENCE. 179 
 
 detected, studied, and pointed out the strange adaptations 
 of the local snails and beetles a series of observations 
 which were duly weighed and made use of by evolutionists. 
 This scientist, as we shall see further, was also a physicist of 
 distinction. 
 
 1766 1844. Dalton propounded the ATOMIC THEORY 
 (1808), demonstrating the doctrine held by Leucippus and 
 Democritus (400 B.C.), who, by that marvellous prescience 
 frequently found among the Greeks, had guessed one of 
 the profoundest secrets of nature. Dalton's discovery of the 
 structure of bodies by atoms caused a revolution in the views 
 held hitherto regarding the composition of the universe. It 
 also caused rapid advance in chemistry and science generally, 
 and it is not too much to say that it entitles its author 
 to be called the NEWTON OF CHEMISTRY despite his 
 occasional inaccuracy as an experimenter. The atomic 
 theory rests on three laws which form the foundation of 
 chemical science : (I.) the law of definite proportions i.e., 
 different chemical elements always combine in definite and 
 invariable proportions : thus water will always contain 2 
 parts by weight of hydrogen to 16 parts by weight of 
 oxygen; every carbonate of lime contains 56 parts of lime 
 and 44 of carbonic acid, each of these being likewise as 
 unalterable in their composition as water lime containing 
 71*43 per cent, of calcium and 28^57 P er cen t. of oxygen, 
 whilst carbonic acid contains 27*28 of carbon and 7272 of 
 oxygen ; (n.) the law of multiple proportions, in virtue of 
 which the proportion of one element, having its own weight 
 (atomic), remains constant in forming compounds, whilst 
 the proportion of the other element is a constantly increasing 
 multiple of its weight (atomic) : for instance, nitrogen and 
 oxygen will combine to form five chemical compounds 
 
 Nitrous oxide . 
 
 
 Volume of 
 
 Weight of 
 
 Ni 
 
 rogen. Oxygen. 
 2 I 
 2 2 
 2 3 
 
 2 4 
 2 5 
 
 Nitrogen. Oxygen. 
 
 28 gr. 16 
 
 28 32 
 28 4 8 
 28 64 
 28 80 
 
 Nitric oxide 
 Nitrous anhydride (acid) . 
 Nitric peroxide (peroxide of 
 Nitric anhydride (acid) . 
 
 Nitrogen) 
 
 So that oxygen enters into composition with other elements 
 
 N 2 
 
i8o PROGRESS OF SCIENCE. 
 
 in weights of 16 or multiples of 16 hence the name of the 
 j aw and the law applies to all elements, each having its 
 particular weight ; carbon will combine in weights of 12 or 
 multiples of 12 ; nitrogen will combine in weights of 14 or 
 multiples of 14 (28, 42, 56, etc.) ; sodium in weights of 23 
 (then 46, 69, etc.) ; phosphorus in weights of 31 (62, 93, etc.) ; 
 iron in weights of 28 (56, 84, etc.) ; arsenic, 75 (then i$o, 225, 
 300, etc.) ; mercury, 100 (then 200, 300, 400, etc.). The 
 third law on which chemistry rests is the LAW OF ATOMIC 
 or equivalent PROPORTIONS, which is that "each element in 
 combining with^ or displacing other elements, does so in a 
 fixed proportion" which may be stated numerically the 
 weights just mentioned being equivalent to the parts : if a 
 slip of copper, for instance, be introduced into a solution of 
 mercuric chloride, proportions of the two metals will change 
 places, since chlorine has a stronger affinity for copper than 
 mercury : cupric chloride is formed and mercury deposited 
 for every 31*7 parts by weight of copper dissolved, 100 of 
 mercury are separated. The atomic theory embraces the 
 question of atomic weight, atomic volume, atom-fixing 
 power, and so forth. The laws involved in the theory, if not 
 all discovered, were all first brought into the light of in- 
 tellectual day, by Dalton. Whether the doctrine of atoms 
 be absolutely true, as it seems to be now admitted, or a 
 working hypothesis only, as some are still contending, 
 Dalton's atomic theory (as distinguished from the doctrine of 
 atoms) is admitted by every philosophical chemist, and is 
 rendering new services to chemistry every day. Dalton 
 meant by an atom <f the smallest possible quantity of any 
 element which can combine with other substances." Dalton 
 fixed the atomic weight of hydrogen, but the atomic weight 
 of elements has not in all cases been determined, nor in some 
 cases determined uniformly some chemists (Berzelius, 
 Olding, Gerhardt, Watts) differing from one another slightly 
 in their determinations. The atomic system, it should be 
 remembered, has given rise to a system of symbols which 
 has become the universal language of chemistry a very 
 great advantage to science. Dalton investigated also the 
 dilatation of gases, and numerous chemical phenomena. 
 
MODERN SCIENCE. 181 
 
 1777 1857. Thenard, in collaboration with Gay-Lussac, 
 obtained sodium and potassium by means of charcoal ; dis- 
 covered BORON, and also oxygenised water. 
 
 17781829. Davy (Sir Humphrey) analysed LAUGHING 
 GAS (nitrous oxide) ; then by the DECOMPOSITION OF WATER 
 into its constituents (oxygen and hydrogen) by means 
 of the ELECTRIC PILE, he established a new method of 
 chemical analysis, called ELECTROLYSIS, or the decomposition 
 of substances by electricity. This was a fact of immense 
 importance because it showed electricity can overcome 
 chemical affinity (or attraction of elements to one another) 
 the power, in other words, which holds several elements 
 together in one compound substance. Faraday developed 
 electrolysis far beyond the point at which Davy left it. After 
 various analyses of compound substances, by means of the 
 powerful electric battery which he constructed for that 
 purpose, Davy established THE LAW : " Chemical affinity is 
 nothing but the energy of opposite electric powers" which led 
 Berzelius to his classification. By the means of the pile 
 Davy separated potassium, sodium, barium, strontium, 
 calcium, and magnesium from fixed alkalis thought to be 
 simple elements until then a discovery again which opened a 
 new era in chemistry. Davy also studied the production of 
 heat (by friction), and was led to the conclusion that "heat 
 is a peculiar motion, probably a vibration of the corpuscles of 
 bodies t tending to separate themselves" a proposition which he 
 proved by experiments thus establishing the doctrine inti- 
 mated by Lavoisier and Rumford a short time before, and at 
 the same time solving the problem of the cause of latent heat, 
 which had puzzled Black. He also upset the theory 
 (Lavoisier's) that oxygen was a necessary element of all acid 
 substances by his famous discovery of chlorine. After 
 numerous observations on flame, he invented the SAFETY- 
 LAMP (1815), which has saved thousands of lives. As early as 
 1802, soon after Ritter's discovery of chemical rays*, Davy 
 saw the possibility of taking images by means of solar rays 
 acting upon chloride of silver, and with Wedgwood actually 
 took some, but he did not succeed in fixing them perma- 
 * See W. Herschel. 
 
1 82 PROGRESS OF SCIENCE. 
 
 nently. This was accomplished later by Niepce and Daguerre. 
 Davy's practical experiment was the earliest step towards 
 photography. He further discovered ELECTRICITY to be AN 
 ILLUMINANT ; for severing the connecting wire of the electric 
 battery, and tipping its points with carbon a sluggish 
 conductor he obtained, not a spark, but actually a dazzling 
 arch of white flame, called voltaic arc.* He used carbon, 
 a poor conductor, because the intense heat would melt the 
 wires, whereas carbon is infusible ; the carbon points being 
 made to touch, and being then slightly separated, Davy 
 obtained the wonderful result just mentioned the new 
 illuminating power, electric light. The light, it may be 
 mentioned, is not produced by the combustion of the carbon, 
 but from bringing the solid particles (of it) into intense white 
 heat a heat in which platinum itself is melted as sealing- 
 wax in a candle-flame. With Davy the French school of 
 chemistry, which had headed science for a long time, receded 
 to the second rank, England taking the lead, and keeping 
 under the banner of Davy, Dalton, and Faraday. 
 
 1778 1850. Gay-Lussac investigated IODINE, and 
 showed it to be an element analogous in its chief reactions 
 to chlorine, thereby putting an end to the oxymuriatic 
 theory; investigated also cyanogen, and fulminating silver; 
 he discovered THE LAW "Equal volumes of elementary gases 
 contain equal numbers of atoms " in other words, correspond 
 to equivalent weights of the substances (1809) a confirma- 
 tion of Dalton's atomic theory. Yet, exceptionally, phos- 
 phorus, arsenic, mercury, and cadmium, do not conform to 
 this law the two first giving vapours twice as dense, the 
 two last half as dense, as it is expected they should. 
 
 1779 1848. Berzelius, one of the founders of modern 
 chemistry: was familiar with all its branches; discovered 
 several elements, and reduced from their oxides thorium, 
 calcium, barium ; developed the use of the BLOWPIPE into 
 a system of qualitative analysis ; made the greatest number 
 of accurate analyses of any chemist in his time ; identified 
 electrical polarity with chemical affinity every atom being 
 regarded by him as both positively and negatively electrified, 
 
 * See Volta. 
 
MODERN SCIENCE. 183 
 
 but in unequal degrees, strongly positive atoms showing 
 affinity for negative atoms, and conversely : thus establishing 
 (for a time) his views of the dual structure of chemical 
 compounds a doctrine partly overthrown by Dumas's 
 unitary theory. By the application of a few rules regarding 
 the combinations of elementary atoms, he extended the 
 bounds of the atomic theory of Dalton : established the 
 fact that the same laws of combination, the same fixity of 
 composition, and the same general features of atomic struc- 
 ture prevail among the so-called organic as among the 
 inorganic compounds, thereby removing the barrier which 
 separated the two branches. He will be remembered beyond 
 all things, however, for his determination of ATOMIC WEIGHTS 
 an investigation which demanded an amount of labour, 
 perseverance, patience, and working power of which those 
 who are unacquainted with the detail of experimentation 
 have no idea. 
 
 17851838. Dulong discovered CHLORIDE OF NITROGEN, 
 a powerful explosive ; in collaboration with PETIT discovered 
 THE LAW, " The atoms of all solid elements have the same 
 capacity for heat" thus putting a most important generalisa- 
 tion in the hands of the chemist ; since guided by it, 
 together with Mitscherlich's law of isomorphism, and Gay- 
 Lussac's law of atomic equality, Berzelius was able to 
 demonstrate Dalton's conception to be applicable to a large 
 range of chemical phenomena. Dulong, in collaboration 
 with Berzelius, determined the exact composition of water 
 (already discovered, but now forcibly corroborated), of 
 carbonic acid, and other bodies. 
 
 1786 1889. Chevreul made a deep study of FATTY 
 SUBSTANCES of animal origin (which led to the making of 
 stearic candles) hence his name of father of the fatty 
 acids; formulated the LAW OF CONTRAST OF COLOURS; 
 published numerous papers ON COLOURS, and the theories 
 expounded therein found a ready application in the colouring 
 of silk, so that several industries are under great obligations 
 to his century of labours. 
 
 1794 1863. Mitscherlich discovered the great physico- 
 chemical LAW OF ISOMORPHISM (1818), " Compounds t/ie atoms 
 
1 84 PROGRESS OF SCIENCE. 
 
 of which contain equal numbers of elementary atoms > similarly 
 arranged, have the same crystalline form" which has been 
 slightly modified, but which nevertheless was a powerful 
 assistance in Berzelius's researches in atomic weights. 
 
 1800 69. Dumas invented the method of determining 
 the DENSITIES OF COMPOUNDS in the gaseous state, known as 
 Dumas's vapour density process; established the relations 
 which exist between ethers and alcohols, and between ethers 
 and acids ; determined the composition of chloral and chloro- 
 form ; formulated the UNITARY THEORY, in opposition to 
 Berzelius's dualism, by which it is conceived that "the mole- 
 cule of a compound is regarded as a unitary structure " ; 
 originated the conception of types developed by Gerhardt and 
 Laurent. 
 
 18031873. Liebig, one of the greatest masters of OR- 
 GANIC CHEMISTRY (so called) ; was more successful than any 
 in applying chemistry to PHYSIOLOGY, PATHOLOGY, and 
 AGRICULTURE. His agricultural chemistry has rendered 
 immense service to Europe and America ; he taught that the 
 chemical state of the soil affected plants in many ways 
 hence crops and animals ; and showed how important it was 
 to preserve the vitality of the soil by sowing it with proper 
 seeds, and how to improve fields by certain processes and 
 manures. Regarding physiology, Liebig was equally scien- 
 tific and practical ; he showed the changes which food under- 
 goes in our bodies, and what part becomes blood, what part 
 fat, or bone, or muscle demonstrating that the body of 
 animals is a chemical laboratory always at work, producing, 
 combining, decomposing substances. He improved manipu- 
 lation by several innovations: his POTASH-BULBS made an 
 organic analysis one of the simplest operations of chemistry, 
 and the process (since 1831) caused rapid advances to be 
 made. He may be said to have changed the whole face of 
 that branch. Invented a condenser for distilling small 
 quantities of liquids. He produced chloroform and chloral 
 (1832), benzoyl, and contributed to establish Dumas's unitary 
 theory. His Letters on Chemistry aroused universal interest 
 in the science. 
 
 18051869. Graham (Thomas) discovered the LAW OF 
 
MODERN SCIENCE. 185 
 
 THE DIFFUSION of gases, " The diffusion-rates of any two- 
 gases are inversely as the square roots of their densities " \ 
 invented the diffusion tube by means of which the rates of 
 diffusion of different gases can be compared ; formulated the 
 conception of acids of different basicity ; discovered the 
 PROCESS OF DIALYSIS, in which, by reason of the law of 
 diffusion of liquids, the (difficult) separation of colloids and 
 crystalloids is easily effected ; discovered also the process of 
 atmolysis, which determines the separation of one gas from 
 another, inventing the tube atmolyser for that purpose ; 
 studied the motion of gases, and their absorption by metals; 
 devoted his energy to trace the movements of atoms and 
 molecules, showing that gases pass through walls as they 
 pass through other gases, and, by measuring their speed> 
 showed how it is possible to determine the rate of motion 
 of a molecule, and to follow the molecule into organic 
 membranes all of which discoveries place their author 
 among the greatest chemists. 
 
 (?) 1811. Avogadro contributed to elucidate the atomic 
 theory by discovering the LAW which bears his name : 
 "Equal volumes of all gases, compound as well as simple, 
 measured at tJie same temperature and under the same pressure ', 
 contain equal numbers of molecules " one of the paramount 
 laws of chemistry; he established the distinction between 
 the ultimate particles of compounds and elements intro- 
 ducing, and explaining too, the idea of molecules. Avogadro's 
 law has, later, been deduced mathematically from the first 
 principles of the mechanical theory of gases by ProL 
 Neumann (1869). 
 
 1816 56. Gerhardt established a THEORY OF TYPES of 
 great simplicity and convenience : the compounds of am- 
 monia, for instance, are grouped into amides, amines, alkala- 
 mides, subdivided according as they are derived from one, 
 two, three molecules of ammonia ; then the compounds con- 
 taining water are grouped and subdivided according to the 
 same principle, and so forth. In this manner we have tables 
 of multiple and mixed types, such as : Bichloride, Dihydrate, 
 Diamide ; then Trichloride, Trihydrate, Triamide ; then 
 Chlorid-hydrate, Chlorid-amide, Hydrat-amide. The deter- 
 
1 86 PROGRESS OF SCIENCE. 
 
 mination of these types was one of great value to the progress 
 of science. It tended among other things to finally remove 
 the distinction between organic and inorganic chemistry. 
 Gerhardt succeeded in obtaining anhydrous organic acids 
 previously unknown ; showed the true value of vapour volume 
 as a means of determining atomic weight, and developed the 
 idea of series in organic chemistry. 
 
 1817 1892. Hofmann (Aug. Wilhelm) studied the BASES 
 OF COAL-TAR, one of the richest sources of chemical products 
 a fact due to the vegetable origin of the substance, since 
 coal must necessarily contain all the principles and elements 
 of the plants which enter into its composition. Hofmann 
 may be said to have explored a new field, to which the DYE 
 INDUSTRY owes a great part of its development. In his 
 investigations he made many discoveries in the chemistry of 
 the compound ammonias and coal-tar colours ; found the 
 composition and chemical character of aniline red, a decisive 
 discovery, being the earliest of a numerous series in the same 
 sphere. Hofmann's studies of the MOLECULAR CONSTITUTION 
 of the organic bases were so important that he was awarded 
 a Royal medal for them. 
 
 b. 1829. Williams (C. Greville) discovered NEW HYDRO- 
 CARBONS, Isoprene among them, from the distillation of 
 india-rubber and gutta-percha; also alkaloids, such as par- 
 voline, lepidine, cryptidine and what Hofmann called one 
 of the most beautiful substances known to chemists, CYANINE, 
 a superb blue colour, used in astronomical spectrum photo- 
 graphy; investigated beryls and emeralds. Greville Williams 
 established a TABLE OF the atomic weights of the elements 
 in their calculated .positions, showing all THE MISSING 
 ELEMENTS, or gaps, between hydrogen and uranium a 
 work the decisive value of which chemical discoveries will 
 demonstrate in the near future. This Table is an elaboration 
 of MendelejefFs periodic law. 
 
 b. 1832. Crookes, besides his high rank among physi- 
 cists, holds a similar position among chemists. His address 
 as President of the Chemical Section at the British Asso- 
 ciation in 1886, is famous for the bold exposition of his 
 belief in chemical evolution. In his view, one primal ele- 
 
MODERN SCIENCE. 187 
 
 mentary matter that is, one antecedent form of matter 
 containing within itself the potentiality of all atomic weights, 
 would have evolved successively, say helium or hydrogen, 
 and then lithium next to it in simplicity of atomic weight, 
 and then glucinum, then boron, then carbon, and, gradually, 
 the rest of the seventy-two elements (which we call simple, but 
 which are in reality compounds), in the same manner that the 
 simplest life-germ, protoplasm, has evolved all organisms 
 so that the elements have been built up from one another 
 according to some general plan. Hydrogen was once 
 thought to have been the unit from which all elements were 
 derived; but this view is now put aside because, granting 
 the soundness of Mendelejeffs principle, the multiple of the 
 atomic weight of hydrogen does not account for twenty-six 
 (if not forty-five) known elements, and leaves too many gaps 
 in the series. It was calculated by Mr. Clarke that about 
 half the atomic weight of hydrogen would satisfactorily 
 account for the weights of all known elements, and of those 
 which would by-and-by be discovered to fill up the gaps 
 from hydrogen to uranium besides. The presence in the 
 sun of an element such as the one which would fulfil these 
 conditions has, it is thought, been detected. Helium, as 
 this element is called, is a much simpler one than hydrogen, 
 for it presents only one ray or line in the spectrum, and its 
 vapour possesses no absorbent power. It would then, if its 
 existence were confirmed, offer the conditions necessary to 
 allow of all the elements to fit in their places, and would 
 therefore be the basis required for the working of the Prout- 
 Mendelejeff law. Crookes thinks there may have been, 
 before helium or hydrogen came into being as such, an 
 antecedent form of matter protyle which evolved either 
 helium or hydrogen, or both in succession the rest coming 
 into existence in the course of cosmic events. That is his 
 hypothesis. "If he has grasped the key to the arrangement 
 he has gone far to unlock some of the deepest mysteries 
 of creation." This doctrine of chemical evolution was not 
 a conception of Crookes's. Sir Benjamin Brodie as early 
 as 1867, Prof. Stokes about the same time, Graham in '68, 
 and later Newlands, Mendelejefif, Prof. Victor Meyer, Dr. 
 
1 88 PROGRESS OF SCIENCE. 
 
 Gladstone, Dr. Carnelley, Clarke and others, have held that 
 our supposed simple elements are really complex, and must 
 have come into existence by the evolutionary development 
 of some primordial matter. But Crookes it was who, for 
 years, investigated the question most elaborately, by his 
 analysis of " rare earths" especially yttria, which he calls 
 his Rosetta Stone present in samarskite, gadolinite, and 
 other minerals,* through the process of chemical fractioni- 
 sation. To settle a single point regarding the nature of 
 yttria he performed upwards of two thousand fractionisations ! 
 He does not claim to have demonstrated or established 
 chemical evolution, but he thinks that the balance of evi- 
 dence fairly weighs in favour of it. If evolution be a cosmic 
 law which enables us to account for the origin and formation 
 of heavenly bodies according to Laplace, of the earth according 
 to Lyell, of plants and animals according to Lamarck, Darwin, 
 and Wallace, then it is difficult to believe that it does not 
 hold good in chemistry development of matter as well. 
 All our knowledge tends more and more to force the con- 
 viction upon us that unity of energy governs the Cosmos, 
 and that principle almost necessarily involves unity of matter 
 as it involves unity of law. Whether one day this be 
 demonstrated, or whether the contrary be established, 
 Crookes will, in either case, always be considered as one 
 of the keenest pioneers of a wonderful age, and one who 
 forwarded in no small degree the settlement of the deepest 
 questions of scientific philosophy. We shall further on see 
 the services which he has rendered to physics. 
 
 b. 1837. Perkin (William Henry) discovered (1856) 
 the first of the ANILINE DYES the source of an immense 
 increase of trade and wealth throughout the world ; made 
 a great number of discoveries in organic chemistry, and 
 greatly distinguished himself by applying the measurement 
 of the MAGNETIC ROTATION OF ORGANIC SUBSTANCES to 
 the study of their constitution. 
 
 18 . Mendelejeff formulated the PERIODIC LAW, 
 
 * To obtain almost pure yttria cost Crookes fifteen months' work, and 
 another ten months to eliminate from it the aWinnrth part of impurity it 
 contained. 
 
MODERN SCIENCE. 189 
 
 which J. A. R. NEWLANDS had already foreshadowed (1864) 
 by his Law of Octaves a law in atomic weights which seems 
 to point to the unity of matter, i.e., singleness of one 
 primordial element (perhaps helium, or, according to Crookes, 
 more probably a primal matter which he calls " protyle ") out 
 of which other elements are evolved. Be this as it may, 
 Mendelejeff, investigating Prout's hypothesis (that the weight 
 of a large number of the elements is an exact multiple of 
 that of the hydrogen atoms), found and enunciated his 
 periodic law (1869) : " The properties of the elements are a 
 periodic function of their atomic weights!' From this principle 
 he predicted the existence of several elements required to 
 fill up the gaps in the series of elements, and some of these 
 have since been discovered (Gallium in 1876 one of them), 
 a feat which somewhat resembles that of Leverrier's astro- 
 nomical deductions which led to the discovery of the planet 
 Neptune. 
 
 Such are in the main the results obtained by modern in- 
 vestigators in a field which had been cultivated for thousands 
 of years without bringing in a harvest at all commensurate to 
 the time, labour, ingenuity bestowed upon it. Ancient Egypt, 
 and later, the Arabs, had certainly composed many things 
 dyes, perfumes, poisons, medical remedies, pigments ; they 
 had invented processes of research, and numerous apparatus; 
 they had taught us the value of experiments ; they had 
 founded in Islam, and prepared mediaeval Europe also to 
 found, the Experimental School ; they had even discovered 
 many phenomena, either relating to pure chemistry or pure 
 physics, remarkable and important in an equal degree. But 
 they had failed in one capital point : although they were the 
 first to clearly see and clearly intimate that law governed the 
 world of matter, they had found and formulated no specific 
 chemical laws. The modern era shows no decisive advance 
 in that respect until the XVIIth century. But with Boyle 
 commences the discovery of laws, and from that period, 
 though the progress is by no means rapid until Lavoisier, we 
 witness a continuous development which marks the new times 
 with a new character, and stamps them with a different set of 
 
190 PROGRESS OF SCIENCE. 
 
 features. From the moment laws became demonstrated, not 
 only was retrogression impossible, but progress must of 
 necessity grow apace. And this was obviously the case in 
 many directions, as we have seen. One material consequence 
 ensued, and that was the immense benefits derived from 
 chemical advancement in all industries, and which promoted 
 human welfare. Another consequence scientific this was 
 doubly beneficial : additional evidence was afforded of the 
 supremacy of law throughout a wide range of the physical 
 world ; next, additional evidence was furnished of the interac- 
 tion of one science upon another, and the necessity of such 
 interaction was made more plain than ever, since chemistry 
 strongly assisted medicine, physiology, geology, and, as we 
 shall see, terrestrial and celestial physics. The third con- 
 sequence was mainly philosophical, and, as such, of greater 
 significance if possible than in other respects, since chemical 
 knowledge throws a luminous ray upon the origin of the 
 Cosmos. For, if an electric current or spark is sufficient, 
 not to decompose substances simply, but also to form 
 new compounds, as we have seen it to be the case in 
 Cavendish's composition of water out of two simple ele- 
 ments, then it may be reasonably inferred that many com- 
 pound substances were in the origin of things formed by a 
 similar process of chemical action ; and if it be so it is not 
 unreasonable to infer also that the life cell, that primordial 
 spark of life out of which all life was evolved, may have 
 been produced by the action of forces, at a stage when 
 conditions of pressure, heat, matter, admitted of such a 
 process. This, however, is a hypothesis unsubstantiated 
 altogether as yet. But it is as well to take note of one 
 of the results of chemical research upon human thought. 
 
 We perceive then what immense strides have been made 
 in this branch of science; how vastly they have extended 
 the area of knowledge, and how small, relatively, had been 
 the advance before the modern era, despite admirable efforts.. 
 These efforts had not been quite fruitless, and we owe much 
 to those who made them. A Giaber, a Rhazes, a Paracelsus, 
 a Van Helmont, are great men still we inherited their modes 
 of inquiry and it would be sheer ingratitude or want of 
 
MODERN SCIENCE. 191 
 
 historical vision to dismiss their names with a shrug of the 
 shoulders, as some have done during the Revival and since.. 
 The only chemist we remember who might have won the 
 approbation of these hypercritics was Stahl, who, last century, 
 waylaid many chemists by his Phlogistic theory until it was 
 at last exploded by the discoveries of Lavoisier. They would 
 no doubt have admired a theory which was wholly imaginary, 
 from the very fact that it displayed ingenuity without verifi- 
 cation, and that it was in accord with their own way of settling 
 difficulties by what they considered an effort of genius without 
 study. Stahl's theory of combustion furnishes a sound analogy 
 to the SPIRIT THEORY of earlier days, with this enormous dif- 
 ference, however, that whereas Phlogiston affected only a set 
 of phenomena and arrested one branch of science only, the 
 doctrine of spirits affected phenomena universally, and would 
 have blocked the way to every branch of science. Fortunately 
 the scientific method prevailed, and science did wonders 
 "undreamt-of by Baconian philosophy." We need hardly 
 point out that chemistry descends from alchemy through 
 Paracelsus, Libavius, Van Helmont, and partly Gilbert the 
 transition being fairly steady after Paracelsus had taught the 
 science in public, although modern chemistry cannot be said 
 to have been in existence until the discovery of oxygen. 
 
 We now come to a series of branches which are so bound 
 together that they should be treated abreast of one another, 
 namely, mathematics, astronomy, physics, and mechanics. 
 But we must be content with taking them separately. It 
 will be easy for the reader to see their connection as we 
 proceed. 
 
 GROUP IV. MATHEMATICS. 
 
 1596 1650. Descartes found the method of determining 
 the tangents of curves ; APPLIED ALGEBRA TO THE GEO- 
 METRY of curves. " He showed," says an excellent master of 
 the subject,* " that every equation may be represented by a 
 curve, or figure in space, and that every bend, point, cusp, 
 
 * Mr. Jevons. 
 
i 9 2 PROGRESS OF SCIENCE. 
 
 or other peculiarity of the curve, indicates some peculiarity 
 in the equation. It is impossible to describe in an adequate 
 manner the importance of this discovery : the advantage was 
 twofold algebra aided geometry, and geometry gave reci- 
 procal aid to algebra. Curves such as the well-known sections 
 of the cone were found to correspond to quadratic equations. 
 The way was thus opened for the algebraic treatment of 
 motions and forces, without which Newton's Principia could 
 never have been worked out. He showed the mechanical 
 fact that every curvilinear deflection is due to a controlling 
 force." He understood and explained the RISE OF WATER 
 in an exhausted space : ft The weight of water," says he, 
 " counterbalances that of the air." As a physicist, he 
 invented a new barometer, made of mercury and a liquid 
 to magnify the effect of the mercurial barometer. He 
 enunciated the UNDULATORY THEORY OF LIGHT (see 
 Fresnel and Young), and formulated the two LAWS OF 
 REFRACTION (confirming Snell's results) after experiments 
 by means of A PRISM, which exhibited the exact colours of 
 the rainbow. It was reserved to Newton to explain the 
 cause of the phenomenon which Descartes pointed out, as 
 it was reserved to Fresnel and Young to elucidate and prove 
 the undulatory theory. (See Appendix VI.) 
 
 1616 1703. Wallis gave an additional impulse to 
 ANALYTICAL GEOMETRY by his Arithmetica Infinitorum, and 
 his improvement of Cavalieri's method of application. 
 
 !6 2 3 62. Pascal invented a CALCULATING APPARATUS, 
 much improved by Leibnitz, Babbage, Scheutz, Thomas, 
 Sir W. Thomson, and Tait, which would have reconciled 
 Francis Bacon to the science he despised, for it made "all 
 men equal in arithmetic." Pascal invented also the humble 
 WHEEL-BARROW an application of the law of the lever; he 
 established the doctrine of THE WEIGHT AND PRESSURE OF 
 AIR, confirming Torricelli's theory, after the barometric ex- 
 periment carried out under his direction by his friend Perrier 
 on the summit of the Puy de Dome ; he also established the 
 law of equality of pressure in liquids, called PASCAL'S LAW : 
 *' Pressure exerted anywhere upon a mass of liquid is trans- 
 mitted undiminished in all directions, and acts with the same 
 
MODERN SCIENCE. 193 
 
 force on all equal surfaces, and in a direction at right angles 
 to those surfaces" This law led to the invention of the 
 HYDRAULIC PRESS by Bramah in 1796, and later, of many 
 machines of tremendous power, such as levers, jacks, lifts, 
 boring and perforating tools, which save immense time and 
 labour all being direct applications of it. Of Pascal's 
 mathematical works, his Traite de la Roulette is the most 
 famous, being a treatise on the Calculus of Probabilities. 
 
 162995. Huygens constructed a PLANETARIUM, in 
 conformity with the Copernican system, and which led to the 
 discovery of CONTINUOUS FRACTIONS ; calculated that the 
 centripetal force at the distance of the moon would be only 
 a fraction of 15 feet per second ; ascertained the VELOCITY 
 OF A FALLING BODY in any latitude. 
 
 1642 1727. Newton worked out his METHOD OF 
 FLUXIONS (1665), which, like the Differential Calculus (of 
 Leibnitz), is one of the most powerful instruments in mathe- 
 matics. This was his first great discovery. We shall see 
 further on that he was a stranger to no science, and turned 
 his attention, not to astronomy only, but to physics also, 
 introducing the idea of attraction even into chemistry; his 
 discoveries on the reflections, refractions, inflections, and 
 colours of light, and likewise on sound, would have sufficed 
 to make him famous. 
 
 16461716. Leibnitz, like Newton, opened a new field 
 in mathematics, by his discovery of the DIFFERENTIAL 
 CALCULUS the basis of higher analysis which is to the 
 mathematician what the microscope is to the naturalist. 
 This Calculus and the Fluxions of Newton are about equal 
 in power, but Leibnitz's Calculus is easier to handle: it 
 almost requires a Newton to handle the formidable Fluxions 
 hence the Differential Calculus is more used. As a geo- 
 logist, Leibnitz propounded the doctrine of the GRADUAL 
 COOLING OF THE GLOBE, the subsidence of its strata by 
 fracture, the deposition of sedimentary rocks and their 
 induration. Of Leibnitz's metaphysics, so famous and 
 influential for a time, we cannot speak a word here. 
 
 1654 1705. Bernouilli (James), one of the very pro- 
 foundest mathematicians, by calculating the return of a 
 
194 PROGRESS OF SCIENCE. 
 
 comet, all but demonstrated the planetary nature of comets ; 
 he solved the problem of the ISOPERIMETERS whence the 
 discovery of the Calculus of Variations by Lagrange ; devoted 
 part of his life to the investigation of combinations, as con- 
 nected with that of Probability. His "Ars Conjectandi " is 
 one of the deepest mathematical works in existence on the 
 THEORY OF PROBABILITY. Bernouilli's Numbers, which 
 show his ingenuity and inventiveness, are among the most 
 familiar natural Constants known. His brother, JOHN 
 BERNOUILLI (1667 1748), also a mathematician, discovered 
 the EXPONENTIAL CALCULUS, and made experiments on the 
 elasticity of gases. DANIEL BERNOUILLI (17001782 
 John's son), a distinguished physicist, composed a celebrated 
 work called Hydrodynamica 1738. (See Thomson.) 
 
 16981746. Maclaurin resolved the problem of the form 
 of the earth by means of certain properties of conic sections 
 a feat comparable to any performed by Archimedes ; found 
 the THEOREM which bears his name, and which is the gene- 
 ralisation of that of Newton upon the Asymptotes. 
 
 1707 83. Euler found the method and the general 
 formulas to determine curves or surfaces for which certain 
 indefinite functions are lesser or greater than all others ; 
 enlarged the limits of the Differential Calculus by his 
 researches on the series of the Infinites, whilst his INTEGRAL 
 CALCULUS, a powerful instrument of his creation, simplified 
 the methods in use before him. As a physicist, he also 
 enunciated, after Descartes, Huygens, and Hooke, the 
 UNDULATORY THEORY OF LIGHT. 
 
 1728 77. Lambert demonstrated the INCOMMENSU- 
 RABILITY OF THE ratio of the CIRCUMFERENCE to the 
 diameter; introduced the hyperbolical sinus; and found 
 the series which became the object of Euler's and Lagrange's 
 labours. 
 
 1736 1813. Lagrange, by his method, called CALCULUS 
 OF VARIATIONS, extended Descartes's discovery in Indeter- 
 minate Analysis. His theories of ANALYTICAL FUNCTIONS, 
 and his theory of (musical) vibrations, proved the efficacy of 
 MATHEMATICS IN PHYSICAL PROBLEMS, whilst his ANALY- 
 TICAL MECHANICS transformed mechanics into a question of 
 
MODERN SCIENCE. 195 
 
 calculation two facts which Newton had already made plain. 
 We shall see what magnificent use Lagrange made of his own 
 mathematical conceptions. Lagrange also brought back the 
 attention of geometers to algebra, which was being neglected, 
 by his Resolution of Numerical Equations. 
 
 17461818. Monge improved DESCRIPTIVE GEOMETRY, 
 and caused its universal adoption; founded the nucleus of 
 the Polytechnic School, which became, under and after 
 Napoleon, the highest scientific school in Europe. 
 
 17491827. Laplace extended the limits of mathe- 
 matical analysis. His " CELESTIAL MECHANICS/' a work 
 of mathematics as much as astronomy, places him by the 
 side of Newton in some respects. His " THEORY OF 
 PROBABILITIES " was a practical revolution : this theory, 
 certainly one of the noblest creations of intellect, is, said 
 its author, " good sense reduced to calculation." This famous 
 work contains Laplace's theory of Generating Functions 
 (Fonctions Generatrices). 
 
 17521832. Legendre continued Ruler's labours in his 
 famous THEORY OF NUMBERS. His Elliptical Functions, 
 his researches on alterations of Homogeneous Spheroids, 
 contain new important theorems, and his THEORY OF 
 PARALLELS contains the famous Method of the Least 
 SQUARES OF ERRORS. These creations of his have given 
 powerful assistance to mathematicians. 
 
 1753 1823. Carnot formulated the THEOREM (on loss 
 of forces) which bears his name, and established the great 
 mechanical principle of REVERSIBILITY OF ENERGY the 
 conversion of heat into mechanical effect : " The amount 
 of mechanical energy obtained from a certain given amount 
 of heat energy -, is the same at all times at the same temperature" 
 This thermodynamic law is held to be strictly true of all 
 matter without exception ; but Carnot failed to grasp its 
 full significance. It was reserved to Joule and Hirn fully 
 to expound and develop it into modern Thermodynamics. 
 Carnot stands high in the sphere of mathematics by four 
 works : On Infinitesimal Calculus, Correlation of Geometrical 
 Figures, Geometry of Position, Relation between the Re- 
 spective Distances of Five Points in Space. 
 
 O 2 
 
196 PROGRESS OF SCIENCE. 
 
 ijj* 1855. Gauss, one of the masterly mathematicians 
 of the XlXth century, established the theory of the 
 DIVISION OF THE CIRCLE ; discovered the LAW OF 
 ERRORS ; was a great master in Transcendental Arithmetic ; 
 found new methods of calculating planets' orbits, explained 
 in his THEORIA MOTUS ; improved geodesy ; invented the 
 MAGNETOMETER for determining the angles which the plane 
 of magnetic meridian makes with the plane of the astro- 
 nomical meridian ; calculated that the total magnetic action 
 of the earth is the same as that which would be exerted if in 
 each cubic yard there were eight bar-magnets each weighing 
 one pound. From data collected by Piazzi, he calculated the 
 whereabouts of Ceres so accurately, that directing his telescope 
 to the probable point he rediscovered this asteroid, which 
 had been lost sight of for months (1801). 
 
 1789 1857. Cauchy discovered the method for finding 
 d priori the number of roots; simplified the THEORY OF 
 ASYMPTOTES. 
 
 17931880. Chasles introduced the adoption of SIGNS 
 IN PURE GEOMETRY, thereby creating uniformity of method ; 
 found the theory of the surfaces of the second degree the 
 starting point of fine discoveries. 
 
 !8o5 1865. Hamilton (Sir W. Rowan) brought into 
 existence the system of QUATERNIONS, an extensive method 
 of mathematical reasoning comparable to the invention of 
 logarithms for power, but of infinitely more value in higher 
 mathematics, for " whatever problem involves the threefold 
 dimensions of space, is treated by a symbolic method of the 
 most comprehensive simplicity" (Jevons). 
 
 1806 1871. De Morgan endeavoured to effect the 
 
 UNION OF LOGIC AND MATHEMATICS " one of the most 
 important steps in the history of science " a connection 
 brought about by Boole. De Morgan effected a great 
 generalisation, for his double algebra is true not only of 
 space relations, but of forces, so that the triangle of forces 
 is reduced to a case of pure geometrical addition ; and more, 
 the triangle of lines, the triangle of velocities, the triangle of 
 forces, the triangle of couples, are reduced by analogy to one 
 simple theorem which amounts to this, " that there are two- 
 
MODERN SCIENCE. 197 
 
 ways, different in length, but identical in their final results, 
 of getting from an angular point of a triangle to another " 
 (Jevons). He also pointed out that "the three symbols of 
 ordinary algebra form but three of an interminable series of 
 conceivable systems." 
 
 The foregoing sketch of the work done by mathematicians, 
 the present writer candidly owns, is here both meagre and 
 unsatisfactory. It gives a list of new instruments of calculation 
 it is true ; but it neither defines the object for which they 
 were created, nor states what discoveries were made by the 
 use of them ; so that the general reader who may not be 
 conversant with mathematical science can form no estimate 
 of the value of the facts just enumerated. But as the two 
 next sections will describe the power of mathematics in 
 solving difficulties in astronomy and physics which would be 
 insuperable without it, the reader will have occasion then to 
 appreciate its effects in a multitude of facts. He will see the 
 imperial sway of mathematics over all other branches, and 
 will plainly understand why it is often called the Queen of 
 Sciences. The names of the mathematicians, which may be 
 names and nothing more to him, will then appear illumined 
 by a halo suddenly revealing all the splendours of genius, for, 
 indeed, in the fame-roll of all times they hold the first rank. 
 
 In order to give an idea of the vastness of modern science, 
 a remark may parenthetically be made here, based on a fact 
 of importance. 
 
 Mathematics, if considered in detail, embrace pure mathe- 
 matics and applied mathematics : 
 
 / I. ARITHMETIC, subdivided into 
 
 A. Pure Arithmetic : 
 
 (a) Theory of Numbers, (b} Ratios, 
 
 (c] Proportions, (d) Scales of Notation. 
 
 B. Applied Arithmetic : 
 
 (a) Weights, (ff) Measures. 
 
 II. ALGEBRA, into 
 
 A. Elementary : 
 
 (a) Analysis of Determinate Quantities, 
 (3) Analysis of Indeterminate Quantities. 
 
 B. Higher Infinitesimal Calculus : 
 
 (a) Differential, () Integral. 
 
198 PROGRESS OF SCIENCE. 
 
 { III. GEOMETRY, subdivided into 
 
 A. Elementary or Euclidian. 
 
 B. Higher or Project! ve vel Descriptive. 
 
 C. Analytical Geometry. 
 w 
 
 a / 
 
 IV. CONICS, or Curves of the Second Order : 
 
 (a) Ellipse, (b) Parabola, (c) Hyperbola. 
 
 
 V. MECHANICS : 
 
 (a) Statics, (b} Dynamics, (c) Kinetics. 
 
 
 VI. APPLIED MATHEMATICS : 
 
 A. Mensuration, B. Hydrostatics, Dynamics, Mechanics, 
 C. Geodesy, D. Astronomy. 
 
 Hence mathematics have been the chief instrument by 
 which the physical sciences have progressed; namely, 
 astronomy, gravity, hydrostatics, hydrodynamics, hydro- 
 mechanics, optics, heat, light, acoustics, magnetism, elec- 
 tricity, meteorology, geography, chemistry, engineering 
 (machinery and surveying), architecture, naval architecture 
 in fact all the phenomena relating to Force and Matter 
 to which may be added political economy, currency, banking,. 
 and insurance. Now, what we have to note and remember 
 is that each branch, so vastly has science extended its area, 
 admits, just as mathematics do, of several important sub- 
 divisions each of which is often extensive enough to engross 
 by itself a man's whole lifetime, each, too, employing an army 
 of earnest workers. 
 
 GROUP V. ASTRONOMY. 
 
 1592 1655. Gassendi was the first to observe, by means 
 of the camera obscura, MERCURY passing across the disk of 
 the sun (November 7, 1631) a phenomenon which recurs at 
 intervals of from seven to thirteen years. As a mathe- 
 matician and physicist, he wrote on the communication of 
 movement. 
 
 161 1 87. Hevelius drew up, after careful observations of 
 the moon, the first SELENOGRAPHICAL MAPS ; increased the 
 catalogue of stars just after Galileo those in the Zodiac 
 especially ; was the first observer of the PHASES OF MERCURY, 
 
MODERN SCIENCE. 199 
 
 and observed in the camera obscura the transit of this planet 
 (May 3, 1661); measured its diameter; determined the 
 rotation of the sun on its axis to take twenty-seven 
 days, after assiduously observing the sun's spots. He in- 
 vented the polemoscope, for observing the movements of an 
 army out of sight. 
 
 1619 41. Horrocks was the first, with his friend Crab- 
 tree, to observe the TRANSIT OF VENUS (over the sun's disk), 
 December 4, 1639, ky means of a telescope. 
 
 1625 1712. Cassini discovered comets to belong to our 
 planetary system, and in some respects to partake of the 
 nature of planets a somewhat hasty conclusion ; he calculated 
 the orbits of a few ; measured the obliquity of the ecliptic ; 
 also the parallax of the sun ; also horizontal refraction ; 
 showed Jupiter to revolve on its axis, and its rotation to take 
 9 hours 56 minutes observing at the same time the 
 flattening of that planet at the poles, a discovery precious to 
 Newton ; discovered FOUR OF SATURN'S MOONS ; and also the 
 ROTATION OF MARS ; drew up the EPHEMERIDES of Jupiter's 
 satellites ; originated a method for determining parallaxes 
 still in use ; and finally studied the zodiacal light, the nature 
 of which remains as yet undetermined. 
 
 162995. Huygens, by means of a ten feet long telescope 
 of his own making, was the first to discover one of SATURN'S 
 SATELLITES (Titan), and also to detect Saturn's rings to be 
 detached from the planet (1659) ; he also discovered the great 
 non-resolvable NEBULA OF ORION. 
 
 16381703. Hooke determined the PARALLAX OF STARS 
 by a surer way than Galileo had proposed (1660) ; approached 
 in a remarkable manner the discovery of universal gravitation, 
 after making the earth's motion a subject of deep study and 
 calculation. 
 
 1642 1727. Newton applying Galileo's principles of 
 terrestrial dynamics to the Universe, demonstrated THE LAWS 
 OF universal attraction and GRAVITATION his second and 
 greatest discovery a feat unparalleled in the annals of science, 
 sublime alike for its magnitude and for the labours it involved. 
 Before dealing with the problem, Newton had to resolve, 
 I. the force according to which a body falls; II. the exact 
 
2oo PROGRESS OF SCIENCE. 
 
 time of the moon's rotation ; III. the exact length of the 
 earth's radius (line drawn from the surface to the centre). 
 The last proposition caused a pause of sixteen years until 
 Picard (Jean, 1620 1682) found the exact measurement of 
 the radius (20,922,000 feet). Then came the great law of 
 Newton (1687), " The force of attraction of a body is equal to 
 the mass divided by the square of the distance " in other 
 words : The attraction varies inversely as the square of the 
 distance or again : As much as the square of the distance 
 increases, so much the attraction decreases.* By this law 
 Newton accounted, not only for I, the three laws of Galileo 
 and Kepler, but for 2, all the movements of the celestial 
 bodies, then for 3, the tides of the ocean (spring and neap 
 tides) ; 4, he proved experimentally the rotation of the earth 
 on its axis; 5, determined the figure of the earth to be an 
 oblate spheroid a phenomenon unsuspected, and solved 
 entirely by calculation ; 6, explained the cause of the pre- 
 cession of the equinoxes, and showed it to be due to the 
 flattening of the earth at the poles, and to the additional 
 attraction of the sun and moon exercised upon the extra 
 mass of matter gathered at the equator ; 7, determined the 
 specific gravity of the planets Saturn, for instance, is com- 
 posed of matter about nine times lighter than that of the 
 earth ; 8, accounted for the elliptical motions of the planets ; 
 9, for irregularities of planetary movements ; 10, saw that 
 some comets must move in parabolas ; n, demonstrated the 
 chief inequalities of the moon; 12, laid down the problem 
 of the nutation of the moon afterwards resolved by Euler, 
 d'Alembert, and Laplace. The great principle Newton dis- 
 covered made it possible to account for, and determine, all the 
 
 * If at a given point a planet is at one million miles from the sun, the 
 sun will attract it, say, at the rate of 100 billions of tons per square foot 
 of its surface ; when the planet is as far again that is two million miles 
 away, the square of 2 being 4 (2 x 2=4), the sun will only attract it one- 
 fourth part, or at the rate of 25 billions of tons per square foot ; if the 
 planet is three million miles off, the square of 3 being 9 (3 x 3=9), the sun 
 will attract it one-ninth part only of the rate it drew it at starting. In 
 other words : If the distance be increased from one to two, three, four 
 units, the attraction will be decreased to the fourth, the ninth, the 
 sixteenth part of its former intensity. 
 
MODERN SCIENCE. 201 
 
 perturbations of the celestial bodies, and even the existence of 
 as yet undiscovered bodies. It is a striking example of the 
 force of prejudice and early training that the great Leibnitz 
 opposed Newton's conclusions. Of all the discoveries made 
 by mankind, Newton's is the sublimest not only the greatest, 
 but the most universal. Hipparchus's discovery of the pre- 
 cession, so marvellous considering the conditions of science in 
 his time, and Laplace's Nebular Hypothesis, so magnificent 
 as a conception, and so imposing as a scientific solution of 
 the problem of universal genesis, must be placed below the 
 discovery of Newton. It may be added that his work 
 "PRINCIPIA" constitutes par excellence the true MODERN 
 ORGANUM of the scientific method : the laws which he dis- 
 covered are wonderful, but his example of the manner of 
 establishing them is nearly as marvellous. " The scientific 
 procedure which he disclosed has been to a great extent 
 the germ of a vast development in the physical and 
 mathematical sciences." The philosophical significance of 
 this discovery was at least equal in importance to its 
 physical meaning for the truth was demonstrated that the 
 government of the planetary system "is under necessity/' 
 and that "it is impossible for the laws presiding over it 
 to be other than they are." 
 
 16441710. Roemer discovered the VELOCITY OF LIGHT 
 (1676) one of the greatest discoveries in astronomical 
 and physical science. By a careful observation of the 
 eclipses of Jupiter's moons, he found that instead of recurring 
 at fixed times and intervals, they regularly varied 16 
 min. 36 sec. every six months. If one for instance, say 
 the first satellite, which passes into Jupiter's shadow at equal 
 intervals (of 42 hours 28 min. 36 sec.), suffers occultation 
 (hiding) on the 1st of January, at eight o'clock at night, it is 
 found to suffer occultation on the 1st of July at 8 hours 16 min 
 36 sec. of the clock a retardation of 16 min. 36 sec. Roemer, 
 having ascertained this phenomenon, rightly inferred the cause 
 to be due to our being in January nearer to, and in July further 
 from, Jupiter by the whole width (or diameter) of the earth's 
 orbit viz. 190 millions of miles, and the light of Jupiter there- 
 fore taking 16 min. 36 sec. longer to reach us in July than in 
 
202 PROGRESS OF SCIENCE. 
 
 January because in July we are further removed from Jupiter 
 by 190 millions of miles; and Roemer consequently found 
 light to travel at the rate of some 190 thousand miles per 
 second, and to reach us, roughly speaking, in 8 min. 18 sec. 
 from the sun that is, nine million times faster than an express 
 train or ten thousand times the velocity of the earth. (See 
 Foucault and Fizeau.) Roemer's discovery was a much more 
 conclusive proof of the motion of the earth around the sun 
 than the calculation of an almost imperceptible parallax (the 
 apparent change of position of a heavenly body in conse- 
 quence of its being viewed from different parts). 
 
 16461719. Flamsteed drew up a TABLE OF THE 
 TIDES, and a catalogue of fixed stars of remarkable accuracy. 
 His observations on the moon were inserted in Newton's 
 Principia. He proved the falsehood of astrology by his 
 Ephemerides. 
 
 1656 1742. Halley went to St. Helena (1676) to study 
 the heavens, and, there, observed the TRANSIT OF MERCURY, 
 and catalogued three hundred and fifty stars in the SOUTHERN 
 HEMISPHERE ; demonstrated the periodical return of comets 
 by his earnest observation (1682) of the one that bears his 
 name, predicting its return in 1758, and every seventy-six 
 years ; pointed out the Secular Inequality of the moon and 
 of the satellites of Jupiter and Saturn ; from his observation 
 of the transit of Mercury, and the time it took, he was able 
 to make (1691 and 1716) the happiest suggestions for the 
 measurement of the sun's distance from us, by means of the 
 transit of Venus a phenomenon which seldom occurs (two 
 coming in eight years, and then only one hundred and 
 twenty-two years after). He left accurate instructions to 
 accomplish that object during the next transit in 1761. 
 The beautiful method he indicated, and which consisted 
 in observing the duration of the transit from two or more 
 stations far apart, east and west, was followed with the 
 best result. Several expeditions, sent out in 1761 and 1769, 
 enabled astronomers to approximate the distance the 
 distance found being 91,368,000 miles, or 108 times the 
 sun's diameter. We may remark that J. N. Delisle (1688 
 1768) proposed another method of observing Venus's transit, 
 
MODERN SCIENCE. 203 
 
 to be applied at stations where Halley's method cannot 
 be used, and which consists in noting the time of the 
 beginning of the transit at a station in the North where 
 it begins earliest, and at another station in the South 
 where it begins latest. These details are given because 
 of the importance of Venus's transit and the great interest 
 attached to the latest transits, those of 1874 and 1882, of 
 which most of us have heard. Halley found also a simple 
 formula to measure the ALTITUDE OF MOUNTAINS with the 
 barometer the mercury sinking one inch in 900 feet ; 
 studied the variations of the compass ; explained the causes 
 of the inequality of level in the Mediterranean Sea to be due 
 to evaporation. He invented the MERCURY THERMOMETER 
 (1680). 
 
 1692 1762. Bradley discovered the phenomenon called 
 the ABERRATION OF FIXED STARS an apparent displacement 
 of celestial bodies due to the progressive motion of light and 
 the orbital motion of the earth the aberration depending 
 upon the ratio between the velocity of light and of the 
 earth's motion. This phenomenon is sometimes called 
 "aberration of light" but rather incorrectly. Bradley 
 discovered and explained the NUTATION (oscillation) of the 
 earth's axis that is, the small gyration of the axis around 
 the mean position due to the precession of the equinoxes. 
 This motion of nutation takes place in about nineteen years 
 in a small ellipse. These two discoveries are of high 
 importance in the study of astronomy. 
 
 17361813. Lagrange demonstrated, with Poisson, 
 Laplace's theory of the INVARIABILITY OF THE GREAT AXES 
 of the planetary orbits ; solved the problem of the libration 
 of the moon that is, he explained with Laplace, with whom 
 he worked hand in hand, that the moon always presents the 
 same side to us because the globe is not a sphere, but an 
 ellipsoid, i.e., it has its equator elongated towards the earth 
 this elongation being due no doubt to the tide of matter (now 
 solidified) which was caused at one time by the earth's 
 powerful attraction. By this elongation, the moon's earth- 
 ward hemisphere contains an excess of matter which, by the 
 earth's attraction the earth having eighty times more matter 
 
204 PROGRESS OF SCIENCE. 
 
 than the moon necessarily keeps this hemisphere facing us. 
 Lagrange also explained that, owing to the balancing 
 movement called ' ' LIBRATION " to which the moon is 
 subjected by going alternately a little faster or a little slower, 
 it must show us a thin edge of the face which is hidden from 
 us a glimpse on either side in turn so that four-sevenths of 
 the moon's surface can be seen instead of one-half only. 
 And owing to the Iteration, too, the moon's apparent 
 diameter varies from a maximum value of 33' 31*1" to a 
 minimum value of 29' 21 "9". Lagrange further solved a 
 -question of much vaster importance, viz. : that of the 
 stability of the orbits of the planets (1776). Uniting his 
 own with Laplace's investigations, together with all the facts 
 known on the subject, in one grand mathematical problem, 
 he formulated the generalisation, that, whatever the infinite 
 changes, perturbations, and variations affecting planets, yet, 
 in the course of ages, every part of the system remains 
 absolutely stable, and subjected to the force of gravitation 
 which keeps them eternally moving round the sun ; so that 
 he demonstrated, as we said at starting, the theory of the 
 Invariability of the great axes. Laplace, himself a mathe- 
 matical genius of the first order, justly said, in admiration 
 of Lagrange's achievements, that " of all the inventors who 
 had contributed most to the advancement of human know- 
 ledge, Newton and Lagrange appeared to possess, in the 
 highest degree, the happy tact of distinguishing general 
 principles among a multitude of objects enveloping them, 
 and this tact he conceived it to be the true characteristic of 
 scientific genius." We may add that Lagrange considered 
 less astronomical questions than the mathematical analysis to 
 which they might give rise. 
 
 17381822. Herschel (William), justly called the CO- 
 LUMBUS OF THE HEAVENS, was indeed the greatest of all 
 observers, and one of the founders of astronomical physics be- 
 sides. With a telescope forty feet long, of his own making, 
 he discovered and mapped nearly 2,500 NEBULA in the 
 Northern Hemisphere, and also numerous double stars, only 
 a few of which were known before his time. He detected 
 over 500 DOUBLE STARS disseminated in the heavens, after 
 
MODERN SCIENCE. 205 
 
 twenty-five years' close observations, and explained their 
 motion to be subject to gravitation, and their revolution to 
 take place around each other, and round a common centre 
 (focus). He also showed that their growing more luminous, 
 and then fainter, was due to their coming nearer to us and 
 then receding further off in the line of our vision. This was- 
 the first evident proof of the law of gravitation holding good 
 throughout the universe, and not merely throughout our solar 
 system. Later investigations have revealed systems com- 
 posed of three and even more stars, and that the increase 
 or decrease of brilliancy in variable stars is due in many 
 cases to other causes than mere motion towards or from us. 
 (See Norman Lockyer and Kirchhoff.) Herschel's theory of 
 the constitution of nebulae has been confirmed, for some 
 nebulae are, as he said, masses of luminous vapours out of 
 which stars are formed, and many others are clusters of stars. 
 But his work went further than this ; for whereas the naked 
 eye can detect 4,100 stars only, .Herschel by means of his 
 powerful telescope could in the course of years compute nearly 
 TWENTY-NINE MILLIONS. Recent computations, supported 
 by photography, make this vast number only a fraction of 
 the whole for it is now thought that 1,000 millions could be 
 mapped. Herschel enunciated the hypothesis that our 
 system belongs to the Milky Way, and is moving along with 
 it towards Hercules, or rather towards X of Hercules, being" 
 attracted thereto at the rate of 150 millions of miles a year by 
 a cluster of some 14,000 suns. He explained the probable 
 constitution of the sun, but his view is no longer accepted. 
 He thought the sun to be a dark body around which lies a 
 luminous atmosphere. The reverse seems rather to be the 
 case. The spectroscope has revealed to us the existence of a 
 central hot and luminous body, called photosphere (light-pro- 
 ducing sphere) ; this is surrounded by an atmosphere, about 
 1,000 miles thick, compose \ of metallic gases (iron, lead, 
 copper, zinc, in fact, most of the metals found on the earth); 
 around this lies a 5,000 mile thick chromosphere (a sphere of 
 hydrogen gas), which shoots flames fifty, seventy, eighty 
 thousand miles high and these eruptions ascend at the rate 
 of 20,000 miles a minute. Beyond and around the chromo- 
 
206 PROGRESS OF SCIENCE. 
 
 sphere is the Corona^ whose nature is not yet determined.* 
 We may state that the sun has 700 times more matter than 
 all the planets put together. Herschel discovered (March 
 13, 1781) the planet Uranus and its six moons with their 
 westerly motion ; he measured the diameter of several 
 planets (Ceres, Juno, Pallas, Vesta) ; he ascribed the streaks 
 of Jupiter and Saturn to be due to clouds driven by regular 
 winds, resembling our trade-winds. He further observed a 
 volcano in activity in the moon, in April, 1787. But Her- 
 schel is to be remembered as having made three capital dis- 
 coveries : I. that binary stars are very numerous ; II. that 
 nebulae are existing throughout the heavens in thousands ; 
 III. that the Newtonian law of GRAVITATION IS A UNIVERSAL 
 LAW. As a physicist, he made CATOPTRIC TELESCOPES 
 (telescopes by reflection in contradistinction to dioptric tele- 
 scopes i.e., by refraction) ; he also made numerous observa- 
 tions of great value. He was the first to study the SOLAR 
 SPECTRUM (with the thermometer, 1800), and thereby caused 
 immense progress in optics nothing less than the opening of 
 a new area of researches. For, wishing to ascertain with a 
 thermometer which of the coloured rays given by the prism 
 were the hottest, he discovered HEAT-RAYS that is, rays of light 
 which are invisible to us beyond the red band of the spectrum. 
 Within a year RITTER (J. W T ., 1776 1810) discovered DARK 
 RAYS at the other extremity of the spectrum, beyond the 
 violet band, which have the property of decomposing nitrate 
 of silver and other compounds, for which reason they have 
 been called CHEMICAL RAYS. Herschel's was the first ex- 
 periment in the history of spectrum analysis. (See Fraunhofer 
 and Kirchhoff.) The discovery made by Ritter was, next to 
 Porta's invention of the camera obscura, the earliest of 
 those which led to photography : we have seen that Davy, in 
 1802, tried to utilise Ritter's discovery. Herschel's magni- 
 ficent labours were worthily continued by his son. 
 
 1746 1826. Piazzi, following the indications furnished 
 by Kepler's empirical law by which the planets' distances 
 
 * Mr. Taylor has calculated that the whole outward envelope of the 
 sun cannot extend to less than 800,000 miles, and the light we receive from, 
 the centre must pass through this vast ocean of matter. 
 
MODERN SCIENCE. 207 
 
 appeared to follow an arithmetical progression, began to 
 observe the heavens between Mars and Jupiter, with a view 
 to discover the missing planet which should, in accordance 
 with the law, be found in that region. This law, called 
 BODE'S LAW, because this mathematician (1747 1826) set 
 it forth clearly and insisted upon its value, is a striking 
 instance of the soundness of empirical knowledge at times, 
 and may be stated thus : If under Mercury we write zero, 
 and under Venus 3, and then go on doubling this number 
 under each planet in succession (from the sun), 6 under 
 Earth, 12 under Mars, 24 under Asteroids, 48 under Jupiter, 
 96 under Saturn, 192 under Uranus, 384 under Neptune, 
 and to these numbers add up 4, we obtain the numbers 
 which closely correspond with the relative distances of the 
 planets Neptune excepted, the discrepancy with regard to 
 it being 88. This law has been of great service to astronomy, 
 for Kepler (and later Titius) expressed his belief, founded 
 upon it, that an undetected planet revolves between Mars 
 and Jupiter, and effectively, after the discovery of Uranus, 
 which afforded an additional proof of the law, Bode having 
 strongly suggested that the gap between Mars and Jupiter 
 should be surveyed, Piazzi, on the first day of our century 
 (January I, 1801), discovered CERES, the first asteroid known. 
 This planet, lost for a few months, was rediscovered by 
 Gauss after remarkable calculations of its orbit. But CERES 
 was only the first of a multitude of asteroids revolving in 
 the gap ; for soon PALLAS and VESTA were found by Olbers, 
 and JUNO by Harding (18021807). In 1845, a fifth 
 asteroid, ASTR^EA, was discovered; in 1847, three more were 
 found, and from that time until now, not a year passed 
 without some being added to their number until there were 
 as many as 389 of them known up to 1894. Seventeen were 
 found by Karl Luther alone, 10 by Hind, 9 by Gasparis, 
 14 by Goldschmidt, 7 by Pogson, 9 by Watson, and so 
 forth. It has been suggested that their large number is 
 due to the explosion of a large planet, but as their distances 
 vary between 200 and over 300 millions of miles, and the 
 inclination and eccentricity of their orbits vary beyond those 
 of other planets, it is more probable that the cause of their 
 
208 PROGRESS OF SCIENCE. 
 
 presence and number lies in the principle of which the 
 nebular hypothesis gives a satisfactory explanation. (See 
 Laplace.) Be this as it may, however, Bode's law was 
 shown to be sound, though empirical, and Piazzi was the 
 first discoverer of a multitude of small worlds. 
 
 1749 1827. Laplace crowned Newton's scientific edifice 
 by his MECANIQUE CELESTE (1799), in which he enunciated 
 the law of universal gravitation gravity being only a 
 particular feature of it. He showed the law ruling Jupiter's 
 satellites, explained, in collaboration with Lagrange, the 
 cause of the moon presenting always the same hemisphere to 
 us ; and he explained the perturbations of our satellite ; why 
 the moon moves round the earth more and more quickly for 
 a lengthy period, and after that gradually more and more 
 slowly. He calculated the long inequality of Jupiter and 
 Saturn, and enunciated therefrom the hypothesis that the 
 mean of the averages in a certain number of planetary 
 revolutions does not vary a cycle, however, covering 
 necessarily thousands, and even millions, of years. This 
 constitutes his theory of the INVARIABILITY OF THE GREAT 
 AXES of planetary orbits, which was further substantiated by 
 Lagrange's calculations. It applies particularly to Jupiter 
 and Saturn, whose orbital perturbations were very striking, 
 and suggested the possibility of a dislocation of our system. 
 Saturn seemed likely to wander away and escape beyond its 
 limits, whilst Jupiter appeared on the contrary to be coming 
 nearer and nearer to the sun threatening to fall into it in 
 the course of time. Laplace showed that these planets 
 behaved in this eccentric manner, because Jupiter makes 
 2^z revolutions round the sun, whilst Saturn makes one only; 
 but as the points of their conjunction (their nearest approach 
 to each other) vary every time, the planets "must right 
 themselves, and resume in time their normal position," and 
 thus obey the law of gravitation. But Laplace is celebrated 
 in particular for propounding the famous theory which bears 
 his name. After long meditations upon the probable origin 
 of the order which reigns in the universe, induced by a 
 striking suggestion due to the genius of Kant (1724 1804), 
 that suns, stars, planets possibly owe their present form to- 
 
MODERN SCIENCE. 209 
 
 the slow cooling and contraction of .incandescent gas-clouds, 
 after long and complicated calculations bearing on physical 
 and mechanical questions which the subject involved, Laplace 
 arrived at the conclusion that planets are condensations of 
 the solar atmosphere at first only rings of gaseous and 
 luminous matter detached from the nebula (sun) by the 
 contraction of the main body, then later^on condensed by 
 cooling into solid bodies (planets), which continue to revolve 
 around the sun, in the same orbits as those which they 
 occupied as vapours at starting. This theory is called 
 Laplace's NEBULAR HYPOTHESIS, and is the theory accepted 
 by most physicists and astronomers. It is in complete 
 harmony with the law. of evolution, of which Laplace is the 
 earliest scientific exponent and demonstrator. The law of 
 evolution, it is clear, accounts for all the phases through 
 which worlds must pass in the course of their birth, growth, 
 maturity, and decay. It was through this famous hypothesis 
 that evolutionism began to work its way throughout Europe 
 for the first time in a clear form, and to become familiar to 
 .scientific minds. The conception of slow natural develop- 
 ment, as opposed to that of sudden creation, steadily spread 
 after the publication of the " Mecanique Celeste." Laplace's 
 hypothesis is in the main a mathematical theory, and as such 
 it "explains a number of the most important facts of our 
 solar system." It may be added that spectroscopic astronomy 
 {see KirchhofT) has been adding a multitude of facts which 
 confirm and strengthen the theory more and more every 
 year. Thus, Laplace, in this as in other respects, advanced 
 the boundaries of science immensely, and must be re- 
 membered as one of the most profound philosophers of 
 modern times. 
 
 17581840. Olbers discovered PALLAS (1802) and VESTA 
 (1807), anc * several comets; formulated the theory of ex- 
 plosion to account for meteorites a theory, however, which 
 is much opposed by other astronomers and particularly 
 Norman Lockyer. (See his meteoritic hypothesis.) 
 
 1791 1865. Encke, by his accurate observations of the 
 comet which bears his name, and which returns every 3^ 
 years, formulated afresh the theory of the existence in spacs 
 
210 PROGRESS OF SCIENCE. 
 
 of an ETHER within the whole area of our planetary system 
 a view now generally accepted, and, since, even extended to 
 universal space, as Huygens had suggested. Encke showed 
 that ether, offering a certain resistance, and decreasing the 
 comet's velocity, enables the sun to attract the body nearer to 
 itself, to contract therefore its orbit, and cause it to reappear, 
 after passing behind the sun, a few hours sooner (two hours and 
 a quarter) than would be the case otherwise. The decrease 
 has been from 1,21279 in 1786 to 1,210*44 in 1858. The 
 importance of this theory can hardly be exaggerated. It 
 confirms the nebular hypothesis, for the comet must one day 
 be attracted into the sun, and be followed likewise, by virtue 
 of the same law, by all the bodies of the system successively 
 in thousands of ages, of course so that in the process of 
 time our system must be merged into a nebula as it was at 
 starting, and begin from that point a fresh course of evolution- 
 ary cycle. 
 
 1792 1871. Herschel (John) established a catalogue of 
 
 2,OOO DOUBLE AND TREBLE STARS (l8l8); and, going to the 
 Cape of Good Hope, he discovered and mapped 2,500' 
 NEBULA in the Southern Hemisphere thereby completing 
 his father's glorious work (1834 1838). Evidence has thus 
 been furnished, by the observations of the two Herschels on 
 the motions of double stars and the constitution of nebulae, to 
 show that Newton's law of gravitation and Laplace's theory 
 apply to the whole universe ; so that there seem to be 
 features of homogeneity in the structure of all celestial systems 
 which may be looked upon as a demonstration of resistless 
 and unchangeable law a point upon which it is necessary to 
 insist. John Herschel showed that the vast MAGELLANIC 
 CLOUDS a distant group of nebulae and star systems pre- 
 senting marvellous complexity, since they exhibit 28 kinds 
 of nebulae are a portion of the Milky Way of the Southern 
 Hemisphere. But Herbert Spencer has thrown a doubt 
 whether some of these nebulae are as remote from us as great 
 astronomers state, and the reasons he gives are both weighty 
 and cogent for, to put it in a nutshell, if they are resolvable 
 into stars by our telescopes they must be within the limits of 
 our sidereal system, otherwise they would not be resolvable 
 
MODERN SCIENCE. 211 
 
 by the telescopic power we possess. As regards the others, 
 photography has confirmed the views of the Herschels they 
 are vast masses of luminous gases, which time and cooling 
 will contract into planetary systems in accordance with 
 Laplace's theory. John Herschel's famous Outlines of 
 Astronomy (1838), treated as Arago had already done in 
 France (Astronomic Populaire 1834), is the earliest and 
 finest work it is possible to read in the English language on 
 the subject. For the first time was the general reader put in 
 a position to understand the wonders of the heavens : it is, in 
 point of clearness, simplicity, and eloquence, on a par with 
 Arago's work. As a physicist, John Herschel's treatises on 
 Sound and Light are valuable contributions to science. He 
 carried on, together with Talbot and Brewster, a series of 
 experiments on light and the colours of burning substances, 
 and suggested, like Talbot, to make the flame-colours a 
 means of chemical analysis (1822). He IMPROVED THE 
 SPECTROSCOPE in collaboration with J. Browning (1870). 
 Herschel may be said to have founded practical mineralogy : 
 he was no stranger to any of the physical sciences, and it 
 is not too much to say that they are all indebted to him in 
 one way or another. As an instance of his scientific 
 universality, we may take his determination of the relative 
 luminosity of heavenly bodies. Wollaston had ascertained 
 that the full moon gives 801,072 times less light than the 
 sun; Herschel determined that the light of the full moon 
 exceeds that of a Centauri 27,408 times ; so that ff the ratio 
 between sunlight and starlight would be that of 22,000 millions 
 to one." 
 
 1811 1877. Leverrier, concurrently with Adams, after 
 calculating the deviation of Uranus from its orbit, ascribed 
 this perturbation to be due to the presence of an unknown 
 body external to Uranus, and this proved to be the case ; 
 for (Berlin) astronomers, instructed by precise directions from 
 Leverrier as to the region where the planet was to be looked 
 for, discovered NEPTUNE on the same night (September 23, 
 1846), the orbit of which is thirty times more remote from 
 the sun than ours. This feat, which may be regarded as 
 one of the greatest triumphs yet achieved by Newtonian 
 
 p 2 
 
212 PROGRESS OF SCIENCE. 
 
 astronomy, showed once more the unrivalled power of 
 mathematics in science. Leverrier rendered a much greater 
 service to astronomy. From 1838 to 1874 he worked out 
 
 the ANALYSIS OF THE ORBITS OF THE PLANETS, by observing 
 
 and calculating all the movements of the eight large planets. 
 This vast work the greatest accomplished in mathematical 
 astronomy in our time includes a determination of the 
 masses, disturbances and their causes, the interaction of 
 planets upon one another, so that it constitutes a table which 
 will enable future astronomers to ascertain within the next 
 2,000 years whether the same order, or a different order, 
 obtains. All this was again accomplished by the masterful 
 handling of mathematics the queen of sciences. 
 
 1 8 . Schiaparelli revealed a NEW FEATURE in the con- 
 stitution of the heavenly bodies. He showed in 1862 that 
 the SWARM OF METEORS of August Qth to nth (that is, 
 the shooting stars called the Perseids) travelled in exactly 
 the SAME ORBIT AS THE COMET which appeared in that 
 year. This was the first time a meteoric orbit was de- 
 termined. The (i3th) November swarm (the Leonids) was 
 next traced out by Leverrier and Adams, the latter calcu- 
 lating it to travel beyond Uranus; and in 1866, a comet 
 was seen to move along precisely the same orbit. Adams's 
 masterly calculations proved the cycle of these November 
 meteoroids to be no less than 33^ years. Since then, 
 meteor swarms have been studied with great care, and an 
 immense number of them, describing rings more or less 
 regular, have been discovered, notably by Schiaparelli, 
 Proctor, and Prof. Newton. It is now ascertained that the 
 earth crosses every year the orbits of the August and 
 November meteoroids, and the meteorites which are met 
 by the earth are ignited by the friction of our atmosphere 
 and dissolved in their course through it, thus causing the 
 phenomenon known as shooting or falling stars. As there 
 are eighteen meteor showers every year, it is concluded that 
 we pass across the orbits of eighteen systems. According 
 to Prof. Newton and Schiaparelli, the August meteoroids 
 are nothing but the continuation of the 1862 comet, whose 
 tail is elongated all along the course of the comet's orbit. 
 
MODERN SCIENCE. 213 
 
 Schiaparelli has identified the orbits of five meteoritic 
 swarms with the orbits of various known comets. Besides 
 the swarms, there are sporadic (chance) meteorites strewed 
 throughout our system, and so numerous are they that no 
 less than TWENTY MILLIONS enter our atmosphere DAILY 
 according to Prof. Newton, and if all were seen their 
 number would probably exceed one hundred millions; so 
 that "our solar system is a meteoric plenum in which 
 sporadic meteorites and swarms of greater or less density 
 are moving in orbits more or less elongated around the 
 sun." There seems also to be conclusive evidence that 
 they are strewed throughout universal space, and not 
 throughout our system only. This question has been worked 
 out by Norman Lockyer very elaborately, and in his book 
 he has co-ordinated all that is known at present about 
 nebulae, comets, and meteorites. 
 
 1836 . Norman Lockyer, besides co-ordinating 
 the labours of other astronomers, physicists, and his own, 
 has contributed important astronomical and SPECTROSCOPIC 
 OBSERVATIONS on meteorites. He has all but proved their 
 ubiquitous presence in countless swarms or streams through- 
 out space as we just mentioned ; he has just pointed out 
 the importance of the part they may play: (i) as factors 
 modifying comets, gravity, light, heat, electricity; (2) as 
 possible and probable elements contributing to the preser- 
 vation of solar energy,* and even the formation of nebulas 
 and stars; (3) as agents causing the phenomena of variable 
 stars, and Novae. With regard to the last mentioned 
 phenomena, he has, upon apparently conclusive evidence 
 spectroscopic in the main supplemented the information 
 given us by W. Herschel and KirchhofT, by the important 
 fact that the intermittent increase of luminosity presented 
 by many of these variable bodies, and not by them alone, 
 but by comets besides, is due to their colliding with meteoric 
 
 * This view is confidently opposed by Helmholtz and Sir William 
 Thomson (now Lord Kelvin), who ascribe the sun's energy to shrinkage 
 by gravity. Lord Kelvin points out that the energy which may be 
 derived from meteoritic impact is insignificant by the side of that derived 
 from shrinkage. 
 
214 PROGRESS OF SCIENCE. 
 
 swarms. These swarms, by the impact, break out into 
 sudden incandescence, and add it to the normal light shed 
 before the collision by the stars and comets. It is, on a 
 large scale, the same phenomenon as that which we witness 
 on our earth when meteorites meet our atmosphere : they 
 are ignited, and become, therefore, intensely luminous. Be 
 this as it may, for the point is not altogether admitted by 
 all astronomers yet, Norman Lockyer, upon what appears 
 to him satisfactory evidence, has broached a new theory 
 of the universe, partially guessed by Waterston, viz., the 
 METEORITIC HYPOTHESIS, as distinguished from the Nebular 
 Hypothesis Lockyer's theory being that meteorites are 
 the material out of which worlds are formed. The two 
 theories are by no means exclusive of each other they 
 are easily reconcilable on the contrary, if it be allowed 
 that the two processes actually occur in succession, the 
 meteoritic phase coming after the nebular (gaseous) phase, 
 as an effect of radiation as an effect, that is, of cool- 
 ing, contraction, and chemical precipitation the meteoritic 
 phase in its turn producing the three series of phenomena 
 just mentioned. Norman Lockyer, besides the work just 
 described, and which by the way is the most recent, has 
 enriched science in several departments by numerous 
 investigations and discoveries. He is a master in spectral 
 analysis and solar physics. He had a great share in the 
 elucidation of the constitution of the sun as sketched out 
 in the paragraph referring to W. Herschel. The name 
 of CHROMOSPHERE is due to him, together with our 
 better knowledge of this portion of the sun. A fine 
 example of the excellence of his work we may cite in 
 Mr. Jevons's words : " Wanting some guide as to what 
 more elements to look for in the sun's photosphere, he 
 prepared a classification of the (chemical) elements ac- 
 cording as they had or had not been traced in the sun, 
 together with a detailed statement of the chief characters 
 of each element. He was then able to observe that 
 the elements found in the sun were mostly those forming 
 stable compounds with oxygen. He then inferred that 
 other elements forming stable oxides would probably exist 
 
MODERN SCIENCE. 215 
 
 in the sun, and he was rewarded by the discovery of five 
 such elements." 
 
 It is hardly necessary to say anything about these magni- 
 ficent results. To state and marshal them is to point out 
 their grandeur. That man, in. his acknowledged insignifi- 
 cance and with his confessed limitation of intellect, should 
 have arrived at detecting, in the infinitude of space, innumer- 
 able phenomena, each of them a new sphere of further in- 
 vestigation, and after detecting them should have explained 
 their relation to one another, and after showing their relation 
 should have found out the far-reaching laws by which they 
 are regulated, is at once the most beautiful and the most en- 
 grossing of all wonders. That this is a subject for meditation 
 which precedes all others in importance, because of the 
 psychological questions it involves, need not be insisted upon, 
 so intuitively do we all feel it. Such was the work of modern 
 astronomers, the sublimest achievement of man, from Coper- 
 nicus who led the van to Norman Lockyer who closes the 
 march. From the survey of astronomy, we learn as forcibly 
 as in all else the one great lesson of modern knowledge the 
 government of the world by law. 
 
 GROUP VI. PHYSICS. 
 
 1608 1647. Torricelli, concurrently with Guericke, 
 showed that air has not only weight, but, at the earth's 
 surface, exerts an enormous pressure. By his invention of 
 the BAROMETER he demonstrated this fact, which had 
 apparently been understood by Hero of Alexandria witness 
 his fountain though not demonstrated. Torricelli by means 
 of his instrument showed that the whole atmosphere is equal 
 to the weight of an ocean of mercury covering the earth, and 
 about thirty inches in height : from which it follows that a 
 pressure of about fifteen pounds (or more correctly 14*6 Ibs.) 
 weighs on each square inch of the earth's surface, so that a 
 man of ordinary size bears a weight of about fifteen tons, but 
 as the pressure of that weight is distributed equally on all 
 sides it is unfelt just in the same manner as the weight of 
 
2i6 PROGRESS OF SCIENCE. 
 
 water which presses on a fish is unfelt by it because the 
 pressure is equilibrated. Torricelli discovered and formulated 
 THE LAW of velocity of efflux by a theorem which bears his 
 name : " That water falls from a vessel with a velocity equal to 
 that with which a body would fall from the same height as the 
 level of the water above the tap " ; so that he was really the 
 founder of hydrostatics. 
 
 1602 1686. Guericke, concurrently with Torricelli, 
 demonstrated atmospheric pressure. He invented the 
 MAGDEBURG HEMISPHERES, which fully proved the pressure 
 of air to be exerted on all sides equally. He also invented 
 the AIR-PUMP, to produce a vacuum the bell-glass, from 
 which the air is exhausted by a pump, being kept down by 
 the outside air pressure. He showed the elasticity of air. 
 He was the first to propose the freezing point of water as the 
 lowest limit of the scale of the thermometer the boiling 
 point being proposed by Renaldini (in 1694) as the opposite 
 limit. He constructed the FIRST ELECTRIC MACHINE 
 using a globe of sulphur and charging it with electricity by 
 turning it in a frame, and pressing it with a cloth which 
 caused the required friction. The electricity produced by 
 sealing-wax or sulphur is called resinous electricity. Guericke 
 found out several electrical phenomena : I, that a spark is 
 produced by electricity passing between two separate bodies ; 
 2, that two bodies charged with the same electricity repel each 
 other so that he was the practical continuator of Gilbert, and 
 the precursor of Muschenbroeck, Franklin, and Galvani. Not 
 long after him a further advance in this branch was made by 
 Du FAYE, who discovered that there exists another kind of 
 electricity. He obtained it by rubbing the end of a glass 
 rod with silk. This is called vitreous electricity in contradis- 
 tinction of Guericke's. Du Faye showed that each electricity 
 repels itself and attracts the other. It was for the purpose of 
 generating vitreous electricity that HAWKSBEE made (1740) 
 the SECOND ELECTRIC MACHINE, on Guericke's principle, in 
 which the sulphur was replaced by a glass globe and the 
 cloth by a piece of silk. We shall soon see how these facts 
 conduced to the electrical marvels of our time. 
 
 1618 1663. Grimaldi discovered and demonstrated the 
 
MODERN SCIENCE. 217 
 
 DIFFRACTION OF LIGHT; after experimenting on the diffraction 
 of light (really on the interference of light), he discovered that 
 light added to light produces darkness a principle which led 
 Young and Fresnel to arrive at the truth of the undulatory 
 theory ; advanced optics generally and prepared the way for 
 Newton. 
 
 162084. Mariotte discovered the LAW OF COMPRESSI- 
 BILITY OF GASES, that is, the contraction or shrinkage of 
 gases in proportion to pressure. This is called Mariotte's- 
 law, and also Boyle's law, the latter having also discovered it. 
 (See Boyle.) Mariotte explained the chief laws of motion by- 
 experiments which made them clearer than their mere 
 enunciation. 
 
 1629 95. Huygens invented the cycloidal PENDULUM, 
 and also PENDULUM CLOCKS (1658); invented the MICRO- 
 METER to measure the apparent diameter of planets ; im- 
 proved the barometer, with which he taught how to measure 
 the altitude of mountains. With rare genius Huygens gave 
 a scientific BASIS TO THE UNDULATORY THEORY OF LIGHT 
 (1678), rightly thinking " that we can explain light," as he 
 said, " only by supposing it to be a VIBRATION LIKE SOUND."" 
 He was THE FIRST modern scientist (Democritus's theory in- 
 volved as much) to suggest that entire space is filled up with 
 an invisible substance called " ETHER," at once elastic and 
 subtle, and that luminous bodies make it vibrate so that its 
 undulations will strike upon the eye, and give us the sensa- 
 tion called light. He pointed out that in ordinary refraction 
 the velocity of propagation of the wave is equal in all 
 directions, so that the front of an advancing wave is spherical 
 and "reaches equal distances in equal times" a wonderful 
 feat of scientific intellect. And his experiments on crystals- 
 prove that he verified his theory. What is especially remark- 
 able and shows he understood the significance of his doctrine, 
 is that he gave a satisfactory explanation of refraction by the 
 undulatory theory. He also explained the phenomenon of 
 DOUBLE REFRACTION (through Iceland spar*) to be due to 
 the greater elasticity of this crystal in one direction than ii> 
 
 * A crystal first made known by Bertholinus observing through it (irk 
 1660) the splitting of a light-ray into two rays. 
 
2iS PROGRESS OF SCIENCE. 
 
 the other, so that a ray was divided into two waves moving at 
 different rates through the crystal. From experiments bear- 
 ing upon this fact, he discovered another phenomenon called 
 POLARISATION of light the effects of which exhibit "the most 
 gorgeous colours in the whole domain of optics." The ex- 
 planation of this phenomenon we owe to the beautiful analysis 
 -of Fresnel. But, as we see, Huygens anticipated the discoveries 
 of Malus, Fresnel, and Young, though he failed to demonstrate 
 their physical causes as they wer,e demonstrated by these 
 three physicists. The main fact, however, remains untouched : 
 he may be said to have understood and explained the un- 
 dulatory theory. But as Newton had formulated a different 
 theory, and his authority in science was held to be supreme 
 in all matters, Huygens's labours were laid aside until the 
 beginning of this century, when it was proved he had been 
 right all along the line. 
 
 1638 1703. Hooke applied a SPIRAL SPRING to the 
 balance OF A WATCH in 1658; invented the dial barometer; 
 the octant, subsequently improved into the sextant ; improved 
 the microscope; discovered THE PRINCIPLE OF INTER- 
 FERENCE a principle of great importance in optics. (See 
 Grimaldi and Young.) He expressed his belief in the 
 undulatory theory of light, and with equally rare insight 
 determined the essential conditions of combustion just about 
 the same time as Boyle and Mayow. 
 
 1642 1727. Newton, as a physicist, enunciated the 
 corpuscular (or emissive) theory of light (1666), in opposition 
 to the undulatory theory of Kepler, Descartes, Huygens, and 
 Hooke. Newton believed that light consists of an emanation 
 of exceedingly minute particles of matter, projected from the 
 sun and other luminous sources with enormous velocity. 
 Modern science has settled the point. For once Newton 
 proved to be wrong. Optics are, nevertheless, deeply 
 indebted to his marvellous genius for his third great 
 discovery : he found out the composition of white light 
 by the same means as Descartes THE PRISM : in other 
 words he DECOMPOSED WHITE LIGHT into the prismatic 
 colours, which he called SPECTRUM, a word to be re- 
 membered ; and then recomposed white light, by the means 
 
MODERN SCIENCE. 219 
 
 of his disk, out of the colours of the spectrum. He next 
 demonstrated the cause of colours to exist in light (not in the 
 eye), and to be dependent upon the bodies which reflect or 
 refract it (1666 1671). ACOUSTICS are likewise under the 
 greatest obligation to him. He discovered how sound is 
 transmitted through the air in waves, thus completing the 
 discovery which Pythagoras and Galileo had already made, 
 though not elaborated, that sound is a vibration of the 
 atmosphere " which we feel when it strikes the drum of the 
 ear" (page 102). Newton explained what sort of vibration 
 it is; he calculated also its velocity the speed of sound 
 ranging between 1,090 feet to 1,112 feet per second at a 
 temperature of from 30 to 50 Fahrenheit. In fact, his theory 
 of sound formed a very important epoch in science opening 
 the way, as it did, to all the later applications of mechanical 
 principles to the insensible motions of molecules. (See Crookes 
 and Thomson.) Even chemistry is indebted to Newton : 
 he pointed out that many substances attract one another and 
 combine to make one compound substance ; the instance of 
 the dissolution of copper in nitric acid, and its reappearance 
 after iron had been plunged into the liquid, was the hint 
 which led Bergmann to draw up his table of elective affinities, 
 as we have seen. Newton also enunciated the law of cooling 
 an important fact determined by mathematical, physical, 
 and chemical considerations, fully elaborated by Dulong. 
 We may finally mention that he constructed the first 
 REFLECTING TELESCOPE. In any one of the branches in 
 which we have had occasion to speak of this unique genius, 
 he would have made his name famous for all time, so im- 
 portant were his labours and discoveries. AVE ! 
 
 1647 I 7 I 4 Papin was the first to study the effects of 
 the production of vapour in closed vessels ; he invented the 
 DIGESTER, now used in the preparation of food and especially 
 in extracting gelatine. This was the earliest steam machine 
 ever invented in the modern era. It is a CYLINDER with a 
 PISTON working inside, and with a SAFETY-VALVE three of 
 the essentials of the modern steam-engine which made the 
 latter a possibility (1690). Papin improved Guericke's air- 
 pump, and showed that the syphon gives the same results 
 
220 PROGRESS OF SCIENCE. 
 
 with limbs of equal length(?) as with limbs of unequal length, 
 pointing out also that air-pressure is the principle of its action. 
 
 1653 1716. Sauveur was the first after Galileo who 
 studied musical acoustics, by calculating MUSICAL VIBRATIONS 
 of particular notes by means of organ pipes of different 
 lengths and stringed instruments. From these experiments 
 and later ones made by Daniel Bernouilli (1700 1782), 
 Euler, and Lagrange, it was ascertained that the sound 
 emitted by a stretched string depends upon its tension, 
 length, thickness, and weight, and any alteration in any of 
 these conditions will necessarily determine a different number 
 of vibrations and hence cause a different note to sound. 
 
 1678 1709. Stancari computed the number of vibrations 
 of a string emitting musical sounds thereby contributing also 
 to advance ACOUSTICS and place that branch UPON SCIENTIFIC 
 FOUNDATIONS. 
 
 1686 1736. Fahrenheit invented a mercury THERMO- 
 METER divided into 212 freezing point being at 32 and 
 boiling point at 212. Reaumur's thermometer is divided 
 into 80, from freezing point o to boiling point 80. Celsius 
 (1701 1744) invented one, now universally used by scientific 
 men on account of its convenient simplicity, which is called 
 Centigrade thermometer, because it is divided from freezing 
 to boiling points into exactly 100. 
 
 1692 1761. Muschenbroeck invented (1746) the LEY- 
 DEN JAR, wherein electricity was accumulated (bottled-up) 
 like a fluid a great stride ; invented also the pyrometer for 
 measuring high temperatures. 
 
 170661. Dollond invented ACHROMATIC TELESCOPES 
 ( 1 757)- C. M - Hall had shown as early as 1729 that a 
 crown-glass lens and a flint-glass lens acting together blend 
 their coloured rays into white light. Achromatic telescopes 
 and microscopes were a great improvement, the coloured 
 edges around the objects viewed now disappearing. 
 
 1706 90. Franklin demonstrated the influence of pressure 
 upon EBULLITION by an experiment which bears his name : 
 an increase of air-pressure raises the boiling point and a 
 diminution of pressure decreases it ; hence THE LAW " The 
 temperature of ebullition, or boiling point, increases with the 
 
MODERN SCIENCE. 221 
 
 pressure" That is, at a great elevation above the sea-level, say 
 at Quito (Peru), which is 9,541 ft. above the sea, and where 
 the pressure of air is only 20*75 (barometric height) instead of 
 30 inches, and therefore no longer 15 Ibs. on the square inch, 
 water will boil at 194*2 Fahr., or 72 Reaumur, or 90 Cent. 
 That is, water will boil at about 18 less than at the sea-level, 
 where it boils at 212 Fahr. the boiling point lowering i 
 Fahr. (or 0*55 Cent.) for every 590 feet of elevation. But the 
 boiling point varies in different liquids : sulphurous acid boils 
 at 10 Cent., water at 100 Cent., mercury at 320 Cent., cad- 
 mium at 860 Cent., zinc at 1,040 Cent. All these facts 
 were determined after Franklin had demonstrated the law. 
 Franklin, next, established the IDENTITY OF LIGHTNING AND 
 ELECTRICITY (1749) the lightning being a spark several 
 miles long, instead of an inch or a few inches, passing from 
 one cloud to another. Through a simple but most ingenious 
 experiment by means of a kite, cord, and key, he caused 
 electricity to pass from a cloud to the key and collect there- 
 in, thus proving lightning to be electricity and thunder to be 
 an electric phenomenon. Franklin invented the LIGHTNING 
 CONDUCTOR (1755) an application of his discovery of the 
 power of points. For, on a sphere or globe, " the electric 
 density is everywhere uniform," but the further a body is 
 removed from the spherical shape, the less regular is its 
 accumulation hence at the point of a rod the electric density 
 will be greatest. The lightning conductor has the double 
 effect of attracting the (say positive) discharge of electricity 
 from a cloud and dispersing it into the soil, and of discharging 
 into the atmosphere the (say negative) electric fluid with- 
 drawn from the soil by the influence of the cloud ; so that it 
 prevents the accumulation of electricity on the surface of the 
 earth, and also restores clouds to their normal state. Franklin 
 proposed a theory of electricity, called the single-fluid 
 hypothesis ; but the theory of Symmer, called the double-fluid 
 hypothesis, because it supposes the existence of two fluids, is 
 the one generally accepted, explaining as it does in a more 
 satisfactory manner most of the electric phenomena. To 
 Franklin, however, are due the terms "positive " and " negative? 
 used to distinguish the two kinds of currents. He called 
 
222 PROGRESS OF SCIENCE. 
 
 positively electrified bodies those which had an excess of 
 electric fluid, and negatively electrified bodies those which 
 had less the current being determined by the want of 
 equilibrium (if we may use the term) between them : abun- 
 dance flowing to scarcity and establishing a level. By the 
 SYMMER THEORY, however, the purely conventional terms 
 positive and negative have received a more definite significa- 
 tion : positive electricity or pole being synonymous with 
 vitreous, and negative electricity or pole being synonymous 
 with resinous. For the reader's guidance it is necessary to 
 remind him that, whilst we make use of these terms, we are 
 nevertheless in complete ignorance of what electricity is in 
 itself. We know at present that motion, light, heat, mechanical 
 energy, electricity are interchangeable forces, that is, they can 
 be transformed into one another ; we also know now that 
 electricity can be produced by friction, mechanical energy, 
 magnetism, chemical energy, heat, and that electricity 
 therefore is, like heat, a mode of motion ; but our 
 knowledge goes no further. We really do not know 
 whether its existence depends on one or on two fluids, 
 or whether it is only an affection of matter, or again, 
 whether it is a form of atomic motion (Helmholtz says it is 
 probably as atomic as matter), or a visible manifestation of 
 ethereal energy : all we know is that it is a force presenting 
 itself to us in two distinct modes in other words, we know of 
 two distinct modes of the force. Hence our terms " positive " 
 and "negative." If the positive force be exhibited, the 
 equivalent negative force is called into action, and so the 
 force is essentially polar, having two opposite currents. The 
 exhibition of the force, though always subjected to certain 
 laws, is infinitely varied, and therefore not limited to the 
 uniformly typical phenomena already indicated. For instance, 
 when two bodies are rubbed together, as wax and flannel or 
 glass and silk, both bodies are found electrified; but the rubber 
 will be positively electrified if the rubbed body is negatively 
 electrified, and conversely. Again, upon the nature of 
 the rubber the kind of electricity depends : glass rubbed 
 with silk will be positively electrified (and the silk 
 negatively), rubbed with cat's skin glass will be negatively 
 
MODERN SCIENCE. 223. 
 
 electrified ; again, glass with a rugged surface becomes 
 negatively charged by rubbing with silk. Thus, electric 
 phenomena present a field of investigation absolutely bound- 
 less. It is seen by these examples that the terms adopted to 
 indicate the currents elucidate nothing as to the nature of 
 electricity, and are simply conventional labels used for our 
 convenience. It is needless to insist upon the importance of 
 Franklin's discoveries ; they caused GREAT STRIDES within a 
 short time. 
 
 1732 181 1. Maskelyne determined, in 1774, the DENSITY 
 (or weight) OF THE EARTH to be five times that of water 
 by an experiment suggested by Newton, and which con- 
 sisted in ascertaining the attraction exerted by a mountain, 
 and comparing it with that of the earth as a whole. This 
 was effected by means of the plumb-line. Maskelyne found 
 the mountain . SCHIEHALLION (Perthshire) made the plumb- 
 line deviate from, instead of pointing straight to, the centre 
 of the earth. The deflection from the perpendicular being 
 calculated, and Hutton having determined the size and 
 weight of the mountain by a series of observations and 
 measurements of its materials, the density of the earth was 
 found out, and it has been confirmed by Cavendish, Baily, 
 Sir Henry James, and Sir Edward Sabine and others who 
 have investigated the question. But the latest verifications 
 (in 1893) give a mean of 5*4 instead of 5. 
 
 17361806. Coulomb discovered the LAWS OF ELECTRIC 
 ATTRACTION and repulsion, and the method of determining 
 magnetic declination the law, that is, of decrease with 
 distance, f( Magnetic attractions and repulsions are inversely 
 as the square of the distances " ; proving it by two methods, 
 that of the TORSION BALANCE and that of oscillation. He 
 also showed (1802) that magnets act upon all bodies an 
 important discovery which Faraday will push much further. 
 Coulomb's main services to science lie in the invention of 
 the TORSION BALANCE just mentioned an apparatus of 
 extreme simplicity, consisting of a suspended wire, at the 
 lowest end of which a ball, to which an index (or hand) is 
 fixed, revolves over a graduated dial : the rotation of the 
 ball and hand, upon a slight twist being given to the 
 
224 PROGRESS OF SCIENCE. 
 
 wire, indicates on the dial the angle, the elasticity, and 
 the force of torsion of the wire facts of extreme importance 
 in metallurgy, in mechanics, and in physics. The torsion 
 balance speedily became essential in numerous branches of 
 inquiry. By means of it Coulomb determined the LAWS 
 OF THE TORSION OF WIRES (or elasticity of torsion), one 
 of the properties of solids which had not been investigated, 
 as elasticity of traction, of flexure, tenacity, ductility, and 
 hardness had been or were to be by Wollaston, Savart, 
 Kohlrausch, and others. By means of the torsion balance 
 Cavendish was able to discover the mean density of our 
 globe to be five and a half times that of water, thereby 
 practically determining the weight of the earth. The balance 
 of torsion applied in the galvanometer gives a delicate test 
 of electrical forces ; it is indispensable in the thermo-electric 
 pile ; the most delicate investigations in the theories of 
 magnetism, electricity, heat are due to it ; so that Coulomb, 
 by his invention, not only discovered three sets of important 
 laws himself, but caused rapid progress in several depart- 
 ments of physics. 
 
 1737 98. Galvani discovered that the hind-legs of a 
 frog touched by two dissimilar metals were convulsed, and 
 as an interpretation of the result he believed it to be caused 
 by ANIMAL ELECTRICITY as distinct from ordinary electricity 
 (1789). Since then Nobili, Mateucci, Du Bois-Reymond, and 
 others have shown that in living animals' muscles and nerves 
 there exist electric currents (whose laws they investigated) ; 
 so that Galvani was not wholly mistaken. His error did not 
 consist in his belief that there was electricity in animals, for 
 there is, but that there were two essentially different kinds 
 of electricity, apart from what we call positive and negative 
 -electricity. 
 
 17401810. Montgolfier (Brothers) invented AEROSTA- 
 TION 1783 (hot air balloons), soon made safer by hydrogen 
 gas and coal gas being substituted for hot air. One of the 
 most celebrated ascents was made by Mr. Glaisher, who rose 
 {1861) to 'an elevation of 36,000 feet. The balloon, which 
 is probably to become a new means of intercommunication, has 
 already proved useful in warfare, and has been serviceable 
 
MODERN SCIENCE. 225 
 
 to science as regards atmospheric phenomena, such as 
 pressure, currents, temperature of the air at different levels, 
 and the characters of the different orders of clouds. 
 
 1745 1807. Attwood invented (1783) ATTWOOD's 
 MACHINE for proving, by a falling weight, the laws of 
 accelerated motion. 
 
 1745 1827. Volta invented the hydrogen lamp; he also 
 invented the ELECTROPHORUS (to excite electricity in small 
 quantities), a convenient substitute, on a small scale, for 
 the electric machine and its objects ; it offers a good instance 
 of the conversion of work into electro-potential energy. 
 Volta also invented the EUDIOMETER (to ascertain the purity 
 of the atmosphere, or the quantity of oxygen in any given 
 bulk of elastic fluid) ; he also invented the ELECTROMETER 
 (to indicate the presence, or measure the quantity and 
 intensity, of electricity) ; and finally (1800) he invented the 
 ELECTRIC BATTERY, partly with the object of disproving 
 Galvani's theory of animal electricity. For he argued that 
 the electricity detected by Galvani was produced by the 
 two dissimilar metals, and not by the frog's leg itself; 
 that it was therefore chemical, not animal, electricity. It 
 was in accordance with this reasoning that he made an 
 apparatus wherein two metals zinc and copper brought 
 into contact with moisture, and separated from other 
 substances, produced electricity. That apparatus was the 
 voltaic battery in its simplest form. The voltaic pile, 
 another form of the battery, is made up of alternate 
 plates of zinc and copper, with pieces of flannel between 
 them wetted with water and salt the top plate being 
 copper and the bottom plate zinc, both connected by 
 a wire, through which a current (or circuit) is produced; 
 or rather, we should say, two currents circulate, the positive 
 current passing from the copper to the zinc and the negative 
 current the opposite way, from the zinc to the copper. Now, 
 if the wire is cut in the middle and each point tipped with 
 a bad conductor such as charcoal, through which electricity 
 runs with difficulty, a spark will glow between the points, 
 and that spark will grow to a brilliant luminous arch of 
 flame (if the battery is a powerful one), and thus become 
 
 Q 
 
226 PROGRESS OF SCIENCE. 
 
 our electric light. But this was the work of Humphrey- 
 Davy, as we stated in our chemical section. Thus was 
 Volta's invention of the battery the STARTING-POINT OF 
 A REVOLUTION IN SCIENCE, and of a succession of dis- 
 coveries in the XlXth century which are unparalleled in 
 the history of mankind. WATT AND VOLTA were the two 
 men who will be known to posterity as the originators of 
 the TWO GREATEST AGENTS OF CIVILISATION next to 
 printing the steam-engine and electric pile. Besides the 
 telegraph, electric light, the telephone, and a thousand 
 other applications, industry, chemistry, medicine, and other 
 sciences owe immeasurable progress to the voltaic battery. 
 
 1749 1827. Laplace, so great as a mathematician and 
 astronomer, was also great as A PHYSICIST. He invented 
 with Lavoisier the ICE-CALORIMETER ; he demonstrated the 
 statical PROPERTIES OF ELECTRICITY, and showed the force 
 to act like gravitation, that is, in the inverse ratio of the 
 square of distances ; made numerous valuable observations 
 on refraction, capillarity, barometrical measurements, pre- 
 pared for future extension the application of mechanics to 
 corpuscular physics, by demonstrating that the molecular 
 compositions of material bodies present so many new worlds, 
 subjected to the laws of mechanics, which science has to 
 investigate; and the science of our day has already shown 
 that his expectations in that respect were well founded. 
 
 1753 1814. Rumford, before Arago, Bunsen, and 
 Wheatstone, invented a PHOTOMETER for measuring the 
 relative intensities of light; he also invented a CALORIMETER 
 which bears his name ; he made numerous observations on 
 heat and light which received practical applications for 
 domestic purposes being the first to use steam for cooking 
 and warming. He showed that the quantity of light is in 
 proportion to the vivacity of combustion, and not to the 
 quantity of the matter burnt; likewise that intensity of heat 
 depends on the intensity of the draught, and not on the 
 quantity of fuel. Housekeepers would find many of his 
 suggestions conducing to economy. He showed ex- 
 perimentally the conductivity of steam, air, and the 
 transparency of a flame. He was, too, the first to de- 
 
MODERN SCIENCE. 227 
 
 monstrate, also by experiments (1798), that HEAT is a 
 KIND OF MOTION, and not a substance as it had been 
 surmised even after Lavoisier's complete and satisfactory 
 theory of combustion ; and Rumford showed also that heat 
 can be produced by friction, actually boiling-water by heat 
 so produced. By his laborious experiments and results he 
 brought the attention of scientific men to heat a power 
 relatively neglected until then. 
 
 1756 1827. Chladni, who may be called the precursor of 
 Helmholtz as regards at least a certain series of the latter 
 physicist's researches, guided by the investigations of Sauveur, 
 Berriouilli, Stancari, and Euler, on musical vibrations, dis- 
 covered the longitudinal vibrations of strings and the 
 MUSICAL VIBRATIONS OF SOLID BODIES, going in that 
 direction much further than Galileo and those just mentioned. 
 His experiments, which are fully described in his Acoustic 
 Figures and his Die Akustik, are as instructive as they 
 are interesting, showing as they do, numerous phenomena of 
 sound unsuspected till then. He invented the clavicylinder 
 and the euphone two instruments fashionable for a time 
 the latter especially on account of its great sweetness and 
 power. Marloye's harp is a fine application of Chladni's 
 elucidation of longitudinal vibrations of rods ; musical boxes 
 are examples of musical vibrations of metallic plates ; the 
 harmonicon an example of those of glass plates. The 
 vibrations of plates are governed by the law : In plates of 
 the same kind and shape, the number of vibrations per 
 second is directly as the thickness of the plates, and in- 
 versely as their areas. In elastic rods of the same kind, 
 " the number of longitudinal vibrations is inversely as their 
 length, whatever be the diameter and form of their transverse 
 section" Helmholtz has worked out this branch with 
 incomparable fulness and skill. 
 
 1758 1815. Nicholson DECOMPOSED WATER by accident 
 by the VOLTAIC BATTERY (1801) a discovery which Davy 
 considered as " the foundation of all that has since been done 
 in electro-chemical science." 
 
 1766 1828. Wollaston invented the CAMERA LUCIDA, 
 and, like Malus, the reflecting GONIOMETER, for measuring 
 
 Q 2 
 
228 PROGRESS OF SCIENCE. 
 
 the angles of crystals ; was the first to see the BLACK LINES 
 in the solar spectrum (1802), but seems to have failed to 
 perceive their significance ; he simply noted their existence. 
 This was the second step in the progress of spectrum 
 analysis. Wollaston invented the CRYOPHORUS, to freeze 
 water by means of rapid evaporation ; he invented also the 
 HYPSOMETER, to determine the height of a place by means of 
 the boiling point (see Franklin); he devised the construction 
 of the lenses of the microscope known as WOLLASTON's 
 DOUBLET. He further investigated the malleability of 
 metals, and found platinum to be the most ductile of all, 
 for he actually obtained a platinum wire O'OOOO3 of an inch 
 in diameter so fine that 1,060 yards of it weighed only 075 
 of a grain. He rendered countless services to science. 
 
 1766 1832. Leslie (Sir John) advanced the knowledge 
 of THE PHENOMENA of reflection, emission, and absorption 
 OF HEAT science is mainly indebted to him in these 
 branches. Invented a HYGROMETER, a differential ther- 
 mometer, and a photometer (1800); also a method of 
 artificial FREEZING BY RAPID EVAPORATION; carried on 
 numerous experiments on the relation of air to heat and 
 moisture (his work on the subject a standard book); in- 
 vented a reflecting tube (bearing his name) by means of 
 which the reflecting power of substances is determined. 
 
 1766 1844. Dalton made fine discoveries in heat: 
 determined the amount of vaporisation of liquids according 
 to heat ; discovered and tabulated the SPECIFIC HEAT OF 
 GASES. 
 
 1773 1829. Young (Thomas), one of the most original 
 thinkers of our age, was, next to Huygens, the first to indicate 
 the right path and lay down the right principle for the 
 ELUCIDATION of the most important and complicated 
 phenomena of light, the development of which was worked 
 out by Fresnel, and led the latter to establish the UNDULA- 
 TORY THEORY OF LIGHT, although the credit of this great 
 discovery is often but erroneously assigned to Young alone. 
 Young, as early as 1801, made experiments upon the "inter- 
 ference of light " and to him is due this denomination of the 
 phenomenon ; but Fresnel, once in possession of the con- 
 
MODERN SCIENCE. 229 
 
 ditions of the problem as stated by Young, seems to have 
 arrived first at the correct solution with the assistance of 
 Arago. Still, it was only after he had communicated his 
 results to Young that decisive experiments were made, and 
 led to the complete settlement of the question (1816) so 
 that their names cannot be dissociated in reference to it. The 
 undulatory theory once established, Young showed that the 
 phenomena of diffraction are to be explained by it. The 
 wave theory also reveals an intimate connection between 
 light phenomena and heat phenomena ; it also shows how 
 completely analogous the phenomena of light are to those of 
 sound ; it readily explains the colours of different bodies 
 opals, mother-of-pearl, butterflies' wings, the feathers of birds, 
 soap-bubbles amongst others. For according to this theory, 
 " certain bodies have the property of exciting undulations of 
 different lengths, and therefore of producing light of given 
 colours " : white light or daylight results from the co-existence 
 of undulations (waves) of all possible lengths. The theory like- 
 wise explains the colours of all transparent bodies, as also the 
 colours of the spectrum, and their alteration according to 
 distance. All these phenomena then depend upon wave- 
 lengths, and these are infinitely varied. They have been 
 calculated to range in parts of an inch from 
 
 Extreme Red 0*0000266 to Extreme Violet 0-0000167 ; 
 whilst according to Sir John Herschel's mathematical 
 investigation, the number of undulations in an inch range 
 from 
 
 Extreme Red 37,640 to Extreme Violet 59,750; 
 and the number of undulations in a second range from 
 
 Extreme ^^458,000,000 of millions, to 
 
 Extreme Violet 727,000,000 of millions. 
 
 But returning to Young, besides the part he took in 
 establishing the undulatory theory, he also laboured to de- 
 monstrate the existence in interstellar space of A LUMINI- 
 FEROUS ETHER a hypothesis entertained by Huygens, and 
 almost demonstrated by Encke since, as we have seen a 
 hypothesis, so far, which is, however, pretty generally accepted. 
 This ether " more solid and elastic than steel," and which 
 must exist if the undulatory theory is true, exerts a pressure 
 
230 PROGRESS OF SCIENCE. 
 
 upon us, according to Sir J. Herschel's calculation, of about 
 seventeen billions of pounds per square inch that is, 1,148,000 
 million times more than the pressure of air at the earth's 
 surface, and which is 15 Ibs. on every square inch. It may 
 be stated, as an evidence of the interaction of the sciences 
 upon one another, that the undulatory theory might be un- 
 known even now, had not the theory of sound suggested an 
 analogy as it did from the first, for this was Huygens's first 
 idea. Young, who had supplied the principle of research in 
 the case of the wave theory, did exactly the same thing in 
 reference to the HIEROGLYPHICS of Egypt, after his examina- 
 tion of the Rosetta Stone. By indicating the process to be 
 followed, he enabled Champollion to work out the decipher- 
 ment of the great mystery enveloping the history of the 
 past. 
 
 17741862. Biot found that a great number of liquids 
 and solutions possess the property of circular or ROTATORY 
 POLARISATION that is, have their light-waves undulating 
 corkscrew fashion ; further, that the deviation of the plane of 
 polarisation that is, alteration of light and direction of light- 
 waves can reveal differences in the composition of bodies 
 where none is exhibited by chemical analysis ; explained the 
 colours produced by polarisation ; devised an apparatus for 
 measuring the rotatory power of liquids ; also found the law of 
 distances in electricity, " that the force decreases as the square 
 of distances" As a mathematician, Biot threw great light 
 upon Egyptian astronomy, and proved it to have been very 
 accurate, and at the same time very ancient. 
 
 1 77S~ I8l2 Malus discovered (1808) the POLARISATION 
 OF LIGHT by reflection (also discovered by Huygens, and 
 rediscovered by Brewster). Malus called polarisation the 
 division of a ray into two, and light so divided polarised 
 light. A ray of light, it must be remembered, is caused by 
 the vibrations of the luminiferous ether, occurring in all 
 directions across the path of the ray. A ray of polarised 
 light is caused by these vibrations occurring in one plane only, 
 and Iceland spar (see Huygens) has the property of altering 
 the multifarious directions of light-waves into two only 
 vertically and horizontally thus causing double refraction. 
 
MODERN SCIENCE. 231 
 
 In other words, a ray of ordinary light passing through 
 Iceland spar is divided into two polarised rays, and by 
 recombining the two polarised rays, common light is re- 
 produced. The NlGOL PRISM is used as a polariser or 
 analyser so that it polarises light, and shows the effects of 
 polarisation ; the polaroscope is another instrument for 
 showing the phenomena of polarised light, such as the colours 
 produced, and so forth. We shall see that Fresnel and 
 Young succeeded in elucidating these beautiful phenomena. 
 
 17/5 1836. Ampere, continuing Oersted's experiments 
 upon the deflection of the magnetic needle, found the north 
 pole of the magnet to act in four different ways accord- 
 ing to the direction of the current, and to simplify the 
 description, he gave the following memoria technica, called 
 AMPERE'S RULE, by which all the various directions of the 
 influence of the current can be remembered : " If an observer 
 will fancy himself to be standing (either on his feet or on his 
 head) in such a manner that the positive current will come 
 out of his mouth and return to his feet, the north pole of the 
 magnet will always be on his left-hand side." Upon this fact 
 depend the signals of the telegraph, as we shall partly see. 
 Ampere invented the galvanometer for determining the exis- 
 tence, intensity, and direction of an electric current. This 
 apparatus, combined with the commutator which will reverse 
 the current, has become one of the chief parts of the electric 
 telegraph : the motions of its needle indicate the signs 
 transmitted. Ampere suggested (1830) the working of signals 
 by the motions of the magnetic needle, and made the first 
 APPARATUS OF TELEGRAPHY, which gradually resulted in the 
 telegraph through the labours of Jacobi, Steinheil, and 
 Wheatstone. Ampere also discovered that two electric 
 currents produce magnetic currents at right angles to them- 
 selves in the air without needing any steel bar to help them. 
 He made another important discovery: as electric currents 
 caused magnetic currents, he thought it possible to turn a 
 steel bar into a magnet by passing an electric current 
 round it and effectively he made ELECTRO-MAGNETS by 
 this means. He was then the founder of ELECTRODYNAMICS, 
 that part of electric science which deals with the attraction 
 
232 PROGRESS OF SCIENCE. 
 
 and repulsion manifested between currents and currents, and 
 between currents and magnets. His fundamental law is 
 that " Two currents flowing in the same direction attract 
 each other ; two currents flowing in opposite directions repel 
 each other" He may be said to have been the first to prove 
 electricity to be a motive power. This motive power, applied 
 to machinery which requires enormous action, is as yet less 
 serviceable than steam; but when a comparatively small 
 force with great velocity and regularity of motion is required, 
 it is superior to all other means. It is, moreover, susceptible 
 of a great variety of applications in this respect as the 
 electric cars and railroads already in existence in America 
 and England conclusively prove. Tesla's experiments will 
 certainly lead to immense development. Ampere propounded 
 a celebrated THEORY OF MAGNETISM, according to which 
 magnetic phenomena would be caused, not by the existence 
 of two fluids, but by the existence of a closed electric current 
 in each individual molecule of a magnetic substance. He 
 also suggested that since an electric current turns metals 
 into magnets, the electric currents which flow round the 
 earth from East to West may turn our globe, which is partly 
 metallic, into a great magnet. If this be absolutely proved, 
 the view of Gilbert will be substantiated. 
 
 17771851. Oersted invented the PIEZOMETER for 
 measuring the compressibility of liquids; discovered ELECTRO- 
 MAGNETISM, one of the most promising principles in modern 
 science (1820); showed the DISSIMILARITY OF MAGNETISM 
 and electricity by experiments which distinctly demonstrated 
 the action of the one fluid upon the other, for he found an 
 electric current passing near a magnetic needle made the 
 latter turn and lie across the path of the current. This 
 discovery of the directive action that a fixed current exerts 
 at a distance and which thus connected magnetism and 
 electricity became in the hands of Ampere as we have seen, 
 and in the hands of Faraday as we shall see, the root of a 
 new branch in physics. 
 
 1778 1850. Gay-Lussac invented a portable barometer, 
 also an ALCOHOLOMETER, the CHRONOMETER, the ALKALI- 
 METER ; made important discoveries in moisture, atmosphere, 
 
MODERN SCIENCE. 233 
 
 and magnetic force in high altitudes (the result of a BALLOON 
 ASCENSION to the height of 7,016 metres) ; devised the method 
 of determining the density of vapours ; was one of the first 
 to determine the COEFFICIENT OF THE EXPANSION OF 
 GASES, finding it to be 0*00375 between o and 100 C. 
 He enunciated the two laws: I. All gases have the same co- 
 efficient of expansion as air. II. This coefficient is the same 
 whatever be the pressure supported by the gas. Was as great a 
 chemist as a physicist ; proved that gases combine chemically 
 in simple proportions by volume, and that the volume of the 
 product always bears a simple relation to the volumes of the 
 combining gases. 
 
 1781 1868. Brewster made valuable observations on 
 light ; found the LAWS OF POLARISATION of light through 
 reflection (see also Malus), and that OF DOUBLE REFRACTION,, 
 of biaxial crystals, of optical mineralogy, of double refraction 
 by compression ; invented the kaleidoscope depending upon, 
 the property of inclined mirrors; he also, concurrently 
 with Sir J. Herschel and Talbot, carried on a series of ex- 
 periments on the colours produced by different burning lights. 
 In time it was discovered that each substance gives a bright 
 line in the spectrum of a colour particular to itself, so that a 
 particular colour reveals the presence of a particular substance: 
 a blue flame reveals selenium ; intense yellow, sodium ; 
 violet, potassium ; red, strontium a fact upon which the 
 value of spectrum analysis rests. It is to be remembered 
 that colours depend upon the velocity of undulation, the 
 direction of light-waves, and the difference of wave-lengths. 
 Brewster invented the LENTICULAR SPECTROSCOPE ; found 
 the different proportions which the colours of the solar 
 spectrum present according to the lines which produce them ; 
 counted 2,000 dark lines in the spectrum (Fraunhofer had 
 found 600), but soon after him the existence of 3,000 dark 
 lines was ascertained ; improved the lighthouse system through 
 DIOPTRIC APPARATUS. 
 
 I 7%5 1838. Dulong.in collaboration with PETIT, analysed 
 the LAWS OF COOLING, and showed "the velocity of cooling to 
 increase as the difference of temperature between the surrounding 
 medium and the coeling bodies is greater'' He made numerous 
 
234 PROGRESS OF SCIENCE. 
 
 investigations on elastic forces and elastic fluids ; determined 
 the heat disengaged during combustion by various substances 
 after experiments corroborated by Favre and Silbermann. 
 
 !^86 1853. Arago (D. Francois) showed, with Dulong, 
 that Boyle's law is perfectly exact up to twenty-seven atmos- 
 pheres ; beyond that point of pressure the law suffers an 
 alteration, as Regnault, and also Cailletet, showed. Arago 
 invented, like Rumford, a PHOTOMETER for measuring the 
 intensity of light and investigating its chemical action. He 
 also made numerous observations on chronometers, on 
 thunder, magnetism, electricity, and optical phenomena, and 
 particularly on the action of polarised rays an investigation 
 which he carried on in collaboration with Fresnel and in 
 harmony with Young. As an astronomer, his " MULTIPLE 
 STARS" and ''Astronomical and Geodesical Observations" 
 proved valuable contributions. He measured the arc of the 
 MERIDIAN OF SPAIN. His "Astronomic Populaire" (1834) 
 and his Lectures on Astronomy are perhaps the most 
 beautiful and clearest exposition of this science extant, the 
 magnificent " Outlines of Astronomy " of Sir John Herschel 
 notwithstanding. 
 
 1787 1826. Fraunhofer may be said to have laid the 
 foundations of SOLAR PHYSICS and STELLAR CHEMISTRY ; he 
 was the first (1814), quite independently of Wollaston, to 
 observe carefully, by means of a prism fixed to a telescope, 
 the DARK LINES OF THE SOLAR SPECTRUM (6OO of them). 
 He pointed out their immense significance ; mapped 576 
 LINES, classifying the chief ones (A to G) and showing their 
 relative positions to be constant. He obtained the SPECTRA 
 OF STARS, and pointed out the presence in them of dark lines 
 wanting in our sun's spectrum, and the absence of dark lines 
 present in the solar spectrum inferring thereby a difference 
 of constitution between the sun and the stars. Fraunhofer 
 was therefore the first who studied the celestial bodies by 
 means of spectral analysis. But the dark lines remained a 
 puzzle to scientific men for forty-five years until 1859. (See 
 Bunsen and Kirchhoff.) Fraunhofer, and others after him, 
 found that the spectrum is exhibited under three types : (i) 
 continuous spectrum in which the colours of the prism are 
 
MODERN SCIENCE. 235 
 
 fully displayed, furnished by ignited solids and liquids; (2) 
 band (or line) spectrum consisting of a number of bright 
 lines, and produced by ignited gases or vapours; (3) 
 absorption (or dark line) spectrum produced by the sun and 
 stars. Fraunhofer found an analytic formula as to the laws 
 of light, and invented several physical instruments, improving 
 lenses particularly. He found the haloes seen round the 
 sun and moon to be the diffraction of light by small globules 
 of fog in the atmosphere. But this admirable inquirer is 
 especially to be remembered as the FOUNDER OF SOLAR 
 PHYSICS. 
 
 1787 1854. Ohm found THE LAW which bears his name : 
 " The intensity of an electric current is equal to the electromotive 
 force divided by the resistance " ; a law which enables us to 
 arrange a battery so as to obtain the greatest effect in any 
 given case. Another electric law was also discovered by 
 another German physicist, POGGENDORFF (17961874) : 
 " The electromotive force between any two metals is equal to 
 the sum of electromotive forces between all the intervening 
 metals." 
 
 1788 1827. Fresnel modified Grimaldi's experiments on 
 the interference of light that is, the mutual action which two 
 luminous rays exercise upon each other and fully explained 
 the fundamental PHENOMENON OF INTERFERENCE, viz., that 
 the combined action of two pencils of red light forms a series 
 of parallel bands alternately red and dark ; if one ray is cut 
 off, the dark bands disappear. Fresnel rendered this a decisive 
 experiment (test experiment) of the truth of the UNDU- 
 LATORY THEORY OF LIGHT. For if light, which travels in 
 straight lines, were made of minute particles darting from the 
 sun and shot forward like bullets, there could not be alternate 
 dark bands, as the more particles there were, the more light 
 there should be ; whereas, if light is produced by the vibra- 
 tions of the luminiferous ether, as sound is produced by the 
 vibrations of air, the dark lines are at once explained. For, 
 the combination of two waves travelling the same distance at 
 the same rate will produce a band of light ; but two waves 
 travelling unequally will destroy each other when combining, 
 and thus cause a dark band. This remarkable fact, therefore, 
 
236 PROGRESS OF SCIENCE. 
 
 is explained in the most satisfactory manner by the wave- 
 theory of light, and itself serves to demonstrate the wave- 
 theory. From that moment then the undulatory doctrine 
 was established, one of the finest demonstrations in the field 
 of science. Fresnel and Young, who worked one part of the 
 problem independently, at once accounted for a large number 
 of optical phenomena. Fresnel showed those of polarisation 
 are explicable by the wave-theory; further, by the mere 
 manipulation of mathematical symbols, he was able by the 
 light afforded by the same theory to foresee several compli- 
 cated phenomena, and explain those of reflection and 
 refraction. In these investigations he had a powerful colla- 
 borator in Arago, who is equally celebrated as a physicist and 
 an astronomer, as we have just seen. Fresnel, besides this 
 grand work, made powerful LENSES for LIGHTHOUSES; 
 invented a RHOMB, which bears his name, for converting 
 plane into circular polarised light ; by the same instrument 
 light can also be polarised elliptically. 
 
 I ySS 1878. Becquerel (Antoine Cesar) made a thermo- 
 electric battery, an apparatus which has caused rapid advances 
 in heat; was one of the founders of ELECTROCHEMISTRY; 
 made numerous and successful researches on thermo-electric 
 phenomena; invented the electric PYROMETER; also an 
 ELECTRIC THERMOMETER used to ascertain the temperature 
 (i) of plants and animals ; (2) of the earth at different depths ; 
 (3) of the air at different heights. 
 
 1791 1867. Faraday, one of the most eminent men of 
 science of our age, immensely contributed to the progress of 
 electricity by his experimental researches; discovered the 
 mutual ROTATION OF ELECTRIC WIRES AND MAGNETS a 
 conclusive proof of the connection between magnetic and 
 electric currents ; reversely to Ampere, he obtained 
 ELECTRICITY WITH MAGNETS a discovery soon to become 
 practically useful in electric telegraphy ; showed the action of 
 magnets on light a phenomenon of high importance. In 
 connection with Coulomb's discovery (of attraction and 
 repulsion), Faraday found (1845) tnat a ^ solids and 
 liquids are either attracted or repelled by a powerful electro- 
 magnet. Those which are attracted he called magnetic 
 
MODERN SCIENCE. 237 
 
 substances (or paramagnetic) ; those which are repelled, 
 diamagnetic bodies. He determined the magnetism and 
 DIAMAGNETISM of solids, liquids, and gases ; and showed that 
 all flames are repelled when placed between the two poles of 
 the magnet. This discovery of diamagnetism was one of 
 capital importance again the key to many physical pheno- 
 mena. Soon after Ampere had made electro-magnets by 
 means of an electric current, and Faraday had PRODUCED 
 ELECTRIC CURRENTS BY means of A MAGNET, the eminent 
 German physicist SEEBECK (1822) discovered THERMO- 
 ELECTRICITY, that is, the production of electricity by heat 
 a new branch of physics which has become very extensive 
 through the investigations of Melloni, Sir William Thomson, 
 Clerk Maxwell, and others. Seebeck's discovery, it has been 
 suggested, would explain the electric currents flowing from 
 East to West round our globe the sun's heat, acting upon 
 the earth's metals, inducing the terrestrial electric current ; 
 and this explanation would also account for the direction of 
 the magnetic needle to the North, because magnetic currents 
 flow across electric currents, and therefore from South to 
 North in accordance with Oersted's experiment and Ampere's 
 rule. Since then, and in connection with the subject, the 
 periodical appearance of spots in the sun has been daily 
 observed for thirty-four years by SCHWABE (from 1826 to 
 1859), an d has been found to attain the maximum every eleven 
 years. These spots are now believed to be great hollows 
 caused by cyclones possibly electric; but whatever their 
 cause or nature, the SUN SPOTS would, according to eminent 
 scientists though their theory is strongly opposed by no 
 less an electrician than Sir W. Thomson exercise a powerful 
 ACTION UPON THE TERRESTRIAL MAGNETISM, for they are 
 
 believed to cause auroras in both hemispheres, and magnetic 
 storms which will last for several days all over the earth. 
 This at least seemed to be the case in September, 1859, f r 
 the first time, and early in the year 1892 for the last time. 
 Thus the electric and magnetic influence of the sun, observed 
 ever since Graham noticed the shifting of the needle in 
 1722, is a phenomenon of vast importance which would 
 affect the whole earth with boundless energy. The point, 
 
238 PROGRESS OF SCIENCE. 
 
 however, is stoutly contested as we just hinted, and there- 
 fore by no means finally determined. Faraday made 
 numerous observations in optics ; invented several kinds of 
 optical glasses; discovered the phenomena and the three 
 LAWS OF ELECTROLYSIS that is, the process of decomposition 
 of substances into their elements by the voltaic battery, 
 which Davy had found "Electrolysis cannot take place unless 
 the substance be a good conductor," being the most important 
 of the three. He also showed that the current does not depend 
 upon the effect that two metals may have upon each other, 
 which was Volta's theory, but is produced by the chemical 
 action taking place between the water and the zinc ; and in 
 order to show the strength of the decomposition taking 
 place, and therefore ascertain the intensity of the current, he 
 invented the VOLTAMETER. The knowledge of this pheno- 
 menon led him to demonstrate that the chemical change gives 
 rise to electricity, just as electricity also produces chemical 
 change another transformation of force. Faraday also 
 formulated the THEORY OF INDUCTION (influence) the 
 mode of action of electricity on which a vast number of 
 electrostatic phenomena closely depend, and chiefly the action 
 of electrified bodies on bodies in their natural state. Of 
 all electric phenomena the most important is induction, 
 because it is tc on account of induction that we can observe 
 electricity at all ; every manifestation charge, discharge, 
 attraction, repulsion is preceded by and dependent upon in- 
 duction. If an uncharged conductor be brought near to an 
 electrified body, and thus placed under its influence, the un- 
 charged body assumes an excited state, one side of it being 
 electrified similarly, the other oppositely, to the charged body. 
 The propagation of electric force across a non-conducting 
 medium is called induction" Faraday, finally, determined 
 the inductive power of various substances. Our limits do not 
 allow us to dwell upon, or even allude to, the very numerous 
 investigations carried on, and the invaluable services rendered 
 to science by this great inquirer. 
 
 iyqi j8 . Pouillet invented the PYRHELIOMETER to 
 ascertain the amount of heat emitted by the sun the heat 
 would boil 700,000 millions of cubic miles of ice-cold water 
 
MODERN SCIENCE. 239 
 
 in one hour ; the quantity of heat which the earth receives is 
 only TFSTTnnnnnr f tne ^ eat emitted by the sun invented the 
 electrical pyrometer to measure temperatures so high that 
 the mercurial thermometer could not be used. 
 
 1798 1854. Melloni discovered numerous phenomena of 
 RADIANT HEAT ; showed radiant heat to have the same 
 general properties as light i.e., it may be reflected, refracted, 
 polarised, and decomposed determining at the same time 
 the specific power of each substance for transmitting heat; in 
 other words discovered the DIATHERMANCY (transmission of 
 heat) through various media in various degrees. The term 
 diathermancy bears the same relation to radiant heat that 
 transparency does to light; and "in like manner the power 
 of stopping radiant heat is called athermancy, which thus 
 corresponds to opacity for light." Melloni invented the 
 THERMO-ELECTRICAL MULTIPLIER such a delicate instru- 
 ment to measure heat, that the warmth of the hand is enough 
 at a distance of a yard to deflect its needle. 
 
 1800 1877. Talbot was the first to propose the bright 
 lines which appear in the spectra of artificial flames as a 
 means of detecting substances too minute in quantity to be 
 detected by any other process a suggestion which he carried 
 out in 1834, and which a few years later made the spec- 
 troscope the finest and surest of all instruments of analysis. 
 After experiments from 1832 to 1840 he applied the discovery 
 of Niepce (Daguerreotype) to paper, giving thereby the 
 finishing stroke to PHOTOGRAPHY. 
 
 1801 1 8 . Jacob! (M. H.) discovered the art (called 
 ELECTROMETALLURGY) of precipitating metals from their 
 solutions by the slow action of a galvanic current (1840). 
 This art is divided into Electrotyping, which is used in 
 producing copies of coins, medals, seals, etc. ; and ELECTRO- 
 PLATING the art of covering base metals with a thin coating 
 of silver or gold. Jacobi has therefore given birth to a vast 
 and rich industry. He was also the first to propose and fix 
 A UNIT OF ELECTRICAL RESISTANCE (i.e., a standard of com- 
 parison of resistances) a determination of great scientific and 
 practical importance. Finally, using Arago's electro-magnets 
 (made by means of an ordinary electric machine instead of a 
 
240 PROGRESS OF SCIENCE. 
 
 battery), Jacobi, in 1830, established in Russia, between the 
 Emperor's palace and his minister Klamachi's office, the 
 EARLIEST ELECTRIC TELEGRAPH, but for a short distance 
 on ly a feat also ascribed to Baron Schiling, of Kanstadt, 
 who seems to have tried to utilise Oersted's discovery. Gauss 
 and Weber, in 1834, constructed a telegraph which com- 
 municated signals to the distance of one mile and a quarter. 
 Steinheil made a similar attempt in 1837. In 1832, Jacobi con- 
 structed another line twenty-one miles long between the 
 Winter Palace and the Summer Palace of Tsarskoie Selo, the 
 wires running through glass tubes. All these, however, were 
 abortive attempts for practical purposes ; but the names of 
 these precursors of Wheatstone should be nevertheless re- 
 membered and preserved from oblivion. 
 
 1802 1876. Wheatstone made a RINGING APPARATUS 
 for electric telegraphy, the current of which was produced by 
 a constant battery ; then he devised RELAYS which ensured 
 the transmission to any distance an invention which made 
 THE ELECTRIC TELEGRAPH practically WORKABLE at last, 
 
 -and made it one of the scientific marvels of our epoch (1837). 
 Soon afterwards several kinds of telegraphs were invented : 
 one by Steinheil in Germany, another by Morse in America ; 
 the latter being much used because the needle pricks holes 
 in a paper strip, and the strips of paper with the messages 
 they convey can be kept. The electrochemical telegraph, 
 invented by Bain, prints the marks on chemical paper ; the 
 telegraphic writing machine, invented by Cowper (1879), 
 actually reproduces the handwriting. Wheatstone, com- 
 pleting Steinheil's discovery, detected that the earth, besides 
 being an excellent conductor, actually intensifies electric 
 currents. He also invented the STEREOSCOPE, as well as a 
 photometer ; also the RHEOSTAT, by which the resistance of 
 any given electrical circuit can be increased or decreased 
 without opening the circuit ; invented the balance or bridge 
 which bears his name, to determine the electrical conductivity 
 of bodies; measured the VELOCITY OF ELECTRICITY, and 
 found it to be 288,000 miles per second, which is about 
 100,000 miles swifter than light. The speed through a con- 
 ductor is slower; Maxwell's determination reducing it to 
 
MODERN SCIENCE. 241 
 
 174,800 miles per second, slightly less than the velocity of 
 light. Wheatstone also invented the polar clock, for as- 
 certaining the hour by observing the amount of polarisation 
 of the sky. 
 
 i8o4(?) Steinheil discovered THE EARTH to be a 
 CONDUCTOR of electric currents a discovery which saved 
 a back- wire in electric telegraphy; constructed (1837) a 
 telegraph (the current of which was produced by an electro- 
 magnetic machine) just after Wheatstone's telegraph had 
 come out. Steinheil was the first to make a three-prism 
 spectroscope. Fraunhofer had made his with one prism 
 only ; Bunsen and Kirchhofif, after Steinheil, used four, 
 arranged at convenient angles between two telescopes an 
 arrangement which constitutes the spectroscope, although 
 improved forms have come out since. We may conclude 
 our notice of Steinheil by stating that he should be re- 
 membered as one of the great physicists of Germany, by 
 the side of Jacobi, Bunsen, Kirchhoff, and Helmholtz. 
 
 1810 1878. Regnault found the method of estimating 
 the density of gases; showed four methods of ascertaining 
 their expansion. an investigation for which he will always 
 be remembered; determined the COEFFICIENTS OF EXPAN- 
 SION another inquiry involving years of patient and skilful 
 labour ; devised a method, and made an apparatus for 
 determining specific heat ; found the specific heat of air to 
 be 0*2377 ; found that air, nitrogen, hydrogen, carbonic acid 
 deviate from Boyle's law, and become less and less com- 
 pressible beyond a given pressure a fact which Despretz, 
 Dulong, Arago also noticed ; so that the law is only ap- 
 proximately true, though true up to a certain pressure in 
 all cases. Regnault also devised a method of discovering 
 the tension of aqueous vapour. He invented a BAROMETRIC 
 MANOMETER for measuring pressures of less than one atmos- 
 phere, and invented also a hygrometer. As a chemist, 
 he investigated the action of chlorine upon chlorhydric 
 ether, and carried out countless successful experiments. In 
 him the physicist and the chemist were blended in an equal 
 degree. 
 
 1811 1 8 . Bunsen, in collaboration with KIRCHHOFF, 
 
 R 
 
242 PROGRESS OF SCIENCE. 
 
 invented the four-prism SPECTROSCOPE, and both these 
 physicists were among the first to use this instrument in 
 CHEMICAL ANALYSIS. By means of it they discovered 
 caesium and rubidium (1860) a decisive step. Before Bun- 
 sen's researches on the chemical action of light in which 
 branch Roscoe did also valuable work there was no mode 
 of measuring the ENERGY OF LIGHT. Bunsen invented a 
 serviceable PHOTOMETER for measuring the different inten- 
 sities of light ; his work in photometry alone would ensure 
 him a high place among physicists. He invented also 
 an ice-calorimeter for determinations of heat in a small 
 quantity of substance. This was improved upon by Favre 
 and Silbermann, who invented another calorimeter which 
 furnishes a very delicate means of ascertaining the caloric 
 capacity of liquids, latent heats of evaporation, and the heat 
 disengaged in chemical actions. Bunsen made COUNTLESS 
 DISCOVERIES in the field of pure CHEMISTRY ; but his name 
 will always be remembered in association with KirchhofFs 
 in spectroscopy. 
 
 1811 18 . Grove (Sir William) showed the CORRE- 
 LATION OF FORCES, one of the mighty laws of nature; 
 and latterly showed the permanence of the LAW OF 
 ANTAGONISM being thereby the discoverer of two great 
 generalisations. He also showed the production of heat 
 by magnetism, the ELECTROCHEMICAL POLARITY OF GASES ; 
 and decomposed water by heat alone. He invented the 
 electric battery which bears his name one of the most 
 powerful piles known ; also invented the gas battery for the 
 decomposition of some compounds such as water, iodide 
 of potassium, etc. 
 
 1818 1889. Joule discovered the law of heat evolved by 
 voltaic electricity ; made a THERMOPILE which would indicate 
 a difference of heat of o*oooii4. But his chief work raised 
 him to the first rank among men of science, for he disclosed 
 and laid down one of the greatest laws of nature, viz., the 
 DYNAMICAL THEORY OF HEAT. The views of Locke, 
 Rumford, Davy, and even Carnot, as regards the production 
 of heat by motion, had no great influence on the progress of 
 scientific investigation. But in 1842, the French physicist 
 
MODERN SCIENCE. 243 
 
 SEGUIN and the German physicist MAYER found a method 
 by which "the mechanical equivalent of heat" as Mayer called 
 it, could be calculated. Joule, independently of them, 
 commenced about the same time a series of experiments on 
 the relation between heat and work, upon which several 
 other physicists, among them Sir W. Thomson, Helmholtz, 
 Regnault, were soon likewise engaged. Joule, after intense 
 labour extending over a period of six years (1843-9), was 
 able to determine the TRANSFORMATION OF HEAT INTO 
 MECHANICAL ENERGY, or of mechanical energy into heat, in 
 a definite numerical ratio the mean number adopted for the 
 mechanical equivalent of one thermal unit being 1,390 foot- 
 pounds (on the Centigrade scale). The law of the relation of 
 heat to mechanical energy stands thus : " Heat and 'mechanical 
 energy are mutually convertible ; and heat requires for its 
 production, and produces by its disappearance, mechanical energy 
 in the ratio of i ^go foot-pounds for every thermal unit" ; that 
 is, the quantity of heat by which a pound of water is raised 
 through one degree Centigrade is generated by the expenditure 
 of the same amount of work as would be required to raise 1,392 
 pounds through one foot, or one pound through 1,392 feet, 
 and this is expressed by saying that the mechanical equivalent 
 of the thermal unit is 1,392 foot-pounds. But Joule's work 
 was a demonstration which had to be supplemented. He 
 had shown that mechanical energy or work can be converted 
 into heat ; it was required also to demonstrate that heat can 
 be converted into work. Carnot had already done so by 
 formulating the principle of the reversibility of energy; but 
 the real significance of this principle was proved by HlRN by 
 .a long series of experiments, the result of which established 
 the fact that heat can be converted into work in exactly the 
 same equivalent proportion as that determined by Joule, viz., 
 that one degree Centigrade (of heat) would raise one pound to 
 1,392 feet, or 1,392 pounds one foot. Great, however, as was 
 Joule's mathematical work so far, he carried it further still by 
 following up its logical, natural, and philosophical consequence 
 and formulating its corollary that THE TOTAL AMOUNT OF 
 ENERGY (or power of doing work) possessed by a bo dy ever 
 remains the same; that is, REMAINS UNALTERED whatever 
 
 R 2 
 
244 PROGRESS OF SCIENCE. 
 
 transformation it may undergo. This energy exists either as 
 potential (or stored up) energy, which is hidden and invisible, 
 but present nevertheless ; or it exists as visible energy, when 
 it is performing work. It may change from one form into- 
 another, but its total amount cannot alter ; and this, whether 
 mechanical energy is changed into electrical energy, work 
 into heat, heat into work, and so forth. This is the LAW OF 
 CONSERVATION OF ENERGY, which Joule propounded and 
 which makes his name doubly famous. The law is thus 
 stated : " The total amount of energy in the imiverse is the 
 same at all times" By this great law Joule confirmed the 
 earlier doctrines of Leibnitz. He did more, for this law is a 
 eorroboration of Laplace and Lagrange's conclusions as 
 regards the stability of forces as exhibited in the invariability 
 of great axes of orbits, and in Laplace's Nebular theory. 
 Lastly, in its philosophical bearing, Joule's law substantiates 
 in the widest manner possible the paramount doctrine of 
 science the permanency of the government of the universe- 
 by unchangeable laws. It should be borne in mind that to 
 this result of Joule's, Sir William Thomson, Balfour Stewart,. 
 Clerk Maxwell, and others contributed largely. But it was- 
 Joule who demonstrated the law, one of the greatest 
 generalisations, if not the greatest, established since Newton- 
 It should also be stated that Thermodynamics, the subject 
 of Joule's earlier determination, have been developed since by 
 Rankine, Clausius, and the universal genius, Sir William 
 Thomson, who has probably exceeded all his rivals by the 
 vastness and value of the work he has done. 
 
 1818 93. Tyndall investigated numerous sound phe- 
 nomena by a series of beautiful experiments, and notably 
 by means of his CHEMICAL HARMONICON an apparatus by 
 which the air in an open tube may be made to give 
 sounds by the introduction of a luminous jet of hydrogen 
 or gas, a phenomenon known under the name of singing 
 flames. * The note depends on the size of the flame and 
 the length of the tube. The apparatus was probably 
 suggested by the SYREN of Cagniard Latour, which is 
 used to measure the number of vibrations of a body in 
 a given time: "with the same velocity the Syren gives 
 
MODERN SCIENCE. 245 
 
 the same sound in air as in water; the same is the case 
 with all gases ; any given sound depends on the number 
 of vibrations, and not on the nature of the sounding 
 body." The syren is so delicate that it has been found 
 by its means that the wings of a gnat flap 15,000 times 
 in a second. By combining the effects of the syren with 
 those of the chemical harmonicon, Tyndall has detected 
 very curious phenomena, such as that in which the 
 pulsations of the flame are the optical expressions of 
 the "beats" i.e., the alternate strengthening and weaken- 
 ing of two sounds acting on each other. Tyndall made 
 researches into the action of SOLAR and of ELECTRIC 
 LIGHT on attenuated vapours, and found that under such 
 conditions they are decomposed a discovery which put a 
 powerful agent of chemical decomposition into the hands 
 of chemists, and led the discoverer to important conclusions 
 regarding the origin of the blue colour of the sky and the 
 polarisation of daylight, these two phenomena being at 
 length accounted for. He also found the absorptive power 
 of several vapours, and discovered the class of phenomena 
 called by him DYNAMIC RADIATION AND ABSORPTION. 
 Tyndall, with Faraday, discovered the magnetism of gases, 
 and showed that very few substances, if any, are devoid of 
 magnetism. He made decisive researches upon the polar 
 character of the diamagnetic force. Being familiar with 
 every branch of physics, Tyndall has assisted science by 
 numerous investigations, but he is one of the chief instructors 
 of our age in sound, heat, light, and electricity. His works, 
 "Heat as a Mode of Motion," and "On Light/' are 
 universally known. 
 
 18191868. Foucault applied electric light; proved the 
 velocity of LIGHT by striking experiments ; determined it in 
 a vacuum, in air, in water. By means of a rotating mirror, 
 which Wheatstone adopted in measuring the velocity of 
 electricity, he found light to travel at the rate of 185,157 
 MILES PER SECOND. He and Fizeau discovered the velocity 
 of light through water to be slower by one -fourth than through 
 air an additional proof of the wave -theory of light. He 
 also demonstrated by means of the PENDULUM the gradual 
 
246 PROGRESS OF SCIENCE. 
 
 MOTION OF THE EARTH ; invented the GYROSCOPE for 
 detecting the astronomical situation without looking at the 
 heavens. 
 
 b. 1819. Fizeau (1849) a ^ so measured directly the velocity 
 of light by a system comprising a toothed-wheel, a mirror, 
 tubes, and lenses, and found as a result 190,000 MILES PER 
 SECOND a result which practically is the same as that 
 obtained by Roemer and Bessel. The latter gives 192,000 
 miles, by dividing the mean distance of the sun, assumed to be 
 95,274,000 miles, by 8 minutes 13 seconds 3 the time taken by 
 a luminous ray to reach the earth.* The last result found 
 (Cornu's) gives 186,660 miles. Roemer calculated the time 
 taken by a ray of light to reach us from the sun to be 
 8 minutes 16 or 18 seconds, which exceeds the average now 
 accepted by from 3 to 5 seconds. Be that as it may, the 
 velocity of light has become the foot-rule, so to speak, for 
 the measurement of the distances which separate us from 
 the fixed stars whose parallax has been approximately 
 ascertained. The nearest star, a Centauri, is at least 400,000 
 times our distance from the sun, its light taking 3^ years 
 to reach us a fact which gives us a notion of the incom- 
 mensurable infinity of space. A beam takes 9^ years to 
 reach us from 61 Cygni, 12 years from a Lyrse. The light 
 of some stars takes 100 years, 1,000 years, 2,000 years to 
 reach us, so that when we see them, we see them not as 
 they are now, but as they were 100, 1,000, 2,000 years ago 
 (as they were when the light-ray left them). Likewise, an 
 inhabitant of a star thus remote would see the earth, granting 
 that he could perceive such a speck, not as it is now, but 
 as it was 2,000 years ago ; that is, he might at this moment 
 see Julius Caesar landing in Great Britain. 
 
 1820 1 8 . Becquerel (Alex. Edward) discovered OXY- 
 GEN to be A MAGNETIC BODY, and to be to other gases 
 what iron is to other metals ; found chlorine of silver 
 capable of receiving and preserving coloured impressions 
 from light ; invented the PHOSPHOROSCOPE. 
 
 1821 94. Helmholtz invented the OPHTHALMOSCOPE 
 for viewing the interior of the eye ; analysed sound by 
 * Sound would take fourteen years. 
 
MODERN SCIENCE. 247 
 
 means of the resonance-globe (improved by Konig's ap- 
 paratus), DECOMPOSING SOUND into its constituents, which 
 he verified by performing the reverse operation, reproducing 
 a given sound by combining the individual sounds of which 
 his resonators had shown that it was composed. By his 
 analytical and synthetical investigations into musical and 
 other sounds of the most varied kinds, he fully succeeded 
 in explaining the different qualities of these sounds, and 
 showed they are due to the various intensities of the har- 
 monics which accompany the primary tones of those sounds ; 
 so that he determined, so to speak, their sound-colour. It 
 is difficult to conceive an analysis more exhaustive. (See 
 his " Popular Scientific Lectures/' Longmans, 1873.) The 
 inner membrane of the ear cochlea is lined (as Corti has 
 shown) with about 3,000 minute fibres, all connected with 
 the acoustic nerve ; each of these is tuned for a particular 
 note as if it were a delicate resonator, and only vibrates 
 in unison with this note, being deaf for all others hence> 
 however complex external sounds may be, these microscopic 
 fibres can analyse and reveal the constituents of which the 
 sounds are formed. Helmholtz has also determined, after 
 numerous experiments on light, the power and limits of 
 microscopic vision, which is not less than one 8o,oooth 
 part of an inch in red light. Likewise, various other 
 branches of physics are indebted to him ; his investiga- 
 tions regarding heat, gravity, solar energy gave results 
 similar to those obtained by Sir William Thomson. Ac- 
 cording to these two great physicists, SOLAR ENERGY* is 
 due to the shrinkage by gravity of the mass of matter 
 constituting the sun, and the supply of heat by the sun 
 at the present rate would not probably obtain for more 
 than twenty millions of years from beginning to end. This 
 computation falls far short of that arrived at by geologists 
 and evolutionists, for the evidence upon which they base 
 their calculations, such as denudation, formation of new 
 strata, subsidence and uprising of continents, growth of coal- 
 
 * The intrinsic lustre of the sun is nearly four times as great as that 
 of electric light, and 5,000 times that of molten metal in a Bessemer's 
 converter. 
 
248 PROGRESS OF SCIENCE. 
 
 fields superposed one over another, or again the development 
 of the organic world from protoplasm to man, reveals a 
 past so remote, and during which too our present laws were 
 at work, that twenty millions of years is a mere fraction of 
 the time required to give the earth its present form and 
 life. Some would speak of no less than 680 millions of 
 years for the accomplishment of that work. Hence the 
 problem remains unsolved, but the divergence between the 
 two sets of philosophers robs neither of our admiration, for 
 the mathematical results of each, considering the premises, 
 stand among the highest achievements of modern science ; 
 the discrepancy existing between the results of geologists 
 and physicists will certainly be bridged one day, and the 
 different conclusions merged into one truth. Helmholtz, 
 like Sir W. Thomson, also directed his attention to mole- 
 cular physics, and their role in the general economy of the 
 universe, and both physicists pretty closely agree in the 
 propounding of a new hypothesis, viz., the Vortex Theory, 
 which would remove the barriers between the various 
 branches of physics. We owe also to Helmholtz a series 
 of demonstrations tending to prove, and proving, that HEAT 
 IS A MODE OF MOTION. His essay on the conservation of 
 energy is the finest composed on the subject. He traces 
 up all the transformations of energy, as presented by heat, 
 for instance, in wind, plants, animals, coals ; in sky, air, 
 and earth ; and shows its reappearance in ways as numerous 
 and unlike as it is possible to conceive. It is stored in 
 coal in its smallest compass : I Ib. being capable of lifting 
 100 Ibs. to a height of 20 miles the sun, we need scarcely 
 add, being to us on earth the one great fount from which 
 all energy is derived. Well may we admire Helmholtz, one 
 of the most brilliant and solid geniuses of our time. 
 
 1824 87. Kirchhoff, in collaboration WITH BUNSEN, 
 invented the four-prism SPECTROSCOPE (1859), and by its 
 means opened a new mode of CHEMICAL ANALYSIS, at 
 once rapid and unerring the presence of a i8o-millionth 
 part of a grain of sodium, for instance, being detected with 
 absolute certainty. The spectroscope is an instrument for 
 separating luminous vibrations of different wave-lengths, 
 
MODERN SCIENCE. 249 
 
 composed of either two or three telescopes mounted on 
 one foot, and whose axes converge towards a prism or a 
 series of prisms, each of which more and more spreads the 
 light coming through one of the telescopes, and causes its 
 spectrum to fall in a high degree of purity on an object 
 glass. Saving a very considerable amount of labour and 
 time, it immensely facilitates chemical manipulation; for 
 investigations which would demand the repetition of the 
 same experiment perhaps twenty times so as to give an 
 average result, and employ as many days, can be carried 
 out within a few hours 3 time. Not the least precious value 
 of the instrument lies in its excellence as a means of 
 verification of much laboratory work. We may here point 
 out that, so far, we are in possession of five processes of 
 chemical analysis* or manipulation; each, except the last, 
 divided into sections according as you want only to discover 
 what the constituents of a compound substance are, in 
 which case the analysis is called qualitative, or to determine 
 also in what proportion the constituents are exhibited, in 
 which case it is called quantitative analysis. The five 
 methods are : i, the process of Geber (800) distillation, 
 supplemented by the analysis of the products ; 2, the testing 
 process precipitation, due to elective affinity Bergmann's 
 system (1761) ; 3, Electrolysis decomposition by electricity 
 Davy's process (1806); 4, the blowpipe process fusion, 
 by means of a fierce flame the development of which is 
 due mainly to Berzelius (1818); 5, lastly, spectral analysis 
 by means of the spectroscope due to Fraunhofer (1814), 
 and to Bunsen and Kirchhoff (1860). By these various 
 methods have the SEVENTY-TWO SIMPLE ELEMENTS known 
 been discovered the seventy- two elements, that is, which 
 constitute the material universe, so far as we have ascertained 
 at present. Qualitative analysis is carried on principally by 
 flame tests and liquid tests, of which there are numberless 
 varieties, and also by the use of the spectroscope, par- 
 
 * It should be remembered that, strictly speaking, analysis is the 
 name given to the decomposition of a compound into its elementary 
 parts, just as the name synthesis is given to the process of forming a 
 compound out of two or more elements. 
 
250 PROGRESS OF SCIENCE. 
 
 ticularly in difficult cases. Quantitative analysis, on the 
 other hand, is carried out by two methods, respectively 
 called analysis by weight and volumetric analysis. The 
 spectroscope, then, as we see, is not a physicist's instrument 
 only, it is one which is just as precious to the astronomer 
 as to the chemist. By means of this unique instrument 
 Kirchhoff and Bunsen solved the PROBLEM OF THE DARK 
 LINES OF THE SOLAR SPECTRUM* which Wollaston and 
 Fraunhofer had detected, and this solution enabled Kirch- 
 hoff to discover the elements constituting heavenly bodies. 
 Kirchhoff found that the black lines are caused by the 
 passage of light through the vapours of bodies which by 
 themselves would give bright lines in the same position 
 in the spectrum when incandescent, and this theory goes 
 far to explain the constitution of meteorites, comets, nebulae 
 and stars, as well as the sun.f Some explanation will not 
 be inappropriate here. The illuminating power of the solar 
 spectrum attains its maximum in the yellow, and decreases 
 on each side of it, and intense yellow, produced by incan- 
 descent sodium, occupies a certain fixed place in the 
 spectrum of bright lines (as distinguished from the continuous 
 spectrum, and from the absorption or dark line spectrum). 
 Kirchhoff showed in the laboratory that when the vapour 
 of a substance intervenes between the observer and the 
 coloured flame produced by the same kind of substance, 
 the colour is extinguished because it is absorbed by the 
 intervening vapour, and instead of a bright line at its fixed 
 place, a dark line appears. In other words, the intervening 
 vapour has screened (because it has absorbed) the colour 
 of the flame beyond, and therefore there is no light, but 
 darkness, at that point of the spectrum that is, a black 
 line. Now this holds good for every substance. This is 
 the key of the problem, and the explanation of the dark 
 lines in the solar spectrum. A dark line is due, then, to 
 
 * Prof. Stokes intimated their significance as early as 1851, and so 
 did Prof. Balfour Stewart, a few years later, in 1858 ; but both failed to 
 demonstrate it fully this was KirchhofFs great work. 
 
 t Kirchhoff read the paper about this immortal discovery on the 2;th 
 of October, 1859. 
 
MODERN SCIENCE. 251 
 
 the absorption of the bright ray (shot from the photosphere) 
 in its passage through the solar atmosphere, by the same 
 kind of substance as that which caused it. If we suppose 
 sodium to exist in the sun, a supposition warranted by the 
 yellow colour found in the continuous and bright line 
 spectra, and look for its intense yellow double line through 
 the spectroscope, we see a dark line at the place it should 
 occupy at the letter D of Fraunhofer's map of dark lines. 
 And knowing that the dark line D can be produced only 
 by the absorption of the sodium ray by the sodium vapour, 
 it is inferred that the sodium light is shot from a centre 
 the photosphere and is arrested or absorbed in its 
 course by an atmosphere of incandescent metallic vapours 
 in which sodium gas is also present. Hence two facts are 
 ascertained, viz., that the sun itself is a luminous body 
 made up of certain substances, and that it is surrounded 
 by an atmosphere composed of (cooler) gases mostly of the 
 same substances, for what is true of sodium is true of other 
 elements. Aluminium, barium, cadmium, calcium, carbon, 
 cerium, chromium, cobalt, copper, hydrogen, iron, lead, 
 magnesium, nickel, potassium, rubidium, strontium, uranium, 
 zinc, etc., are known to be present in the sun, because 
 their lines are suppressed by the solar atmosphere. So far 
 as we know, thirty-six of our terrestrial elements exist in 
 the sun, eight are doubtful, fifteen have not been found 
 yet in the solar spectrum. Likewise, stars seem to be 
 constituted like our sun, and to consist of a nucleus and 
 an atmosphere composed of some of the elements existing 
 in our globe. Meteorites are also composed of some of 
 our elements, iron particularly. Comets differ little from 
 meteorites, if at all. Nebulae exhibiting no dark lines can 
 be gaseous bodies only, so far as we are aware at present. 
 All these facts have become known to us by the use of 
 the spectroscope, one of our most admirable agents. The 
 services this instrument has rendered science by far surpass 
 in number and importance those done by any other, the 
 telescope and microscope not excepted. It led at once 
 Bunsen and Kirchhoff to the discovery of two new metals, 
 CESIUM and RUBIDIUM. It has enabled astronomers to 
 
252 PROGRESS OF SCIENCE. 
 
 ascertain that the sun's spots are immense hollows or de- 
 pressions a fact which would tend to corroborate the cyclone 
 theory. It has made solar and stellar physics a possibility 
 and a reality. Not simply has it revealed, as we just saw, 
 the chemical components and some of the physical arrange- 
 ments of celestial bodies ; but it has also revealed the 
 existence of solar systems unsuspected hitherto such as 
 binary systems, one body of which is a dark star the 
 existence of dark suns, already suspected, being thereby 
 demonstrated ; and with their existence, the cause of the 
 increase and decrease of light in some of the variable stars 
 was explained, the decrease of light being due to the 
 eclipse of the luminous by the dark star. It has further 
 revealed the rate of velocity of motion of stars and nebulae, 
 and particularly that of double stars (within less than half 
 a mile per second of time),* together with the distance 
 from each other of such stars, the magnitude of their 
 bodies, the magnitude and the ellipticity of their orbits, 
 hence the time of their revolution. The spectroscope 
 has even revealed the approximate temperature and almost 
 the evolutionary stage of many celestial bodies. THREE 
 THINGS this truly marvellous instrument seems to have 
 MADE PLAIN : (l.) the common or identical nature of the 
 substances composing the cosmos ; (u.) the variety of its 
 plan and construction; (ill.) the identity of the forces and 
 principles governing it. Many of the facts brought to our 
 knowledge by the spectroscope seemed, only thirty years 
 ago, for ever to lie beyond the scope of human achieve- 
 ment and even beyond the conception of human intellect. 
 To the genius of Kirchhoff mainly we are indebted for these 
 scientific wonders. 
 
 1824 1 8 . Huggins (Dr.) has advanced celestial physics 
 
 by his fine SPECTROSCOPIC STUDY of the HEAVENLY BODIES 
 many of the results described in our notice of Kirchhoff 
 being due to him. He found the spectra of numerous 
 irresolvable nebulae to consist of three or four bright lines 
 
 * Some proceed at the rate of 23, 25, 26 miles per second ; one 67 
 miles ; our own solar system travels through space at the rate of 18 miles 
 per second, besides the motion particular to each body separately. 
 
MODERN SCIENCE. 253 
 
 indicating the presence of hydrogen and nitrogen among 
 them a character showing these nebulae to be gaseous 
 bodies in an evolutionary stage towards the constitution of 
 suns, thereby strengthening the nebular hypothesis of Laplace. 
 He also discovered that comets yield a spectrum consisting 
 of a few (three or four) luminous bands much wider apart 
 than those in the nebulae : they too exhibit the character 
 of gaseous bodies. He discovered in the light of Jupiter, 
 Saturn, and Mars, several lines like those exhibited by our 
 own atmosphere, thus proving that these planets are sur- 
 rounded by an atmosphere like the earth, though certainly 
 of a different degree of density. Some stars which he 
 studied he found to be wrapped by a metallic atmosphere 
 like our sun : Aldebaran contains antimony, bismuth, 
 mercury, and tellurium, which are not found in the sun, 
 and hydrogen, iron, calcium, magnesium, and sodium which 
 are present in the sun. In Pegasi and Batelgeux (a- 
 Orionis), he found no hydrogen, although he found that 
 gas in all the other stars which he has studied by the side 
 of many other substances, some of which have not yet 
 been found upon the earth. Dr. Huggins, among other 
 phenomena as regards the motion of stars, found that 
 SlRlUS was moving away from us at the rate of 25 miles 
 per second. That in our ignorance of the actual distance 
 from us of Sirius and of a multitude of very remote stars, 
 for we indeed know the distance of very few the nearest 
 yet we should be able to determine the velocity of their 
 motions is another wonder due to the magical spectroscope, 
 for the instrument reveals the motion of distant bodies, 
 " by the alteration which it causes in the apparent rapidity 
 of vibration, and consequently in the refrangibility of rays 
 of light of definite colour/' For it must be remembered 
 that (i) the undulations of the luminiferous ether cause the 
 points of the retina to vibrate and produce the sensation 
 of light ; (2) that any given colour depends upon the rapidity 
 of light waves impinging upon the eye; (3) that the eye 
 will receive in a second less undulations from a body 
 receding from it, and more undulations from a body 
 moving towards it, just as an anchored boat will be struck 
 
254 PROGRESS OF SCIENCE. 
 
 by less waves than if it were moving towards them. By this 
 principle, which Doppler (180353) discovered in reference 
 to sound (1841), but which holds good for light, it is clear 
 that if a celestial body moves towards us, the succession 
 of light waves upon the eye will be more rapid than if it 
 recedes from us ; and therefore the spectral colour will 
 shift towards the red end of the spectrum if the body be 
 approaching us, and towards violet if the body be receding. 
 Now this shift of the spectral lines from their normal 
 position in the spectrum is detected with absolute certainty 
 by the spectroscope, and by that means we are able to 
 tell not only that a star moves, but also in what direction 
 it does move, and the rate at which it moves. Thus THE 
 SPECTROSCOPE which can reveal to us what bodies are 
 made of, whether these bodies be air, straw, paper, wood, 
 lava, stone, or heavenly bodies ; whether heavenly bodies 
 are gaseous, liquid, solid ; whether they shine by intrinsic 
 or reflected light, can also reveal NEW WORLDS, together 
 with the DIRECTION AND RATE of their MOTION. In these 
 researches Dr. Huggins, Dr. MILLER, and Mr. ALEXANDER 
 HERSCHEL contributed their share the last mentioned 
 rinding different kinds of spectra among meteorites Norman 
 Lockyer meanwhile working in the same direction, and 
 gathering data upon which to build his meteoritic hypothesis 
 as we have seen. 
 
 b. 1824. Thomson (Sir William), now Lord Kelvin, invented 
 
 the MARINE GALVANOMETER, which made MARINE CABLE 
 telegraphy a complete success; invented the electrometer for 
 measuring the amount of electrical charge; also an apparatus 
 for investigating atmospheric electricity ; in collaboration 
 with Prof. Haughton, determined the numerous varieties of 
 ocean tides (lunar diurnal, solar diurnal, lunar fortnightly, 
 monthly, yearly ; solar semi-annual and annual, etc.) ; applied, 
 with John Hopkinson, to lighthouses a SYSTEM OF SIGNALS, 
 suggested by Babbage, by which each lighthouse perpetually 
 spells its own number or name " by flashes or obscurations 
 of various duration and succession." Concurrently or con- 
 jointly with other physicists, and amongst others, Clausius, 
 CLERK MAXWELL, and HELMHOLTZ, Sir William Thomson 
 
MODERN SCIENCE. 255 
 
 has ascertained that a MOLECULE of hydrogen MOVES to 
 and fro about 6,200 feet per second, but in such a limited 
 space that it rebounds from other molecules in a second 
 of time 17,000 million times. Further, pursuing the in- 
 vestigations of Loschmidt and Stoney, Clausius and Clerk 
 Maxwell, Thomson was able to determine the size of a 
 molecule : two millions of them in a row would measure one 
 millimetre in length which makes fifty millions in one half- 
 inch the concussions causing waves of coloured light just 
 as a ringing bell causes vibrations and waves of sound. 
 Again, among the problems he has investigated and solved 
 by mathematical or experimental demonstration, Sir W. 
 Thomson may be said to have successfully expounded (1852) 
 the LAW OF DISSIPATION OF ENERGY, which has exercised 
 the ingenuity of several other physicists. According to Sir 
 W. Thomson, "there exists a predominating tendency to 
 the conversion of all other forms of physical energy into 
 heat, and to the uniform diffusion by conduction and radiation 
 of all heat throughout all matter " a fact which would 
 conduce to the uniform cooling, hence extinction of life, 
 of the universe, but which would be counteracted by the 
 general law of conservation of energy determined by Joule, 
 and further, probably, by the Reconcentration of Energy 
 (of Rankine), if the latter be not a mere speculation, for 
 otherwise there would be an end to all physical phenomena. 
 In close connection with this problem Sir W. Thomson has 
 assisted science by removing some of the barriers between 
 its different branches, for " our views of the phenomena of 
 light and heat, of electricity and magnetism, and even of 
 matter and motion, are rapidly merging into a general 
 theory of molecular physics, which is perhaps best ex- 
 pressed by his 'VORTEX RING THEORY,' which was ex- 
 pounded in 1868." According to this theory, "the whole 
 of space is filled up with a fluid ether " as we have already 
 seen in previous notices. Huygens, Encke, Young, Huggins, 
 and others who helped to establish this hypothesis, may be 
 considered as the founders of the present school of Plenum 
 so-called because it holds the doctrine of the existence of 
 one universal and omnipresent ether for (the transmission 
 
256 PROGRESS OF SCIENCE. 
 
 of) light, heat, electricity, and magnetism. This fluid is 
 "almost infinitely thin and elastic." Now, then, Thomson 
 holds that all that which we know as matter consists of 
 vortices or whirlpools of this ether, which, from their rapid 
 rotating motion, "resist displacement, and therefore show the 
 common properties of hardness and strength in the same 
 way as a spinning-top or gyroscope tends to keep its axis 
 in a fixed position." But whether the molecules or particles 
 of what we know as matter are independent matter, or 
 whether they are ether whirlpools, we know that they keep 
 up an incessant hammering one on another, and thus on 
 everything in space. This atomic bombardment was in the 
 first instance one of Daniel Bernoulli's theories, but in a 
 restricted sense only, for to his mind " the pressure exerted 
 by a gas on the walls of the vessels enclosing it was due 
 to the constant hammering of the walls by the atoms of 
 which the gas consisted." Sir W. Thomson, Helmholtz, 
 and Crookes see in this fact a law which applies universally 
 to all matter throughout space. The future will disclose 
 whether the "vortex theory" is a mere hypothesis or an 
 absolute law. 
 
 1 8 . Cailletet and Pictet LIQUEFIED and solidified 
 GASES hitherto held to be permanent. Faraday was the 
 first physicist who liquefied gases, and soon after him all of 
 them, with the exception of oxygen, hydrogen, nitrogen, 
 carbonic oxide, nitric oxide, and marsh gas, have been 
 liquefied. Cailletet and Pictet succeeded at last (1877-8) 
 in liquefying and even solidifying oxygen, nitrogen, and 
 hydrogen, mainly by intensity of cold. The belief in 
 " permanent gases " was destroyed by these fine results : all 
 substances, according to conditions, were proved capable of 
 assuming the solid, liquid, and gaseous forms a fact which 
 points to the unity of matter. In the course of 1892, Pictet 
 showed that substances subjected to extreme cold "lose 
 the power of chemical combustion, and under this process 
 can be produced in a state of purity hitherto unattainable." 
 In experiments on the compressibility of gases, Cailletet 
 carried the pressure as high as 600, and Petit 650, atmos- 
 pheres. The decisive experiments proving the liquefaction 
 
MODERN SCIENCE. 257 
 
 of gases have (in January, 1893) been supplemented by 
 the beautiful discovery of Prof. Dewar, who succeeded in 
 LIQUEFYING AIR ITSELF, as distinguished from its con- 
 stituents. This result was obtained by getting a vacuum 
 approaching a point vastly nearer the ideal vacuum than 
 had ever been obtained before, since exhausted vessels con- 
 tain less than the Qoopooth of the air which the best air- 
 pumps of thirty years ago left in them. This almost perfect 
 vacuum is, he found, an absolute barrier to the passage of 
 heat rays, and allows the liquid air to remain permanently 
 in its vacuum envelope. Should verification permit the 
 formulation of a new law, this law, it is surmised, would 
 lead to a revision of some of our astronomical conclusions. 
 These discoveries, it is almost needless to add, imply the 
 highest skill in investigation, not to speak of an adequate 
 command of means. 
 
 b. 1 8 . Faure invented the ELECTRIC ACCUMULATOR 
 a new and fruitful apparatus for storing power, which makes 
 the electric train or car an inexpensive possibility. 
 
 1832 1 8 . Kirk invented an ICE MACHINE depending 
 upon the cold produced by the expansion (or rarefaction) 
 of air gas compression causing a rise, and expansion a 
 decrease, of temperature (because a quantity of sensible heat 
 disappears when a gas increases in volume). This law 
 explains the cold produced by nocturnal radiation. In 
 Bengal the nocturnal cooling is used in manufacturing ice. 
 " Large flat vessels containing water are placed on non- 
 conducting substances such as straw or dry leaves." In 
 consequence of the radiation the water freezes, even when the 
 temperature of the air is ten degrees Centigrade. 
 
 b. 1832. Crookes invented a SPECTRUM MICROSCOPE 
 which overcomes some of the difficulties due to slightness 
 of light dispersion; discovered (1861) Thallium with the 
 spectroscope the third metal found by that means; in- 
 vented the RADIOMETER (April, 1875), b y means of which 
 he claimed to have discovered and proved light to be a 
 motive power a conclusion which, however, has not found 
 general acceptance, for it is suggested that the mechanical 
 action seen in the instrument is probably due to the more 
 
 s 
 
258 PROGRESS OF SCIENCE. 
 
 rapid and powerful motion of the molecules which still 
 remain in the vacuum glass bulb the increased velocity of 
 their motion being caused by the undulatory progress of 
 light. Be this as it may, the radiometer is capable of 
 giving much useful assistance to the photographer for 
 regulating the light (i) in the operating room, so as to 
 obtain negatives of the same quality ; (2) in the dark 
 room, so as to prevent all injury to the sensitive surfaces 
 there exposed. " The instrument is also capable of giving 
 much information in climatology, since the. amount of light 
 received at any given place has its effect upon life and 
 health, vegetable, animal, and human, and its relative 
 amount at any given place is hence a point of no small 
 physiological moment. For we can now ascertain and 
 distinguish how much of the annual temperature of a place 
 is due to the direct influence of the sun alone, and how 
 much to the other factors, such as geological influence, 
 altitude, atmospheric and oceanic currents, warm or cold, which 
 sweep over or near it." In connection with the radiometer 
 Crookes made wonderful experiments ON ATOMS AND 
 MOLECULES BY THE APPLICATION OF ELECTRICITY, which 
 demonstrated the bombardment of particles on one another 
 so that Crookes at one stroke seems to have disclosed 
 and substantiated the soundness of numerous theories which 
 hitherto were held as mere speculations. It should be stated 
 that in 1871, Varley, unknown to Crookes, had made an 
 almost similar discovery, by controlling a molecular current 
 by a magnet. Concurrently also, although not directly 
 connected with Crookes's experiments, the famous physicist 
 Hertz well known for his discovery of a finite velocity 
 of propagation of electro- magnetic action, and his de- 
 monstration of electro-magnetic waves in air, and their 
 reflection worked in the same direction as Varley and 
 Crookes. The one result which surpasses all others in 
 importance, and adds immensely to our knowledge of the 
 elementary forces which govern the universe, is the ascer- 
 taining that atomic energy as shown by Crookes, Thomson, 
 and Tesla is millions of times greater and more powerful 
 than any with which we were acquainted ; for if a stream 
 
MODERN SCIENCE. 259 
 
 of molecules, reduced to a minimum in a glass bulb 
 by the air-pump, is focussed by means of electricity on 
 any point, and a piece of platinum is placed at that 
 point, its hammering is so mighty that the platinum be- 
 'comes white-hot in a few moments. Mr. Crookes believes 
 that he is on the track of a fourth condition of matter, 
 as distinct from the gaseous as the gaseous is from the 
 liquid condition, and the liquid from the solid ; and the 
 assumption does not seem unfounded. The certainty of 
 the existence of this tremendous force opens a field to 
 human possibilities the extent of which it is impossible to 
 exaggerate, as the following paragraph will show. Crookes 
 has already described, with that fertility of imagination 
 which distinguishes him, some of the multifarious and 
 beneficent applications which science may devise from the 
 knowledge he has imparted to us. Crookes, as we have 
 seen in our Chemical section, has carried on researches of 
 the very highest import in Chemistry. 
 
 b. i863(?). Tesla (Nikola) constructed a dynamo which 
 gives 20,000 ALTERNATIONS per second instead of 100 ; and 
 by means of condensers he multiplied the alternations until 
 they exceeded 1,500,000 PER SECOND obtaining thereby 
 a current 15,000 times more powerful than hitherto.* Once 
 in possession of this undreamt-of engine, he launched into 
 a series of experiments the phenomena of which open a 
 new and mysterious region : (i.) Whereas a current of less 
 than 2,000 volts kills a man, a current of 50,000 as obtained 
 by Tesla gives no shock it cannot even be felt so that 
 the experimenter is able to play with flashes of lightning; 
 (II.) whereas our insulators effectually stop an ordinary 
 current, the Tesla current will shoot a stream of sparks 
 between two poles through such a safe insulator as vulcanite 
 just as it would through air; (ill.) whereas in Crookes' 
 radiant matter experiments the aid of 'wires is necessary, 
 the Tesla forces take effect at a considerable distance 
 through space, and "if metal plates are fixed on the roof 
 and walls of a room, and connected with the terminals, 
 
 * Nineteenth Century Review. March, 1892, Number. J. E. H. 
 Gordon. 
 
 S 2 
 
26o PROGRESS OF SCIENCE. 
 
 such a violent electro-atmospheric storm will ensue, that 
 globes from which air has been partially pumped out will 
 glow and throb as if powerful electric currents were directed 
 upon them." These and other unsuspected phenomena were 
 disclosed by Tesla (as recently as February, 1892) which 
 will probably be the starting-point of a new series of 
 discoveries of natural laws and applications, as already 
 hinted in the preceding notice, that will effect changes in 
 humanity even " more general and more wonderful than 
 those brought about by steam and electricity." For, if we 
 once are able to make direct use, as we do in the case of 
 electricity, of the molecular ocean which surrounds us and 
 which "we have let slip through our ringers since the be- 
 ginning of time," we shall then, as M. Tesla put it, "hook 
 our machinery on to the machinery of nature, or harness 
 natural forces to our machinery, and obtain unlimited power, 
 so that manual labour would become unnecessary." 
 
 GROUP VII. INVENTORS. 
 
 To those great men of science we should add a few 
 of the practical men who made important applications of 
 scientific laws, mentioning only those whose inventions 
 have proved to be powerful springs of progress. 
 
 1647 1714. Papin applied to his steam-pump his 
 invention of. the PISTON, the CYLINDER, and the SAFETY 
 
 VALVE (1690). 
 
 17361819. Watt invented the SEPARATE CONDENSER 
 and the DOUBLE-ACTION STEAM-ENGINE the essentials of 
 all steam machinery and made the law of elasticity of gases 
 (explained to him by Black) a new power. 
 
 1765 1815. Fulton, after the STEAMBOATS of Jouffroy 
 D'ALBANS (1783)* and of W. SYMINGTON (1789), arrived at 
 the practical application of STEAM TO NAVIGATION, and 
 
 * Jouffroy d'Albans (1751 1832), whose original drawings can be 
 seen in the South Kensington Museum, built a paddle-steamer which 
 was launched on the I5th of July, 1783, and plied for traffic on the Saone 
 and Rhone for more than a year. Fulton is said to have been a pupil of 
 his, but this is doubtful. 
 
MODERN SCIENCE. 261 
 
 1781 1848. Stephenson (G.), after SEGUIN'S invention 
 of the TUBULAR BOILER, invented the LOCOMOTIVE, the 
 culminating triumph of a series of wonders which transformed 
 the world. 
 
 The filiation of the foregoing is, be it observed, absolutely 
 unbroken. 
 
 In connection with this rapid progress of steam applica- 
 tion, we should remember, as a real benefactor of humanity, 
 
 1728 1809. Boulton, who, by the encouragement, 
 workshops, capital which he magnanimously gave James 
 Watt (1769), rapidly enabled the latter to propagate the 
 use of steam machinery all over the world. Boulton was 
 therefore one of the powerful PROMOTERS OF MODERN 
 INDUSTRY, to whom the English capitalist and the English 
 artisan should be equally grateful. He is said to have 
 introduced gas-lighting at Birmingham as early as 1798. 
 
 I 759(- ? ) Murdoch, of Redruth (Cornwall), dis- 
 covered COAL GAS, and applied it to lighting purposes 
 (1792); but London enjoyed the new lighting system only 
 in 1817, after Birmingham, where Boulton introduced it in 
 1798, and even after Paris, where Winsor had successfully 
 lighted the Passage des Panoramas. 
 
 1765 1833. Niepce (Nicephore), by succeeding in fixing 
 images produced by the camera obscura a thing attempted 
 by Davy in 1802 invented PHOTOGRAPHY (1824); but it was 
 his partner Daguerre who, after Niepce's death, propagated 
 the new art hence the name of Daguerreotype. DAGUERRE 
 (1787 1851) invented the DIORAMA. The photographic 
 apparatus is one of the most serviceable in our possession. 
 The assistance it gives to sundry branches of knowledge 
 (light, physiology, anthropology, zoology, geography, history) 
 is unrivalled. In art it has become of immense value. It 
 is to astronomy, however, that it renders the most valuable 
 services; for it not only maps the heavens with absolute 
 precision, records the phenomena of momentary eclipses, 
 reveals events of cosmical history, such as the evolutional 
 stage and form of nebulae (the nebulae in Andromeda, Orion, 
 Ursa Major, Canes Venatici), but it also records with 
 complete accuracy the small shift of the celestial (spectrum) 
 
262 PROGRESS OF SCIENCE. 
 
 lines from their true spectroscopic position, and thereby 
 corroborates the beautiful exactness of the spectroscopic 
 revelations (due to the working of Doppler's principle) 
 as regards the speed and direction of stars' motions. But 
 more wonderful than all this, it detects and shows us 
 stellar and nebular systems existing far beyond the reach 
 of telescopic and spectroscopic power, thereby opening new 
 regions of astronomical knowledge in a way wholly undreamt- 
 of by Newton or Laplace. 
 
 1771 1834. Senefelder invented LITHOGRAPHY, which 
 has proved so useful to industry and the propagation of 
 artistic works. 
 
 1791 1872. Morse invented the TELEGRAPHIC APPA- 
 RATUS which bears his name and has been all but universally 
 adopted. 
 
 18031859. Stephenson (Robert) by his gigantic con- 
 struction of the BRITANNIA TUBULAR BRIDGE across the 
 Menai Straits (1850), and the Victoria tubular bridge across 
 the St. Lawrence, near Montreal, proved engineering to be 
 capable of overcoming every mechanical problem ; a fact 
 of which living engineers have afforded us numerous evi- 
 dences by their colossal structures witness the Eiffel Tower 
 and the Tay Bridge. 
 
 18031887. Whitworth (Sir Joseph) invented a whole 
 set of MACHINE-TOOLS that have revolutionised the labour 
 of our workshops, and thereby was one of those who 
 ushered in the Age of Steel. Before him the rule of 
 thumb was pretty universal. Whitworth introduced ACCU- 
 RACY of machine-tools. Such a thing as a true lathe did 
 not exist before him. We owe to him a measuring machine 
 to the 2OO,oooth part of an inch, so true, that if a rod of 
 iron is laid upon it and the hand holding it is not removed, 
 the expansion of the rod by the heat of the hand will be 
 at once indicated. Whitworth also introduced a UNIVERSAL 
 THREAD in screws an improvement which every one can 
 appreciate. 
 
 18081890. Nasmyth (James) invented the steam 
 hammer, without which the modern steel industry could 
 never have been carried out (1842). 
 
MODERN SCIENCE. 263 
 
 I. 1813. Bessemer (Sir Henry) discovered a rapid and 
 inexpensive process of MANUFACTURING STEEL (1856). 
 By passing a blast of air through liquid cast iron and 
 thereby removing from the molten mass the whole amount 
 of carbon it contains, the cast iron is converted into malle- 
 able iron ; into this decarbonised metal a measured quantity 
 of cast iron is introduced which restores the quantity of 
 carbon requisite to constitute steel (about 1*5 per cent). 
 An idea of the WEALTH CREATED by Bessemer may be 
 obtained by the fact that the amount of steel rails made 
 in England and America by the Bessemer process up to 
 1892, would make 52 SOLID BLOCKS of steel 50 feet square 
 and 400 feet high each, the value of which would be a 
 solid COLUMN OF GOLD 4 feet in diameter and 400 feet 
 high. Physics are also indebted to Bessemer for devising 
 a process of dividing an inch into 14,000 lines a feat 
 which has aided the development of spectroscopy in a 
 striking manner, by enabling physicists to divide the 
 spectrum into minute sections. Sir Henry Bessemer, it 
 may be added, will have rendered another service to science 
 when his great telescope, to the construction of which he 
 has devoted sixteen years, is finished a result anticipated 
 to be accomplished in the course of the present year 
 (1894). In connection with Sir H. Bessemer as a metal- 
 lurgist, we should not omit to mention Benjamin Huntsman 
 (1704 76), the Bessemer of his times, who invented cast 
 steel, and was therefore one to whom we are deeply in- 
 debted. Again, the contribution of Sir Henry Bessemer to 
 the grandeur of the Age of Steel was almost equalled by 
 Henry CORT (1740 1800), who should be remembered as 
 the inventor of " puddling " (converting cast iron into 
 wrought iron). His various improvements in iron manu- 
 facture are said to have added more to the wealth of England 
 than the whole amount of the national debt. 
 
 b. 1847. Edison invented the TELEPHONE, the 
 PHONOGRAPH, and devised numerous APPLICATIONS OF 
 ELECTRICITY, by which he is recognised as one of the 
 most creative geniuses, if not indeed the most creative 
 genius of which humanity has reason to be proud. 
 
264 PROGRESS OF SCIENCE. 
 
 The telephone, which has been so rapidly adopted after 
 Edison's improvements had made it serviceable, was, like 
 photography, of comparatively slow growth. Attempts to 
 produce a workable apparatus were begun in 1837: Reiss 
 and De la Rive on the Continent, Varley in England, 
 Page and Gray in America, tried to solve the problem of 
 transmitting sound-vibrations to a great distance. Prof. 
 GRAHAM BELL (of Boston) succeeded at last (in 1876) in 
 constructing the desired instrument. To Edison, however, 
 is due the. credit of having made the telephone capable of 
 transmitting a conversation to a distance of hundreds of 
 miles. It is one of our modern wonders, like the spectro- 
 scope of Kirchhoff. But marvellous as these two instruments 
 are, the phonograph strikes the imagination still more, and 
 seems even more extraordinary : for what indeed can be 
 so fascinating, so prodigious, so impressive, what in the 
 world can in an equal degree appeal to the emotions, as 
 this apparatus which stores up speech and melodies, and 
 will reproduce them at any future period any number of 
 times? which has preserved the tone of Browning's voice 
 for us, as it would have Homer's, Shakespeare's, Milton's, 
 and as it will preserve the speech of Gladstone and 
 Tennyson ? This is, undoubtedly, the marvel of the XlXth 
 century, and probably of all times. 
 
 Next to those admirable men come the numerous in- 
 ventors of PRIME-MOVERS for the transmission of energy, 
 by means of high-pressure water, compressed air, steam, 
 gas, electricity, the civilising potency of whose labours 
 cannot be too much valued and praised. We have already 
 natural forces, such as waterfalls, generating and transmitting 
 power to a great distance : a wire transmits the energy 
 generated by a waterfall from LaufTen, on the Neckar, to 
 Frankfort, 108 miles distant, and that city is partly lighted 
 by electricity through this means ; Rome is lighted at 
 night by electricity by power transmitted from the Tivoli 
 Falls, across the Campagna, a distance of 15 miles; the Niagara 
 Falls will within a few years transmit energy round within 
 a radius of over 300 miles so as to light cities as it did 
 the Chicago Exhibition, and 200,000, perhaps 400,000 horse- 
 
MODERN SCIENCE. 265 
 
 power a fraction derived from the cataract will turn the 
 machinery of Buffalo and some other neighbouring towns. 
 The Niagara Falls are capable of producing 15 million 
 horse-power. The Rhone, the Falls of the Rhine have 
 likewise been utilised either to generate electric light or 
 drive machinery at a great distance, and other rivers will 
 be used in the same way. 
 
 Soon, no doubt, the tidal power of the sea will be 
 pressed into service and turned to similar advantage. The 
 time is probably not far distant when sunlight and heat 
 will be stored directly, and turned into mechanical energy. 
 Modern science has brought the solution of every physical 
 problem within the compass of possibility. 
 
CHAPTER XL 
 
 THE VALUE OF INSTRUMENTS. 
 
 WE cannot leave the survey of facts without alluding to the 
 value of instruments in scientific research. 
 
 With true instinct did the ancients, .as soon as they 
 began to study nature, see the necessity of "endowing the 
 human senses with additional power," and of creating aids 
 which could " increase the steadiness of the hand, the strength 
 of the arm," the keenness, compass,, accuracy of vision, the 
 grasp of the mind. To assist the hand, the ruler and the 
 plumb-line ; to assist the arm, the lever and the balance ; 
 to assist the eye, the gnomon and the dioptra; to assist 
 the mind, numbers and imaginary lines (arithmetic and 
 geometry) were ingeniously devised, all of which increased 
 man's natural gifts "and guided his early footsteps in the 
 path of knowledge. This fact, which history, philology, and 
 archaeology show us to have obtained in remote antiquity, 
 was one which every age, every country, every race has 
 accentuated more and more as time rolled on. In Egypt, 
 in Greece, in Asia, in Europe, century after century con- 
 trived new means, invented new agents, created new imple- 
 ments, machines, appliances, until such a degree of progress 
 was reached that it became impossible to take one step 
 in any pursuit without the succour of instruments the 
 senses becoming secondary guides, and being reduced to 
 the function, so to speak, of simple supervisors and con- 
 trollers. It is not too much to say that a history of 
 instruments would well-nigh amount to a history of science 
 
THE VALUE OF INSTRUMENTS. 267 
 
 itself. We have been able to perceive the priceless value 
 of some scientific instruments in the foregoing pages. It 
 has become commonplace to say that the invention of an 
 instrument may change the face of a science and give it 
 a new start. Remove the telescope from our scientific 
 development, and at once astronomy is dwarfed into common 
 knowledge : its scientific aspect disappears. Mathematics, 
 it is undeniable, would have done much, and had indeed 
 done much, to elucidate the constitution of the heavens. 
 Copernicus, by means of calculation, empirical observations 
 aiding, arrived at the truth. But his conclusions would have 
 remained a field of controversy, and seemed to many mere 
 speculations, without Galileo's instrument and Tycho Brahe's 
 accurate observations by the use of it : the telescope sub- 
 stantiated his doctrines. The calculations of Kepler were 
 grounded on telescopic data, and would have been valueless 
 without. Newton himself would have been powerless in 
 the absence of the same telescopic revelations. He would 
 have remained a great physicist instead of being the prince 
 of astronomers and mathematicians. The telescope settled 
 the problem irrevocably, and set doubt at defiance. Take 
 away the microscope, and physiology ceases to exist as a 
 science, and not physiology merely but a large number of 
 chemical and physical facts would never have been ascer- 
 tained, or even so much as investigated at all. The prism, 
 simple and unassuming as it seems, was the key to celestial 
 physics, and more, to a vast area of philosophical' solutions. 
 Thermology would .have been not so much as a word> 
 without the thermometer. We' have been able in the course 
 of our rapid survey to gauge, not indeed the whole extent, 
 but at least the main bulk of the services rendered by 
 instruments. As we owe the knowledge of our planet's 
 size and configuration, geography, to the compass; so we 
 owe to the pendulum and the barometer our mastery of 
 barology and meteorology ; to magnifying glasses our 
 mastery of optics ; to the balance mainly, our mastery of 
 chemistry ; to the camera obscura, photography ; to the 
 battery, our mastery of electricity and a wide range of 
 phenomena. How mathematics, which are a means to an 
 
268 PROGRESS OF SCIENCE. 
 
 end, and therefore an instrument of varied powers, how 
 mathematics have stamped with the mark of truth countless 
 solutions in chemistry, physics, geology, mineralogy, astro- 
 nomy, we cannot for a moment doubt after reading the 
 preceding chapters of this work, much less after reading 
 the history of any of these branches. Even unpretentious 
 instruments have proved invaluable. It has been well 
 pointed out by Liebig that chemistry is deeply indebted 
 to four things which to all appearance are insignificant 
 agents, viz., glass, cork, India rubber, and gas ; the absence 
 of any one of these four things would have caused the 
 impossibility of undertaking a certain number of investiga- 
 tions, and their collective absence would have made chemistry 
 relatively barren in recent times ; whereas their united effects 
 have secured a harvest of products which have enriched the 
 whole of the working world. Thus does human intellect 
 derive powerful assistance from materials and appliances, 
 little in themselves perhaps, but fruitful of innumerable benefits. 
 Another standard of the value of instruments, besides their 
 material and profitable assistance, lies in the reliance we 
 can repose in their accuracy in the solution of problems 
 which demand minute exactness : we can now perceive 
 the 9 ; oooth part of a degree in temperature, i,coo,oooth 
 of a second in time, i ; ooo y oooth of an inch in space, 
 i ; ooo,cooth of a gramme in weight, the presence of the 
 io,ooo,oooth part of a gramme of a substance. We can in 
 fact observe "quantities 300,000 cr 400,000 times as small 
 as in the time of the Egyptians." Where would the eye 
 or the intellect be without instruments? We owe to them 
 our most surprising results. 
 
CHAPTER XII. 
 
 SUMMARY OF FOUR CENTURIES OF SCIENCE. 
 
 THE preceding survey, by its arrangement, presents the 
 progress of each branch without a break, the author wishing 
 by that means to convey an idea of the accelerated pace 
 at which the scientific march has been proceeding. But 
 as a pause at the end of any historical period, for the 
 purpose of viewing its striking features at a glance, would 
 help the reader to get a clear impression of the distinct 
 characters of the modern era, the writer will now briefly 
 point out the separate nature of each century since the 
 beginning of the Revival. 
 
 I. Foundation. The XVIth century has several strongly 
 marked characteristics. I. It was essentially an age of PAR- 
 TURITION. It was during that century that many branches 
 of science came into existence, as we have shown (Chapters 
 V. and IX.) the work done in some of them being exceed- 
 ingly important. This certainly was the case in astronomy, 
 physics, geography, anatomy, and natural history. When 
 we consider the magnitude of the discoveries made by the 
 navigators, and chiefly Magellan, early in the century ; 
 then by the astronomers, and chiefly by Copernicus and 
 Tycho Brahe ; then by the physicists, and chiefly by Galileo 
 and Porta; then by the anatomists and naturalists, chiefly 
 Gesner, Csesalpinus, Paracelsus, and Vesalius, we at once 
 feel that we are witnessing an intellectual revolution un- 
 surpassed in its effects in the history of civilisation. 2. 
 The second character of the XVIth century is not less 
 
2/o PROGRESS OF SCIENCE. 
 
 striking, since it includes the one just described and all 
 those which we shall define, and that was the general 
 contempt of authorities allied to SPIRIT OF FREE INQUIRY. 
 Men of learning refused to take anything for granted, and 
 began to examine everything for themselves hence the 
 new roads struck out in all directions : in the spheres of 
 religion, politics, philosophy, literature, art, and science. 
 We find this to be the common feature of men broadly 
 separated by their training or way of life : Copernicus ex- 
 hibits it just as much as Paracelsus, Galileo just as much 
 as Bruno. " Let nature replace Aristotle," was the motto. 
 Spirit of emancipation was the spring of all that was done 
 in that age. 3. A third characteristic of that revolutionary 
 time, an effect of the preceding one, was the craving for 
 PRACTICAL, as strongly distinguished from theoretical, WORK. 
 Among men keeping abreast of their time a qualification 
 which of course excludes the schoolmen from the move- 
 ment experiment and verification became the test of all 
 things. This spirit had been growing for generations, 
 fostered as it had been by the alchemists ever since Roger 
 Bacon, and it became ingrained in the habits of the XVIth 
 century inquirers. This hunger for practical results ex- 
 plains the great number of inventions, of instruments, of 
 discoveries which make the age so dissimilar from the 
 past. 4. A fact typical of the century, due again to in- 
 dependence of spirit, and one to which we desire to give 
 particular weight, was the promulgation of the TRUE METHOD 
 OF RESEARCH INDUCTION by some of the great men of 
 the age a fact proving that practical spirit or experimental 
 pursuit was no haphazard, happy-go-lucky, or empirical 
 bent ; but a consistent line of conduct, a well-conceived 
 and maturely-considered course, a well-thought-out resolve, 
 a well-laid scheme of procedure. Leonardo, embodying the 
 moods of the times, may be said to have given a code of 
 research to all inquirers by his forcible injunction to 
 observe phenomena, to resort to nature for information, to 
 question her by experiments, to verify experimental results, 
 and then, only then, to venture to formulate a law. This 
 was so completely the plan of action that we see it followed 
 
SUMMARY OF FOUR CENTURIES OF SCIENCE. 271 
 
 by every man of science, insisted upon and often recom- 
 mended by them to their disciples. 5. The XVIth century 
 is marked by another character which clearly makes its 
 appearance in the European world for the first time 
 namely, the discovery of the existence of NATURAL LAWS 
 the recognition of which is a fact of the highest import, 
 for it will end in gradually altering the spiritual, and the 
 temporal, world. To sum up, then, this century is marked 
 by discoveries of the first order and the foundation of 
 the sciences ; spirit of free inquiry ; experimental work ; 
 the working and formulation of the inductive process ; the 
 recognition of natural laws. These are the five features 
 of the modern world, for the following ages, while striking 
 out new roads in unbeaten fields, accentuate these features 
 more and more, without, however, altering their nature, 
 so truly and unmistakably was the XVIth century an age 
 of real science a fact which is unanswerably demonstrated 
 by its work. 
 
 II. Constitution. In many respects the XVIth century 
 is grander altogether than the following age. Its startling 
 discoveries, its varied revolutionary movements, naturally 
 strike the imagination far more deeply. The Reforma- 
 tion, which is the main expression of the energetic spirit 
 of the period, would be sufficient to make it a colossal 
 century. Yet the XVI Ith century is, scientifically, more 
 imposing. If it is less original and versatile, it is also 
 less tentative and more sterling. The feature which dis- 
 tinguishes it strongly is the discovery of GRAND LAWS, and 
 the extremely rapid development of four branches astro- 
 nomy, mathematics, physics, and physiology. The march 
 in these is the same as in the XVIth century. Facts are 
 first collected with patient and untiring labour, then laws are 
 determined after careful experimentation, i. ASTRONOMY 
 enters a new stage. The telescope has revealed a universe 
 undreamt-of, and from this fact two consequences ensue : 
 the Copernican system is proved to be true, and authority 
 receives its death-blow, although it will die hard, and 
 during its agony exercise its might with desperate cruelty 
 for a time. 2. MATHEMATICS also enter a new era. Des- 
 
272 PROGRESS OF SCIENCE. 
 
 cartes, Newton, Leibnitz, gifted with intellectual power of 
 extraordinary originality, create methods of calculation at 
 once infallible and mighty which will enable men to solve 
 the deepest problems in astronomy, mechanics, and physics. 
 3. Three men of exceptional genius, Galileo, Kepler, and 
 Newton, discover the LAWS OF MOTION, and all of them 
 are found by the immortal Newton to be due to one primary 
 principle the law of GRAVITATION by which the heavenly 
 bodies are ruled. This was the greatest feat of the century 
 and, it may be added, of all times. 4. For PHYSICS, 
 likewise, fresh horizons are opened. The new departure 
 begins with Galileo's discoveries in barology, followed by 
 those of Torricelli, Pascal, Guericke who formulate ATMOS- 
 PHERIC LAWS; then come Huygens, Roemer, and Newton, 
 who investigate the LAWS OF LIGHT; whilst a new power, 
 practically unknown till then ELECTRICITY becomes a re- 
 cognised force through Guericke. 5. PHYSIOLOGY, founded 
 in the previous century, also accelerates its rate of progress, 
 by the beautiful discoveries of Harvey, Malpighi, Rudbeck, 
 Leuwenhoeck, and Swammerdam. In this branch a new 
 world has been revealed through the microscope, neither 
 less wonderful nor less varied than the one discovered by 
 the telescope. The philosophical lesson of the XVIth 
 century is repeated and learnt more earnestly : that is, 
 THE IDEA OF LAW becomes more widely and more deeply 
 rooted, and the recognition of this principle militates against 
 superstition and for truth, with all the vigour which inspires 
 the great thinkers of the end of the XVIIth century. 
 
 III. Expansion. The work of the XVIIth century lies 
 chiefly in the discovery of grand laws. The XVIIIth 
 century presents different features, i. It witnesses in ASTRO- 
 NOMY a VAST ACCUMULATION OF FACTS which at one and 
 the same time corroborates those laws, and extends their 
 application universally. This is the work of W. Herschel, 
 Lagrange, and Laplace. The study of the heavens which 
 Cassini, Bradley, Halley, Flamsteed, Huygens, and Newton 
 had apparently exhausted, was in reality found to be an 
 inexhaustible field of search ; and the XVIIIth century, 
 as indeed the XlXth, showed that the great astronomers 
 
SUMMARY OF FOUR CENTURIES OF SCIENCE. 273 
 
 just mentioned had seen only the fringe of space. 2. The 
 next distinguishing feature of the XVIIIth century is that 
 it witnesses the appearance of scientific GEOLOGY, ushered in 
 by Hutton; of scientific CHEMISTRY, ushered in by Lavoisier; 
 of ELECTRICITY, ushered in by Franklin and Volta; of THER- 
 MOLOGY (heat), ushered in by Black four great branches 
 rich in material and philosophical consequences. 3. Another 
 character of the age lies in the rapid growth of BIOLOGY 
 in all its branches : Linnaeus classifies, Buffon describes, 
 Boerhaave analyses chemically, Haller anatomically, Hunter 
 comparatively, and Lamarck throws his luminous philosophy 
 over it all ascending to the origins of life. Thus the 
 XVIIIth century inaugurated two natural sciences of deep 
 interest : the study of the earth, and the study of the 
 organic world on the earth. 4. A fourth characteristic is 
 given to the century by the sudden appearance of STEAM 
 MACHINERY, the combined wonder of Watt and Black a 
 new agent of immeasurable variety and power, the creator 
 of wealth on a large scale, and more, the most beneficent 
 destroyer of misery, poverty, wretchedness among the toil- 
 ing millions of mankind one, therefore, of the greatest 
 blessings of the modern era; so that the XVIIIth century, 
 which was beyond all things a humanitarian age, contrived 
 also by a happy coincidence an irresistible means of giving 
 effect to its main idea. 5. The same age is also marked 
 by another feature which embodies the result of profound 
 investigations and scientific interaction, namely, the dis- 
 covery of numerous PHYSICAL LAWS not, indeed, so striking 
 as those discovered in the XVI Ith century, but valuable 
 and important all the same some of the laws of heat, of 
 compressibility, of magnetism, of electricity, of sound, of 
 light, of chemical action, of biology, besides the invention of 
 numerous apparatus and instruments illustrating those laws. 
 6. Finally, as a synthetical result of the enlargement of so 
 many branches, but mainly of mathematics, astronomy, 
 mechanics, and physics, the century ends with the broaching 
 and formulation of a THEORY OF THE UNIVERSE by Laplace, 
 which later investigations to a great extent substantiate, 
 and prove, despite the mysteries it involves, to be one of 
 
 T 
 
274 PROGRESS OF SCIENCE. 
 
 the grandest conceptions of our race. Such are the labours 
 of the beautiful XVII Ith century. We are able to see 
 the powerful CRESCENDO which science has exhibited since 
 the Revival : the three centuries just summed up may be 
 characterised each by one word FOUNDATION, CONSTI- 
 TUTION, EXPANSION. 
 
 IV. Universality. i. UNIVERSALITY is the general and 
 striking character of the XlXth century. To whatever 
 point of the scientific compass we may direct our glance, 
 we see progress ; and the diversity of the progress is so 
 complex, its advance so rapid that it is quite impossible 
 to embrace it all, much less to generalise it in the same 
 manner as we have done in the case of the three previous 
 centuries. We must therefore be content to indicate its 
 most wonderful features. 2. The two marvels of the XlXth 
 century are steam and electricity. The application of steam 
 to machinery, introduced before, becomes a ubiquitous fact. 
 STEAM becomes the prevalent means of industry and of 
 transport by sea and by land. The steamer, so strange 
 and astonishing, is within less than twenty years succeeded 
 by a prodigy still more surprising and bewildering the 
 railway train. The age of steam has become stupendous. 
 Manufacture and trade are completely revolutionised, and 
 the same force at work, by gigantic strides, multiplies 
 wealth and diminishes misery in an equal degree. The 
 law that Boyle, Mariotte, and Black have elucidated has 
 become the spring of production and welfare. 3. ELECTRICITY, 
 by the side of steam, finds applications even more un- 
 expected and more fascinating. A force which is capable 
 of abolishing distances, of flashing thought round the world 
 seven times in a second, of carrying the voice 500 miles, 
 nay, of bringing the face of your interlocutor before your 
 eyes from that distance, is one thing; but another thing 
 is to devise means of mastering, controlling, directing that 
 force, and make it our servant. Yet the ingenuity, inven- 
 tiveness, the genius of the XlXth century man of science 
 found the means, after discovering the laws which govern 
 the force. 4. Apart from these two wondrous facts, which 
 will for ever give our time the title of "AGE OF STEAM 
 
SUMMARY OF FOUR CENTURIES OF SCIENCE. 275 
 
 AND ELECTRICITY," the same period has seen the progress 
 of Mechanics as such, and, as a consequence, the far- 
 reaching development of machinery, whether it be moved 
 by air, water, hand, steam, or electric labour ; so that, failing 
 the title we have just mentioned, the XlXth century would 
 have been known as the " AGE OF MACHINERY." But this is 
 only a part of what the knowledge of the laws of mechanics 
 has done for us : this knowledge led to the performance 
 of engineering works, the conception of which would have 
 seemed senseless and extravagant in the last century; so 
 that again the XlXth century may claim another title, that 
 of the " AGE OF ENGINEERING." 5. Again, the discovery of 
 further physical laws shall we call them PHYSICO-CHEMICAL 
 LAWS ? conduced to another effect, the powerful use of 
 iron and steel, for which our period deserves the name 
 also of the "AGE OF STEEL." 6. The study of physics, 
 which became the absorbing attraction of genius, conduced to 
 the elucidation of the LAWS OF LIGHT AND SOUND, and, as 
 a consequence, to the comprehension of terrestrial and 
 celestial phenomena, which is one of our greatest triumphs. 
 What rash mind only a couple of generations ago would 
 have ventured to predict that we should ever arrive at 
 the knowledge of the constitution and composition of 
 heavenly bodies ? Yet, the problem has been propounded 
 and solved ! Who could have conceived the possibility of 
 your voice, your speech, your song, your laughter, your 
 sighs being "bottled up," and being reproduced to those 
 who love, admire, and remember you ? Yet, an Edison 
 has achieved that miracle ! Who would have thought we 
 could have a picture of a ball-room, or a battlefield, or 
 the remotest regions of space in a few moments? Yet, 
 the photographer does this with faultless accuracy. 7. 
 One of our difficulties, when we wish to gauge the XlXth 
 century, is that it is impossible to say, even after medita- 
 tion, the thing in which the age is greatest. If, being 
 impressed by the power of steam and electricity and the 
 applications of them, we declare them to be the main 
 points, we are met by the claims of the Engineer, the 
 claims of the Physicist, the claims of the Chemist, each 
 
 T 2 
 
276 PROGRESS OF SCIENCE. 
 
 of whom may justly intimate that without him the success 
 in this or that branch would have been problematical ; 
 and this is true, for the XlXth century has made the 
 INTERACTION of the sciences a fact so commanding that all the 
 mathematical, astronomical, mechanical, physical, chemical 
 sciences tend to become one, so intimately and indissolubly 
 are they connected with one another. Look at the labour 
 accomplished by chemistry. Do not the metallurgist, the 
 astronomer, the geologist, the biologist, the physicist, the 
 photographer rely upon the data or the analyses furnished 
 by the chemist in order to carry out their own work ? It 
 might almost be said that chemistry has become the key 
 of the secret palace of science. But CHEMISTRY is even 
 more intrinsically : it has devised new means of analysis, 
 through which it has revealed to us the components of 
 the universe. That, by itself, would be sufficient to make 
 the XlXth century equal to the age of Newton. 8. In 
 the natural sciences, our time has been no less thorough 
 than in other departments ; the earth is now known, thanks 
 to geology, which has raised the veil which concealed the 
 past ages, and shown us the growth of the crust, the 
 revolutions it has undergone, the life it has supported, 
 the age it has lived ; so that the XlXth century has 
 given us the knowledge of our EARTH, and has completed 
 or at least immensely extended the knowledge of the 
 HEAVENS. 9. Another feature, as engrossing as the others 
 if indeed it be not more so, is that afforded by the rapid 
 advance and grand revelations made in all the branches 
 of biology, including anthropology. Here again the XlXth 
 century inquirer found the secret of nature, life, describing its 
 innumerable delineations, explaining its countless varieties, 
 ascending to its primitive forms. And not this only, but 
 his brother, the physiologist, the good magician, has dis- 
 covered the means of abolishing pain, and of preventing 
 disease. 10. Finally, in all the branches just alluded to, 
 laws have been found, and of all these laws, one which 
 could never have been elucidated in earlier ages the grand 
 LAW OF EVOLUTION, which embraces a sheaf of others. 
 
 In all branches the XlXth century has touched the 
 
SUMMARY OF FOUR CENTURIES OF SCIENCE. 277 
 
 bottom, found the principles that rule phenomena, and 
 arrived at the barriers of ultimates beyond which the 
 limitation of the human intellect forbids us to proceed. 
 But within these limits universality stamps each science in 
 all its ramifications, as universality stamps the age as a 
 whole. Such is the XlXth century in its main characters, 
 if it be not sheer presumption to point out in a brief and 
 inadequate form its most magnificent achievements in 
 science. 
 
CHAPTER XIII. 
 SCIENTIFIC COUNTRIES. 
 
 THE description of modern scientific achievements would 
 be incomplete as an historical presentment, if the contri- 
 bution of each country to the advancement of knowledge was 
 not clearly indicated. 
 
 Four countries may be said to have run almost abreast 
 of one another in the race of progress and far in the van of 
 European science ITALY, FRANCE, GERMANY, ENGLAND. 
 These four nations were not equal to one another in the 
 rapidity of their advance, for Italy preceded the others in the 
 scientific revival and kept the lead for a long time, so that 
 she acted as the instructress of other nations, and these owe 
 to her on that account as much affection and gratitude as 
 healthy and intellectual daughters owe to the mother who 
 nurtured and trained them. But each of these four has 
 the right to consider herself entitled to proudly stand in 
 the front rank. 
 
 The following table of eminent men in each country will 
 prove the most convenient form of exposition : 
 
280 
 
 PROGRESS OF SCIENCE. 
 
 
 ITALY. 
 
 FRANCE. 
 
 Mathematics.../ 
 
 Tartaglia, 
 Cardan, 
 Ferrari, 
 
 Galileo, 
 Cavalieri, 
 Ghetaldi. 
 
 Viete, 
 Fernel, 
 Fermat, 
 Descartes, 
 
 Pascal, 
 Lambert, 
 Lagrange, 
 Carnot, 
 
 Monge, 
 Legendre, 
 Laplace, 
 Cauchy. 
 
 Astronomy ..A 
 
 Toscanelli, 
 Lelio, 
 Galileo, 
 Cassini, 
 
 Piazzi, 
 Secchi, 
 Schiaparelli. 
 
 Gassendi, 
 Lalande, 
 
 Lagrange, 
 Laplace, 
 
 Arago, 
 Leverrier. 
 
 Geography ... 
 
 Columbus, 
 
 Vespucci. 
 
 Bougainville, 
 
 Caillie-. 
 
 
 Geology ...f 
 
 Leonardo da 
 Vinci, 
 
 Caesalpinus, 
 Moro. 
 
 Palissy, 
 Hatty, 
 
 Brochant, 
 Prevost, 
 
 Cuvier, 
 Elie de Beaumont. 
 
 Physics 
 
 Leonardo, 
 Scarpi, 
 Galileo, 
 Ubaldi, 
 Antonio, 
 Bruno, 
 Castelli, 
 
 Stancari, 
 Porta, 
 Torricelli, 
 Grimaldi, 
 Galvani, 
 Volta, 
 Melloni. 
 
 Mariotte, 
 Papin, 
 Sauveur, 
 Dollond, 
 Reaumur, 
 Coulomb, 
 Lavoisier, 
 Montgolfier, 
 Carnot, 
 
 Mains, 
 Laplace, 
 Fresnel, 
 A mpere, 
 Arago, 
 Dulong, 
 Gay-Lussac, 
 Cauchv, 
 Biot, 
 
 Petit, 
 Becquerel, 
 Pouillet, 
 Foucault, 
 Fizeau, 
 Regnault, 
 Cailletet, 
 Pictet, 
 Faure. 
 
 Chemistry ..A 
 
 Avogadro, 
 Mateucci. 
 
 Nobili, 
 
 Lavoisier, 
 Gay-Lussac, 
 Berthollet, 
 Vauquelin, 
 
 Gerhardt, 
 Regnnult, 
 Thenard, 
 
 Dumas, 
 Wurtz, 
 Chevretil. 
 
 Biological < 
 Group 
 
 Piccolomini, 
 Fracastoro, 
 Santorio, 
 Caesalpinus, 
 Fabricius, 
 Achillini, 
 Fallopius, 
 Eustachius, 
 
 Arantu', 
 Asellius, 
 Alpinus, 
 Malpighi, 
 Spallanzatii, 
 Nicolucci, 
 Corti. 
 
 Belon, 
 Pare", 
 Lobel, 
 Buffon, 
 Bonnet, 
 Reaumur. 
 Lavoisier, 
 Tournefort, 
 Daubenton, 
 
 Lamarck, B. de Perthes, 
 Ciivier, Bernard, 
 G. St. Hilaire, Milne-Edwards 
 Serres, Quatrefages, 
 Lacepede, D'Orbigny, 
 Jussien, Pouchet, 
 Beaumont, Broca, 
 Vicq d'Azir, Paste^^r. 
 
 Philology ...f 
 
 
 Anquetil Du- 
 perron, 
 
 Burnouf, 
 
 Champollion 
 
 Jullian. 
 
 Sociology ...j 
 
 Beccaria, 
 
 Colbei t, 
 Quesnay, 
 
 Helvetius, 
 Rousseau, 
 
 Tur&ot, 
 Comte. 
 
 Inventions ...< 
 
 Spectacles, 
 Microscope, 
 Camera 
 Obscura. 
 
 Compass ? 
 Glazed 
 Pottery, 
 Telescope. 
 
 Lithography, 
 
 Photography, 
 
 Aerostation. 
 
SCIENTIFIC COUNTRIES. 
 
 281 
 
 
 GERMANY. 
 
 ENGLAND. 
 
 Mathematics. .A 
 
 Stiefel, Euler, 
 Kepler, Jacobi, 
 Leibnitz, Gauss. 
 
 Napier, Newton, Hamilton , 
 Wallis, Maclaurin, De Morgan. 
 
 Astronomy ...Y 
 
 Peurbach, W. Herschel, 
 Kepler, Biela, 
 Hevelius, Humboldt, A. 
 Olbers, Encke. 
 
 Horrocks, Bradley, /. Herschel, 
 Hooke, Halley, Huggins, 
 Flamsteed, Newton, Lockyer. 
 Sir R. Ball, 
 
 Geography ...-J 
 
 Behaim, C. Ritter, 
 Waldseemuller, Humboldt, &.. 
 
 Sir H. Gilbert, Bruce, Burton, 
 Davis, Parry, Baker, 
 Cook, Livingstone, Stanley. 
 
 ( 
 
 Geology ...< 
 
 Leibnitz, Keferstein, 
 Werner, Humboldt. A. 
 Buck, 
 
 Woodward, Mantell, Buckland, 
 Hutton, Murchison, Lyell, 
 Hall, Sedgwick, Scrope, 
 Playtair, W. Smith, Geikie. 
 
 Physics 
 
 Kepler, Ohm, 
 Guericke, Seebeck, 
 Fahrenheit, Schwabe, 
 W. Herschel, Kirchho/, 
 Chladni, Bunsen, 
 Fraunhofer, Steinheil, 
 Jacobi, Helmholtz, 
 W. Ritter, Dove, 
 Gauss, Hirn. 
 
 Roger Bacon, Wollaston, Joule, 
 Harriot, Dollond, Maxwell, 
 W. Gilbert, Faraday, Nicholson, 
 Hooke, Brewster, Crookes, 
 Hawksbee, Talbot, Thomson, 
 Halley, /. Herschel, Balfour Stewart 
 Boyle, Murdoch, Tyndall, 
 Watt, Grove, Lockyer, 
 Bradley, Leslie, Attwood, 
 Maskeline, Wheatstone, Huggins, 
 Newton, Young, Bessemer. 
 Kirk, 
 
 ( 
 Chemistry ...-J 
 
 Agricola, Bunsen, 
 Stahl, Liebig, 
 Kichter, Mitscherlich, 
 Klaproth, Hofmann. 
 
 Boyle, Cavendish, Graham, 
 Mayow, Wollaston, Williams, 
 Black, Davy, Perkin, 
 Priestley, Dalton, Crookes. 
 
 Biological 
 Group ...< 
 
 Tragus, Gijthe, 
 Haller, Gall, 
 Blumenbach, Pruner-Bey, 
 Vogt, Von Mohl, 
 Sprengel, Haeckel, 
 Oken, Virchow, 
 Schwann, Weismann, 
 Humboldt, A. Schleiden. 
 /. von Mutter, 
 
 Harvey, Jenner, Wallace, 
 Grew, E. Darwin, Brodie, 
 Willis, Sir J. E. Smith, Gould, 
 Ray, Mantell, Huxley, 
 Willughby, Owen, Bates, 
 Hunter, Knox, Romanes, 
 Brown, Simpson, Lubbock. 
 Sydenham, Darwin, 
 
 Philology ...J 
 
 Bopp, Roth, 
 Bunsen, Grimm, 
 Humboldt, ZW . Max-Muller. 
 
 Jones, Rawlinson, Geo. Smith. 
 Colebrocke, 
 
 Sociology ...-J 
 
 Humboldt. A. 
 
 Adam Smith, Bentham, Herbert Spencer 
 Malthus, 
 
 Inventions ..< 
 
 Printing, 
 Spectroscope. 
 
 Steam-engine, Telegraph, Safety-lamp, 
 Steam-ship, Machine-tools, Steam-ham- 
 Railway, Gas, mer. 
 Panorama, Steel, 
 
282 
 
 PROGRESS OF SCIENCE. 
 
 In a second group, in the order of their importance, 
 come : 
 
 AMERICA. 
 
 POLAND. 
 
 PORTUGAL. 
 
 DENMARK. 
 
 Franklin 
 
 Copernicus 
 
 Vasco de Gama 
 
 Tycho Brake 
 
 Rumford 
 
 
 Magellan 
 
 Steno 
 
 Morse 
 
 
 
 Roemer 
 
 Maury 
 
 
 
 Malte-Brun 
 
 Edison 
 
 
 
 Oersted 
 
 SWEDEN. 
 
 HOLLAND. 
 
 SWITZERLAND. 
 
 RUSSIA. 
 
 Linntzus 
 
 Snell 
 
 Guldinus 
 
 Baer 
 
 Bergmann 
 
 Stevinus 
 
 Paracelsus 
 
 Mendelejejf 
 
 Scheele 
 
 Van Helmont 
 
 Gesner 
 
 
 Berzelius 
 
 Grotius 
 
 Gall 
 
 
 Retzius 
 
 Drebbel 
 
 Agassiz 
 
 
 
 Mercator 
 
 Pictet 
 
 
 
 Vesalitis 
 
 Bernouilli 
 
 . . ' 
 
 
 Huygens 
 
 
 
 
 Leuwenhoeck 
 
 
 
 Muschenbrock 
 
 
 
 Sivammerdam 
 
 ' 
 
 
 Boerhaave 
 
 
 
 Camper 
 
 
 
 Maleschott 
 
 
 From the foregoing exposition it is clear that, although it 
 seems almost invidious to award the palm to one of the four 
 great scientific countries ; although each has such strong 
 claims to the obligations of the others; although Italy led 
 the van ; yet it is clear that ENGLAND, when the number 
 and weight of her achievements are considered, must be 
 declared the leading country in the world of science. She 
 gave birth to a score of men, every one of whom either 
 created, or extended, branches cf knowledge in a manner 
 unapproached by the great scientists of other nations in the 
 same departments ; and this, notwithstanding the fact that 
 ITALY has the glory of having given birth to Columbus, 
 Leonardo, Galileo, Cassini, and Volta ; GERMANY to Leibnitz, 
 Humboldtj Fraunhofer, Kirchhoff, Bunsen, and Helmholtz ; 
 
SCIENTIFIC COUNTRIES. 283 
 
 FRANCE to Descartes, Pascal, Lavoisier, Jussieu, Laplace, 
 Lamarck, and Cuvier. In almost every great branch, if not 
 the initiator in the same sense as Italy, England has been 
 the improver and perfecter. She has given the decisive, the 
 finishing stroke of genius necessary to carry science or its 
 application to its culminating point. After such physio- 
 logists as Servetus, Vesalius, and Caesalpinus, there comes 
 HARVEY, who towers over them by his beautiful discovery ; 
 after the Arabs and the alchemists, there comes William 
 GILBERT, who founds a new science ; after Copernicus and 
 Leonardo, Galileo and Kepler, all giants, after Tycho, 
 Torricelli, and Pascal, there comes NEWTON with his unsur- 
 passable results ; after a Quesnay and a Turgot, there comes 
 ADAM SMITH with his economical revolution ; after Papin, 
 there comes JAMES WATT with his steam machinery ; after 
 Jouffroy d'Albans and Marc Seguin there comes STEPHEN- 
 SON and his flying locomotive ; after Scheele and Lavoisier, 
 Richter, Berzelius, great discoverers all, there comes DALTON 
 with his atomic law ; after Volta and Ampere, there comes 
 W T HEATSTONE with his electric telegraph ; after a number of 
 practical metallurgists in all countries, there comes BESSEMER 
 who opens the Age of Steel ; after Werner and Cuvier, LYELL 
 comes with his geological laws ; after Lamarck and Geoffroy 
 St. Hilaire, there comes DARWIN with his evolutionary law 
 of natural selection ; after Carnot, Coulomb, Lagrange, and 
 the great Laplace, there comes JOULE with his conservation 
 of energy; after Comte and Diderot, there comes Herbert 
 SPENCER and his magnificent synthesis just as in the 
 Middle Ages there had been a ROGER BACON and a WlCLIF. 
 In very few branches indeed can it be said that the climax 
 was reached outside England. 
 
 If the English were of Jewish extraction and were swayed 
 by theological ideas, they would, no doubt, ascribe their 
 greatness to a supernatural cause, and aver that they were 
 "the chosen people"; but their success is due to natural 
 causes easily detected. Their MIXED ANCESTRY, descending 
 as they do from Iberians and Celts, Romans and Scandi- 
 navians, Teutons and French, has left an indelible impress 
 upon their race. They have inherited the different characters 
 
284 PROGRESS OF SCIENCE. 
 
 of their parent-stocks, and are gifted with the spirit of enter- 
 prise and fearlessness which distinguished one, the tenacity 
 and seriousness which distinguished another ; with the in- 
 ventiveness and spirituality of this stock, the reflectiveness 
 and depth of that one, the strength and adaptiveness of all. 
 And added to that primary cause, two other causes, besides, 
 have tended to accentuate their native disposition and 
 characteristics, viz., INSULARITY, due to their habitat, and 
 LIBERTY, due to their institutions. These two elements have 
 endowed the race with a strong individuality, and every man 
 has his own strongly marked idiosyncrasy, his own indepen- 
 dent spirit which hardly ever excludes that flexibility of 
 adaptation the common heritage of all which is the 
 product of heterogeneous ancestors. This doubtless is the 
 powerful spring, the fruitful source of the PRODIGIOUS 
 SUCCESS which has attended the progress of England in so 
 many ways, and in the pursuit of science, no less in letters, 
 politics, colonisation, and empire. 
 
CHAPTER XIV. 
 
 GENERAL RESULTS. 
 
 As a conducting thread through the maze of science 
 the brief outline we have given will suffice; but it is by 
 no means, as we have already said, a commensurate pre- 
 sentment of what science has accomplished. Yet, the 
 facts recorded, fractional though they be, constitute an 
 aggregate at once so weighty, pregnant, and substantial, 
 so vast, stupendous, and imperishable, that no one can 
 possibly appreciate and realise its full significance. We 
 need only remember that each discovery, each law, each 
 invention, is a new source of immeasurable development 
 to entire mankind, both intellectually and materially, to 
 form an idea, if not an estimate, of what science has done 
 for us. Chemistry, steam, electricity no sooner sprang into 
 life, than they became the greatest elements of progress 
 and wealth in the world. A man handles a crystal, gives 
 it a geometrical shape, polishes it; another man adapts it 
 to a tube, and, lo ! men see the same components as those 
 which make up the earth, burning in stars so remote that 
 a cannon ball would not reach them in ten millions of 
 years. A Bessemer makes a new kind of steel, a Perkin 
 finds a new kind of dye, and, behold, England reaps 
 millions upon millions, by scores and scores, and untold 
 wealth circulates throughout East and West : capital is 
 increased a hundredfold and labour is multiplied a thousand- 
 fold ! A Gilbert demonstrates a law which a Volta fructifies, 
 and, at once, the pile ensures progress by leaps and bounds 
 
286 PROGRESS OF SCIENCE. 
 
 to numerous industries, to medical science, to chemistry, 
 and the electric light, the telegraph, the telephone, the 
 phonograph appear ! A modest genius finds out the law 
 of elasticity of gases, another genius constructs a ship, 
 another an engine, and, see, man crosses a sea or a 
 continent with the eagle's speed, while innumerable markets 
 are opened in all regions and resistless machines move the 
 countless arms of industry ! And so forth without limits. 
 
 And the general consequence ? The whole world is 
 transformed ! Short words, these, and soon said, but slowly 
 apprehended. THE WORLD IS TRANSFORMED ! Industry and 
 trade are ubiquitous and incessant, enlightenment spreads 
 like a fertilising inundation, misery is reduced, health is 
 made more secure, barbarism yields to humane influences, 
 nations visit one another, the most distant countries are 
 brought within a few days' journey, Pekin speaks with 
 London, new continents open new homes for the European 
 races and nourish the Old World, the Western peoples see 
 trade and wealth flowing to and from the East, the seat 
 of civilisation is being transferred to other climes and 
 younger nationalities, brotherhood and kindliness soften 
 and elevate humanity, and lastly morality and freedom, in 
 the wake of knowledge, extend the horizon of peace the 
 supreme blessing. And all this the fruit of our scientific 
 men's labours, the fruit of a certain number of discoveries 
 of divine laws divine indeed in their simplicity, grandeur, 
 and bountifulness. 
 
 By the side of material results, Intellect has reaped 
 results equally beneficent, fruitful, and admirable ; each step 
 forward leading it to a new field of reflection and explo- 
 ration, and ensuring its enlargement, elevation, and depth. 
 Of the results which the preceding survey records, there 
 is one particularly to which we are compelled to attach 
 paramount importance, because of the immense consequences 
 it involves both in the scientific and in the philosophical 
 spheres, affecting as it does almost everything which the 
 human mind prizes in the highest degree we mean the 
 establishment of the doctrine of the universal predominance 
 of natural law in the government of the world. As the 
 
GENERAL RESULTS. 287 
 
 sciences obtain a sounder footing we see them revealing 
 to us, one after another, all the great principles pervading 
 the Cosmos. First the laws of motion are discovered, soon 
 followed by the discovery of the law of gravitation, and 
 these are found to be ruling principles of all heavenly 
 bodies, and to pervade the whole of space. And what 
 mathematics and astronomy have done for space, geology 
 does for time; time is shown to have brought about all 
 the changes which have been necessary to metamorphose 
 the gaseous mass which formed a nebula into rings, then 
 into planets with a central sun, and then each planet into 
 a harmonious little world giving life to myriads and myriads 
 of plants and animals: the law of evolution gives an 
 explanation of this everlasting Becoming. Next, chemistry 
 shows us law universally and uniformly obtaining from 
 suns to atoms, and through the spectroscope reveals "the 
 identity of matter and energy throughout this extreme 
 range." Then the laws of conservation of energy and 
 matter, and their transformation into new forms or modes 
 of action, are found, which reduce "all the phenomena of 
 the inorganic universe to one of law of universal simplicity 
 and generality." Lastly, the demonstration of the theory 
 of natural selection and the survival of the fittest extends 
 the domain of law to the organic world a law confirmed 
 every day more strongly by the discovery of intermediate 
 forms on the one hand, and by our better knowledge of 
 embryology on the other ; both guiding us back from the 
 present forms of life to less complex ancestral forms, and 
 from these further back still to simpler primitive ancestral 
 links until we arrive at the lowest original form of organism 
 the cell. 
 
 It is unnecessary to dwell upon the scientific conse- 
 quences, both theoretical and practical, which the certainty 
 of knowledge of the presence of unchangeable laws must 
 inevitably bring about, for the preceding survey itself affords 
 numerous instances of the effects due to the discovery of 
 the permanence of law ; but it is needful we should point 
 out the one effect which most intimately affects every one 
 of us personally, and that is the revolution or modification 
 
288 PROGRESS OF SCIENCE. 
 
 in religious belief it has caused. The sense of this revolu- 
 tion is the extinction of the belief in a supernatural agency 
 presiding over, ordering, and directing the working of the 
 universe, from the making of a new world to the fall of a 
 stone. Whether we should deplore this profound change 
 or rejoice at it is a grave question which shall be dealt 
 with in the ending chapter of this book ; all we need 
 notice at present is the fact itself the most momentous 
 by far of all those which can touch the heart of mankind. 
 The knowledge of the existence of law leaves the integrity 
 of pure belief untouched : science has explained only the 
 working of the Cosmos, but neither its cause, nor its creation, 
 nor its meaning. And more, science has brought conviction 
 to us of the limited range of the human intellect. It has 
 owned itself powerless ever to discover ultimates. It has 
 owned that the existence of an atom is as much beyond 
 its grasp as the existence of a million of stars; it owns 
 that mystery meets man just as much now as it ever did, 
 or more; but it has removed that mystery further back 
 into the infinity of the Unknowable, and thereby removed 
 also into further depths the Object of belief, making it 
 more awful and incomprehensible. Whether it can be 
 said that by killing anthropomorphism science has purified 
 belief will no doubt be solved affirmatively at no distant 
 date by all the schools of theology, as it has already been 
 by some of the highest. Such are the chief bearings of 
 the most important effect which science has produced and 
 brought home to us with irresistible might. 
 
CHAPTER XV. 
 
 MATERIAL EFFECTS OF SCIENTIFIC PROGRESS. 
 
 Now that we have sketched the sources and march of the 
 sciences, there only remains to describe their outcome ; to 
 their effects then we shall now devote remarks of great 
 importance. 
 
 The benefits accruing to civilisation from the advance of 
 the sciences and their practical applications have been pointed 
 out at pages 285-7 in general terms, but as it may be interesting 
 to the reader to understand how material welfare is promoted 
 either by a scientific discovery or a mechanical invention, it 
 is fitting that several instances of the matter-of-fact increase 
 of prosperity and well-being should be described. 
 
 Let us take the invention of the flour- mill as an 
 example. 
 
 TVfpTi ^ f- a n ^^>r|\r stticf? of social lifs- ihftv^r IM? otbftffl 
 of preparing corn for food, beyond boiling it, than by manual 
 labour. Cgrn is spread on a flat or a hollowed stone, and 
 then crushed by hammering at it with another stone. Each 
 family prepares rnrn in this way for its own consumption, 
 and the work, whether it be done by the head of the family 
 or his wife or children, is slow and roughly done ; the flour 
 resulting from the crushing is coarse and scarcely fit for 
 kneading into dough. AJime comes when a savage of genius 
 conceives the. idea of grinding corn between two heavy flat 
 stones, the upper of which is moved backward and forward 
 or in a circular manner by one or several hands. This 
 manipulation gives finer flour than before and does so in less 
 
 u 
 
290 PROGRESS OF SCIENCE. 
 
 HtYip frnp. A double benefit is at once effected ; the corn- 
 grinder has obviously saved time, and provided better and 
 more digestible food. The. process spreads quickly among 
 the community and a rise of material welfare ensues, for those 
 who. feed on the improved nourishment are more healthy and 
 stronger, so that they can accomplish their work more 
 efficiently, and the time spared by the new system can be 
 speut in the pursuit of other kinds of work, whether it be 
 hunting game for food, or tilling the soil for any purpose, or 
 weaving, or implement-making. Time comes when _the two 
 grinding-stones are replaced by a handmill. The inventor 
 of this machine is a greater benefactor than the first ; the 
 upper stone is now moved round and round rapidly by one 
 hand ; the work is far more satisfactory than by the previous 
 process ; for, as one person is sufficient to grind corn for the 
 whole tribe, the other members of the tribe are relieved from 
 thejiecessity of grinding for themselves, and can, undisturbed, 
 attend to various occupations. The benefit is not limited to 
 this ; with the new appliance there also arises a new state of 
 things : the corn-grinder is paid in kind for his labour, and if 
 the tribe, be a numerous one, he has to hire assistance in order 
 \ to carry out the whole work ; and thence there come to be two 
 orrWg of men, the master and the workmen. The latter 
 have secured a means of existence ; they can marry and 
 bring up a family with their earnings, be the wages what they 
 may corn, fruit, garden produce, game, or garments. Later, 
 say during the Egyptian or the Roman period, the water- 
 mill is invented an improvement by which numerous 
 benefits are secured : i, hand-labour is now replaced by 
 machinery ; 2, a natural force, water, becomes man's ser- 
 vant, and saves the employment of a score of hands ; that is, 
 it has economised or, more properly, multiplies labour ; 3, 
 the miller making flour for the whole district now becomes a 
 trader; he buys corn from the grower, thereby benefiting 
 the tiller of the soil, who gets a return for his labour sufficient 
 to keep himself and his family, and to pay working hands ; 
 4, the miller also sells his flour to the bakers, who obtain it 
 from him at a lower rate than if they had to grind their own 
 corn ; 5, the consumer buys ready-made bread at a mode- 
 
MATERIAL EFFECTS OF SCIENTIFIC PROGRESS. 291 
 
 rate price, since the machinery used has reduced the first cost 
 by saving wages to the miller, and certainly far cheaper than 
 if he had to leave off his own pursuit, say, weaving, for a 
 whole day in order to procure corn, grind it himself, make 
 and bake his loaves. The consumer would lose work, wages, 
 and eat dearer and worse bread into the bargain. 6. The 
 consumer has a family, and the whole family benefits by the 
 invention of the water-mill ; 7, the miller, saving hand-labour 
 as he does, nevertheless employs as many or more men than 
 before the new invention, no longer as corn-grinding hands, 
 but as porters, drivers, buyers, sellers, travellers ; 8, the trade 
 thus extended necessitates the making of sacks, hence weavers 
 have more work and more food ; the making of carts, hence 
 wheelwrights, if they do not exist already, are brought into exis- 
 tence ; smiths have more to do ; harness-makers have more 
 work, and in their turn increase the leather trade; this promotes 
 cattle-breeding, and the landowner finds a new source of profit 
 in the improved industry. 9. But the general distribution of 
 benefits does not stop there ; the water-mill has to be built, 
 and its construction gives work, hence wages and food, to a 
 crowd of people : labourers to excavate the soil for the 
 foundations ; wood-cutters to fell trees ; carpenters to prepare 
 and fit the timber ; smiths to make cog-wheels, tires, bolts, 
 nails; mill-stone quarriers and mill-stonecutters; tool-makers 
 to provide implements for all these; brick-makers, brick- 
 layers, tile-makers, and tilers ; an architect or clever artisan 
 to plan, direct, and supervise the building. The new invention 
 thus does good to the whole community, for the general 
 increase of prosperity, on account of the greater purchasing 
 power of the people, improves the clothing and building 
 trades in fact everything. And not material good only 
 has been brought about, but moral good also. Work 
 being easily obtainable, men who, from want, might have 
 been driven into violence and crime, respectably bring up a 
 family, use their natural abilities to improve their social 
 condition, live orderly lives, and benefit the country. Some 
 will even spend their leisure time in mental and mechanical 
 work which may be fruitful of ulterior benefits to all. One 
 thing is clear : crime has decreased, order and discipline have 
 
 u 2 
 
292 PROGRESS OF SCIENCE. 
 
 become a habit, peace has become dear that is, relatively 
 speaking. And when it is remembered that the new process 
 of milling finds a ready acceptance everywhere, that water- 
 mills are constructed wherever a water stream is available for 
 the purpose, it is easy to see how immensely beneficial it is 
 to mankind, and what a great benefactor its inventor has 
 proved. His invention has made life easier to every one, has 
 secured a living to a multitude, has, with the prosperity it has 
 caused, permitted a large increase of population. The 
 increase of people extends the area and power of peaceful 
 labour (if the word civilisation be inapplicable), since they 
 will spread beyond the former limits of the community, 
 cultivate more land, raise the amount of produce, and thus 
 add to the augmentation of the general prosperity. After 
 the water-mill comes the windmill, which at once doubles 
 the results obtained by the water-mill, and in addition causes 
 competition, a new factor which works to the consumer's 
 advantage. Later comes the steam flour-mill, which multiplies 
 these results a hundred times ! The modern miller stands 
 intellectually and socially far above his predecessor. He has 
 travelled and has acquired an extensive knowledge of the 
 world ; he is more than a trader ; he is to a certain extent 
 a learned man : he is conversant with some questions of 
 political economy, and somewhat, maybe, with chemistry a 
 branch of knowledge which enables him to know the different 
 properties of every description of wheat grown in various 
 countries, each weed being affected by the climate and soiL 
 Socially, too, he stands very high; his sons are brought up 
 to become merchants, engineers, manufacturers, politicians, 
 writers, lawyers, scientific men, each of them an agent of 
 progress or a centre of social influence. 
 
 Each industry has a history similar to that of milling ; so 
 that the preceding description of growth and results applies 
 to brewing, from the poorest beverage to the richest product 
 of the modern brewery; weaving, from sackcloth to silk, 
 velvet, lace, tapestry, and so on ; glass-making, from opaque 
 glass to lenses, spectacles, the telescope, the microscope, the 
 spectroscope ; metallurgy, from the rough bronze weapon 
 and implement to the steel engine, physical implements, 
 
MATERIAL EFFECTS OF SCIENTIFIC PROGRESS. 293 
 
 cannon, bridges, tunnels, steam trading and war ships, rail- 
 ways ; paper, from packing-paper to the finest vellum, papier- 
 mache trays, tables, and cabinets ; furniture, from the rough 
 stool to the throne ; printing, from the label to the book, 
 advertising placards, printed calico, engravings ; lighting, 
 from the primitive torch to the oil-lamp, gas, and electric 
 light; and so forth continuously. Each cause producing a 
 multitude of effects, all good and beneficial ; progress being 
 initiated in the main by the four things which mark the 
 great strides of civilisation THE TOOL which enabled men 
 to face and overpower the wild beast, and to protect them- 
 selves by garments and dwellings against climatic evils ; the 
 machine, and first THE PLOUGH, which enabled them to work 
 the ground and grow food ; THE SWORD, which enabled them 
 to secure the survival of the fittest by mastering the un fittest 
 races, and founding society ; THE BOOK, which enabled them 
 to preserve and propagate accumulated experience. 
 
 But how thoughtless and ungrateful humanity has been ! 
 It remembers the names of early " men-of-prey 3> and sur- 
 rounds those names with a glorious halo, whilst, of its early 
 benefactors, none is known even by name. The inventor of 
 the plough, the earliest and greatest of them, is forgotten 
 utterly ; equally unknown, to speak of a few only, are the 
 inventors of the mill, the compass, the clock, the organ, 
 glass, paper ; and just as unknown are the creators of as- 
 tronomy, arithmetic, geometry, algebra, alphabetical writing, 
 and many other men, all of them progenitors of human 
 happiness. Let every one of us cherish the remembrance 
 of the forgotten ones ; we owe them the life we live to-day, 
 for, "the discoveries of great men," as Buckle has finely 
 observed, " never leave us ; they are immortal ; they contain 
 those eternal truths which survive the shock of empires, 
 outlive the struggles of rival creeds, and witness the decay 
 of successive religions." 
 
 And turning from mechanical applications to pure science, 
 the material benefits to civilisation resulting from the latter 
 are still more astonishing and fruitful than those spread by 
 the former. In the forefront of all the benefits which science 
 has succeeded in bestowing upon humanity, we must name 
 
294 PROGRESS OF SCIENCE. 
 
 that which is felt in a direct manner by every man, woman, 
 and child, viz. : prevention of disease by inoculation a 
 scientific result which has saved many lives every year in 
 every country, and preserved us from much suffering and 
 sorrow. And so, the names of Jenner and Pasteur should 
 be revered universally. And the system having been ex- 
 tended to animals, husbandmen have been spared losses 
 which might have involved them in total ruin during 
 epidemic times. Akin to the same category are the daily 
 wonders wrought by medical science : every living man 
 knows by personal experience those priceless results. If we 
 go beyond that sphere, we find science again acting the 
 part of a rich and bountiful fairy, never tiring from out- 
 pouring her gifts upon us. Take, for instance, meteorology 
 allied to physical geography. The discovery of the per- 
 manency of the trade-winds and sea currents has led to the 
 scientific and practical development of navigation. Vessels 
 taking advantage of these currents make a voyage more 
 rapidly than before the scientific discovery. The rapidity 
 of transit decreases the cost of freight, the amount of wages 
 to sailors, and thereby benefits universal trade, and also the 
 consumer, who obtains cheaper and a greater quantity of 
 goods that is, cheaper and more food-stuff, cotton, wool, 
 raw material of every kind. Increase of wealth and pros- 
 perity ensues as a matter of course, and in its wake 
 brotherhood and love of peace among nations, together with 
 intellectual and moral progress. The discovery of the law 
 of the elasticity of gases applied to industry has led to 
 transformations in humanity which it is impossible to gauge, 
 so universal and multifarious they are, ranging from clothing 
 and transport to political economy and colonisation, which 
 are in the modern world dependent chiefly upon steam 
 machinery. Electricity, in its essence, is a force unknown 
 to us just as gravitation is; we cannot explain what it is, 
 but we are certain of its existence as a power, and we control 
 and use that power for our benefit. We have electric 
 machines, phonographs,* TELEGRAPHS, TELEPHONES, the 
 
 * The phonograph, though not an electric apparatus, is an offshoot 
 of the telephone, hence a grandchild of electric applications. 
 
MATERIAL EFFECTS OF SCIENTIFIC PROGRESS. 295 
 
 manufacture, fitting, and working of which secure the existence 
 to two hundred thousand families at least in England alone ; 
 and the use of which enables a merchant, say in the corn trade, 
 to know the climatic situation of the day in every latitude 
 in Asia, America, Africa, Europe, Australia ; to know also 
 the prices of every market in the world on that day; and 
 at the same time to know also the quotations in every stock 
 in all the Exchanges of the whole world on the same day ! 
 
 With that knowledge before his eyes he is able to regulate 
 his purchases in America, India, Russia, Australia; to order 
 his shipments at Odessa, New York, San Francisco, Val- 
 paraiso ; to direct the landing and delivery of corn, maize, 
 oats at Liverpool, Hull, Amsterdam, Marseilles, Trieste. 
 He does all this from his desk in his own office, or from the 
 Mark Lane Exchange, or from " the Baltic." And he does 
 all this by SPEAKING to his correspondents. He does it in 
 a few words. He speaks to fifty people in one short hour 
 instead of sending them as many different messages, most of 
 them fruitless, or as many written communications, most of 
 them incomplete at best. In the course of an hour he has 
 transacted business which would have taken six months to 
 transact fifty years ago, and that business amounts in bulk to 
 a hundred times more than that which his father would have 
 dared to face at a time. He has not saved time only; he has 
 also saved the salary of ten or twenty clerks ; and the rapidity 
 and increase of trade is such that the corn trade which his 
 father carried on before him in its entirety, but on a small 
 scale, has now been divided in thirty or forty separate 
 branches, of which he takes up two or three only. He takes 
 up perhaps only Russian wheat, or Indian wheat, or American 
 or English wheat ; or perhaps only maize, either American, 
 or Danubian, or Russian ; or perhaps only oats, either 
 Swedish, or Russian, or American ; or maybe barley, and of 
 this only brewing or feeding, French or Russian ; or again it 
 may be beans, peas, lentils, gram, and mutter ; putting aside 
 the flour and meal trade which is almost as large and just as 
 divided into sub-branches too. And then all these are again 
 subdivided into specialities, such as parcels, cargoes, options 
 each of which constitutes a separate trade. So, our corn 
 
296 PROGRESS OF SCIENCE. 
 
 merchant transacts a hundred times more business than his 
 father, but of the trade, he only deals in a couple of branches. 
 The other branches are taken up probably by the men who, 
 without that division of labour, would be his own salaried clerks. 
 This division of labour has just been explained in detail in 
 order to show the reader how men, who otherwise would 
 have remained unproductive trade units (clerks), have 
 become productive springs for the fructification of capital, 
 and the expansion and remuneration of labour. The con- 
 sumer, meanwhile, is the chief benefiter of the vast 
 improvement effected by electricity, for he obtains cheaper 
 food at an almost uniform rate without the fear of having to 
 face either famine or famine prices. If India and Russia 
 suffer from these two evils still, it is due to the comparative 
 absence of our means scientific appliances, railway and 
 telegraphic communication. 
 
 What is the case as regards electricity is the case with 
 every scientific discovery, with more or less general conse- 
 quences. The man who makes one is a benefactor to the 
 whole of mankind. He provides for the existence of ten 
 thousand, a hundred thousand, a million of families ; he gives 
 life to a whole population. Photography, steel-making, 
 chemical manufacture, and so forth, are so many sources from 
 which flow untold wealth, well-being, and peace, in a con- 
 tinuous and ever more powerful stream. That is why 
 chemists like Lavoisier, Davy, Dalton, Liebig, Perkin; 
 electricians like Volta, Ampere, Wheatstone, Morse, Thom- 
 son, Edison; physicists like Faraday, Brewster, Kirchhoff, 
 Grove; experimentalists like Watt, Murdoch, Niepce, 
 Bessemer ; engineers like Fulton, Stephenson, Lesseps ; 
 physiologists like Harvey, Jenner, Huxley, Pasteur, together 
 with their scientific brethren in any branch, are more glorious 
 and deserving of fame, each of them, than the greatest 
 conquerors whose deeds are the subject of historians for 
 conquerors, even those who spread civilisation, have destroyed 
 thousands and hundreds of thousands of lives, whereas 
 men of science have given life to millions and millions : a 
 theme -for reflection this, and one which necessarily makes us 
 lovers of science and its promoters. 
 
CHAPTER XVI. 
 
 MORAL EFFECTS OF SCIENTIFIC PROGRESS. 
 
 BUT the preceding description may leave as a main im- 
 pression on the reader's mind that the promoters of science 
 have been agents of material welfare, and little more; and 
 as material welfare does not after all constitute the best 
 part of a high civilisation, he may doubt whether science 
 has contributed much to the development of the moral and 
 intellectual condition of modern Europe ; he may vaguely 
 suspect that the deep sentiments which animate us nowadays 
 with regard to religion, religious and political government, 
 justice, truth, virtue, philanthropy, humanity, devotedness 
 have sprung from other sources than science. It therefore 
 behoves us to demonstrate that science has been the chief 
 fount from which moral and intellectual progress has flowed. 
 Not that science has been the sole source. By no means. 
 That the Christian idea, sown broadcast for ages, had 
 exercised a vast and beneficent influence, despite the 
 superstition, the craftiness, the craving for wealth and power 
 of its Roman ministers, is too obvious a fact to be dis- 
 puted for a moment.* Its essential doctrines charity and 
 godliness had sunk deep into the heart of many, and 
 nurtured Europe for a higher civilisation ; they had even 
 produced, and shown to the world, model men whose lives 
 and characters would compare with the highest poetical 
 ideals. But the spiritual force of those doctrines and 
 those men was buried alive, so to speak, under the weight 
 * See pages 47, 65. 
 
298 PROGRESS OF SCIENCE. 
 
 of the ecclesiastical army, and was insufficient to overcome 
 and kill the dominant evils. Slavery, despotism, oligarchy, 
 injustice, violence, rapine, cruelty, war were supported by 
 churchmen as things belonging to Caesar, and were therefore 
 represented as natural and lawful rights. It was reserved to 
 science to overcome these at last. Other factors, and fore- 
 most among them literature, naturally worked in the same 
 direction as science, and preceding it, powerfully assisted 
 it; but of these factors some owed their very existence to 
 the growth of science, so that the latter has been on the 
 whole the most potent and ubiquitous mainspring of human 
 elevation. 
 
 It has been already pointed out that Industry, by 
 the very fact of its coming into being, brought about 
 SOCIAL CHANGES of great importance, the principal of 
 which were the emancipation of Europe from serfdom ; next, 
 decrease of violence ; then municipal liberties ; next, in- 
 crease of population; then the disappearance of the 
 stigma attached to labour. But as industry depends on 
 machinery chiefly, and machinery is an application of 
 scientific principles, whether these be properly reduced to 
 law or empirical only, it follows that ordinary knowledge 
 at first and the sciences afterwards were the causes of the 
 social changes just recited, the Crusades being the para- 
 mount event which accelerated them and strongly co- 
 operated in several ways to bring them about. The 
 progress, however, goes much further. Industry has, ever 
 since the Xllth century, knit into greater and closer com- 
 mercial intercourse nations of different creeds, amongst 
 whom a feeling of reciprocal amity arose in consequence, 
 in the place of the unreasoning animosity which was 
 prevalent before. From the same period also date the 
 great mercantile companies and enterprises; also the com- 
 mercial leagues of great cities, which grew powerful enough 
 to become independent republics. Social order, too, began 
 to grow, despite the popular disturbances due to the 
 aggression of the aristocracy, for it was felt that prosperity 
 and that of the working class especially depended upon 
 the stability of the state, property, and capital, if we may 
 
MORAL EFFECTS OF SCIENTIFIC PROGRESS. 299 
 
 use words of modern speech. Later, Political Economy 
 a science of pure reasoning demonstrated principles for 
 a long time hidden from men's eyes, yet inherent in industry 
 and commerce, which brought about results of immense 
 magnitude and variety : the principle, for instance, that 
 trade suffers from restriction free trade and the partial 
 disappearance of evil interference,, monopolies, exorbitant 
 and prohibitive duties followed accordingly; next, the 
 principle that not precious metals, but labour^ is the basis 
 of value; next, the principle that capital and therefore 
 its accumulation is a necessity for the expansion and 
 remuneration of labour; the principle, too, that labour in 
 its turn is a necessity to the fructification of capital the 
 co-operation of both conducing to the increase of national 
 wealth. Concurrently, a new factor, due to the progress 
 of trade, had been created, viz., Credit* an increment of 
 capital artificial, but nevertheless effective, since it permits 
 a vast number of extensive transactions and long enterprises 
 which ready capital could not possibly cover. Now credit 
 has had two consequences -one moral, the other political. 
 It has been a great moralising agent in all communities 
 by the importance it attaches to character, and therefore 
 by the influence it exercises over it. Second, it has become 
 a guarantee or pledge of peace. Political Economy and 
 the working out of its principles tend to universal peace 
 "each nation having an interest in the prosperity of those 
 with which it trades, and the richest and most solvent 
 being its best market"! War is in consequence deprecated 
 as a folly, a sort of national suicide ; warlike habits are 
 weakened and tend to disappear. Political economy will 
 ultimately destroy militarism and the last vestiges of 
 despotism, both of them remnants of the age of violence. 
 It also tends to bring a closer and closer union of the 
 different classes of society, the capitalist and workman 
 alike being tied to the same undertaking. It goes further 
 
 * The Bill of Exchange dates from the Middle Ages. Banks date 
 from the XVI Ith century ; the Bank of Amsterdam, the earliest, was 
 founded in 1609. 
 
 t See Lecky's Rationalism. 
 
PROGRESS OF SCIENCE. 
 
 still in its effects : the working classes, relying upon labour 
 and being made independent by it, cease to be the 
 tools of their masters, and democracy ensues. Finally, 
 the desire for wealth gives a new impulse to human 
 energies, whilst wealth itself promotes the expansion of 
 science, art, and literature. All this chain and interaction 
 of consequences, it is clear, have in the main originated 
 from science. 
 
 In the sphere of POLITICS we find the same fact. The 
 invention of gunpowder and the use of it by scientific 
 appliances altered the political organisation of Europe. 
 Cannon, the arm of royalty, destroyed feudalism; the castles 
 of the Barons could not hold on against powder and shot, and 
 the aristocracy, ruled by a power superior to its own, ceased 
 to wage universal war ; whilst the musket, against which the 
 armour was no longer proof, destroyed the ascendency of 
 the knight on the battlefield. Cavalry had to yield to 
 infantry. " Force passed from the hands of the nobility to 
 those of the people " ; the further ascendency of foot over 
 horse, of musket over lance and sword, being secured by 
 Vauban's bayonet. Gunpowder also permitted dynasties 
 to weld into nations the people of the same kindred a result 
 which feudalism rendered impossible. It had another effect : 
 it made battles less lengthy, less bloody, and thus had a share 
 in the growth of humanising feelings. The downfall of the 
 political power of the nobility was so much gain to democracy ; 
 the desire for political equality was parent to it, and grew 
 apace from the confidence in their own strength which the 
 people gradually felt. Meanwhile, the civil power, too, so 
 arbitrary and inhuman for centuries, underwent numerous 
 alterations beneficial to the multitude. The rise and force of 
 public opinion became a factor with which civil power had 
 to reckon to prevent rebellion and revolution. The 
 influence exercised by the middle classes and due to 
 their possession of wealth ; the democratic sentiment due to 
 the craving for freedom both offspring of the industrial 
 spirit compelled governments to yield to the aspirations first 
 of the burgess class, and next to those of the working class. 
 The executive became less and less despotic ; the franchise 
 
MORAL EFFECTS OF SCIENTIFIC PROGRESS. 301 
 
 was granted and extended ; savage laws were repealed ; 
 numerous laws protecting labour were passed, which embodied 
 the philanthropic tendencies of modern times ; liberty of 
 conscience, of speech, of meeting, of publication were de- 
 manded and obtained. Class privilege disappeared. Equality 
 before the law came to be a recognised principle in legislation 
 and in the administration of justice. The governmental 
 fabric itself became the embodiment of popular wishes the 
 people making and unmaking cabinets, and gradually altering 
 the oligarchal form of the body politic until government 
 became either a mixed monarchy or a republic. These vast 
 changes were brought about by the concurrence of numerous 
 causes, no doubt, some of which were distinct or more or less 
 remote from science. They did not come without political 
 convulsions, but these were the explosions of the INDUSTRIAL 
 SPIRIT and its tendencies, struggling for existence and recog- 
 nition, and breaking up the superficial obstacles which opposed 
 natural growth, so that the industrial spirit, fostered and 
 made day by day more resistless by science and its applications, 
 has been from beginning to end at once the most powerful, 
 permanent, and general cause of the eventful changes just 
 indicated. 
 
 Passing on now to RELIGION and RELIGIOUS GOVERNMENT, 
 we find science more mighty than in all else. The conceptions 
 of God and the World which priests and men had formed 
 before the advent of scientific knowledge were very limited 
 and baleful. The earth constituted the universe, the sun, 
 moon, and stars being attached to a solid firmament for the 
 lighting of it. Suddenly Columbus and Copernicus revealed 
 the constitution of the world we live in. A little later, 
 Galileo's telescope revealed a universe undreamt of. The 
 sun, moon, stars are no longer mere flames. The earth 
 becomes a speck an appendage of the sun ; the stars 
 become suns, and their numbers, where none were visible 
 before, are counted by millions and millions; man, who 
 thought himself the centre and purpose of creation, becomes 
 an atom ; theological conceptions, in a word, are revolu- 
 tionised. The universe and its creation, God and His work, 
 appear in their true light, and the notion of the Divinity 
 
3O2 PROGRESS OF SCIENCE. 
 
 becomes overwhelming. Puerile ideas are swept away, and 
 the whole majesty and incomprehensibleness of the creation 
 are enhanced a thousandfold. God can no longer be repre- 
 sented as an angry Jehovah, swayed like ourselves by petty 
 passions, and ever ready to chastise and scourge His people, 
 but as the Essence of all good, ever shedding beneficence on 
 all the beings and worlds to which it has given existence. 
 Religion became more exalted and sublime. Furthermore, 
 Galileo, after many tentative efforts to the same end for 
 centuries, demonstrated the predominance of law, of which 
 astronomy and physics gave then numerous proofs, but 
 which geology later on made strikingly evident to all minds. 
 This had results of different kinds : it brought about, 
 by its influence on man's thoughts, changes in religious 
 and civil government, which had far greater practical 
 beneficent effects than all the others put together. For the 
 substitution of the conception of permanent law for that 
 of daily supernatural intervention destroyed, though only 
 gradually, but in the end entirely, the belief in witchcraft, 
 evil spirits, magic, necromancy, theurgy, thaumaturgy, 
 sortilege, and sorcery of every kind. This mental disease 
 had for centuries been the cause of abominable horrors. 
 Thousands of victims were daily burnt alive upon suspicion 
 of witchery, by batches of twenty, two hundred, four hundred 
 at a time, even in small towns, and the burnings were 
 regarded as popular festivals witchery being considered as 
 the working of Satan and heresy. Religious government had 
 become religious terrorism, in comparison with the evil of 
 which the revolting atrocities of the Roman emperors, or the 
 violence of the French Revolution, or the savagery of Dahomey 
 sink into insignificance into insignificance because these 
 evils were only intermittent and momentary, whereas the 
 religious Reign of Terror lasted without intermission for 
 centuries and centuries, and was a relentless ever-present and 
 ever-active scourge from which no escape was possible. All 
 religions seemed heresies in the eyes of the one in power, 
 and the heretics were looked upon as enemies whom it was 
 righteous to visit with massacre, exterminating wars, torture, 
 and the stake. All these frightful things gradually ceased 
 
MORAL EFFECTS OF SCIENTIFIC PROGRESS. 303 
 
 by the evidence which science furnished of the non-existence 
 of witchcraft. 
 
 RELIGIOUS GOVERNMENT BECAME MORE HUMANE. 
 
 But the belief in supernatural agency had also demoralised 
 men, clerical or lay : the contemplation of suffering had 
 blunted and even destroyed emotional instincts. Indifference 
 to acts of barbarity, familiarity with the spectacle of daily 
 cruelties, callousness at the sight of the infliction of torture, 
 insensibility to the natural affections had debased humanity 
 as it had never been since it had emerged from the lowest 
 condition of cannibalism.* 
 
 The scientific demonstration of the permanence of natural 
 laws revived MEN'S GOOD INSTINCTS. 
 
 One of the effects of the belief in witchcraft was of a 
 different kind. It had induced men to entertain a hatred 
 of all intellect and intellectual honesty ; f ' it had induced 
 a negation of everything that was good and noble in 
 morality.".* Provided a man believed, the rest did not 
 matter. Justification by faith, not by work, was the one 
 dogma which sanctified all acts hence denunciations, con- 
 fiscations, disabilities, imprisonments, tortures, and burnings. 
 Often, too often, alas ! faith was only a mask, and those 
 evils were perpetrated for private or corporate benefits 
 regardless of conscience the clergy seeking the gratifica- 
 tion of their greed for lucre and craving for power, the 
 laity the gratification of their passions. So long as the 
 victims were only heretics or persons suspected of heresy 
 or witchcraft, it mattered not. 
 
 The promulgation of the doctrine of the permanency 
 of natural law restored mankind to a SENSE OF JUSTICE. 
 And likewise, the belief in the eternal damnation of all 
 but Christians also gave way to the teachings of science 
 and the intellectual elevation it brought in its train ; so 
 that science can boast of one of the greatest triumphs of 
 civilisation.* 
 
 The intellectual movement originated by science had 
 other effects besides the decay and disappearance of religious 
 persecution. It gave a higher incentive to the performance 
 
 * Mr. Leckv. 
 
304 PROGRESS OF SCIENCE. 
 
 of duty, for it decreased the influence of fear as the motive 
 of duty, and substituted for it the " motive of DUTY FOR ITS 
 OWN SAKE." It likewise destroyed the importance of 
 dogmatic teaching, and thereby contributed to bring in the 
 Reformation. It further established the SUPREMACY OF 
 CONSCIENCE, and this now became the prime mover of 
 individual and collective actions. 
 
 In the MORAL SPHERE the improvements have been 
 equally important, and are due principally to the same cause 
 elevation of intellect consequent upon science. Conscience, 
 it was just said, dictates most of our acts nowadays; it 
 also gives us all a notion of right and wrong, and right 
 is no longer considered as based upon statute law, or 
 tradition, or dogma, but upon the notion of ideal justice 
 hence the substitution of the SENSE OF RIGHT for the fear 
 of punishment as the chief incentive of virtue. In other 
 words, we pursue VIRTUE FOR ITS OWN SAKE. Next, the 
 intellectual movement had a consequence of extreme im- 
 portance with regard to legislation and the improvement 
 of the penal code, and that was the ABOLITION OF TORTURE 
 in religious, political, and civil procedure. And when we 
 remember the cruelty of its infliction and the variety of 
 its means fire, water, red-hot pincers, the rack, the wheel, 
 the boots ; when we remember that the innocent, even 
 when found so, generally died or were frightfully crippled 
 for life from its effects ; that witnesses might be, and were, 
 tortured as well as the accused, we can but bless the 
 movement which swept away this appalling barbarity. So 
 that the humane alteration of the law, together with pro- 
 portioning the penalty to the offence, is one of the most 
 precious conquests of the present knowledge upon the past. 
 
 The elevation of moral sense is seen again in another 
 sphere, that is the search, the LOVE OF TRUTH for its own 
 sake an element of good which had been absent in 
 Europe for more than a thousand years, from the time 
 of Augustine to the time of Galileo and even Newton's. 
 The Christian Church " supported its teaching by what it 
 called pious fraud" the name given to imposture and false- 
 hood. This had become a principle of religious government 
 
MORAL EFFECTS OF SCIENTIFIC PROGRESS. 305 
 
 and was due " to the doctrine of exclusive salvation." St. 
 Augustine first, and all the doctors who came after him 
 for centuries, made it an act agreeable to God to propagate 
 and strengthen the faith by it mattered not what means, 
 " provided they conduced to the edification of the people " 
 hence forgeries of sacred revelations, divine decree?, 
 papal bulls, spurious miracles, twenty-five thousand of which 
 are known to have been recorded as actual occurrences 
 between the Vth and XVIth centuries. Mendacity of every 
 description practised by the priesthood of Europe was the 
 usual device resorted to to keep a hold upon the converts 
 and the faithful. Absolute credulity, as all writers have 
 remarked since the XVIIIth century, was inculcated as a 
 virtue, and doubt punished as a crime. The moral type 
 had become perverted. 
 
 Science and its intellectual consequences brought back 
 TRUTHFUL SPIRIT. It caused the disappearance of doctrines 
 which clashed with conscience and are opposed to our moral 
 sense. " Science made men intolerant of what is false " ; 
 scientific truth, whatever its effects, is now received as the 
 revelation of divine law, whilst the practice of truthfulness 
 has become the principle of our conduct. 
 
 Modern Philanthropy is another sphere in which the 
 intellectual movement inaugurated by scientific knowledge 
 has played a conspicuous part. Philanthropy is the essence 
 of true humanity. It existed before science. The poor were 
 tended, and tended tenderly, it is only fair to acknowledge, 
 by the religious power. But it was limited to the distribution 
 of alms and the institution of hospitals. Modern philanthropy 
 is far deeper and wider. It has become, as it has justly been 
 observed by recent writers, what asceticism was in the Middle 
 Ages, a ubiquitous fact which pervades the whole European 
 community. Sympathy with suffering, so restricted until the 
 XVIIIth century, is one of the vital sentiments which makes 
 our age so superior to all ages. It is the soul of philanthropy. 
 It has caused the disappearance of barbarous habits and 
 cruel amusements ; it has extended to the enemy fallen on 
 the battlefield ; it has brought in tenderness in the treatment 
 of the epileptics and lunatics who were tortured as demoniacs ; 
 
306 PROGRESS OF SCIENCE. 
 
 it has led to the creation of innumerable beneficent institu- 
 tions and associations, of friendly societies, all of them 
 regardless of creed ; it has induced the wealthy to consider it 
 a duty to use part of their wealth in benefactions ; it has 
 killed indifference to the misery of the disinherited, drawn 
 every one of us nearer to the lonely, elicited help from all to 
 all ; it has led to the abolition of slavery the shame of 
 modern times ; it is being extended to subjected races ; it 
 has, in short, given new features to Europe and America. It 
 is not too much to say that the XlXth century laws pro- 
 tecting the weak and the laborious are the living embodi- 
 ment of UNIVERSAL SYMPATHY. To this great work many 
 simultaneous causes may again be assigned ; but the para- 
 mount cause was intellectual elevation born of science, and 
 this embraces several of the concurrent elements. The 
 movement was made decisive and irresistible by the descrip- 
 tions of the appalling miseries of the poor classes and the 
 impetuous torrent of splendid eloquence of Rousseau, the 
 father of the poor and of democracy. 
 
 The ideas which SWEPT away RELIGIOUS TERRORISM: 
 and PERSECUTION, TORTURE, MENDACITY, and BROUGHT 
 in PHILANTHROPY, were exceedingly slow to germinate. 
 They took over two hundred years to have practical 
 effects. They were at first opposed by an aggravation of 
 the evils they were intended to destroy ; they were com- 
 bated by men-of-tradition, by scholars, by princes and 
 law-makers ; they were anathematised by the churches 
 of all denominations ; they were checked by fire and 
 sword, exile, confiscations, expulsion, law, by the whole 
 "panoply of brute force;" but they were triumphant in the end, 
 just as the Christian idea had been against the might of the 
 Roman Empire fifteen hundred years before. And they 
 conquered because they were supported by advocates of 
 intellect and eloquence, who devoted their lives and energies 
 to their propagation, fearless of prison and gibbet. These 
 benefactors of the human race are to this day denounced by 
 those who were stripped of their sway and who cannot brook 
 their defeat. The weapon used by the vanquished to revile 
 
MORAL EFFECTS OF SCIENTIFIC PROGRESS. 307 
 
 the victors is the only one that remains in their hands, viz., 
 calumny. The benefactors are called scoffers, abettors of 
 Satan, atheists ; the faithful are warned against reading their 
 execrated works if they cherish religion, and the innocent 
 and pious Christians live on in the ignorance of the evils 
 destroyed and the good done by John Weir and Cornelius 
 Agrippa, by Montaigne and Charron, by Descartes and Locke, 
 by Bayle and Voltaire, by Middleton and Rousseau. Nor 
 should we omit Raynal, whose animated cosmorama, which 
 rapidly went through twenty successive editions and was read 
 by all in every part of the world, gave currency to the ideas 
 of the time and universally popularised them.* These were 
 the true deliverers. 
 
 They did not attack things truly holy any more than 
 Luther had done before. Nor did they use the extreme 
 violence, crudity, virulence, and coarse invectives which 
 Luther poured out in his six thousand pamphlets. Far 
 from assailing the essence of the Christian teaching, they 
 on the contrary fertilised the precept of the modern world, 
 " Love one another." This sublime precept had until then 
 practically remained a dead letter in Europe. For ages it 
 had been replaced by the Inquisitors' tacit command, " Hate 
 one another," " Kill all those who differ from us in opinion " 
 a command not expressed in words, but acted upon with 
 ferocious ruthlessness against the so-called heretic, Mussul- 
 man, Jew, Indian; against Protestants in Roman Catholic 
 kingdoms, against Romanists in Protestant countries. 
 Whereas Christian charity, so distorted by fanatical teachers 
 and so barren until the XVIIIth century, was of all others 
 the one seed which the benefactors we just mentioned dis- 
 seminated all round. They it was who brought into 
 fruition the radiant doctrine of brotherly sympathy, en- 
 lightened as they were, not by dogma, but by the SPIRIT OF 
 TRUE HUMANITY. But they attacked, and attacked fiercely, 
 " with an eloquence and force never surpassed," f a religious 
 tyranny and an unscrupulous sacerdotal order. They, like 
 
 * Mr. John Morley : s Encyclopedists. 
 t Mr. John Morley. 
 
 X 2 
 
3o8 PROGRESS OF SCIENCE. 
 
 Luther, assaulted illegitimate and untenable dogmas and a 
 spurious and despotic hierarchy. Their onslaught was, with 
 equal energy, also directed against social and political evils. 
 And because the privileged interests they overthrew were 
 more numerous than those assailed by Luther, their traducers 
 are also more numerous than those of Luther they include 
 all the social, political, and religious supporters of bygone 
 systems. The representatives of the dethroned castes, still 
 trained in the traditions of the past, raise a cry which appeals 
 to the indiscriminating feelings of artless souls. For in order to 
 decoy the pious into credulity and enlist their aid ; in order 
 to keep on their remaining authority ; in order to put out of 
 sight the real causes of the conflict, they raise the cry of 
 " Religion in danger ! " Once more, it was not religion 
 which was attacked, but its pseudo-priests. 
 
 The victors were not faultless ; they were in the fierce- 
 ness of the strife, often unjust and one-sided ; they were 
 assisted by a few irreverent^ offensive, and discreditable co- 
 adjutors; they often were inexact and superficial; they 
 frequently were extravagant and paradoxical ; the lives 
 they led were not exemplary all this is true. But they 
 fought stoutly and well the great BATTLE OF HUMANITY 
 AGAINST INJUSTICE ; they thought not -of themselves but of 
 mankind alone ; they daily risked imprisonment, fines, 
 exile; and when we are told, "Touch not their books," 
 let us at least remember that the authors above mentioned 
 did more than armies for the abolition of persecution, of 
 torture, of mendacity, and the rise of modern philanthropy, 
 liberty of conscience, political equality, and social re- 
 generation.* And they did so much because they were 
 the exponents of the ideas born of the sciences, without 
 which all human efforts would have remained fruitless. 
 
 The proposition which was laid down at the beginning 
 of this concluding chapter has now, so far as this survey 
 permits, been fairly substantiated : science has been, in the 
 main, the prime mover of all that is highest in civilisation, 
 as it has been in all that is material. It is, from all 
 * Mr. John Morley. 
 
MORAL EFFECTS OF SCIENTIFIC PROGRESS. 309 
 
 points of view, the chief force which has directed progress, 
 improved society, embellished man's life, shaped the modern 
 world. Such are its results. And if by the side of this 
 philosophical conclusion, the writer has in any degree 
 succeeded in conveying a pretty clear notion of the origin 
 and growth of science to the student of scientific history, 
 he will have contributed a spark to the present enlighten- 
 ment, and thus accomplished his humble task. 
 
APPENDICES. 
 
312 
 
 APPENDICES. 
 
 APPENDIX A. EMINENT 
 
 ANTIQUITY. 
 
 ARABIAN PERIOD. 
 
 MIDDLE AGES & REVIVAL. 
 
 s\> 
 
 /s 
 
 A 
 
 r ^\ 
 
 /*""" ^ 
 
 /^""^ ~~^ 
 
 VI th CENTURY 
 
 Ilnd CENTURY 
 
 IXth CENTURY. 
 
 XHIth CENT. 
 
 XVth CENTURY. 
 
 XVIth CENT. 
 
 B.C. 
 
 B.C. 
 
 
 
 
 
 
 
 Albumazar, A. 
 
 Abba Mari, P. 
 
 Columbus, E. 
 
 Achillim, B. 
 
 
 
 Anaximander, A. 
 
 Hipparchus, A. 
 
 Alfergani, A. 
 Al Mamun, A. 
 
 Abdallatif, G. 
 Al Beithar, B. 
 
 Cusa, A. 
 
 Agricola, C. 
 Alberti, B. 
 
 Pythagoras, A. 
 
 
 Assamsh(7 20), M . 
 
 Albert us 
 
 Guttenberg, I. 
 
 Alpinus, B. 
 
 
 
 
 Magnus, B. 
 
 
 Antonio de 
 
 Xenophanes, G. 
 
 
 Ben Corrah, A. 
 Ben Musa, M. 
 
 Ebn Zoar, B. 
 
 Leonardo da 
 Vinci, P. 
 
 Dominis, P. 
 Arantus, B. 
 
 Thales, A. 
 
 
 Geber al 
 
 Karwiny, P. 
 
 Magellan, E. 
 
 Asellius, B. 
 
 
 
 Batani, A. 
 Giaber, C. 
 
 Roger Bacon, P. 
 
 Peurbach, A. 
 
 Belon, B. 
 Bruno, A. 
 
 
 
 
 Tasi, A. 
 
 Piccolomini, B. 
 
 
 
 
 Masue, B. 
 
 Vitellio, P. 
 
 Prince Henry, E. 
 
 Csesalpinus, B. 
 Cardan, M. 
 
 
 
 
 
 Regiomontanus, 
 
 Castelli, P. 
 
 
 
 
 
 A. 
 
 Cavaliere, X 
 
 
 
 
 
 
 Cavalieri, M. 
 
 Vth CENTURY 
 
 1st CENTURY 
 
 Xth CENTURY. 
 
 XlVth CENT. 
 
 Toscanelli, A. 
 
 Coiter, B. 
 
 B.C. 
 
 B.C. 
 
 
 
 
 Copernicus, A. 
 
 Anaxagoras, A. 
 Melon, A. 
 
 Posidonius, M. 
 Sosigenes, A. 
 
 Aboul Rihau, A. 
 Aboul Wefa, A. 
 Alchid Bechir, C. 
 Al Farabi, B. 
 
 Al. da Spina, P. 
 
 Gioja 
 d'Amalfi, P. 
 
 Ulugh Begh, A. 
 
 Vasco de 
 Gama, E. 
 
 Waltherus, A. 
 
 Drebbel, )j|' 
 Eustachius, B. 
 
 Fabricius, B. 
 Fallopius, B. 
 
 
 
 Gerbert, . P. 
 
 Mondini, B. 
 
 
 Fernel, M. 
 
 
 
 
 
 
 Ferrari, M. 
 
 
 
 Rhazes, C. 
 
 Salvinus 
 
 
 Fracastoro, B. 
 
 
 
 
 Armatus, P. 
 
 
 
 
 
 
 
 
 Galileo, A. 
 
 
 
 
 
 
 Gesner, B. 
 
 
 
 
 
 
 Ghetaldi, P. 
 
 
 
 
 
 
 Gilbert, C. 
 
 IVth CENTBTRY 1st CENTURY 
 B.C. A.D. 
 
 Xlth CENTURY. 
 
 
 
 Guldinus, P. 
 
 Harriot, P. 
 Harvey, B. 
 Helmont, C. 
 
 Aristotle, A. Pliny, B. 
 
 Aboul Hassan, A. 
 Alberuni, G. 
 
 
 
 Kepler, A. 
 Kircher, I. 
 
 Berosus, A. ^^ A 
 
 Arzachael, M. 
 Avicenna, G. 
 
 
 
 Lelio, A. 
 
 Cahppus, A. Strabo, G. 
 
 Ben Ezra, B. 
 
 
 
 Lobel, B. 
 
 Democritus, A. j 
 
 Ebn Junis, A. 
 
 
 
 Mercator, G. 
 
 Eudoxus, A. 
 
 Ebn Zohr, B. 
 
 
 
 Monteverde, X 
 
 Hippocrates, B. 
 
 
 Marcus 
 Graecus, C. 
 
 
 
 Napier, M. 
 
 Plato, P. 
 
 
 Rashi, B. 
 
 
 
 Palestrina. X 
 
 Theophrastus, B. 
 
 1 
 
 Sufi, ' P. 
 
 
 
 Palissy, G. 
 Paracelsus, C. 
 
 
 
 
 
 
 Pare, B. 
 Plater, B. 
 
 Illrd CENTURY 
 
 Ilnd CENTURY 
 
 Xllth CENTURY. 
 
 
 
 Porta, P. 
 
 B.C. 
 
 A.D. 
 
 
 
 
 
 Santorio, B. 
 ScaiDi P 
 
 Apollonius, A. 
 
 Galen, B. 
 
 Abn Othman, B. 
 Albucasis, B. 
 
 
 
 Servetus, B. 
 Snell M. 
 
 Archimedes, M. 
 Aristarchus, A. 
 
 Ptolemy, A. 
 
 Algazzali, B. 
 Alhazen, P. 
 
 
 
 Stevinus, P. 
 Stiefel, M. 
 
 Ctesibius, P. 
 
 
 Al Idrisi, G. 
 Artefius, B. 
 
 
 
 Tartaglia, M. 
 
 Erasistratus, B. 
 Eratosthenes, A. 
 
 
 Avtrroes, A. 
 
 
 
 Tragus, B. 
 Tycho Brahe, A. 
 
 Euclid, M. 
 
 
 Geber of 
 
 
 
 
 
 
 Seville, A. 
 
 
 
 Ubaldi, M. 
 
 Hero, P. 
 Herophilus, B. 
 
 
 Kalid, B. 
 
 
 
 Vesalius, B. 
 Viete, M. 
 
 * The letters A, B, C, E, G, I, M, P, S, respectively stand for Astronomer, Biologist, Chemist, Explorer, Geologist, 
 
MEN OF SCIENCE.* 
 
 APPENDIX A. 
 
 MODERN PERIOD. 
 
 XVIIth CENT. 
 
 XVIIIth CENTURY. 
 
 XlXth CENTURY. 
 
 Beecher, C. 
 
 Anquetil 
 
 Lambert, M. 
 
 Adams, A. 
 
 Galle, A. 
 
 Oersted, P. 
 
 Bernouilli, 
 
 Duperron, S. 
 
 Laplace, M. 
 
 Agassiz, G. 
 
 Gauss, M. 
 
 Ohm, P. 
 
 Jas., M. 
 
 Attwood, P. 
 
 Lavoisier, C. 
 
 Airy, A. 
 
 Gerhardt, C. 
 
 Oken, B. 
 
 Boyle, P. 
 
 Avogadro, C. 
 
 Legendre, M. 
 
 Ampere, P. 
 
 Goethe, B. 
 
 Olbers, A. 
 
 
 
 Leslie, P. 
 
 Andrews, C. 
 
 Graham, 
 
 Orbigny, D', B. 
 
 Cassini, A. 
 
 Beccaria, S. 
 
 Linnaeus, B. 
 
 Arago, P. 
 
 Thorn., C. 
 
 Owen, B. 
 
 Colbert, S. 
 
 Bergmann, C. 
 
 
 
 Grimm, S. 
 
 
 
 Bernouilli, 
 
 Maclaurin, M. 
 
 Baer, Von, B. 
 
 Grove, P. 
 
 Pasteur, B. 
 
 Descartes, M. 
 
 Dan., M. 
 
 Maschelyne, A. 
 
 Ball, Sir R., A. 
 
 
 Perkin, C. 
 
 
 Bernouilli, 
 
 Monge, M. 
 
 Bates, B. 
 
 Haeckel, B. 
 
 Ferthes.B.de, B. 
 
 Flamsteed, A. 
 
 John, M. 
 
 Montgolfier, P. 
 
 Beaumont, Elie 
 
 Hall, Asaph, A. 
 
 Piazzi, A. 
 
 
 Berthollet, C. 
 
 Moro,Lazzaro,G. 
 
 de, G. 
 
 Hamilton, Sir 
 
 Pictet, P. 
 
 Gassendi, A. 
 Grew, B. 
 Grimaldi, P. 
 
 Black, C. 
 Blumenbach, B. 
 Boerhaave, B. 
 
 Murdoch, P. 
 Muschenbroeck, 
 P. 
 
 Becquerel, 
 A. C., P. 
 Becquerel, 
 
 W. R., M. 
 Helmholtz, P. 
 Herapath, C. 
 
 Pouchet, B. 
 Pouillet, P. 
 Prevost, G. 
 
 Guericke, P. 
 
 Bonnet, B. 
 
 
 A. E., P. 
 
 Herschel, Sir 
 
 Pruner Bey, B. 
 
 
 Bouguer, M. 
 
 Newcomen, I. 
 
 Bell, ' P. 
 
 J., A. 
 
 
 Halley, A. 
 Hevelius, A. 
 
 Boulton, I. 
 Bradley, A. 
 
 Nicholson, C. 
 
 Bentham, S. 
 Bernard, E. 
 
 Him, P. 
 Hodgson, A. 
 
 Quatrefages, B. 
 
 Hooke, P. 
 
 Buffon, B. 
 
 Playfair, G. 
 
 Berzelius, C. 
 
 Hofmann, C. 
 
 Regnault, P. 
 
 Horrocks, A. 
 
 
 Priestlty, C. 
 
 Bessemer, I. 
 
 Hooker, Sir 
 
 Retzius, B. 
 
 Huygens, A. 
 
 Camper, B. 
 Carlisle, C. 
 
 Quesnay, S. 
 
 Biela, A. 
 Biot, C. 
 
 W., B. 
 
 Huggins, A. 
 
 Ritter, P. 
 Ritter, G. 
 
 Leibnitz, M. 
 
 Carnot, M. 
 
 
 Bopp, S. 
 
 Humboldt, S. 
 
 Rumford, P. 
 
 Leuwenhoeck, B. 
 
 Cavendish, C. 
 
 Reaumur, B. 
 
 Boucher de 
 
 Humboldt, G. 
 
 
 
 Celsius, P. 
 
 Richter, C. 
 
 Perthes, B. 
 
 Huxley, B. 
 
 Sabine, P. 
 
 Malpighi, B. 
 
 Chladni, P. 
 
 Rousseau, S. 
 
 Brewster, P. 
 
 
 St. Hilaire, 
 
 Mariotte, P. 
 
 Colebrooke, S. 
 
 Rutherford, C. 
 
 Broca, B. 
 
 Jacobi, P. 
 
 G. de, B. 
 
 Mayow, C. 
 
 Cook, G. 
 Coulomb, P. 
 
 Saussure, De, G. 
 
 Brown, R., B. 
 Buch, Von, G. 
 
 Joule, P. 
 
 Schiaparelli, A. 
 Schleiden, B. 
 
 Newton, A. 
 
 
 Sauveur, P. 
 
 Buckland, G. 
 
 Keferstein, G. 
 
 Schwabe, A. 
 
 Noble, P. 
 
 Darwin, E., B. 
 
 Scheele, C. 
 
 Bunsen, P. 
 
 Kirchhoft, P. 
 
 Schwann, B. 
 
 
 Daubenton, B. 
 
 Smith, Adam, S. 
 
 Burnouf, S. 
 
 Kirk, P. 
 
 Scrope, G. 
 
 Papin, P. 
 Pascal, M. 
 Pecquet, B. 
 Petty. P. 
 Picard, M. 
 Pigot, P. 
 
 Ray, B. 
 Rivinus, B. 
 Roemer, A. 
 Rudbeck, B. 
 
 Savery, I. 
 
 Delisle, A. 
 De Saussure, G. 
 Dollond, P. 
 Du Faye, P. 
 
 Euler, M. 
 
 Fahrenheit, P. 
 Faye, Du, P. 
 Franklin, P. 
 
 Gall, B. 
 Galvani, P. 
 
 Smith, William, 
 G. 
 Spallanzani, B. 
 Sprengel, B. 
 
 Turgot, S. 
 
 Vicq d'Azir, B. 
 Volta, P. 
 
 Watt, I. 
 Werner, G. 
 Wollaston, C. 
 
 Cailletet, C. 
 Candolle, De, B. 
 Carrington, A. 
 Cauchy, M. 
 Champollion, S. 
 Chasles, M. 
 Chevreul, C. 
 Clausius, P. 
 Clerk Max- 
 well, P. 
 Comte, S. 
 Cooke, P. 
 
 r^^r,*> -r> 
 
 Knox, B. 
 
 Lamont, P. 
 Lescarbault, A. 
 Leverrier, A. 
 Liebig, C. 
 Lindley, B. 
 Lockyer, A. 
 Lyell, G. 
 
 McEnery, G. 
 Malthus, S. 
 Malus, P. 
 
 Sedgwick, G. 
 Seebeck, P. 
 Seguin, I 
 Senefelder, I. 
 i-erres, B. 
 Simpson, B. 
 Spencer, 
 Herbert, S. 
 Steinheil, P. 
 Stephenson, 
 G., I. 
 Stephenson, 
 R., I. 
 
 Scilla, G. 
 Stahl, C. 
 
 Gay-Lussac, C. 
 Graham, Geo., P. 
 
 
 Cope, D. 
 Crookes, P. 
 
 Mantell, G. 
 Marsh, B. 
 
 Talbot, P. 
 
 Stancari, P. 
 
 
 
 Cuvier, B. 
 
 Maury, G. 
 
 Tesla, P. 
 
 Steno, B. 
 
 Hales, C. 
 
 
 Daguerre, I. 
 
 Maxwell, 
 
 Thenard, C. 
 
 S wammerdam, B. 
 
 Hall, More, P. 
 
 
 Dalton, C. 
 
 Clerk, P. 
 
 Thomson, Sir 
 
 
 Hall, Sir J., C. 
 
 
 Darwin, C, B. 
 
 Mayer, P. 
 
 W., P. 
 
 Torricelli, P. 
 
 Haller, " B. 
 
 
 Davy, C. 
 
 Mellonf, P. 
 
 Tyndall, P. 
 
 Tournefort, B. 
 
 Wallis, M. 
 Willis, B. 
 Willughby, B. 
 
 Haiiy, G. 
 Hawksbee, P. 
 Helvetius, S. 
 Herschel, Sir 
 W., A. 
 
 
 De Morgan, M. 
 D'Orbigny, B. 
 Dove, G. 
 Dulong, P. 
 Dumas, C. 
 
 Mendelejeff, C. 
 Miller, C. 
 Mirbel, B. 
 Mitscherlich, C. 
 Mohl, Von, B. 
 
 Vauquelin, C. 
 Virchow, B. 
 Vogt, B. 
 
 Woodward. G. 
 Worcester, P. 
 
 Hunter, B. 
 Hutton, G. 
 
 
 Edison, I. 
 Encke, A. 
 
 Moldenhauer, B. 
 Morgan, De, M. 
 
 Wallace, B. 
 Watson, A. 
 
 
 Jenner, B. 
 Jussieu, De, B. 
 Jussieu, A. de, B. 
 
 
 Endlichtr, B. 
 
 Faraday, P. 
 Faure, P. 
 
 Morse, I. 
 MullerJ.Von.B. 
 Muller, Max, S. 
 Murchison, G. 
 
 Weber, P. 
 Wheatstone, P. 
 Whitworth, Sir 
 J-, I. 
 
 
 
 
 Fizeau, P. 
 
 
 Williams, Gre- 
 
 
 Klaproth, C. 
 
 
 Foucault, P. 
 
 Nageli, B. 
 
 Mlle, C. 
 
 
 
 
 Fraunhofer, P. 
 
 Nasmyth, I. 
 
 Wohler, C. 
 
 
 Lagrange, M. 
 
 
 Fresnel, P. 
 
 Niepce, I. 
 
 
 
 Lamarck, B. 
 
 
 Fultcn, I. 
 
 Nobili, P. 
 
 Young, P. 
 
 Inventor, Mathematician, Physicist, and Scciologist, taking these titles in their widest sense. X Music. 
 
APPENDIX AA. 
 
 DEFINITIONS OF THE SCIENCES. 
 
 Mathematics (Greek, /m^^ara, from pavdaveiv, to know). This 
 science is that of magnitudes (or of quantities) whether in time 
 or in space ; it bears upon rigorous truths which reason is capable 
 of discovering without the aid of experiments, but which, neverthe- 
 less, experiments can confirm. It is a deductive science so that 
 it is wrong to believe that deductive reasoning should be discarded ; 
 the fact being that both deductive and inductive reasoning must be 
 used in science both are equal in power. 
 
 Mathematics is an exact science par excellence. It is divided 
 into two chief branches : arithmetic (of which algebra is an offshoot), 
 or the science of numbers, and geometry and its offshoots (trigono- 
 metry, conic sections, mechanics, etc.), or the science of space 
 or extent. (A fuller subdivision is given at page 197.) 
 
 This science was cultivated from the earliest antiquity, in 
 Chaldaea, Egypt, India, and even China. It passed from Egypt into 
 Greece, where its limits were extended. It was reserved to modern 
 times to make mathematical discoveries and applications which may 
 be called sublime. 
 
 The practical importance of this science has been pointed out at 
 page 198. 
 
 Mechanics (/^x aI/7 7> a machine), that branch of mathematics 
 which considers the nature and laws of moving powers with their 
 effect in machines, and the nature, generation, and communication 
 of motion ; in other words, the science which treats of the laws 
 of equilibrium and motion, or which demonstrates the laws of 
 motion and mechanical combinations. 
 
APPENDIX A A. 315 
 
 Statics (o-rard?, remaining still). A branch of mechanics. That 
 branch of mechanics which considers the relations of forces which 
 act upon bodies at rest. 
 
 Dynamics (Swa/ik, force or power). A branch of mechanics. 
 That branch which treats of the action of force in producing motion. 
 It is divided into two parts : 
 
 Kinematics (uvelv, to move, to put in motion), which investigates 
 the circumstances of mere motion without reference to the bodies 
 moved, the forces producing motion, or to the forces called into 
 action by the motion ; 
 
 Kinetics (welv), which investigates the nature and relation of the 
 forces which produce motion. 
 
 Astronomy (farrpov, a star, i>o/*os, law) is the science of celestial 
 bodies. It includes every notion relating to planets and stars, to 
 their motions, distribution in space, their respective distances, their 
 physical constitution, and the reciprocal influence which they 
 exercise upon one another. 
 
 The utility of astronomy, apart from its sublimity, gives it the 
 first rank among sciences. Astronomy, in the first place, serves to 
 measure time and fix chronological periods ; secondly, to determine 
 the different points on the surface of the globe ; thirdly, to regulate 
 navigation. 
 
 This science although it degenerated into astrology at times, 
 and thus hardly deserved the name of science is one of the most 
 ancient ; but it was in modern times only that a real knowledge of 
 the constitution of the world was attained. 
 
 Geography (yy, earth, ypa$e/, to describe) is the description of the 
 earth ; it embraces everything relating to the state or condition 
 (either natural or artificial) of the globe which we inhabit. It is 
 divided into three branches : 
 
 (1) Mathematical geography, the object of which is to determine 
 the shape and dimensions of the earth, its relation to the heavenly 
 bodies, the relative positions and distances of places on its surface, 
 and the representation of the earth upon globes or maps ; 
 
 (2) Physical geography, the object of which is the description of 
 the principal features of the globe's surface (seas, continents, islands, 
 mountains, valleys, rivers) with their extent and configuration. 
 Meteorology and climatology belong to this branch, and hence, also, 
 the distribution of plants and animals in every part of the earth ; 
 
316 APPENDICES. 
 
 (3) Political geography, the object of which is to consider the 
 earth as the habitat of the human species. It defines the territories 
 of different nations, and treats of population, morals, religion, 
 government, wealth, civilisation. It might be considered as a branch 
 of history and statistics. 
 
 Geography has deserved the name of science only in modern 
 times, although the Arabs made great advance in it ; for in modern 
 times only have we arrived at a complete knowledge of our planet. 
 
 Geology (y), earth, Xdyos, discourse), or the science of the earth, 
 treats of the physical constitution of our globe. It is called 
 geognosy when it is limited to the study of the structure, the 
 respective situation, and the nature of the matter composing the 
 earth ; but it receives the name of geogeny when it aims at com- 
 bining observed facts in order to ascend to the causes, finding the 
 laws which regulated the formation, and explaining the very origin 
 of our globe. 
 
 This science is quite modern, although antiquity (Pythagoras, 
 Aristotle, and Strabo, for instance) had very clear notions about 
 geological problems; but until the Arabs and Leonardo da Vinci, 
 none of the germs of its study, which is one of persevering observa- 
 tion, can be said to have existed. 
 
 As a practical science it is hardly necessary to point out how 
 important to our material welfare the study of the earth's crust is, 
 especially in these days when mining has become the greates 
 industry of mankind ; in its philosophical bearings it is of greater 
 importance still, throwing light as it does upon the history of extinct 
 species and the antiquity of man. 
 
 Physics or Natural Philosophy (foais, nature). The most 
 extensive sense of natural philosophy is that which Sir John Herschel 
 has given to it, viz. : " to describe the phenomena of nature, to show 
 their cause?, and to analyse the constitution of the Universe." But 
 the study of nature has developed so immensely in recent times, 
 that natural philosophy has been divided into many branches, each 
 of which has received its characteristic denomination, such as heat, 
 optics, acoustics, magnetism, electricity, chemistry, etc. the last- 
 mentioned becoming an entirely distinct science. The chemist 
 studies the phenomena which depend upon the specific properties of 
 substances, whereas the physicist studies the phenomena which 
 result from the aggregate properties of bodies. At present, there- 
 fore, the name of natural philosophy is more or less restricted 
 to the knowledge of matter independently of the molecular composi- 
 tion of bodies. 
 
APPENDIX AA. 317 
 
 Archimedes's discoveries were, strictly speaking, the starting- 
 point of physics, but Galileo immensely extended the area of the 
 science by connecting isolated facts with general principles, and by 
 founding dynamics. To Aristotle we owe the scientific method of 
 studying the phenomena of nature, namely, observation, experiment, 
 and induction what is, in fact, called the inductive method. 
 
 It is scarcely necessary to add that science has been revolutionised 
 by the discoveries made in physics in modern times, and that 
 humanity is indebted to them for the increased prosperity it now 
 enjoys. 
 
 Barology (^apor, weight, or pdpeiv, to weigh down), the science of 
 weight (gravity) in solids, liquids, and gases. The study of gravity 
 in liquids is subdivided into four branches : 
 
 Hydrostatics (v8a>p ) water), the science of equilibrium of liquids 
 and of the pressure they exert, whether within their own mass or on 
 the sides of the vessels in which they are contained ; 
 
 Hydrodynamics is that branch of physics which considers the 
 motion of liquids ; 
 
 Hydraulics considers the application of liquid motion to machinery, 
 and the application of mechanical force to procure required motion 
 in liquids; in other words, hydraulics is the application of the 
 principles of hydrostatics to conducting and raising water in 
 pipes ; 
 
 Hydromechanics is concerned with the energy of machinery in 
 its application to fluids. 
 
 Thermology (0f'p/*7, heat), the science of heat, the phenomena of 
 which are, next to those of gravity, the most universal in the 
 economy of the world. Heat is the chief antagonist of gravity. 
 Gravity presides over the geometrical and mechanical action of 
 bodies, while heat relates either to the state of aggregation or the 
 composition of molecules. Gravity tends to agglomerate bodies, 
 heat tends to disintegrate or separate them. The application of 
 heat constitutes the chief action of man upon nature. 
 
 The study of heat is quite modern, since it was the great 
 discovery of Black (at the end of last century) which imparted to it a 
 scientific character. 
 
 Acoustics (aKovfiv, to hear) is the science which considers the 
 phenomena of sound. 
 
3i8 APPENDICES. 
 
 Optics (oTrro/icu, to see) considers the phenomena of light (and 
 vision). It is subdivided into : 
 
 Catoptrics (KUTOTTTPOV, a mirror) treats of the reflection of light ; 
 
 Dioptrics (SioTrrpiKos-, fit for seeing remote objects) treats of the 
 effects produced on rays of light passing through different media, 
 as through glass, water, air in other words, it treats of the refractions 
 of light ; 
 
 Diffraction is a change which light undergoes, when, passing very 
 close to the borders of an opaque body, it forms parallel bands or 
 fringes. 
 
 Electrology (fjXfKrpov, amber) is the science which considers the 
 phenomena and laws of electricity a subtle fluid or agent, usually 
 excited by friction. The phenomena of electricity are such as 
 attraction, repulsion, certain luminous appearances, physiological 
 effects, light, heat, mechanical violence, etc. It is the most powerful 
 agent with which we are acquainted. 
 
 Although it has exercised the attention of men ever since Thales 
 (600 B.C.), it has become a subject of study only since Gilbert (1600 
 A.D.). But it advanced only after Franklin and Volta. The services 
 it has rendered to science and the application of science, to the 
 material improvement of the social system, since it vies with steam in 
 procuring us the benefits to be derived from rapid intercommunica- 
 tion, are too numerous and too well known to necessitate more than 
 an allusion here. 
 
 Chemistry (\vp.ia, mixture). Physics is divided into two principal 
 branches physics and chemistry each distinct from, although in- 
 timately bound with, the other. Physics embraces the phenomena 
 and laws regulating the general properties of bodies regarded in the 
 mass ; chemistry embraces the particular phenomena modifying the 
 specific properties of matter it relates, not to masses, but to mole- 
 cules. Chemistry has, therefore, for its object the modifications that 
 all substances may undergo in their composition, alteration, decom- 
 position, in virtue of their molecular reactions. Without this new 
 order of phenomena, the most important operations of terrestrial and 
 celestial nature would be incomprehensible to us, and there is no 
 other class of phenomena so intimate and so complex. 
 
 Theoretical chemistry was until lately divided into inorganic 
 (mineral and gaseous) and organic (plants and animals) chemistry ; 
 but the more advanced chemists refuse to admit this distinction. 
 
APPENDIX A A. 319 
 
 Applied chemistry (or practical chemistry) is subdivided into many 
 branches medical, industrial, agricultural, etc. 
 
 It is a modern science, although chemical processes were known 
 in antiquity and the Middle Ages, since metallurgy, pottery, the use 
 of alkaline, acid, and saline substances, the preparation of drugs, 
 perfumes, colouring matters, were by no means unknown ; but the 
 want of knowledge of the laws which govern matter led experimental 
 observers into alchemy, or attempts to convert common metals into 
 gold. The alchemists, it must be owned, made many important and 
 useful discoveries, but the XVIth, XVIIth, and XVIIIth centuries 
 witnessed their gradual disappearance. Like steam, chemistry has 
 become one of the greatest elements of progress and wealth in the 
 world. 
 
 Biology (jStor, life) embraces the study of the phenomena of life, 
 whether vegetable or animal. Some of these phenomena are ex- 
 plained by the general laws of physics and chemistry ; others, on the 
 contrary, escape all explanation of that kind, and constitute what 
 may be called the vital phenomena properly speaking, and these are 
 the object of biology. This science therefore includes anatomy, 
 physiology (of plants and animals), palaeontology, and anthropology. 
 Biology may be said to have received its first impulse from the 
 anatomists of the Revival period. 
 
 Anatomy (dvd, across, re>i><, I cut), considered as a science apart 
 from dissection, is concerned with the study of organised beings 
 (whether vegetal or animal), to discover the organs and elementary 
 parts which enter into their composition, not only as regards form, 
 structure, connections, physical properties and functions, but also as 
 regards texture, chemical properties, developmem, and alteration. It 
 is the basis of zoology, physiology, and medical science, and there- 
 fore intimately bound to these. It is divided into human, compara- 
 tive, and vegetal anatomy. 
 
 The science originated among the Greeks, but in modern times 
 only was it cultivated with success after Mondini and Leonardo da 
 Vinci. 
 
 Physiology (^(m, nature) deals with the phenomena of life, and 
 is almost synonymous with biology yet, there is a difference, for if 
 in many instances the scope of biology and physiology is absolutely 
 identical, biology embraces the phenomena of life which are more in- 
 timately bound with the exterior world that is, the most general 
 phenomena of life, whilst physiology is more intimately bound with 
 the classes of phenomena which affect particular individual orders 
 
320 APPENDICES. 
 
 of beings (vegetal or animals). The phenomena resulting from 
 change of habitat, food, temperature, health would fall more within 
 the domain of physiology than within that of biology. The fact that 
 physiology may affect the moral and political sciences makes it one 
 of the most important studies we can pursue. 
 
 This study may be said to have been originated by the Greeks, 
 but in recent times only has it been completely detached from meta- 
 physics, which impeded its progress. 
 
 Botany (pordvr), a plant) is concerned with the study of the 
 vegetable world. It is of extreme antiquity, but modern botany was 
 inaugurated by Linnaeus and Jussieu. 
 
 Zoology (&OV, animal) is that part of natural history which treats 
 of animals. It embraces the study of exterior organs (descriptive 
 -zoology), interior organs (comparative anatomy), and the functions 
 of each organ (which is a section of physiology). The ancients, 
 Pliny particularly, left very interesting descriptions of animals. The 
 science was revived by Gesner in the XVIth century. It has been 
 immensely extended in recent times. 
 
 Palaeontology (jraXaios, ancient, &v, ovros, being). This science 
 treats of the beings whose remains are found buried in the crust of 
 the earth, or who lived at different geological periods before the 
 species which inhabit its surface at the present time. This term is 
 generally applied to the study of fossil zoology, but it also refers to 
 the fossil vegetable kingdom, so that palaeontology is an extension 
 of botany and zoology. It is, of course, closely connected with 
 geology, and is, like the latter, of modern growth. 
 
 Anthropology (avdpcvrros, man) is the natural history of man con- 
 sidered and studied in his diverse varieties. It is altogether of 
 recent origin. It will acquire the greatest importance when time 
 has matured its results, for laws and governments will be framed 
 more in accordance with the physical and mental requirements of 
 each race than in accordance with tradition and abstract ideas. 
 
 Sociology (sociuS) an ally), or social science, treats of every 
 question relating to the organisation and well-being of communities. 
 It embraces therefore, jurisprudence, government, education, 
 punishment, legislation, public morality, public health, and political 
 economy. Of all these, political economy was the latest founded, at 
 the end of last century. 
 
APPENDIX AA. 321 
 
 Philology (<{>i\os, lover, Xoyoy, language) is the study of languages. 
 As an instrument of historical research and anthropological study 
 especially in questions of origin, descent, and race philology has 
 proved one of the most interesting and fruitful branches of human 
 knowledge. On the Continent, comparative philology has received 
 the name of linguistique, the term philology referring only to the 
 study of a particular language in its entirety (/.., grammar, etymology, 
 lexicology, filiation, interpretation, and criticism). Philologists are 
 inclined to settle question of origin and distinctions of race by philo- 
 logy ; but we must beware of hasty conclusions of this kind, for 
 identity of speech by no means implies identity of race ; distinction 
 of race mainly rests upon physical and mental characteristic 
 differences which are not affected by language ; in other words, a 
 form of speech may have spread by conquest or otherwise to 
 different races, and these races remain distinct, the co-existence 
 of speech notwithstanding. 
 
APPENDIX I. 
 ARISTOTLE ON EXPERIENCE. 
 
 1. " Let us first understand the facts, and then we may seek for 
 the cause." (De Part. I. i, 639.) 
 
 2. " Reasons not drawn from the inherent principles of things 
 are hollow. The hollow argument seems potent, but is powerless." 
 (De Gener. Animal. HI. 10, 760.) 
 
 3. "There are not facts enough to warrant a conclusion, and 
 more dependence must be placed on facts than on reasonings, which 
 must agree with facts." (On the Parthenogenesis of Bees, De Gen. 
 Animal. HI. 10, 760.) 
 
 4. " The peculiar principles indeed in every science are many, 
 hence it is the province of experience to supply (furnish) the prin- 
 ciples of everything ; for, from phenomena being sufficiently appre- 
 hended, demonstrations have thus been invented (found) in every 
 art and science." (Prior Anal. i. 30.) 
 
 5. lt From sense, therefore, as we say, memory is produced, but 
 from repeated remembrance of the same thing, we get experience, 
 for many remembrances constitute one experience." (Post An. n. 
 18.) 
 
 6. "The reason why men do not sufficiently attend to facts 
 is their want of experience. Those who are accustomed to physical 
 inquiries are more competent to lay down the principles which have 
 an extensive application. It is easy to distinguish those who argue 
 from facts and those who argue from notions." (De Gen. i. 2, 316.) 
 
 7. "We do not possess scientific knowledge through sensation, 
 neither is sense science, though they are employed about the same 
 things, for sense apprehends particulars (facts), science universals 
 (laws)." (Post Anal. i. 31.) 
 
APPENDIX I. 323 
 
 8. " Some philosophers, treating of phenomena, say things which 
 by no means correspond with the phenomena the cause being 
 that they have not rightly conceived principles, but reduce every- 
 thing to prescribed notions, and they persist in these, despite all the 
 contradiction which phenomena give them." (De Coelo n. 13 ; 
 in. 8.) 
 
 (Is not this last citation the severest censure ever passed on the 
 schoolmen's process and Bacon's work ?) 
 
 9. " Aristotle's reliance was on experience and induction the 
 one furnishing (particular) facts, from which the other found a path- 
 way to general facts (laws)." This remark is quoted from the 
 Life of Aristotle by G. H. Lewes, who cites numerous passages from 
 Topics L 10, also Post Anal. i. 31, Hist. Animal, i. 6, in support 
 of it. Our limits do not allow us to do more than refer to the works. 
 
 10. " Without sensation thought is impossible. It is from sense 
 that we gain knowledge of particulars (facts). It is from induction 
 that we gain knowledge of universals (laws) and these can be reached 
 only through experience." 
 
 This is a summary of what is explained in De Sensu vi. 445 ; 
 De Anima m. 3, 8, 432 ; Metaph. iv. 5, and elsewhere. 
 
 11. We have to remind the reader that Aristotle's Organon 
 includes 242 chapters, and is all devoted to the elucidation of the 
 Syllogism, Induction, and Experience so that the quotations we 
 have given are but an insignificant fraction of the whole ; but they 
 will, we think, be sufficient to prove Aristotle's lucidity and com- 
 petence. 
 
 Y 2 
 
APPENDIX II. 
 
 ARISTOTLE ON INDUCTION. 
 
 1. " Induction is nothing but the Syllogism without a middle 
 term." (Prior Anal. n. 12.) 
 
 2. " Induction is the pathway which leads from the particular to 
 the general." (Topics i. 10.) 
 
 3. "There is no induction without generality." (Pr. An. 
 
 II. 22.)* 
 
 4. " Induction is a progression from singulars to universals. . . 
 It is more persuasive, clear, more known according to the sense, and 
 common to many things ; syllogism, on the other hand, is more 
 cogent and efficient against opponents in disputation " (on account 
 of the presence of the middle term). (Top. i. 12.) 
 
 5. " We believe all things either through syllogism or from in- 
 duction. . , . Induction, then, is the inductive syllogism. ... It 
 is occurrent in those demonstrations which are proved without a 
 middle term. . . . Induction is more evident" (because general). 
 (Prior An. n. 23.) 
 
 6. "Universals (general laws) depend upon induction, but in- 
 duction depends upon sense." ..." It is (also) clear that if any 
 sense be deficient, a certain science must also be deficient (i.e., a 
 blind man could not study colours, astronomy) . , . since we learn 
 either by induction or by demonstration. Now, demonstration 
 is from universals, but induction from particulars (/.<?., particular 
 facts). ... It is impossible for those who have no sense to make 
 an induction, for sense is conversant with singulars (i.e., particular 
 facts), since the knowledge of them cannot be received, nor can 
 that knowledge be obtained from universals without induction > 
 nor through induction without sense." (Post An. i. 18.) 
 
 * " f] cnroTwv KCL& e'/caoroi/ fin ra KadoXov c(po8os." 
 
APPENDIX III. 
 
 ARISTOTLE ON SYLLOGISM. 
 
 1. "A syllogism is a sentence in which ascertained things being 
 laid down, something else different necessarily results, in consequence 
 of their existence." (Examples are given all through. Prior An. 
 
 1. 1.) 
 
 2. "A syllogism, then, is a discourse in which certain things 
 being laid down, something different from the posita (premises) 
 happens from necessity through the things being laid down." (Top. 
 n. i.) 
 
 3. " Evidently, then, all syllogisms are produced through the 
 middle figure." (Pr. An. n. 12.) 
 
 4. " The enthymeme is a kind of syllogism a short syllogism 
 an argument of two propositions one antecedent, another a 
 consequence deduced therefrom." 
 
 5 . " The enthymeme is that discourse which forces consent 
 through propositions assented to." (Rhet. n. 22, Pr. An. n. 27.) 
 
 In like manner are all the different kinds of syllogism, the 
 catasyllogism (Pr. An. n. 19), the parasyllogism (Top. I. i), the 
 elenchus (Pr. An. n. 20), the epichereme (Top. n. 5, vm. n), and 
 others, defined and explained. 
 
 We have only to add that Aristotle, having shown the laws of 
 the syllogism and its many varieties, and furnished examples to 
 illustrate its transformations in all ways, never used, nor taught any 
 one to use, the syllogistic method (i.e., the schoolmen's process) in 
 any of the rational or experimental sciences. The schoolmen 
 reduced Aristotle's process to a mere method of argumentation. 
 
APPENDIX IV. 
 
 LEONARDO'S PHYSICS. 
 
 Dr. Whewell, who seems to have studiously screened from view 
 the claims of Leonardo da Vinci to be considered as a powerful 
 exponent and advocate of experiment and induction more than a 
 century before Bacon, has to acknowledge Leonardo's greatness as a 
 scientist. 
 
 1. " Leonardo," he says, "understood before Stevinus the oblique 
 action of pressure ; 
 
 2. " Entertained the hypothesis of the earth's rotation ; 
 
 3. "Gave a perfectly correct statement of the proportions of the 
 forces exerted by a cord which acts obliquely and supports a weight 
 on a lever. He distinguishes between the real levers and the 
 potential levers ; i.e., the perpendiculars drawn from the centre upon 
 the directions of the forces. Nothing can be more entirely sound 
 than this. It is quite as good as the proof of Stevinus. These 
 views must have influenced Galileo's reasonings concerning the 
 lever. 
 
 4. " Leonardo," he goes on, " also anticipated Galileo in assert- 
 ing that the time of descent of a body down an inclined plane is to 
 the time of descent down its vertical height, in the proportion of the 
 length of the plane to the height." 
 
 The reflection which these quotations suggest, Dr. Whewell has 
 the good grace to own, is that " both the heliocentric doctrine and 
 truths of mechanics were fomenting in the minds of intelligent men, 
 and gradually assuming clearness and strength, some time before 
 they were publicly asserted." 
 
 And this being the case, what are we to think of Dr. WhewelFs 
 award of the palm of knowledge and influence to one who knew 
 
APPENDIX IV. 327 
 
 nothing of such matters, and scorned them as trumperies if they 
 were pointed out to him ? It is simply incredible and yet it is a 
 fact. 
 
 It would have been easy for Dr. Whewell to give a fuller and 
 more adequate sketch of Leonardo's scientific worth, had he been 
 animated by a sincere desire to tell the whole truth and nothing 
 but the truth, instead of seeking to inflate a huge air-bag, for 
 he had only to quote the language of the great Italian which we 
 have cited (pp. 104 107), or give the passages which show that 
 Leonardo understood before Galileo the problem of the acceleration 
 of velocity in falling bodies : 
 
 5. " If a weight falls from 200 fathoms, how much quicker will 
 it fall through the second 100 fathoms than through the first 100 
 fathoms " (le seconde cento braccia che le prime).* 
 
 6. When we bear in mind that Leonardo was a musician, an 
 inventor, a mechanist, a chemist, an engineer, an anatomist, a poet, 
 a painter of the highest order, besides being a philosopher, a mathe- 
 matician, a physicist, a geologist, an artillerist (for there exist in the 
 British Museum specifications, with drawings by himself, of a steam- 
 cannon which he suggested !), it is doubtful whether the world ever 
 saw a genius so universal and marvellous as this great man. He 
 had, beyond all others, that practical and scientific training which 
 enabled him to formulate the law of research with the authority of 
 a thorough master who had manipulated and investigated all he 
 spoke about. Yet, we find people who do not even deign to 
 mention Leonardo among inductive philosophers a judgment on 
 their part which it is only charitable to ascribe to ignorance. 
 
 * For further information see Ventori's Essay on Galileo's Physics, 
 and Essay on the Physico-Mathematical Works of Leonardo. Paris, 
 I797- 
 
APPENDIX V. 
 
 SIR DAVID BREWSTER ON INDUCTION. 
 
 "In a letter from Tycho Brahe to Kepler, the great observer 
 urges his pupil ' to lay a solid foundation for his views by actual obser- 
 vations, and then by ascending from these to strive to reach the cause 
 of things: " 
 
 " The reasonings of Copernicus, who preceded Bacon by more 
 than a century, were all founded upon the most legitimate induction." 
 
 " Leonardo da Vinci had described in the clearest manner the 
 proper method of philosophical investigations." 
 
 "The whole scientific career of Galileo was one continued 
 example of the most sagacious application of observation and ex- 
 periment to the discovery of general laws." 
 
 "Dr. Gilbert had exhibited in his treatise on the Magnet the 
 most perfect specimen of physical research." (Newton, p. 331.) 
 
APPENDIX VI. 
 
 DESCARTES' ACHIEVEMENTS. 
 
 As the short notice we have on Descartes fails to do full justice 
 to this great man, a few more remarks about him will not be 
 inappropriate. 
 
 His influence is twofold : philosophical and scientific. It is 
 easy to detect the consequences of Descartes' philosophy on the 
 one hand, and those of his scientific labours on the other. 
 
 His Philosophy, in the first place, ruined Scholasticism defini- 
 tively ; in the second place, it brought in the taste for psychological 
 analysis, which was to distinguish the age of Louis XIV. ; in the 
 third place, it supplied material for Idealism, Pantheism, Mate- 
 rialism, and Positivism, since it gave birth successively to the 
 philosophy of Malebranche, to Spinoza's, to Leibnitz's, Locke's, 
 Berkeley's, Hume's, Cabanis's, Condillac's, and, through Spinoza, to 
 Kant's, Schelling's, Fichte's, Hegel's, and last, Comte's. 
 
 With reference to Science, he was the first in modern times to 
 sketch the theory of association of ideas (see Aristotle); he dis- 
 covered the theory of reflex action a profound idea which modern 
 science has expounded. He analysed musical sounds geometrically, 
 and found out that the number of vibrations producing the notes 
 are in the inverse ratio of the lengths of the chords; he was the 
 first to maintain that Major Thirds are not discordant but con- 
 cordant. But his greatest scientific feat was mathematical his 
 application of algebra to geometry extended the power of mathe- 
 matics tenfold, and made the road of Newton, Laplace, Legendre, 
 Gauss, and others less arduous to ascend. By his inquiry into the 
 nature of certainty his best known claim upon us " he stands as 
 the founder, not of modern philosophical criticism only, but of 
 
330 APPENDICES. 
 
 modern philosophy itself" (Huxley). And look at the effect 
 suddenly produced by the appearance of a genuine philosopher ! 
 Descartes' influence was immediate and lasting. No sooner had 
 he conceived his philosophical scheme than an immense sensation 
 was created throughout Europe. He was at once read, discussed, 
 commented, admired in every country. His reputation was so 
 universal that Queen Christina invited him to come to her. His 
 " Physics," though unsound, (?) were nevertheless taught everywhere 
 for one hundred years, so commanding was his influence. His 
 theory of Vortices at least propagated the general notion of regular 
 laws. If his doctrine of Vortices was discredited, the cause must 
 not be sought in the fact, as some think, that it was intrinsically 
 absurd and inconceivable, but in the fact that it could not give 
 results in accordance with the heavenly bodies (Jevons). Besides, 
 may it not be said to be revived in a different form by the theory of 
 Vortices of Helmholtz and Thomson (Lord Kelvin) ? 
 
 The Cartesian School the effect of which was the complete 
 severance of ethics from revealed theology affected all the branches 
 of moral philosophy logic, ethics, theology, metaphysics and 
 bears witness to the weight and greatness of its founder. It may 
 be doubted whether any genius, ancient or modern, Aristotle and 
 perhaps Galileo and Newton excepted, ever exercised so powerful 
 and universal an influence as Descartes, considering the impulse 
 which his ideas, doctrines, and principles gave to philosophical 
 thought and scientific activity. 
 
INDEX. 
 
 ABBA Mari, "Almagest," 40. 
 Abbon of St. Germain, 48. 
 Abdallatif, Animals and Plants, 
 
 Nile Mud, 41. 
 Abderrahman III., 30. 
 Abelard, 44, 65. 
 Aberration of Fixed Stars, 203. 
 Abn Othman, Zoology, 41. 
 Abolition of Torture, 155, 304. 
 Aboul Hassan, Diopters, 34. 
 
 Rihau, Ecliptic, Quadrant, 34. 
 
 Wefa, Variation (of the 
 
 Moon), Obliquity, 34. 
 Abur Raihan, Tables of Sp. Gr., 37. 
 Academy del Cimento, 6j. 
 Accumulation of Astronomical 
 
 Facts in the XVIIIth Century, 
 
 272. 
 
 Accumulator, Electric, 257. 
 Accuracy of Instruments, 268. 
 Achillini, 62, 96. 
 Acids, 37, 38. 
 Acoustics, 219, 220, 227 ; Definition 
 
 of, Appendix AA. 
 
 Acquirements in Islam and Christen- 
 dom, 46. 
 Aerolites, 212. 
 Aerometer, 42. 
 Aerostation, 224. 
 Affiliation of Discoveries, 73. 
 Agassiz [Geol.], 144; Ice Age, 167. 
 Age of Engineering, 275. 
 
 Machinery, 275. 
 
 Steam and Electricity, 274. 
 
 Steel, 262, 263, 275, 283. 
 
 Agricola, 56, 98. 
 
 Air, Pressure and Weight of, 192,. 
 215, 216. 
 
 Air Pump, 216, 219. 
 
 Al Batani (Albategnius), The Year, 
 Tables, 33. 
 
 Al Beithar, Botany, 41. 
 
 Alberti, 97. 
 
 Albert of Saxony, 44. 
 
 Albertus Magnus, 44,65 ; Work of, 
 74, 90 (note). 
 
 Alberuni, Minerals, 41. 
 
 Albucasis, Surgical Instruments, 39. 
 
 Albumazar, Tables, 33. 
 
 Alchemy, Importance of, 70, 72. 
 270, 283. 
 
 Alchid Bechir, Phosphorus, 38. 
 
 Alcohol, 37. 
 
 Alcoholometer, 232. 
 
 Alcuin, 47. 
 
 Alessandra da Spina, 53. 
 
 Alexandria, 19. 
 
 Alexandrian Museum, 19, 27. 
 
 Al Farabi, Respiration of Plants, 
 41. 
 
 Alfergani, Astronomical Calcula- 
 tions, 33. 
 
 Alfred the Great, 47. 
 
 Algazzali, Certainty of Knowledge,. 
 42. 
 
 Algebra, 33, 44, 53, 56. 
 
 applied to Geometry, 191.. 
 Double, 196. 
 
 Alhakem's Library, 43. 
 
 Alhambra, 31. 
 
332 
 
 INDEX. 
 
 Alhazen, Density of Atmosphere, 
 Nature of Vision, Optics, Re- 
 fraction, Retina, 35 ; Atmospheri- 
 cal Refraction, Capillary At- 
 traction, Centre of Gravity, 
 Convex Lens, Gravity, Height 
 and Weight of the Atmosphere, 
 Hydrostatics, Twilight, Velo- 
 cities, 36; Hydrometer, Physio- 
 logy, Specific Gravity of Liquids, 
 Tables of Specific Gravity, 37; 
 Doctrine of Evolution, 37. 
 
 AH, 29. 
 
 Al Idrisi, Geography, Globe, 41. 
 
 Alkalimeter, 232. 
 
 " Almagest," 40. 
 
 Al Mamun, 29 ; Obliquity of the 
 Ecliptic, Degree, 33. 
 
 Al Mansor, 29. 
 
 Alpinus, 63, 97. 
 
 Altitude of Mountains, 203. 
 
 Ambrosius (Bishop), 51. 
 
 America, 282. 
 
 Ampere (Physicist), 283 ; his Rule, 
 231 ; the Founder of Electro- 
 dynamics, 231 ; his Law, 232. 
 
 Analysis, Chemical, 210, 242. 
 Five Methods of, 248. 
 of Orbits of Planets, 212. 
 Qualitative, 249. 
 Quantitative, 249. 
 Spectrum, 210. 
 
 Analytical Functions, 194. 
 Geometry, 193. 
 Mechanics, 195. 
 
 Anatomists, Discoveries of, see 
 Discoveries. 
 
 Anatomy, 22, 27, 38, 57, 60, 62, 63, 
 96,116,269; Def. of, Appendix AA. 
 
 Anaxagoras, 9. 
 
 Anaximander, 8. 
 
 Ancestry of the English People, 283. 
 
 Ancients (The), our Juniors by 2,000 
 Years, 18. 
 
 Angilbert, 47. 
 
 Animal Electricity, 224. 
 
 Animals and Plants of Egypt, 41. 
 
 Anquetil Duperron [Philologist], 
 152. 
 
 Anthropologists, Discoveries of, see 
 
 Discoveries. 
 Anthropology, 148, 276 ; Definition 
 
 of, Appendix AA. 
 Antiquity, Drawbacks to Science 
 
 in, 15. 
 
 of Man, 1 1 6, 129, 130, 
 142, 146-149, l6 7> 170- 
 Political Economy in, 1 7. 
 
 Science in, 15. 
 
 Antonio de Dominis, 59. 
 Apollonius, 24. 
 Apparatus, 38 ; Calculating, 192 ; 
 
 Ringing, 240. 
 Appendix A., Eminent Men of 
 
 Science. 
 AA., Definition of the 
 
 Sciences. 
 
 I., Aristotle on Ex- 
 
 perience. 
 
 II., Aristotle on In- 
 
 duction. 
 III., Aristotle on the 
 
 Syllogism. 
 
 IV., Leonardo's Physics. 
 V., Brewster on In- 
 
 duction. 
 
 VI., Descartes' Achieve- 
 ments. 
 Apsides, 25. 
 Aquapendente (Fabricius ab), 56, 
 
 96. 
 
 Aquinas (Thomas), 65, 90 (note). 
 Arabian, Arts of Life, 31 ; Astro- 
 nomy, 33 ; Chemistry, 37 ; Chi- 
 valry, 31; Cities, 29; Civilisation 
 (Grandeur of), 29 ; College of 
 Music, 31 ; Commerce, 32 ; Con- 
 tributions to Progress, 43 ; Dis- 
 coveries, 46; Horses, 31 ; Houses, 
 32 ; Industry, 32 ; Intellect, 29 ; 
 Libraries, 43 ; Men of Science, 
 43; Merchant Navy, 31, 32; 
 Palaces, 32 ; Physicians, 38 ; 
 Policy, 29 ; Positive Philosophy, 
 42 ; Practical Science, 40 ; Re- 
 venue, 32 ; Trade, 32 ; Wealth, 
 
 32- 
 Arabs, 283. 
 
INDEX. 
 
 333 
 
 Arabs, in the Van of Civilisation for 
 Centuries, 48. 
 
 Arabs, the Precursors of Modern 
 Science, 49. 
 
 Arago [Physicist], 228, 229, 234, 
 239, 241. 
 
 Arantus, 62, 97. 
 
 Archimedes, 22. 
 
 Aristarchus, 23. 
 
 Aristophanes ("Clouds" of), 13. 
 
 Aristotle, 7, 9, 21, 39. 
 
 Aristotle, Inductive Process of Re- 
 search, 10 ; Organon, 10 ; Syllo- 
 gism, II ; on Evolution, 12 ; the 
 Father of Inductive Philosophy, 
 12 ; on Natural History, 12 ; on 
 Physiology, 12; on Association 
 of Ideas, 13 ; on Astronomy, 13; 
 on Physics, 13 ; on Politics, 13; on 
 Psychology, 13 ; the Founder of 
 Science, 14 ; the Founder of the 
 Objective Method, 14; Correction 
 of Eudoxus' Discoveries, 13 ; on 
 Experience, Appendix I. ; on In- 
 duction, Appendix II. ; on the 
 Syllogism, Appendix III. 
 
 Arithmetic, 44. 
 
 Arithmetica infinitorum, 193. 
 
 Armils (armillary spheres), 15, 23. 
 
 Arnault de Villeneuve, 44. 
 
 Artefius, Minerals, Soap, 41. 
 
 Artificial System, 114. 
 
 Artillery, 42 ; Moorish, 52 (note). 
 
 Arts, Practical, 64. 
 the Plastic, 64. 
 
 Aryan Languages, 152. 
 
 Arzachael, Obliquity, 34. 
 
 Asellius, 63, 97. 
 
 Assamsh, Statistics and Topo- 
 graphy, 41. 
 
 Asteroids, Discovery of, 207. 
 
 Astrolabe, 15, 25, 42. 
 
 Astrology, Importance of, 72. 
 
 Astronomers, Discoveries of, see 
 Discoveries. 
 
 Astronomy, 44, 61, 100, 198, 261, 
 269, 271, 272, 280, 281. 
 
 Astronomy, Definition of, Appendix 
 AA. 
 
 Astronomy, General Remarks on, 
 
 215. 
 
 in Chaldaea, 5. 
 in Egypt, 5. 
 
 in Greece, 7-9, 13, 2O r 
 
 21, 23-27. 
 
 in Islam, 33-35. 
 Atmosphere, Density, 35 ; Height, 
 36 ; Refraction, 36, 37 ; Weight,, 
 103. 
 Atmospheric Laws, 272. 
 
 Phenomena, 224. 
 Atomic Bombardment, 255. 
 Energy, 258. 
 Heat (Law of), 183. 
 Law, 283. 
 System, 179. 
 Theory, 179. 
 Weights, 183. 
 Atoms and Molecules, 258. 
 Attraction (Capillary), 36, 193 ; 
 
 (Chemical), 219. 
 Attwood [Physicist], his Machine,, 
 
 225. 
 
 Authority in Islam and Christen- 
 dom, 45. 
 
 Authors Consulted, xix. 
 Avenzoar, see Ebn Zoar. 
 Averroes,"Colliget" (medical work),, 
 Comments on Aristotle, In- 
 fluence of, Sun Spots, 39. 
 Aviaries, 43. 
 
 Avicenna, " Canon " of Medicine, 
 38 ; Encyclopaedia, Fossils, Free 
 Inquiry, Geological Formations, 
 Medical Plants, Small-pox, 39. 
 Avicenna, Influence of, 39. 
 Avogadro [Chemist], his Law, 185. 
 
 BABBAGE, 254. 
 
 Bacon, F., behind his Age in 
 
 Science, 108. 
 Bacon's "New Atlantis," 14; his 
 
 Claim as a Natural Philosopher, 
 
 108. 
 Bacon, R., 44, 52, 65, 72, 74, 75, 
 
 270, 283. 
 Bacon, R., his Work, Discoveries, 
 
 and Errors, 75 ; his Correct No- 
 
334 
 
 INDEX. 
 
 tions, 76; Criticism of Aristotle 
 and " Offendicula," 77 ; on Ex- 
 periment, 78 ; Founder of the Ex- 
 perimental School, 78, 89 ; Ency- 
 clopaedic Mind, 79 ; a Mathema- 
 tician, 81, 82 ; a Chemist, 82 ; a 
 Physicist, 83 ; an Astronomer, 
 86 ; his Reform of the Calendar, 
 86; attacks the Ptolemaic System, 
 88 ; his Confidence in Science, 89; 
 a Pupil and " Continuator" of the 
 Arabs, 90 ; one of the Five Great 
 Men of Ten Centuries, 90. 
 
 Bacon, R. v. Bacon, F., x., xiv., 74. 
 
 Baer (Von) [Biol.], Founder of Em- 
 bryology, 132, 138. 
 
 Bagdad, 29. 
 
 Baily [Physicist], 223. 
 
 Bain [Physicist], 240. 
 
 Balance, 62, 223, 267 ; Torsion, 174. 
 
 Balfour Stewart, 244. 
 
 Balloons, 233. 
 
 Banks, 299 (note). 
 
 Barbarossa, 65. 
 
 Barology, 102, 272 ; Definition of, 
 Appendix AA. 
 
 Barometer, 215, 218, 267. 
 
 Barometric Manometer, 241. 
 
 Basalt, 161. 
 
 Bates [Biol.], 144. 
 
 Battery, 225; Electric, 267; Gas, 
 242 ; Voltaic, 227 ; Thermo- 
 electric, 236. 
 
 Battle of Humanity against In- 
 justice won by Benefactors, 308. 
 
 Bayonet, 300. 
 
 Beaumont (Elie de) [Geol.], 167. 
 
 Beccaria [Sociol.], 155. 
 
 Becquerel [Physicist], 246. 
 
 Bede, 48 (note). 
 
 Bell (Graham), 264. 
 
 Belon, 61. 
 
 Ben Corrah, The Year, Anatomy of 
 Birds, 34. 
 
 Ben Ezra, Travels, Practical Medi- 
 cine, 40. 
 
 Benefactors, Great Social, 307. 
 
 Benefits (Material) from Electri- 
 city, 294. 
 
 Benefits (Material) from Hand, 
 Water, Wind, and Flour Mill, 
 291, 292. 
 
 Benefits (Material) from Industries, 
 
 293- 
 
 Benefits (Material) from Meteo- 
 rology, 294. 
 
 Benefits (Material) from Physical 
 Geography, 294. 
 
 Benefits (Material) from Pure 
 Science, 293, 294. 
 
 Benefits (Material) from Steam, 294. 
 
 Benefits (Moral) from Political 
 Economy, 299; from 'Science 
 generally, 300-309. 
 
 Ben Musa, Algebra, Indian Nume- 
 rals, 33. 
 
 Berenger, 48. 
 
 Bergmann [Chemist], Crystallo- 
 graphy, Theory of Chemical Af- 
 finities, 176, 248. 
 
 Bernard [Physiol.], 127. 
 
 Bernouilli (Daniel) [Math.] 194, 
 
 255. 
 
 (James) 193. 
 (John) 194,227. 
 
 Berosus, 21. 
 
 Bertholinus [Physicist], 217 (note). 
 
 Berthollet [Chemist], Laws of Mix- 
 ture, 178. 
 
 Berzelius [Chemist], Blowpipe, De- 
 termination of Atomic Weights, 
 182,248,283. 
 
 Bessel, 245. 
 
 Bessemer, 262, 263, 283, 285. 
 
 Bessemer Steel, 263. 
 
 Beverley (John of), 48 (note). 
 
 Bill of Exchange, 299 (note). 
 
 Binary Stars, 204, 209. 
 
 Biological Group, 113; Remarks 
 on, 158. 
 
 Biologists, Discoveries of, see Dis- 
 coveries. 
 
 Biology, 60, 127, 273, 276, 210, 
 
 281. 
 Definition of, Appendix 
 
 AA. 
 General Remarks on, 158. 
 
 Biot [Physicist], his Law, 230. 
 
INDEX. 
 
 335 
 
 Black [Chemist], Latent Heat, 230. 
 
 Blowpipe, 182. 
 
 Blumenbach [Anthropol.], 148. 
 
 Boccaccio, 65, 66. 
 
 Bode's Law, 103, 206. 
 
 Boerhaave [Physiol.], Founder of 
 Organic Chemistry, 124, 273. 
 
 Boiler (Tubular), 261. 
 
 Boiling Point, 220. 
 
 Bombardment of Particles, 258. 
 
 Bonaventura, 44. 
 
 Bonnet [Physiol.] held the Doctrine 
 of Progressive Evolution, 125. 
 
 Book (The), 293. 
 
 Boole [Math.], 196. 
 
 Bopp [Philologist], 152. 
 
 Botanists, Discoveries of, see Dis- 
 coveries. 
 
 Botany, 21, 41, 44, 61, 62, 96, 113 ; 
 Definition of, Appendix AA. 
 
 Boucher de Perthes [Anthropol.], 
 149. 
 
 Boulton, 261. 
 
 Boyle [Chemist], Combustion, his 
 Law, 172, 274. 
 
 Boyle's Law, 172 ; Deviation from, 
 241. 
 
 Brain (The), 22, 27. 
 
 Bradley [Astron.], 203, 272. 
 
 Bramante, 64. 
 
 Brewster on Induction, xviii., Ap- 
 pendix V. 
 
 Brewster as a Physicist, 210, 233. 
 
 Bridge (Tubular), 262. 
 
 Britain, 27. 
 
 Broca [Anthropol.], 150. 
 
 Brown [Physiol.], 126. 
 
 Browning (J.) [Physicist], 210. 
 
 Browning's Voice, 264. 
 
 Bruno, 58, 97, 270. 
 
 Buch (Von) [Geol.], 138, 163. 
 Buckle quoted, 293. 
 
 Buffon [Naturalist and Biologist], 
 held the Doctrine of Organic 
 Evolution, 117, 273. 
 
 Bunsen [Chemist and Physicist], 
 
 241, 242, 247, 248, 282. 
 Burgess Class, 68. 
 Burnouf [Philologist], 152. 
 
 C^ESALPINUS, his Classification, 61, 
 
 96, 97, 269, 283. 
 Caesar, 26, 246. 
 Cailletet [Chemist and Physicist], 
 
 234, 256. 
 
 Calculating Apparatus, 192. 
 Calculus, Differential, 193. 
 
 " Exponential, 194. 
 
 of the Indivisible, 101. 
 
 Infinitesimal, 195. 
 
 Integral, 194 
 
 of Probabilities, 193, 194, 
 195. 
 
 of Variations, 194. 
 Calendar, 4 ; Julian, 26, 58, 86. 
 Calippus (Cycle of), 21. 
 Callisthenes, 6, 11. 
 Calorimeter, 226 ; Ice, 226, 242. 
 Cambrian Rocks, 164. 
 Camera Lucida, 227. 
 
 Obscura, 57, 98, 198, 267. 
 Camper [Anat.], 118. 
 Candolle [Botanist], 115. 
 Cannon, Muskets, and Pistols, 53, 
 
 300. 
 
 " Canon '' of Avicenna, 38. 
 Capillary Attraction, 36. 
 Capital, 69, 299. 
 Capture of Constantinople, 91. 
 Cardan, 56. 
 Carnot [Math.], 243, 283 ; his Law, 
 
 195 ; his Theorem, 195. 
 Cassini [Astron.], 199, 272, 282. 
 Castelli, 60, 98. 
 Catapults, 22. 
 Cathedrals, 69. 
 Cato, 17. 
 Catoptrics, Definition of, Appendix 
 
 AA. 
 
 Cauchy [Math.], 196. 
 Causes of Scientific Progress, xiv., 
 
 68. 
 
 Cavaliere, 59. 
 Cavalieri, 101. 
 Cavendish [Chemist], Hydrogen, 
 
 Water, 174, 223. 
 
 " Celestial Mechanics," 195, 208. 
 Cellini, 64. 
 Cellular Tissue, 62. 
 
336 
 
 INDEX. 
 
 Celsius [Physicist], 220. 
 Centigrade Thermometer, 220. 
 Centre of Gravity, 36, 60. 
 Centuries XVI., 269. 
 XVII., 271. 
 XVIII., 272. 
 XIX, 274. 
 Chaldaean Astronomy, 5, 6. 
 Saros, 6. 
 Science, 6, 7. 
 Ziggurats, 6. 
 Chambers, 139. 
 
 Champollion [Philologist], Hiero- 
 glyphics, 151, 230. 
 Changes, Political, due to Science, 
 
 300. 
 Changes, Social, due to Industry, 
 
 298. 
 
 Character of the Revival, xv., 91. 
 Charlemagne, 47. 
 Chasles [Math.], 196. 
 Chaucer, 65, 66. 
 Cheap Food, 289, 296. 
 Chemical Action of Light, 242. 
 Analysis, 210, 242, 247. 
 ,, Attraction, 219. 
 Effects of Cold, 256. 
 Elements, 242, 257, and 
 
 see Discovery of. 
 Evolution, 1 86, 187; Che- 
 mists holding the 
 Theory, 187. 
 
 Fractionisation, 188. 
 Harmonicon, 256. 
 Laws, 1 80. 
 Manipulation, 37, 38. 
 Rays, 206. 
 Chemico-physical Laws, 275. 
 Chemists, Discoveries of, see Dis- 
 coveries of. 
 Chemistry, 243, 273, 275, 276, 280, 
 
 281, 283, 285. 
 
 Chemistry (Arabian), 37, 44, 60 ; 
 Definition of, Appen- 
 dix AA. 
 General Remarks on, 
 
 189. 
 
 Modern, 172. 
 Organic, 124, 184. 
 
 Chemistry, Solar and Stellar, 234. 
 Chevreul [Chemist], Fatty Sub- 
 stances, his Law of Colours, 183. 
 Chinese (The), 21 (note). 
 
 (The Compass of the), 51- 
 
 54- 
 
 Chivalry, 31. 
 Chladni [Physicist], 227. 
 Christian Idea (The), 297. 
 Christian Times witness Great 
 
 Evils, 298. 
 Chromosphere, 214. 
 Chronometer, 232. 
 Circle (Division of), 196. 
 Circulation of the Blood, 60, 62. 
 Circumference (Incommensurability 
 
 of), 194. 
 
 Civilisation (Strides of), through 
 the Tool, the Plough, the Sword, 
 and the Book, 293. 
 Classification, 21, 61. 
 
 Artificial, 114. 
 
 Comte's, no. 
 
 Natural System of> 
 
 115. 
 
 Spencer's, 112. 
 
 Clausius, 244, 254. 
 Clavicylinder, 227. 
 Clement IV., 65. 
 
 of Ireland, 47. 
 Clepsydra, 24, 42. 
 Climate of Greece, 16. 
 Climatology, 162, 258. 
 Clocks (Pendulum), 42, 55. 
 "Clouds" of Aristophanes, 13. 
 Coal, 1 6, 247. 
 Gas, 261. 
 Tar, 1 86. 
 Ccelium Theory, 147. 
 Coefficient of Expansion of Gases, 
 
 233, 241. 
 Coiter, 63, 96. 
 Colbert [Sociol.], 153. 
 Cold (Chemical Effects of), 256. 
 Colebrook [Philologist], 151. 
 " Colliget " of Averroes, 39. 
 Colours (Law of Contrast of), 183. 
 
 of the Sky, 257. 
 
 (Prismatic), 218. 
 
INDEX. 
 
 337 
 
 Columbus, 55, 282. 
 
 Combustion, 172, 173, 176. 
 
 Comets, 98, 194 ; Encke's, 211, 212. 
 
 Commentaries on Aristotle, 39. 
 
 Common Knowledge, 2. 
 
 Compass, 42, 51-54, 267. 
 
 Competition, 292. 
 
 Compressibility (Law of), 172, 217 ; 
 of Liquids, 232. 
 
 Comte [SocioL], Founder of Posi- 
 tive Philosophy, 156. 
 
 Comte,Classification of the Sciences, 
 no, in, 283. 
 
 Concentric Mirrors, 22. 
 
 Concrete and Abstract Knowledge, 
 H. Spencer on, 3. 
 
 Condenser (Separate), 260. 
 
 Conscience, 304. 
 
 Conservation of Energy, 244, 283. 
 
 Constants (Natural), 194. 
 
 Constitution of the Heavenly 
 
 Bodies, 250. 
 of the Sun, 205. 
 
 of Science, 271. 
 
 Contempt of Authorities, 270. 
 
 Industry in Antiquity, 
 
 16. 
 
 Continuous Fractions, 193. 
 
 Contrast between Islam and Chris- 
 tendom, 44. 
 
 Cope [Palaeontologist], 123. 
 
 Copernican System, 58, 99, 193, 271, 
 272. 
 
 Copernicus, 55, 270. 
 
 Cordova, 29, 31. 
 
 Cork, 268. 
 
 Corn Grinding, 289, 290. 
 Trade, 295. 
 
 Corpuscular Physics, 226. 
 
 Corpuscular Theory of Light, 218. 
 
 Correggio, 64. 
 
 Correlation of Forces (Law of), 242. 
 Structure, 120. 
 
 Cort, 263. 
 
 Corti's Fibres, 246. 
 
 Cosmo de' Medici, 91. 
 
 Coulomb [Physicist], Torsion 
 Balance, 223, 283. 
 
 Countries (Scientific), xvi., 279-284. 
 
 Countries (Scientific-), Table of, 280- 
 
 282. 
 
 Craniology, 149. 
 Credit, 299. 
 Creed in Islam and Christendom, 
 
 44- 
 
 Crookes [Chemist and Physicist], 
 his Theory of Chemical Evolu- 
 tion, 1 86, 187, 256, 257 ; Analysis 
 of Rare Earths, 188 ; Chemical 
 Fractionisation, 188. 
 
 Cross-Staff, 54. 
 
 Cruelty, 298. 
 
 Crusades, 68, 71, 298. 
 
 Cryophorus, 228. 
 
 Crystallisation, 61. 
 
 Crystallography, 176. 
 
 Ctesibius, 24. 
 
 Currents, Electric and Magnetic, 
 
 237- 
 
 Cusa, 97. 
 Cuvier, Founder of Comparative 
 
 Anatomy and of Palaeontology, 
 
 118, 161, 283. 
 Cycle of Calippus, 21. 
 
 Melon, 20. 
 
 Cyclone Theory, see Sun Spots. 
 Cylinder (The), 22, 219; Papin's, 
 
 260. 
 
 Cypher, 42. 
 Cyril, 32. 
 
 DAGUERREOTYPE, 239, 261. 
 
 Dalton, John, the "Newton" of 
 Chemistry, the Atomic Theory, 
 179 ; [Physicist], 228, 283. 
 
 Dante, 65, 90 (note). 
 
 " Dark Ages " a Misnomer, 64. 
 
 Dark Lines in Spectra, 223, 228, 
 234, 249. 
 
 Dark Rays, 206. 
 
 Darwin, Charles [BioL], established 
 the Law of Biological Evolution, 
 134 ; proved the Variability of 
 Species by Natural Selection, 
 134 ; his place among Evolution- 
 ists, 138; his Works, 142, 143, 
 283. 
 
 Darwin (Erasmus) [Biol.], held the 
 
338 
 
 INDEX. 
 
 Doctrine of Organic Evolution, 
 128, 139, Hi- 
 Darwinism in the Present Day, 143. 
 Daubenton [Anat.], 118. 
 Davy [Chemist], 243, 248 ; Elec- 
 trolysis, 181 ; his two Laws, 181 ; 
 Safety Lamp, 181 ; Electricity 
 an Illuminant, 182, 226; Photo- 
 graphy, 182. 
 Decay of Belief in Witchcraft, 302, 
 
 303- 
 
 Decomposition of Light, 218. 
 
 Vapour by Light, 
 
 257. 
 
 Sound, 246. 
 
 Deductive System of Plato, 9. 
 
 Definition of Acoustics, App. AA. 
 
 Anatomy, 
 
 Anthropology, 
 
 Astronomy, 
 
 Barology, 
 
 Biology, 
 
 Botany, 
 
 ,, Catoptrics, ,, 
 
 Chemistry, 
 
 Diffraction, 
 
 Dioptrics, 
 
 Dynamics, 
 
 Electrology, 
 
 Geography, 
 
 Geology, 
 
 Hydraulics, 
 
 Hydrodynamics, 
 
 Hydromechanics, 
 
 Hydrostatics, ,, 
 
 Kinematics, ,, 
 
 Kinetics, 
 
 Mathematics, ,, 
 
 Mechanics, ,, 
 
 Optics, 
 
 Palaeontology, 
 
 Philology, 
 
 Physics, 
 
 Physiology, 
 
 Sociology, 
 
 ,, Statics, 
 
 Thermology, 
 
 Zoology, 
 
 the Sciences, 
 
 Degree, 33, 56, 60. 
 De la Rive, 264. 
 Delisle [Astron.], 202. 
 Democracy, Rise of, 300. 
 Democritus, Discoveries of, 20. 
 De Morgan [Math.], 196. 
 Denmark, 282. 
 Density of the Earth, 223. 
 Deposits, Fluvial and Marine, 164; 
 
 Palaeozoic, 164. 
 Descartes [Math.], 191, 272, 283, 
 
 Appendix VI. 
 Descriptive Geometry, 195. 
 Despotism, 298. 
 Despretz, 241. 
 
 Deviation from Boyle's Law, 241. 
 Dewar [Physicist], 256. 
 Dialysis, 185. 
 Diamagnetism, 237. 
 Dias, 55. 
 
 Diathermancy, 239. 
 Dictionaries, 43. 
 Didactic Poems, 71. 
 Diderot, 283. 
 Dietetics, 40. 
 
 Differential Calculus, 193. 
 Diffraction, 217 ; Definition of, 
 
 Appendix AA. 
 Digester, 219. 
 Diogenes Laertius, 6, 9. 
 Diophantus [Algebra], 33. 
 Diopters, 34. 
 Dioptra (The), 15. 
 Dioptrics (Apparatus), 233; Defini- 
 tion of, Appendix AA. 
 Diorama, 261. 
 Discoveries of Anatomists, 22, 27, 
 
 38, 57, 60, 62, 63, 
 
 96, 1 1 6. 
 
 Anthropologists, 148. 
 
 the Arabs, 46. 
 
 Astronomers, 5-9, 
 
 21-23, 25, 26, 33, 
 
 34, 54-58, 86, 97, 
 
 98, 100, 102, 198. 
 
 Biologists, 37, 127. 
 
 Botanists, 41, 113. 
 
 Chemists, 37, 38, 
 
 55,57,60,82,172. 
 
INDEX. 
 
 339 
 
 Discoveries of Geographers, 23, 
 
 54-56. 
 Geologists, 8, 22, 
 
 41, 159. 
 the Greeks, 7-14, 
 
 20-27. 
 ,, Mathematicians, 25, 
 
 55, 56, 60, 82, 96, 
 
 100-102, IQI. 
 
 the Medievalists, 
 
 51-64, 70. 
 , , M en of the Revival, 
 
 96-104. 
 the Moderns, 109, 
 
 113-265. 
 
 ,, Palaeontologists, 1 1 6. 
 
 Philologists, 151. 
 
 Physicists, 13, 23, 
 
 35-37, 57-63, 82- 
 
 85, 98-100, IO2, 
 215. 
 
 Physiologists, 22, 
 
 37-41, 55, 57, 
 60, 62, 96, 98. 
 Discovery of America, 55. 
 Asteroids, 207. 
 
 Chemical Elements, 
 
 38, 172-178, 187. 
 Dissipation of Energy, 254. 
 Distance of Stars, 245. 
 Distillation, 38. 
 Division of the Circle, 190. 
 Inch, 263. 
 Labour, 296. 
 
 Doctrine of Evolution (Progressive 
 Development), 12, 37, 82, 116, 
 117, 126, 128-148, 157, 167, 187, 
 
 209, 211, 276, 287. 
 
 Dollond [Physicist], 220. 
 Dominis (Antonio de), 59. 
 Doppler's Principle, 253, 262. 
 D'Orbigny [Naturalist], 120. 
 Double Refraction, 217. 
 
 Stars, 204, 209, 251, 252. 
 Doublet of Wollaston, 228. 
 Dove [Geol.J, 167. 
 Draper, 29, 46. 
 Drawbacks to Science in Antiquity, 
 
 Drebbel, 60. 
 
 Du Bois-Reymond [Physicist], 224. 
 
 Du Faye [Physicist], 216. 
 
 Dulong [Chemist], his Law, 183; 
 [Physicist], 233, 241. 
 
 Dumas [Chemist], Density of Com- 
 pounds, Unitary Theory, 184. 
 
 Duns Scotus, 44, 65. 
 
 Dunstable, 51. 
 
 Duration of Ideas, 18. 
 
 Solar Energy, 247. 
 
 Duty (Performance of), 304. 
 
 Dyes, 1 86, 188. 
 
 Dynamical Theory of Heat, 242. 
 
 Dynamic Radiation and Absorp- 
 tion, 257. 
 
 Dynamics (Galileo's), 58, 6l ; 
 Definition of, Appendix AA. 
 
 Dynamo (Tesla's), 259. 
 
 EARLY Knowledge, xiti., i. 
 Earth, Density of, 223. 
 
 an Electric Conductor, 240, 
 
 245- 
 
 Knowledge of the, 276. 
 
 Magnitude of, 24. 
 
 Motion of, 246. 
 Earthquakes, 41. 
 
 Ebn Junis, Hakemite Tables, Pen- 
 dulum, 34. 
 Ebn Zoar ( Avenzoar), Acarus of the 
 
 Itch, Pharmaceutics, 40. 
 Ebn Zohr, Cure of Diseases, 40. 
 Ebullition (Law of), 220. 
 Eclipses, 6. 
 Ecliptic, 5. 
 
 Economy, 69, 283, 299. 
 of Cato, 17. 
 of Xenophon, 17. 
 Edison, 260, 275. 
 Eginhard, 47. 
 Egypt, Astronomy in, 5- 
 
 Geometry in, 5. 
 Egyptian Science, 5, 6, 7. 
 
 Temples, 5. 
 Ehrenberg [Physiol.], 124. 
 Eighteenth Century, Character of, 
 
 272. 
 Elastic Forces and Fluids, 234. 
 
 Z 2 
 
340 
 
 INDEX. 
 
 Electrical Applications, 263. 
 
 Resistance, Unit of, 239. 
 Electric Accumulator, 257. 
 
 Attraction and Repulsion 
 
 (Law of), 223. 
 Battery, 225. 
 Car, 257. 
 Currents, 237. 
 Induction, Theory of, 238. 
 Light, 182, 225. 
 Machine (First), 216 ; 
 (Second), 216, 220, 294. 
 Metallurgy, 239. 
 Pile, 225. 
 Plating, 239. 
 Telegraph, 231, 240, 283, 
 
 286, 294. 
 
 Thermometer, 236. 
 Typing, 239. 
 Electricity, 57,61,98, 243, 272-274, 
 
 283, 285. 
 Electricity and Lightning (Identity 
 
 of), 221. 
 
 Steam, Great 
 
 Agents of Pro- 
 gress, 226. 
 Animal, 224. 
 
 Application of, to Mole- 
 
 cules, 258. 
 
 ,, Benefits from, 294. 
 
 an Illuminant, 182. 
 
 Statical Properties of, 
 
 226. 
 
 Theory of, 221. 
 
 Two Kinds of, 216, 220, 
 
 221. 
 
 Velocity of, 240. 
 
 Electro-chemical Theory, 181, 182. 
 Electro-chemistry, 236. 
 Electrology, Definition of, Appen- 
 dix AA. 
 
 Electrolysis, 181 ; Law of, 238. 
 Electro-magnet, 231. 
 Electro-maznetic Action and Waves 
 
 258. 
 
 Electro-magnetism, 232. 
 Electrophorus, 225. 
 Elements, Chemical, 242, 248, 250, 
 251, 259. 
 
 Elements, Chemical, Discoveries of, 
 
 see Discoveries. 
 Elements, Chemical, Mendelejeff, 
 
 188. 
 
 Missing, 187. 
 
 ,, Williams, 186. 
 
 Eminent Men of Science (Table of), 
 
 Appendix AA. 
 Enamelling, 53. 
 Encke [Astron.], his Comet, 209, 
 
 229, 255. 
 
 Encyclopaedia, 39, 71. 
 Endlicher [Botanist], 115. 
 Energy, 283. 
 
 Conservation of, 244. 
 Dissipation of, 254. 
 Mechanical, 195. 
 of Light, 242. 
 Reversibility of, 195. 
 Solar, 246. 
 Transmission of, 264. 
 Enfranchisement, 68. 
 Engine, Fire, Steam, 23 ; Railway, 
 
 261. 
 
 Engineering, 262. 
 England, 279 ; the Leading Country 
 
 in Science, 282, 283. 
 English Ancestry, 283. 
 Greatness, 284. 
 Engraving, 53. 
 Ephemerides, 54, 55 ; of Jupiter's 
 
 Satellites, 199. 
 Epicycles, 24. 
 Equality and Justice, 301. 
 Equinoxes, 5. 
 Equivalent (Mechanical, of Heat), 
 
 243. 
 
 Erasistratus, 22. 
 Eratosthenes, 23. 
 Erigena, 47. 
 Errors, Law of, 196 ; Least Square, 
 
 of, 195. 
 
 Esthonian Theory, 149. 
 Ether, 211, 217, 229, 255. 
 Euclid, 22 ; " Geometry," 54. 
 Eudiometer, 225. 
 Eudoxus, 13, 21. 
 
 Euler [Math.], 194; [Physicist], 227. 
 Euphone, 227. 
 
INDEX. 
 
 34i 
 
 Eustachius, 62, 97. 
 Evection of the Moon, 26. 
 Evils despite Christianity, 298. 
 Evils swept away by Science, 306. 
 Evolution, Chemical, 187. 
 
 Doctrine of, 12, 37. 
 Evolutionists, 157. 
 Exalted Idea of God, 301, 302. 
 Exchange (Trade), 18. 
 Executive Power less despotic, 300. 
 Exhibitions, i. 
 
 Exodus of Greeks to Italy, 92. 
 Expansion of Gases, Coefficient of, 
 233, 241, 242. 
 
 the Two Laws of, 233. 
 
 of Science, 272. 
 Experience, Aristotle on, xviii., Ap- 
 pendix A. 
 
 R. Bacon on, 78-9, 81-2. 
 
 Leonardo on, 104-7. 
 Experimental Geology, 161. 
 
 School, 44, 72. 
 
 Experiments on High Electric 
 
 Currents, 259. 
 on Molecules, 258. 
 
 Exponential Calculus, 194. 
 Extension of Modern Industry, 261. 
 Eyck (Brothers), 53. 
 
 FACTS, Astronomical, Accumulation 
 of, in the XVIIIth Century, 272. 
 
 Facts stronger than Wisdom, 64. 
 
 Fahrenheit [Physicist], Thermome- 
 ter, 220. 
 
 Falling Bodies, Velocity of, 193. 
 
 Fallopius, 62, 97. 
 
 Faraday [Physicist], 236, 257. 
 
 Faure [Physicist], 257. 
 
 Favre [Physicist], 234, 242. 
 
 Fernel, 51. 
 
 Ferrari, 56. 
 
 Fetis on the Indian Bow, 54. 
 
 Fixed Stars, 24, 27 ; Aberration of, 
 203. 
 
 Fixity of Composition (Law of), 174. 
 Species, 119, 137. 
 
 Fizeau [Physicist], 246. 
 
 Flame Phenomena, 257. 
 
 Flamsteed [Astron.], 202, 272. 
 
 Flaws in Arabian Science, in Greek 
 Science, in Modern Science, 48. 
 
 Flour Mill, Benefits from, 292. 
 
 Fluvial Deposits, 164. 
 
 Fluxions, Method of, 193. 
 
 Foot i'. Horse, 300. 
 
 Force (Molecular), 226. 
 
 Fossils, 39, 56, 169. 
 
 Foucault [Physicist], 245. 
 
 Foundation of Science, 269. 
 
 Four Centuries of Science (Sum- 
 mary), xvi., 269. 
 
 Fracastoro, 62. 
 
 Fractionisations (Chemical), 188. 
 
 Fractions (Continuous), 193. 
 
 France, 279, 282. 
 
 Franco, 51. 
 
 Franklin [Physicist], 273 ; his Law 
 of Ebullition, 220 ; his Theory 
 of Electricity, 221. 
 
 Fraunhofer [Physicist], Founder of 
 Solar Physics and Stellar Che- 
 mistry, 234, 241, 248, 250, 282. 
 
 Frederick II., 44, 65. 
 
 Free Inquiry, 39, 270. 
 Trade, 299. 
 
 Freezing by Evaporation, 228. 
 
 Fresnel [Physicist], 192, 217, 218, 
 228, 235; his Rhomb, 236. 
 
 Friction, 227. 
 
 Fulton, 260. 
 
 Functions, Analytical, 194. 
 Geometrical, 195. 
 
 GALEN, 27. 
 
 Galileo, 13, 36, 58, 100, 270, 272, 
 
 282, 283. 
 Galileo's Barology, 102. 
 
 Doctrine of Permanent 
 Law, 101. 
 
 Dynamics, 100. 
 
 Laws of Falling Bodies, 
 100. 
 
 Laws of Motion, 101. 
 
 Mathematics, 100. 
 
 Mechanics, 100. 
 Gall [Anatomist], 108. 
 Galvani [Physicist], 224. 
 Galvanometer (Marine), 253. 
 
342 
 
 INDEX. 
 
 Gas, 268. 
 
 Battery, 242. 
 
 Lighting, 261. 
 Gases, Coefficient of Expansion of, 
 
 233- 
 Fundamental Importance 
 
 of, 177- 
 Law of Compressibility of, 
 
 233- 
 
 Liquefaction and Solidifica- 
 tion of, 255. 
 
 Gassendi [Astron.], 198. 
 Gastraea Theory, 147. 
 Gaston Phoebus, 44. 
 Gauss [Math.], 196, 240. 
 Gautama, Syllogism of, 10. 
 Gay-Lussac [Chemist], his Law of 
 
 Volumes, 182; [Physicist], 232. 
 Geber, see Giaber. 
 Geber Al Batani, 33. 
 Geber (of Seville), Observatory, 34. 
 General Progress, 289. 
 General Results of Science, xvi., 
 
 285. 
 
 Generating Functions, 195. 
 Geoffrey St. Hilaire [BioL], held 
 
 the Doctrine of the Mutability 
 
 of Species, 131. 
 Geoffrey St. Hilaire (Isidore) [Biol.], 
 
 131* 
 Geographers, Discoveries of, see 
 
 Discoveries. 
 
 Geography, 24, 26, 41, 44, 56, 269, 
 281 ; (Physical), 167 ; Definition 
 of, Appendix AA. 
 Geological Laws, 165, 283. 
 Geologists, Discoveries of, see Dis- 
 coveries. 
 Geology, 39, 273, 281 ; Definition 
 
 of, Appendix AA. 
 Geology, British, 162. 
 
 Comparative, 163. 
 Early, 159. 
 Experimental, 161. 
 General Remarks on, 170. 
 Geometry, Analytical, 193. 
 Descriptive, 195. 
 
 in Egypt, 5, 22, 195, 196. 
 Signs in Pure, 196. 
 
 Gerbert, 44, 47, 69 (note). 
 
 Gerhardt [Chemist], his Theory of 
 Types, 185. 
 
 Germany, 279, 282. 
 
 Gesner, 61, 269. 
 
 Ghetaldi, 59. 
 
 Giaber, Founder of Chemistry, 
 Chemical Manipulation and Ap- 
 paratus, Alcohol, Gases, Oxida- 
 tion, Strong Acids, 37, 248. 
 
 Gilbert, 57, 98, 283. 
 
 Gioja d' Amalfi, 52. 
 
 Giorgione, 64. 
 
 Glacial Period, 167-169. 
 
 Glaisher [Physicist], 224. 
 
 Glass, 1 6, 268. 
 
 Glazed Pottery, 53. 
 
 Globe (The), 41. 
 
 Globes, 43. 
 
 Gnats' Wings, Flapping of, 257. 
 
 Gnomon (The), 15, 24, 266. 
 
 Goethe [Botanist and Biologist], 
 
 115. 
 
 Golden Number, 21 (note). 
 Goniometer, 227. 
 
 Government (Religious), 301, 302. 
 Graham [Chemist], his Law of 
 
 Diffusion, 184; his Process of 
 
 Dialysis, 185. 
 
 Grammar, Comparative, 152. 
 Granada, 29. 
 
 Grand Laws discovered, 271. 
 Gravitation, Laws of, 200; Uni- 
 versal, 206, 272. 
 Gravity, Centre of, 36, 60. 
 Force of, 36. 
 
 Specific, 23, 59. 
 Gray, 264.. 
 Great Men in the Middle Ages, 65, 
 
 66 (note). 
 Great Pyramid, 6. 
 Great Schism caused the Delay of 
 
 the Revival, 94. 
 
 Greatness of Xlllth Century, 67. 
 Greek, 47 (note). 
 
 Discoveries, 7. 
 
 Exodus to Italy, 92. 
 Science passes to the 
 Persians and Arabs, 28. 
 
INDEX. 
 
 343 
 
 Greek Syllogism, 10, II. 
 
 Gregory I., 32, 51. 
 
 Gregory I., II., III., 47- 
 
 Grew [Botanist], 113. 
 
 Grimaldi [Physicist], 224. 
 
 Grimm [Philologist], 151. 
 
 Grimm's Law, 151. 
 
 Growth of Milling, 289-292. 
 
 of Science rapid in the 
 Middle Ages, 71-73. 
 
 Grove [Physicist], 242. 
 
 Guericke [Physicist], Air Pump, 
 Magdeburg Hemispheres, First 
 Electric Machine, 216, 272. 
 
 Guido d' Arezzo, 51. 
 
 Guldinus, 60. 
 
 Gunpowder, 38, 42, 52, 300. 
 
 Gyroscope, 245. 
 
 HAECKEL [BiolJ, 141 ; one of the 
 
 Pillars of Darwinism, 146. 
 Hales [Botanist], 113. 
 Hall [Geologist], Experimental 
 
 Geology, 161. 
 
 Hall, C. M. [Physicist], 220. 
 Hallam, 99. 
 
 Haller [Physiol.], 125, 273. 
 Halley [Astron.], 202, 272. 
 Hamilton, W. R. [Math.], 196. 
 Hand Mill, Benefits from, 290. 
 Harmonicon (Chemical), 256. 
 Harp of Marloye, 227. 
 Harriot, 58. 
 
 Harvey, 60, 98, 272, 283. 
 Hatcher [Palaeontol.], 123. 
 Haughton, 254. 
 Haiiy [Geol.], 160. 
 Hawksbee [Physicist], 216. 
 Health (Physical and Moral), 18. 
 Heart (The), 21, 22. 
 Heat, Dynamical Theory of, 243. 
 
 Latent, 173- 
 
 Mechanical Equivalent of, 
 
 243. 
 a Mode of Motion, 227, 247, 
 
 257. 
 
 Phenomena, 228. 
 produced by Friction, 227, 
 
 228, 236. 
 
 Heat, Radiant, 102, 239. 
 Rays, 206. 
 Solar, 239. 
 Specific, of Gases, 228. 
 
 Heavenly Bodies, Composition of, 
 250. 
 
 Heavens, Knowledge of the, 276. 
 
 Heliocentric Doctrine (Solar Sys- 
 tem), 23, 26, 55, 58, 99, 193, 271- 
 272. 
 
 Helium, 187. 
 
 Helmholtz [Physicist], 213 (note), 
 222, 227, 241, 243, 246, 254, 255, 
 282. 
 
 Helmont (Von), 60. 
 
 Helvetius [Sociol.], 154. 
 
 Hemisphere, 21. 
 
 Henry IV. of Germany, 65. 
 
 Henry VIII., 30. 
 
 Henry (Prince), the Navigator, 54. 
 
 Herbert (Dean), 138. 
 
 Hero, 23, 215. 
 
 Heroism of Mediaeval Inquirers, 50. 
 
 Herophilus, 21. 
 
 Herschel (Alexander), 253. 
 
 Herschel (John) [Astron.], 210 ; 
 [Physicist], 229, 230. 
 
 Herschel (W.) [Astron.], the " Co- 
 lumbus of the Heavens," dis- 
 covered and mapped Nebulae, 
 Double Stars, 204, 272. 
 
 Hertz, 258. 
 
 Hevelius [Astron.], 198. 
 
 Hieroglyphics, 151, 230. 
 
 Hildebrand, 48, 90 (note). 
 
 Hincmar, 47. 
 
 Hindus, 54, 137 (note). 
 
 Hindu Syllogism, 10, n. 
 
 Hipparchus, 24, 201. 
 
 Hippocrates, Aphorisms, 20. 
 
 Hirn [Physicist], 244. 
 
 Hofmann [Chemist], Basis of Coal 
 Tar, Dye Industry, Molecular 
 Constitution, 186. 
 
 Holland, 282. 
 
 Hooke [Astron.], 199. 
 
 Hooke [Physicist], Dial Barometer, 
 Interference of Light, Spiral 
 Spring, 218. 
 
344 
 
 INDEX. 
 
 Hooker, William and Joseph [Bota- 
 nists], 115, 141. 
 
 Hopkinson, 254. 
 
 Horrocks [Astron.], 199. 
 
 Horse (Pedigree of), 135. 
 
 Hospitals, 47 (note), 305. 
 
 Hucbald, 51. 
 
 Huggins,his Spectroscopic Studies, 
 252-255. 
 
 Humane Influence of Science, 286. 
 
 Human Ingratitude, 293. 
 
 Humanitarian Age, 273. 
 
 Humanity (Spirit of), 307. 
 
 Humboldt (A.) [Sociol.], 156,282; 
 [Geol.], Founder of Meteorology, 
 162 ; on Utility, 3. 
 
 Humboldt (C.W.) [Philologist], 151. 
 
 Huntsman, 263. 
 
 Hunt (Dr. J.) [Anthropol.J, 151. 
 
 Hunter [BioL], 127, 273. 
 
 Hutton, 49, 273. 
 
 Hutton [Geol.], his Great Idea of 
 Law, 160; Plutonian Theory, 160. 
 
 Huxley [BioL], his Immense Ser- 
 vices to Science, Pedigree of 
 Birds, his Works, 145. 
 
 Huygens [Astron.], 199, 272 ; 
 [Math.], 193 ; [Physicist], Mi- 
 crometer, Pendulum and Pendu- 
 lum Clocks, Undulatory Theory, 
 Ether, 217; Double Refraction 
 and Polarisation of Light, 218. 
 
 Hydraulic Press, 192. 
 
 Hydraulics, 60,61, 101 ; Definition 
 of, Appendix A A. 
 
 Hydrodynamics, 194 ; Definition of, 
 Appendix AA. 
 
 Hydrogen, 174. 
 
 Hydromechanics, Definition of, Ap- 
 pendix AA. 
 
 Hydrometer, 37. 
 
 Hydrostatics, 23, 36, 61, 101, 192, 
 216 ; Definition of, Appendix AA. 
 
 Hygrometer, 62, 228, 241. 
 
 Hypsometer, 228. 
 
 Hyperbolical Sinus, 194. 
 
 Hypothesis, Evolutionary, 157. 
 Meteoritic, 214, 253. 
 
 Nebular, 209. 
 
 Hypothesis, Single and Double 
 Fluid, 221. 
 
 ICE Age, 167. 
 Calorimeter, 226, 242. 
 Machine, 242. 
 Iceland Spar, 217. 
 Idea of Law, 272. 
 
 Identity of Lightning and Elec- 
 tricity, 221. 
 Ilkanic Tables, 34. 
 Inch, Division of, 263. 
 Incommensurability of the Circum- 
 ference, 194. 
 Increase of Population, 292, 298. 
 
 Wealth, 263. 
 India, 54, 137 (note). 
 Indian Numerals, 33, 42. 
 India-Rubber, 186, 268. 
 Induction, Aristotleon, Appendix 1 1. 
 Brewster on, Appendix 
 
 V. 
 
 Leonardo on, 104. 
 (Electric), Theory of, 
 
 238. 
 
 Inductive Method, 10, 55, 57, 78, 
 98, 104, Appendices 
 II. and V. 
 Process of Research of 
 
 Aristotle, 10. 
 Process of Leonardo da 
 
 Vinci, 104-107. 
 Industrial Spirit, 300, 301. 
 Industries, Benefits from, 292, 293. 
 Industry (Dye), 186. 
 
 in Islam and Christendom, 
 
 45- 
 
 Infinitesimal Calculus, 195. 
 Influence of Science on Belief, 288. 
 ,, in the Moral 
 
 Sphere, 304. 
 
 on Philan- 
 
 thropy, 305. 
 on Religion, 
 
 301-303- 
 
 on Religious 
 
 Government, 301 303. 
 
 ,, on the Social 
 
 System, 298-301. 
 
INDEX. 
 
 345 
 
 Injustice, 298. 
 Innocent III., IV., 65. 
 Inquisition, 33 ; Doctrine of the, 
 
 307. 
 Instruments, Accuracy of, 268. 
 
 Surgical, 39, 43. 
 
 Value of, 266. 
 
 Want of, in Antiquity, 
 
 15- 
 
 Insularity, 284. 
 Integral Calculus, 194. 
 Intellectual Results of Science, 
 
 286. 
 Interaction of the Sciences, 17, 190, 
 
 276. 
 
 Intercommunication, 17. 
 Intercourse (Social), 18. 
 Interference of Light, 217, 218, 
 
 235- 
 
 Intolerance, 307. 
 Introduction, xxix. 
 Invariability of the Great Axes, 203, 
 
 208. 
 
 Inventions (Mediaeval), 54, 69, 99. 
 (Modern), 260,280, 281. 
 Inventors, 260. 
 Isoperimeters, 194. 
 Isothermal Lines, 163, 167. 
 Italy, 279, 282. 
 Itch, 40. 
 
 JACOBI [Physicist], 231 ; founded 
 
 Electrometallurgy, 239, 241. 
 James [Physicist], 223. 
 Janssen, 58. 
 Jenner, 294. 
 Jevons, 59, 136, 196, 197, Appendix 
 
 VI. 
 
 Jewish Teachers, 28. 
 Jews (The) of Spain, 31, 40. 
 Jouffroy d'Albans, 260, 283. 
 Joule [Physicist], 242 ; his Law, 
 
 244, 283. 
 
 Jupiter's Moons, 100. 
 Jussieu (Antoine and Bernard) 
 
 [Botanists], 115, 283. 
 Justice and Equality, 301. 
 
 Ideal, 155. 
 
 Revival of Sense of, 303. 
 
 KALID, Improvements in Chemical 
 
 Manipulation, 38. 
 Kant [Philosopher], 208. 
 Karwiny, Earthquakes and Vapours, 
 
 41. 
 
 Keferstein [Geol.], 161. 
 Kepler, 60, 97, 272, 283 ; Telescope, 
 Tides, 102 ; Attraction, 103, 104 ; 
 Laws of Motion, 103 ; Optics, 
 Physics, Rotation of the Sun, 103. 
 Kindly Instincts revived, 303. 
 Kinematics, Definition of, Appendix 
 
 AA. 
 Kinetics, Definition of, Appendix 
 
 AA. 
 
 Kircher, 57. 
 Kirchhoff [Physicist], 241, 242, 248, 
 
 282. 
 
 Kirk [Physicist], 257. 
 Klaproth [Chemist], 178. 
 Knight's Law, 143. 
 Knowledge, Common, the Root of 
 
 Science, 2. 
 Common, H. Spencer 
 
 on, 3. 
 
 Concrete and Ab- 
 stract, 3. 
 
 Early, xiii., I. 
 
 Uncertainty of, 42. 
 
 Knox [Anthropol.], 149. 
 Kohlrausch [PhysicistJ, 224. 
 
 LABORATORIES, 43. 
 Labour, 154, 299. 
 
 Division of, 296. 
 Lagrange [Math.], 194 ; [Astron.], 
 
 203. 244, 272, 283. 
 Laing (S.), xi., xxii. 
 Lamarck [Naturalist, Anat., Biol.], 
 the First Demonstrator of Bio- 
 logical Evolution, 129, 141, 142, 
 275, 283. 
 
 Lambert [Math.], Incommensura- 
 bility of the Circumference, 194. 
 Lanfranc, 48. 
 Languages, Aryan, 152. 
 
 Cuneiform, 152. 
 Greek, 47 (note), 91,92, 
 95- 
 
346 
 
 INDEX. 
 
 Languages, Hieroglyphics, 151,230. 
 
 Kawi, 151. 
 Persian, 152. 
 Sanscrit, 151, 152. 
 Laplace [Math.], 34, 138, 195, 208 ; 
 [Physicist], 226, 244, 272, 273, 
 283. 
 
 Latent Heat, 173. 
 Latitude, First Parallel of, 24. 
 Latour (Cagniard), 256. 
 Lauffen Waterfall, 264. 
 Lavoisier, 37 ; Founder of Modern 
 Chemistry, Nomenclature, Oxy- 
 gen, 176 ;" [Physicist], 178, 226. 
 Law, Idea of, 272. 
 
 Notion of, 72. 
 Law of Adaptation, 116. 
 ,, Antagonism, 242. 
 Atomic Equality (Gay- 
 
 Lussac), 183. 
 
 Atomic Heat(Dulong), 183. 
 Avogadro (Molecules), 185. 
 Biogenesis (Recapitulation 
 
 Theory), 147. 
 Bode, 103, 206. 
 Boyle, 172. 
 Compressibility, 172. 
 Conservation of Energy, 
 
 244. 
 Contrast of Colours (Chev- 
 
 reul), 183. 
 
 ; , Correlation of Forces, 242. 
 ,, Definite Proportions, 178. 
 Diffusion of Gases (Gra- 
 ham), 184. 
 
 Dissipation of Energy, 254. 
 Distances in Electricity, 
 
 230. 
 
 ,, Ebullition (Franklin), 220. 
 Elasticity of Torsion, 223. 
 Electric Attraction and Re- 
 pulsion, 223. 
 
 Electric Current, 232. 
 ,, Resistance, 234. 
 
 Electromotive Force, 235. 
 Embryological Develop- 
 ments, 132 
 
 Equivalent Proportions, 1 80. 
 Errors, 196. 
 
 Law of Evolution, 276. 
 
 Fecundation, 133. 
 
 Fertilisation, 116. 
 
 Fixity of Composition, 174. 
 
 Grimm, 151. 
 
 Homology, 126. 
 
 Hydrostatics, 23. 
 
 Inheritance, 116. 
 
 Isomorphism! Mitscherlich),, 
 
 183- 
 
 Joule, 244. 
 Knight, 143. 
 the Lever, 22, 57, 98. 
 Mariotte, 172, 217. 
 Mechanical Energy, 195. 
 Mechanics (in Animals), 
 
 125. 
 
 ,, Metamorphosis, 115. 
 Octaves (Newlands), 189. 
 Organic Evolution, 117, 121, 
 126,130, 131, 138, 141,142. 
 See Doctrine of Evolution. 
 Periodic, 188. 
 Pressure (Pascal's), 192. 
 Thermodynamics, 195. 
 Torricelli, 216. 
 Volumes (Gay-Lussac), 182. 
 Laws, Atmospheric, 271. 
 Geological, 283. 
 Grand, 271. 
 Natural, 271. 
 Universal, 286, 287. 
 Laws of Chemistry, 179, 180. 
 
 Cooling, 233. 
 
 Davy, 1 8 1. 
 
 Double Refraction, 233. 
 
 Electrolysis, 238. 
 
 Equilibrium of Liquids, 
 101. 
 
 Expansion of Gases, 233. 
 
 Falling Bodies, 100. 
 
 Geology, 165. 
 
 Gravitation, 200. 
 
 Light, 272, 275. 
 
 Mechanics, 102, 125. 
 
 Mixture, 178. 
 
 Motion, 60, 101, 103, 201,. 
 225, 272, 283. 
 
 Polarisation, 233. 
 
INDEX. 
 
 347 
 
 Laws of Pressure, 98. 
 
 Refraction, 62, 192. 
 Sound, 275. 
 Torsion of Wires, 223. 
 Vibration, 227. 
 
 Learned Societies in the Revival, 
 64. 
 
 Learning in Islamand Christendom, 
 46. 
 
 Lecky quoted, 299. 
 
 Lecoq, 138. 
 
 Legendre [Math.], 195. 
 
 Leibnitz [Math.], 193 ; [Geol.], 193, 
 244, 272, 282. 
 
 Leidy [Palaeontol.], 123. 
 
 Lelio, 58, 97. 
 
 Lens (Convex), 36, 102, 267. 
 
 Lenses for Lighthouses, 236. 
 
 Lenticular Spectroscope, 233. 
 
 Leo III., 47. 
 
 Leonardo da Vinci's Discoveries, 
 55, 56,64,98,282,283. 
 
 Leonardo da Vinci's Geology, 99. 
 
 Leonardo da Vinci's Inductive Pro- 
 cess, and Injunctions thereon, 
 104-107, 270. 
 
 Leonardo da Vinci's Inventions, 99, 
 104. 
 
 Leonardo da Vinci's Physics, Ap- 
 pendix IV. 
 
 Leslie [Physicist], 228. 
 
 Leuwenhoeck [Physiol.], 124, 272. 
 
 Lever, The Law of the, 22, 57, 98. 
 
 Leverrier [Astron.], 211. 
 
 Leyden Jar, 220. 
 
 Liais, Height of the Atmosphere, 
 36. 
 
 Libavius, 56. 
 
 Liberty, 284. 
 
 Libraries, Arabian, 43 ; Cairo, 43, 
 European, 70. 
 Spanish, 43. 
 Tripoli, 43. 
 
 Libration, 204. 
 
 Liebig [Chemist], Chemistry ap- 
 plied to Agriculture, Organic 
 Chemistry, Potash Bulbs, 184. 
 
 Life, 55. See Primitive Forms of 
 Life. 
 
 Lifts, 22. 
 Light, 210. 
 
 Decomposition of, 218. 
 
 Diffraction of, 217, 235. 
 
 Electric, 182, 225, 227. 
 
 Energy of, 242. 
 
 Interference of, 217, 218, 235. 
 
 Laws of, 272, 275. 
 
 Polarisation of, 218. 
 
 Solar, 257. 
 
 of Stars, 211. 
 
 Undulatory Theory of, 103, 
 192,194,217,218,228,229. 
 
 Velocity of, 199, 245. 
 
 Zodiacal, 199. 
 Lighthouses, 236. 
 Lightning and Electricity, Identity 
 
 of, 221. 
 
 Lightning Conductor, 221. 
 Lindley [Botanist], 115. 
 Linnaeus [Botanist], 115, 273. 
 Lippershey, 58. 
 Liquefaction of Gases, 255 ; (of Air), 
 
 256. 
 
 Liquids, Compressibility of, 232. 
 Literature, 43, 66, 70, 91-2, 95, 298, 
 
 307. 
 
 Lithography. 261. 
 Lobel, 62, 96. 
 Lockyer (Norman) [Astron.], 213 ; 
 
 his Meteoritic Hypothesis, 214. 
 Locomotive, 261, 283. 
 Logarithms, 55, 58. 
 Logic and Mathematics (Union of), 
 
 196 
 
 Longitudes, 25. 
 Louis IX., 65. 
 
 XL, 30. 
 
 Love of Truth revived, 304, 305. 
 Lubbock [Biol.], 148. 
 Luminiferous Ether, 211, 217, 229. 
 Luther's Attacks on the Church, 
 
 307. 
 
 Lyell [Geol.], 138, 139, 141, 283 ; 
 Geological Laws, 165. 
 
 MACHAULT [Sociol.], 155. 
 Machinery, Electric, 216. 
 
 Steam, 219, 275, 283. 
 
348 
 
 INDEX. 
 
 Machine Tools, 262. 
 Maclaurin [Math.], 194. 
 Magdeburg Hemispheres, 216. 
 Magellan, 55, 269. 
 Magellanic Clouds, 210. 
 Magi of Persia, 10 (note), 20. 
 Magic Lantern, 57. 
 Magnetic Currents, 237. 
 
 Rotation of Organic 
 
 Substances, 188. 
 Magnetism, 98, 237. 
 
 of Gases and other 
 
 Substances, 257. 
 ,, Theory of, 232. 
 Magnetometer^ 196. 
 Magnets, 236, 237. 
 Magnifying Glass, 53. 
 Majolica, 53. 
 
 Malpighi, Founder of Vegetable 
 Anatomy, 113; [Physiologist], 
 123, 272. 
 
 Malus [Physicist], 218, 227, 230. 
 Malthus [Sociol.], 138, 155. 
 Man, Antiquity of, 116, 129, 130, 
 142,146,148, 149,167, i?o. 
 of Science the Greatest of 
 
 Benefactors, 296. 
 Manetho, 6. 
 
 Manipulation, Chemical, 37, 38. 
 Manometer, Barometric, 241. 
 Mantell [GeoL], Saurians, 164. 
 Marco Paolo, 52. 
 Marcus Grascus, Gunpowder, 38. 
 Marine Deposits, 164. 
 Mariotte [Physicist], 172 ; his Law, 
 
 217, 274. 
 
 Marloye's Harp, 227. 
 Mars, Rotation of, 199. 
 Marsh, Palaeontologist of the 
 Highest Order, 121, 136; 
 Descent of the Horse, 135. 
 Maskelyne [Physicist], Density of 
 
 the Earth, 223. 
 
 Masue, Comparative Anatomy, 38. 
 Material Effects of Scientific Pro- 
 gress, xvii. 
 Progress, 289. 
 Results of Science, 286, 
 289. 
 
 Material Welfare, how Promoted, 
 
 289-296. 
 
 Mateucci [Physicist], 224. 
 Mathematics, 267, 271, 272, 280, 
 
 281. 
 Definition of, Ap- 
 
 pendix AA. 
 General Remarks 
 
 on, 197, 198. 
 ,, and Logic, Union 
 
 of, 196. 
 
 ,, in Physics, 100, 194. 
 
 Power of, 198. 
 
 Queen of Sciences, 
 
 197. 
 
 Subdivisions of, 197. 
 
 Want of, in An- 
 
 tiquity, 15. 
 Mathematicians, Discoveries of, 
 
 see Discoveries. 
 Mathematicians of XVth and 
 
 XVIth Centuries, 96. 
 Matter, Unity of, 256. 
 Matthew, 138, 141. 
 Maury [GeoL], Meteorology and 
 
 Physical Geography, 167. 
 Maxwell [Physicist], 240, 244, 254. 
 Mayer [Physicist], 243. 
 Mayow [Chemist], Combustion, 172. 
 Means of Transport, 18. 
 " Mecanique Celeste," 195, 208. 
 Mechanical Energy, 195. 
 
 Equivalent of Heat, 
 
 243- 
 Mechanics, 61,272, 275; Definition 
 
 of, Appendix AA. 
 Analytical, 195. 
 
 Celestial, 195. 
 Mediaeval Contributions to Science, 
 
 ., Discoveries, 70. 
 Europe not in Profound 
 
 Darkness, 47. 
 Inquirers, Heroism of, 
 
 50. 
 
 ,, Inventions, 51. 
 Medicat Plants, 39. 
 
 Treatment in Islam and 
 Christendom, 46. 
 
INDEX. 
 
 349 
 
 Medicine, 20, 38, 40, 44, 63, 96. 
 Melloni [Physicist], 239. 
 " Melopeia" of the Greeks, 60. 
 Menageries, 43, 
 
 Mendacity in the Middle Ages, 305. 
 MendelejefT [Chemist], his Peri- 
 odic Law, 1 88. 
 Mendicity, 155. 
 Mercantile Companies, 298. 
 Mercator, 56, 98. 
 Mercury, Phases and Transit of, 
 
 198, 199, 202. 
 Meridian of Spain, 234. 
 Metallurgy, 98, 283. 
 Metamorphism, 166. 
 Meteorites, 26, 253. 
 Meteoritic Hypothesis, 214, 253. 
 Meteorology, 162, 167. 
 Method of Fluxions, 193. 
 Oscillation, 223. 
 Research, xiii., i, 270. 
 Torsion Balance, 223. 
 Meton, Cycle of, 20. 
 Michel Angelo, 64. 
 Microscope, 100, 123, 267, 273 ; 
 
 Spectrum, 257. 
 Milky Way, 20. 
 Miller, Dr., 253. 
 Milling, Growth of, 289-292. 
 Minerals, 41. 
 Mirbel [Physiol.], 126. 
 Mirrors, Concentric, 22, 53. 
 Misery, Decrease of, 274. . 
 Mitscherlich [Chemist], Law of 
 
 Isomorphism, 183. 
 Modern Discoveries, 109. 
 
 Industry (Extension of), 
 
 261. 
 
 Inventions, 280, 281. 
 Merchant, 295. 
 Science, 109. 
 Mohl (Von) [Biol.], originated the 
 
 Theory of Protoplasm, 133. 
 Moldenhauer [Physiol.], 126. 
 Molecular Constitution, 186. 
 Current, 258. 
 Force, 226. 
 Ocean, 262. 
 Physics, 255 
 
 Molecules, 185, 186. 
 
 Motion and Size of, 254. 
 Mondini, 60. 
 
 Monge [Math.], Descriptive Geo- 
 metry, 195. 
 Monteverde, 60. 
 Montgolfier [Physicist], Balloons,, 
 
 224. 
 
 Moon, Evection of, 26. 
 Moons of Jupiter, 100. 
 Moral Effects of Scientific Progress,, 
 
 xvii. 
 
 Progress, 297. 
 Results of Science, 297-309. 
 Morgagni [Biol.], 128. 
 Morley (J.) quoted, 307, 308. 
 Moro [Geol.], 160. 
 Morse [Physicist], 240. 
 Telegraph, 262. 
 Motion, 247, 257. 
 
 Heat a Mode of, 227. 
 of the Earth, 245. 
 ., Planets, 20. 
 
 Stars, 262. 
 
 Mountains, Altitude of, 203. 
 Mtiller, Fritz and Hermann Biol.J,. 
 
 147. 
 
 Johann [Physiol.], 127. 
 Max (Philologist], 152. 
 Multiple Stars, 234. 
 Multiplier, Thermo-electric, 239. 
 Municipal Liberties, 68, 298. 
 Murchison [Geol.]., Silurian and" 
 
 Devonian Systems, 164. 
 Murdoch, 261. 
 Muschenbroeck [Physicist], Leyden 
 
 Jar, 220. 
 
 Museums of Alexandria, 19, 27. 
 Museums, i. 
 Music, 51. 
 
 Musical Vibrations, 102, 191, 194^. 
 220, 227. 
 
 NAPIER, 55, 58. 
 Nasmyth, 262. 
 Natural Constants, 194. 
 
 History, 96, 269. 
 
 Laws, 271. 
 
 Philosophy, 70. 
 
350 
 
 INDEX. 
 
 Natural Sciences (Medicine, Ana- 
 tomy, Zoology, Natural 
 History, Botany), 96. 
 Selection, 283. 
 System, 115. 
 Nature a Great Teacher, 63. 
 
 of Vision, 35. 
 Navigation, 31, 69. 
 Nebula of Orion, 199. 
 Nebulae, 261. 
 
 in the Northern Hemi- 
 sphere, 204. 
 
 in the Southern Hemi- 
 sphere, 210. 
 
 Nebular Hypothesis, 209. 
 Neckam (Alexander), 52. 
 Neptune, Discovery of, 211. 
 Neptunian Theory, 44, 161. 
 Nero, 51. 
 
 Nerves (The), 22, 27. 
 Nestorian Teachers, 28. 
 Neumann [Chemist], 185. 
 Newlands [Chemist], Law of Oc- 
 taves, 189. 
 
 Newton, 13, 26, 272, 283 ; Acous- 
 tics, 219; [Astron.], 199; [Math.], 
 J 93 > [Physicist], Corpuscular 
 Theory of Light, 218. 
 Niagara Falls, 264. 
 Niagara, Supply of Horse Power, 
 
 264. 
 
 Nicholas V., 91. 
 Nicholson [Physicist], 227. 
 Nicol Prism, 230. 
 Niepce, 239, 261. 
 Nile Mud, 41. 
 Nineteenth Century, Character of, 
 
 274-277. 
 
 Nobili [Physicist], 224. 
 Numbers, Bernouilli's, 194. 
 
 Theory of, 195. 
 Nutation, 203. 
 Nyaya School, 10. 
 
 OBLIQUITY of the Ecliptic, 23, 24, 
 
 33, 34- 
 
 Observatories, 5, 6, 34, 43, 97. 
 Oersted [Physicist], 232, 240. 
 Oil Paintings, 53. 
 
 Oken [Bio].], 131. 
 
 Olbers [Astron.], 209. 
 
 Oligarchy, 298. 
 
 Opera, 60. 
 
 Optics, 35, 61, 103, 217, 218 ; Defi- 
 nition of, Appendix AA. 
 
 Oratorio, 59. 
 
 Orbits of the Planets (Analysis of), 
 212. 
 
 Order (Social), 290. 
 
 Organ, 51. 
 
 Organic Chemistry, 124, 184. 
 Group, 113. 
 
 " Organon " of Aristotle, 10. 
 
 Oscillation (Method of), 223. 
 
 Owen [Naturalist, Anat, Palaeon- 
 tol.], held the Doctrine of Fixity 
 of Species, 120; Founder of the 
 Microscopic Society, 121 ; or- 
 ganised Natural History Mu- 
 seum, 121. 
 
 Oxidation, 37, 176. 
 
 Oxygen, 174, 176. 
 
 Oxygen a Magnetic Body, 251. 
 
 PAGE, 264. 
 
 Palaeontologists, Discoveries of, see 
 
 Discoveries. 
 Palaeontology, 116; Definition of, 
 
 Appendix AA. 
 Palaeozoic Deposits, 164. 
 Palestrina, 56. 
 Palissy, 53, 56, 97. 
 Pallas, 209. 
 Panini [Philol.j, 151. 
 Paper, 42, 52. 
 Papin [Physicist], 219, 260. 
 Paracelsus, 55, 96, 269, 270. 
 Parallax of Stars, 199. 
 Parallels, Theory of, 195. 
 Pare, 63, 96. 
 Pascal [Math.], his Law, 192, 272, 
 
 283. 
 
 Pasteur [Biol.], 144, 294. 
 Pathology, 63. 
 Peace promoted by Science, 286, 
 
 299. 
 
 Pecquet, 63. 
 Pendulum, 34, 59, 102, 217, 245, 267. 
 
INDEX. 
 
 35i 
 
 Pendulum Clocks, 42, 217. 
 
 Performance of Duty, 304. 
 
 Peri, 60. 
 
 Periodic Law [Mendelejeffj, 188. 
 
 Perkin, W. H. [Chemist], Aniline 
 Dyes, 1 88 ; Magnetic Rotation 
 of Organic Substances, 188, 285. 
 
 Permanency of Laws, 101, 102, 160, 
 165. 
 
 Persecution, Religious, 302. 
 
 Perthes, see Boucher de Perthes. 
 
 Perversion of Moral Type, 305. 
 
 Peter of Pisa, 47. 
 
 Petit [Physicist], 233. 
 
 Petrarca, 65, 66. 
 
 Peurbach's Ephemerides, 54, 97. 
 
 Pharmacy (Pharmaceutics), 38, 40, 
 44. 
 
 Phases of Venus, 6. 
 
 Phenomena, Atmospheric, 224. 
 Heat, 228. 
 
 of Flames, 257. 
 
 of Sound, 256. 
 
 Philanthropy, Immense Expansion 
 of, due to Scientific and In- 
 dustrial Spirit, 306. 
 
 Philanthropy the Feature of Re- 
 cent Times, 306. 
 
 Philippe Augustus, 47 (note). 
 
 Philologists, Discoveries of, see 
 Discoveries. 
 
 Philology (Comparative), 151, 280, 
 281 ; Definition of, Appendix 
 AA. 
 
 Phlogistic Theory, 173, 191. 
 
 Phonograph, 263-4, 275, 286, 294. 
 
 Phosphoroscope, 252. 
 
 Phosphorus, 38. 
 
 Photography, 182, 239, 258, 261, 
 275. 
 
 Photometer, 226, 234, 242. 
 
 Photometry, 142. 
 
 of Stars, 34. 
 
 Physical Geography, 167. 
 Laws, 273. 
 
 Physicists, Discoveries of, see Dis- 
 coveries. 
 
 Physics, 44, 61, 100, 215, 269, 272, 
 280, 281. 
 
 Physics, Alhazen's, 35. 
 Corpuscular, 226. 
 Definition of, Appendix AA. 
 Solar and Stellar, 234. 
 Physico-Chemical Laws, 275. 
 Physiologists, Discoveries of, see 
 
 Discoveries. 
 
 Physiology, 22, 37, 41, 55, 57, 60, 
 62,96,98,123,272,283. 
 Comparative, 127. 
 Definition of, Appendix 
 AA. 
 
 Physiological Chemistry, 177. 
 Piazzi [Astron.], 206. 
 Piccolomini, 62. 
 Pictet [Physicist], 256. 
 Piezometer, 232. 
 Pile, Electric, 225. 
 Piston, 219, 260. 
 Planetarium, 15, 193. 
 Plants, Medical, 39. 
 
 Respiration of, 175. 
 Plastic Arts, 64. 
 Plater, 63, 97. 
 Plato and Aristotle brought to 
 
 Italy, 93. 
 
 Plato's Deductive Process of Re- 
 search, 9. 
 
 " Republic," 14. 
 Playfair (John) [GeoL], 160. 
 Pleiades, 100. 
 Plenum (Universal), 255. 
 Plough (The), 293. 
 Plutonian Theory, 49, 160. 
 Poggendorff [Physicist], his Law, 
 
 235- 
 
 Poisson [Math.], 203. 
 Poland, 282. 
 Polar Clocks, 241. 
 Polarity of Gases, 242. 
 Polarisation of Light, 218, 230. 
 
 Rotatory, 230. 
 Political Changes due to Science, 
 
 300. 
 
 Economy, 153-156, 283. 
 > in Antiquity, 1 7. 
 
 Moral Benefits 
 
 from, 299. 
 Porta (G. Delia), 57. 
 
352 
 
 INDEX. 
 
 Portugal, 282. 
 Posidonius, 26. 
 Positive Philosophy, 42. 
 Potash Bulbs, 184. 
 Pottery (Glazed), 53. 
 Pouchet [Biol.], 29, 133. 
 Pouillet [Physicist], 238. 
 Practical Art, 64. 
 
 and Artistic Skill, 69. 
 
 Men and their Inventions, 
 260. 
 
 Science, 98. 
 
 Work, 270. 
 
 Precession of the Equinoxes dis- 
 covered by Hipparchus, 25, 35, 
 
 201. 
 
 Preconceived Theories in Antiquity, 
 
 16. 
 
 Preface, v. 
 Pressure of Air, 192. 
 Prevost [Geol.], 164. 
 Priestley [Chemist], 37 ; Oxygen, 
 
 174. 
 
 Prime Movers, 264. 
 Primitive Forms of Life, 116-7, 
 126, 128, 130-133, I35 138-9, 
 147, 276. 
 
 Prince Henry, the Navigator, 54. 
 "Principia," 136, 201. 
 Printing, 54, 92. 
 Prism, 192, 267 ; Nicol, 230. 
 Prismatic Colours, 218. 
 Probabilities, Calculus of, 193, 194. 
 
 Theory of, 195. 
 
 Problem of Dark Lines in Spec- 
 trum, 249. 
 
 Progress among the Arabs, xiv., 28. 
 in Antiquity, xiii., 19. 
 in the Middle Ages and 
 during the Revival, xiv., 
 50. 
 
 General, 282. 
 Material, 289. 
 Moral, 292. 
 Protyle, 187. 
 Prout's Theory, 189. 
 Pruner Bey [Anthropol.], 149. 
 Ptolemaic System, 19. 
 Ptolemies (The), 19. 
 
 Ptolemy, 26. 
 Public Opinion, 300. 
 Puddling, 263. 
 Pulse, 21. 
 Pump, Air, 216, 219. 
 
 Spiral, 22. 
 
 Steam, 260. 
 
 Suction, 54. 
 Pyramid, The Great, 6. 
 Pyrheliometer, 238. 
 Pyrometer, 220, 236. 
 Pythagoras, 8. 
 
 QUADRANT (The), 15, 34. 
 Qualitative Analysis, 249. 
 Quantitative Analysis, 249. 
 Quaternions, System of, 196. 
 Quatrefages [Anthropol.], 1 50. 
 Quesnay [Sociol.], 153, 283. 
 
 RADIANT Heat, 102, 239. 
 Matter, 261. 
 
 Radiometer, 257. 
 
 Railway Engine, 261. 
 Train, 274. 
 
 Rainbow, 58, 59. 
 
 Rankine, 244. 
 
 Raphael, 64. 
 
 Rapine, 298. 
 
 Rashi, Dietetics and Remedies, 40,, 
 
 Rawlinson [Philol], 152. 
 
 Ray [Botanist], 113. 
 
 Rays, Heat and Dark, Chemical, 
 206. 
 
 Rdaumur [Biol.], 127 ; as a Physi- 
 cist, 127, 220. 
 
 Refraction, 35, 37, 60, 98. 
 Double, 217. 
 Laws of, 60, 192. 
 
 Regiomontanus, 55. 
 
 Regnault [Physicist], 234, 241, 243. 
 
 Reign of Terror, 302. 
 
 Reiss, 264. 
 
 Religion and Religious Govern- 
 ment, 301-2. 
 
 Religious Government more Hu- 
 mane through Science, 302-3. 
 
 Remarks (General) on Biol., 158;; 
 
INDEX. 
 
 353 
 
 on Geol., 170; on Chem., 189; 
 on Mathem., 197, 198 ; on 
 Astron., 215. 
 Remedies, 40. 
 Renaldini [Physicist], 216. 
 Renan, 29. 
 
 Requirements of Progress, 17. 
 Resentment of Dethroned Castes, 
 
 308. 
 Respiration of Plants, 41 ; of 
 
 Animals, 172, 173, 177. 
 Results of Science, General, 285 ; 
 Material, 286, 289 ; Intellectual, 
 286 ; Moral, 297. 
 Retina, 35. 
 
 Retzius [Anthrop.], 149. 
 Reversibility of Energy, 195. 
 Revival (The), Character of, 91 ; 
 of Kindly Instincts and Sense of 
 Justice, 303 ; of Sense of Right, 
 of Love of Truth, 304. 
 Revolution in Science, 226. 
 Rhsetius's Tables, 54. 
 Rhazes, Sulphuric Acid, Distilla- 
 tion, 38. 
 Rheostat, 240. 
 Rhomb of Fresnel, 236. 
 Richer of St. Remi, 47. 
 Richter [Chemist], Law of Definite 
 
 Proportions, 178, 283. 
 Ringing Apparatus, 240. 
 Rise of Democracy, 300. 
 
 Industry, 32. 
 Ritter, C. [Geol.], 163. 
 
 J. W. [Physicist], 181. 
 Robbia (Lucca Delia), 53. 
 Roemer [Astron.], 201, 245, 272. 
 Romanes [Biol.], 132, 143. 
 Roscelin, 48. 
 Roscoe, 242, 
 
 Rotation of the Sun, 103, 199 ; of 
 Winds, 167 ; of Organic Sub- 
 stances, 1 88 ; of Mars, 199 ; of 
 Electric Wires, 236. 
 Rousseau, 153; Social Influence 
 
 of, 306. 
 
 Royalty versus Feudalism, 300. 
 Riidbeck, 63, 272. 
 Rudolphine Tables, 4, 59, 98. 
 
 Rumford [Physicist], 155, 226, 243. 
 Russia, 282. 
 
 SABINE [Physicist], 223. 
 Safety Lamp, 181. 
 
 Valve, 219, 260. 
 Salvinus Armatus, 53. 
 Santorio, 60, 62, 97. 
 Sargon I., 6. 
 Saros, Chaldsean, 6. 
 Saturn's Satellites, 199. 
 Saurians, 164. 
 
 Sauveur [Physicist], 220, 227. 
 Savart [Physicist], 224. 
 Scarpi [Physicist], 60. 
 Scheele [Chem.], Oxygen, 176,283. 
 Schiaparelli [Astron.], 212. 
 Schiehallion Experiment, 223. 
 Schiling, 240. 
 Schleiden [Biol.], 132. 
 Schoolmen, 97, 158, 170, 270. 
 Schools, 69. 
 
 Schwabe [Physicist], 237. 
 Schwann [Biol.], 132. 
 Schwartz, Monk, 52. 
 Science, an Extension of Common 
 
 Knowledge, 2. 
 Chaldaean, 5, 6. 
 Egyptian, 5, 6. 
 Four Centuries of, and 
 Foundation of, 269 
 Constitution of, 271 
 Expansion of, 272 
 Universality of, 274. 
 in Antiquity, 15. 
 in Egypt and Chaldaea, 
 
 Stationary, 7. 
 in Islam and Christendom, 
 
 46. 
 
 in the Middle Ages, 70. 
 in Modern Times, 109. 
 the Prime-mover of the 
 Highest Civilisation,3o8. 
 Sciences, Definitions of, Appendix 
 
 A A, page 314. 
 
 Scientific Countries, 279-284. 
 Influence on Belief, 288. 
 Interaction, 276. 
 , Revolution, 226. 
 2 A 
 
354 
 
 INDEX. 
 
 Screw of Archimedes, 23. 
 Screws, 262. 
 Scrope [Geol], 165. 
 Sedgwick [Geol.], 164. 
 Seebeck [Physicist], 237. 
 Seguin, 261, 283. 
 Selection, Natural, 283. 
 Semaphoric Telegraph of the Arabs, 
 
 42. 
 
 Seneca, 26. 
 Senefelder, 261. 
 Sense of Justice, Revived, 303 ; of 
 
 Right, Revived, 304. 
 Serapion (The), 27. 
 Serres [Physiol.], 127. 
 Servetus, 62, 97, 283. 
 Seventeenth Century, Character of, 
 
 271. 
 
 Signals, System of, 254. 
 Signs in Pure Geometry, 196. 
 Silbermann [Physicist], 234, 242. 
 Simpson [Physiol.], 127. 
 Singing Flames, 256. 
 Sinus, Hyperbolical, 194. 
 Sismondi, 29. 
 
 Sixteenth Century, Character of, 269. 
 Sky, Colour of, 257. 
 Slavery a Drawback to Science in 
 
 Antiquity, 15, 298. 
 Small-pox, 39. 
 Smith, Adam [Sociol.], 154, 283. 
 
 W. [Geol.], 138, 162. 
 Snell, 60, 96. 
 Soap, 41. 
 Social Changes due to Industry, 
 
 248-9. 
 
 Intercourse, 18. 
 Order, 298. 
 Societies, Learned, 64. 
 Sociologists, Discoveries of, 153. 
 Sociology, 153; Definition of, Ap- 
 pendix AA, 280, 281. 
 Solar Energy, 246 ; Duration of, 
 247. 
 
 Heat, 239. 
 
 Light, 257. 
 
 Physics, 234. 
 
 System, Heliocentric Doc- 
 trine, 23, 26. 
 
 Solstices, 5. 
 Sosigenes, 26. 
 
 Sound, 102, 210; Velocity of, 245 
 (note) ; Decomposition of, 246 ; 
 Phenomena of, 256, 275. 
 Spain, the Centre of Arabian Learn- 
 ing, 44. 
 
 Spallanzani [Physiol.], 126. 
 Specific Gravity, 23, 59. 
 
 Heat of Gases, 228. 
 Spectacles, 53. 
 Spectra of Stars, 235. 
 Spectral Lines, 262. 
 Spectroscope, 210, 233, 241-2, 
 
 247-8,251,263. 
 
 Spectroscopic Observations, 213. 
 Spectrum, 218 ; Analysis, 210. 
 
 (Dark Lines of), Ex- 
 plained, 249. 
 Microscope, 257. 
 ,, Solar, 206 ; Dark Lines, 
 
 233-234. 
 
 Spencer (Herbert) on Common 
 Knowledge and 
 Science, 3. 
 his Genesis of Science, 
 
 27 (note). 
 on Concrete and Abstract 
 
 Knowledge, 3. 
 
 on Evolution, 157, 283. 
 on Science, 109. 
 on Utility, 3. 
 Spencer's Classification of the 
 
 Sciences, 112, 138, 141-2. 
 Sphere (The), 22 . 
 Spiral Spring (of Watches), 218. 
 Spirit of Free Inquiry, 269. 
 
 of True Humanity, 307. 
 Sponges, 147. 
 Sprengel [Botanist], 116. 
 Square (Least) of Errors, 195. 
 Stahl [Chemist], Phlogistic Theory, 
 
 173, 181. 
 
 Stained Glass, 53. 
 Stancari [Physicist], 220, 227. 
 Stars, Fixed, 24, 27 ; Photometry 
 of, 34 ; Parallax of, 199 ; Double, 
 204, 209 ; Treble, 209 ; Multiple, 
 234- 
 
INDEX. 
 
 355 
 
 Stars in the South Hemisphere, 
 
 202. 
 
 ,, Aberration of Fixed, 203. 
 Distance of, 245 ; Velocity 
 of, 251 ; Motion of, 262. 
 
 Statics, 22 ; Definition of, Appen- 
 dix AA. 
 
 Statistics, 41. 
 
 St. Anselm,48. 
 
 St. Augustine's Doctrine of Re- 
 ligious Government, 305. 
 
 St. Bernard, 48. 
 
 St. Hilaire (Geoffroy), 283. 
 
 Steam, 274, 285 ; Age of, 274. 
 
 Steam and Electricity, Great Agents 
 of Progress, 226. 
 
 Steamboats, 260. 
 
 Steamer, 274. 
 
 Steam-engine, 260. 
 Hammer, 262. 
 Machinery, 261, 273, 280. 
 Navigation, 261. 
 Pump, 260. 
 
 Steel, Age of, 262, 263. 
 Bessemer, 262. 
 
 Steinheil [Physicist], 231, 240, 241. 
 
 Steno [Anat. and Geol.], 116. 
 
 Stephenson (G.), 261, 283. 
 (R.), 262. 
 
 Stellar Chemistry, 234. 
 
 Stereoscope, 240. 
 
 Stevinus, 57, 98, 101. 
 
 Stiefel, 55. 
 
 Stiorn Oddes, 44. 
 
 Stewart (Balfour), 244, 249 (note). 
 
 Stokes, 250 (note). 
 
 Stoney, 254. 
 
 Strabo, 26. 
 
 Sufi, Photometry of Stars, 34. 
 
 Sun, Constitution of, 205, 250. 
 Light and Heat, 265. 
 Rotation of, 103, 199. 
 Spots, 39 ; Action of, 237, 250. 
 
 Supremacy of Conscience, 304. 
 
 Surgery, 44, 63. 
 
 Surgical Instruments, 43. 
 
 Swammerdam [Physiol.], 124, 272. 
 
 Sweden, 282. 
 
 Switzerland, 282. 
 
 Sword (The), 293. 
 
 Syene, 24. 
 
 Syllogism, Greek and Hindu, 10,11. 
 
 Symbols (Algebraic), 57. 
 
 Symington, 260. 
 
 Sympathy (Universal), 306. 
 
 Symmer (Physicist), 221. 
 
 Syntaxis of Ptolemy, 26. 
 
 Syren, 256. 
 
 System, Artificial, 114. 
 
 Atomic, 20. 
 
 Copernican, 58, 108. 
 
 Devonian, Silurian, 164. 
 
 Natural, 115. 
 
 of Laplace, 209. 
 
 Ptolemaic, 26, 108. 
 
 of Quaternions, 196. 
 
 TABLE of Albumazar, 33. 
 
 Chords, 26. 
 
 Hakemite, 34. 
 
 Ilkanite, 34. 
 
 Rhaetius, 54. 
 
 Rudolphine, 4, 57, 98. 
 
 Specific Gravities, 37. 
 
 the Sun, the Moon, 26. 
 
 ,, Tides, 200. 
 
 Scientific Countries, 280-2. 
 Table of Eminent Men, Appendix 
 
 A. 
 
 Talbot [Physicist], 210, 239. 
 Tartaglia, 56. 
 Tasi, Ilkanite Tables, 34. 
 Taylor [Physicist], 206 (note). 
 Telegraph, Semaphoric, 42 ; Elec- 
 tric, 231, 240, 283, 286, 294-5. 
 Telegraphy, 24, 262 ; Marine, 253. 
 Telephone, 263-4, 286, 294-5. 
 Telescope, 34, 58, 206, 219, 220, 
 
 263, 267, 271. 
 Temple, Bishop, 140. 
 Temples, Egyptian, 5. 
 Temple of Serapis, 27. 
 Tesla [Physicist], 232, 258, 259-260. 
 Thales, Discoveries of, 7. 
 Thebit Ben Corrah, 34. 
 Thenard [Chemist], 181. 
 Theodulf of Spain, 47. 
 Theophrastus, 21. 
 
356 
 
 INDEX. 
 
 Theorem of Maclaurin, 194 ; of 
 
 Carnot, 195. 
 Theoria Motus, 196. 
 Theoretical Work, 270. 
 Theory of Asymptotes, 196. 
 Atomic, 179. 
 of Chemical Affinities, 175. 
 Evolution, 1 87. 
 
 Ccelum, 147. 
 Corpuscular, 218. 
 of the Division of the Cir- 
 cle, 195. 
 Dual, 183. 
 
 Dynamical, of Heat, 243 ; 
 of Vortices, 247, 255, 
 Appendix VI., 230. 
 of Electricity, Single and 
 
 Double Fluid, 221. 
 Electro-chemical, 182-2. 
 ,, of Electric Induction, 238. 
 Esthonian, 149. 
 Gastraea, 147. 
 of Laplace, 209. 
 Norman Lockyer, 214. 
 Magnetism, 233. 
 Neptunian, 49, 161. 
 ,, of Numbers, 195. 
 Parallels, 195. 
 Phlogistic, 173, 191. 
 ,, Plutonian, 49, 160. 
 of Probabilities, 195. 
 Prout, 189. 
 Recapitulation, 132, 147. 
 Symmer, 222. 
 Types, 185. 
 Undulatory, 103, 192, 194, 
 
 217-8, 228-9. 
 Unitary, 184. 
 of Unity of Organic Com- 
 position, 131. 
 the Universe, 273. 
 Thermo-dynamic Law, 195. 
 Thermo-dynamics, 195, 244. 
 Thermo-electrical Multiplier, 239. 
 Thermology, Definition of, Appen- 
 dix AA, 273. 
 Thermometer, 58, 60, 62, 100, 203, 
 
 220, 228, 236, 267. 
 Thermopyle, 243. 
 
 Thomas Aquinas, 65. 
 Thomson (Sir W., Lord Kelvin), 
 213 (note), 243-4, 246-7, 254, 258. 
 Tides, 26, 102, 200 ; Kinds of, 254. 
 Tidal Power, 265. 
 Tissue (Cellular), 62. 
 Titian, 64. 
 
 Tivoli Waterfall, 264. 
 Toleration in Islam and Christen- 
 dom, 45. 
 Tool (The), 293. 
 Tools (Machine), 262. 
 Topography, 41. 
 Torricelli [Physicist], 36, 102, 215; 
 
 his Law, 216, 272, 283. 
 Torsion Balance, 174, 223. 
 Elasticity of, 223. 
 of Wires, 223. 
 Torture, Abolition of, 155, 304. 
 Toscanelli, 54, 97. 
 Tournefort [Botanist], 114. 
 Trade, 18, 69. 
 Tragus, 61, 96. 
 Transformation of the Earth, 18 ; 
 
 of the World, 286. 
 Transformation of Heat into Me- 
 chanical Energy, 243-4. 
 Transformation of Mechanical 
 
 Energy into Heat, 243-4. 
 Transmission of Energy, 264. 
 Trigonometry, founded by Hippar- 
 
 chus, 25, 54. 
 Tripoli Library, 43. 
 Tubular Boiler, 261 ; Bridge, 262. 
 Turgot [Sociol.], 154. 
 Twilight, 36. 
 
 Tycho Brahe, 34, 57, 97-8, 283. 
 Tyndall [Physicist], 244. 
 Types, Theory of, 185. 
 
 UBALDI, 57, 98. 
 Ultimates (Unknowable), 288. 
 Ulugh Begh, Obliquity, 34. 
 Undulations of Light, 229. 
 Undulatory Theory of Light, 103, 
 
 192, 194, 217, 218, 228, 230, 235. 
 Union of Logic and Mathematics, 
 
 196. 
 Universal Laws, 286, 287. 
 
INDEX. 
 
 357 
 
 Universal Sympathy, 306. 
 Universality of Science in the 
 
 XlXth Century, 274. 
 Universities, 40, 70. 
 Unit of Electrical Resistance, 239. 
 Unity of Matter, 82, 187, 256. 
 Uranus, 206. 
 Urban 1 1., 65. 
 
 Utility (an Incentive to Science), 
 H. Spencer on, 2-3. 
 
 Humboldt on, 3. 
 
 in the Middle Ages, 4. 
 
 in Modern Times, 4. 
 
 VACCINATION, 126. 
 Vacuum now Obtained, 256. 
 Value of Instruments, 266. 
 Valve, 219. 
 Van Helmont, 60. 
 Vaporisation of Liquids, 228. 
 Vapours, 41 ; Decomposition of, 
 by Light, 257. 
 
 Absorbing Power of, 257. 
 Variation (of the Moon), 34. 
 Variations (Calculus of), 194. 
 Varley, 258, 264. 
 Vasco de Gama, 55, 85. 
 Vauquelin [Chemist], 178. 
 Velocity of a Falling Body, 193 ; 
 of Electricity, 240. 
 
 of Light, 199, 241, 245 ; 
 of Sound, 245 (note). 
 
 of Stars, 252-4. 
 
 Vibrations, 257. 
 Velocities, 36, 99. 
 
 Venus, Phases, 6; Transit, 198, 203. 
 Vesalius, 67, 97, 269, 283. 
 Vesta, 209. 
 
 Vibrations (Musical), 102, 191, 194, 
 220 ; Rod, Glass, Metallic Plates, 
 Laws of, 227. 
 
 Vicq d'Azir [Physiol.], 125. 
 Viete, 57. 
 
 Villeneuve (Arnault de), 44. 
 Vincent de Beauvais, 44. 
 Violence, 298. 
 Violin, 54. 
 
 Virchow [Biol.], Founder of Cellular 
 Pathology, 144. 
 
 Virtue, 304. 
 
 Vision, Nature of, 35. 
 
 Vitellio's Optics, 54. 
 
 Vitry (James de), 52, 71. 
 
 Vogt [Anthrop.], 1 50. 
 
 Volcanoes, 26, 165. 
 
 Volta [Physicist], 225, 273, 282-3. 
 
 Voltaic Battery and Pile, 225, 
 
 227. 
 
 Voltameter, 238. 
 Vortex Theory, 247, 255, Appendix 
 
 VI, 330. 
 Von Baer, see Baer. 
 
 Buch, see Buch. 
 
 Mohl, see Mohl. 
 
 WALLACE [Biol.], 139, 141* H3-4- 
 
 Wallis [Math.], 192. 
 
 Waltherus, 55, 97. 
 
 Want of Instruments in Antiquity, 
 
 IS- 
 of Material Substances in 
 
 Antiquity, 16. 
 of Mathematics in Antiquity, 
 
 15- 
 
 War, 298 ; Decline of, 299. 
 
 Warfare, 69. 
 
 Watches, 53, 218. 
 
 Water, Decomposition of, 227. 
 
 Watermills, Windmills, 51 ; Bene- 
 fits from, 290, 292. 
 
 Watt, 174, 226, 260-1, 273, 283. 
 
 Watts' Dictionary of Chemistry, 
 vii. 
 
 Wave Lengths (of Light), 229. 
 
 Wealth, Increase of, 263, 274. 
 
 Weber, 240. 
 
 Weight and Pressure of Air, 192, 
 
 215-6. 
 of the Earth, 223. 
 
 Weismann [Biol.], 142-3. 
 
 Wells, Dr., 138. 
 
 Werner [Geol.], 49 ; Neptunian 
 Theory, 161, 283. 
 
 Wheatstone [Physicist], 231, 240, 
 245, 283. 
 
 Whitworth, 262. 
 
 Whewell, Dr., 27 (note). 
 
 Wiclif, 65, 283. 
 
358 
 
 INDEX. 
 
 William of Tyre, 71. 
 
 Williams [Chemist], Missing Ele- 
 ments, 1 86. 
 
 Willis [Anatomist], 116. 
 
 Willughby [Naturalist], 117. 
 
 Witchcraft, Decay of, 302-3. 
 
 Wollaston [Chem., Biol], 178 ; 
 [Physicist], 224, 227. 
 his Doublet, 228* 
 
 Woodward [Geol.], 159. 
 
 Work, Practical and Theoretical, 
 270. 
 
 Workshops, 261. 
 
 World (The) Transformed, 286. 
 
 Wyck, Henry de, 51. 
 
 XENOPHANES, 8. 
 Xenophon's Economics, 17. 
 
 YEAR (The), 26. 
 Yeber, see Giaber. 
 Young [Physicist], 192, 217, 218, 
 228, 236, 255. 
 
 ZERO, 42. 
 
 Ziggurats, Chaldaean Observatories, 
 
 6. 
 
 Zodiac, 5. 
 
 Zodiacal Light, 199. 
 Zoology, 41, 6 1, 96, 1 1 6. 
 
 Definition of, Appendix 
 AA, 320. 
 
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BOOKS PUBLISHED BY 
 
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 OUR MUTUAL FRIEND 40 
 
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 CHRISTMAS BOOKS 17 
 
 A TALE OF TWO CITIES 16 
 
 GREAT EXPECTATIONS 8 
 
 PICTURES FROM ITALY & AMERICAN NOTES 8 
 
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CHAPMAN S- HALL, LIMITED. 33 
 
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 (WITH LIFE.) 
 
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 OLIVER TWIST. With 28 Illustrations by J. MAHONEY. 
 
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 As s lected and read by himself and now published for the first time. Illustrated. 
 
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CHIPMAN & HALL, LIMITED. 35 
 
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 ENGLISH PRISONERS. By CHARLES DICKENS and WILKIR 
 
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 * * These Stories are now reprinted in complete form for the first time. 
 
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