August 8, 1907] 



NA TURE 



357 



iiioie interested in derp questions affecting all knowledge, 

 and should at least examine with some care the gifts that 

 Philosophy is so anxious to bestow upon us. 1 have a 

 fear that otherwise in the elaboration of scientific theory 

 we may find ourselves embroiled in an unequal contest 

 with what I cannot but regard as the traditional enemy — 

 I mean the unmitigated metaphysician — and the sugges- 

 tion that I make is, to tell the truth, not so much from 

 the hope of gain as from the desire for self-defence and 

 the safe preservation of the methods that have served us 

 so well in the past. 



I think the accusation that we delude ourselves into 

 the belief that our hypotheses are final truth is not true 

 of any thoughtful chemist ; the great men of science have 

 surelv possessed that qualitv of mind which philosophy 

 would most approve. If. as has often been remarked, 

 Faraday was mathematically-minded, though untrained in 

 mathematics, it seems not less true that he stood in the 

 same relation to philosophy. When, for example, he was 

 asked to express his opinions on the atomic theory, he 

 wrote as follows : — 



" I do not know that I am unorthodox as respects the 

 atomic hypothesis. I believe in matter and its atoms as 

 fn>ely as most people — at least I think so. As to the 

 little solid particles, which are by some supposed to exist 

 independent of the forces of matter, and which in different 

 substances are imagined to have different amounts of these 

 forces associated with, or conferred upon, them (and which 

 even in the .same substance, when in the solid, liquid, and 

 gaseous state, arc supposed to have like different propor- 

 tions of these powers), as I cannot form any idea of them 

 apart from the forces, so I neither admit nor deny them. 

 They do not afford me the least help in my endeavour to 

 form an idea of a particle of matter. On the contrary, 

 they greatly embarrass me ; for after taking account of 

 all the properties of matter, and allowing in my consider- 

 ation for them, then these nuclei remain on the mind, and 

 I cannot tell what to do with them. The notion of a solid 

 nucleus without properties is a natural figure or stepping- 

 stone to the mind at its first entrance on the consider- 

 ation of natural phenomena : but when it has become 

 instructed, the like notion of a solid nucleus, ap.nrt from 

 the repulsion, which gives our only notion of solidity, or 

 the gravity, which gives our notion of weight, is to me 

 too difficult for comprehension ; and so the notion becomes 

 to me hypothetical, and, what is more, a verv clumsv 

 hynnthesis. At that point, then, I reserve mv mind as I 

 feel bound to do in hundreds of other cases in natural 

 knowledge." 



This is the attitude of mind, I think, of all thoughtful 

 chemists; if they do not exhibit it ostentatiously it is only 

 because it is as disturbing to the proper work of a chemist 

 for him to be constantly dwelling on the inward nature 

 of his hypotheses as it is distracting In ordinary life to 

 have men always talking about their emotions. 



Few, I think, will deny that the atomic theory stands 

 to-day as an indispensable instrument for productive 

 chemical work; it has neither had its day nor ceased to 

 be. Physicists have never been quite satisfied with the 

 hard indivisible ball of specific substance and definite mass 

 which has served chemistry so well. Thev have given it 

 bells, have made a vortex ring of it, and have indeed 

 done much that few chemists can understand to make it 

 meet the exacting requirements of their science. But to 

 us it has always been the same ; what we have done to it 

 has been external ; wo have given it, vaguelv perhaps, a 

 charge of electricity, a store of energy ; we have attached 

 the hooks or rods of valency, but we have not meddled 

 with its interior. We are now called upon bv chemical 

 considerations of change of composition, as well as by 

 other considerations more recondite, to subdivide ouV atom, 

 to credit it with an unsuspected store of energy, to consider 

 it a congeries of unsubstantial electrons. We should wish, 

 of course, to know that the evidence is good enough, but 

 otherwise there can be no nossible objection from our side ; 

 it will undo nothing that has been done, and we may have 

 good hopes that it will lead to the doing of many new 

 things in chemistry. The newer theories are in conson- 

 ance with the old in one most vital point : they afford 

 those mental oictures of chenomena which most of us 

 find indispensable for fruitful work. They do not belong 

 NO. IQ"?!, VOL. 76"! 



to what Prof. Schuster has characterised as " the evasive 

 school of philosophy." "Those," he says, "who believe 

 in the possibility of a mechanical conception of the 

 universe, and are not willing to abandon the methods 

 which from the time of Galileo and Newton have uniformly 

 and exclusively led to success, must look with the gravest 

 concern on a growing school of scientific thought which 

 rests content with equations correctly representing 

 numerical relationships between different phenomena, even 

 though no precise meaning can be attached to the symbols 

 used." Most of us, I think, will take coinfort in this 

 pronouncement and rejoice that if our conception of the 

 atom is to be transformed, it may still be represented as 

 having some kinship with what Sir Henry Roscoe's famous 

 e.xaminee described as the " square blocks of wood invented 

 by Dr. Dalton." 



SECTION C. 



GEOLOGY. 



Opening Address by Prof. J. W. Gregory, D.Sc, 

 F.R.S., President of the Section. 

 I. The Geological Society of London. 



1007 ! This is the centenary year of the Geological 

 Society of London ; next month the British geologists will 

 celebrate the event, and their pleasure will be enhanced 

 by the sympathetic presence of a distinguished company 

 of foreign geologists. 



With a just feeling of satisfaction may we celebrate 

 this event ; for to the Geological Society of London is due 

 the conversion of Geology from a fanciful speculation to 

 an ordered science. Yet so quietly has this society done 

 its work that the debt due to it is inadequately realised. 

 When we consider what the world owes to Geology in 

 respect of its economic guidance — the intellectual stimulus 

 of its conceptions — the reverence it inspires for the vener- 

 able and majestic universe — its liberating influence from 

 dogma — we may rightly regard the work of the Geological 

 Society as one of the most valuable British contributions 

 to intellectual progress during the nineteenth century. 



A hundred years ago the spirit of the eighteenth century 

 still controlled much of the then orthodox Geology. 

 Jameson's " Elements of Geognosy," of which the preface 

 is dated January 15, 1808, taught, as the certain con- 

 clusions of Geology, doctrines that had been reached by 

 applying prejudiced speculation to imaginary facts. It 

 was a manual of pure, a priori, Wernerian Geology. The 

 author claimed that to Werner " we owe almost every- 

 thing that is truly valuable in this important branch of 

 knowledge"; and that it was Werner "who had dis- 

 covered the general structure of the crust of the globe 

 and pointed out the true mode of examining and ascertain- 

 ing those great relations which it is one of the principal 

 objects of geognosy to investigate." 



But Jameson's book was the death-song of Wernerian 

 Geology in British science. A new Geology was develop- 

 ing; and the Geological Society of London ushered in its 

 birth. No more should observations be made through the 

 distorting medium of preconceived fancies ! No more 

 should Geology be inspired by that heedless spirit, which 

 cares not to distinguish betv.'een fancy and fact ! With 

 youthful vigour the new Geology would have nothing tci 

 do with the search for cosmogonies and such like fancy 

 foods ; and the Geological Society of London should be 

 nourished on unadulterated facts. 



The time was ripe for the change. No less a person 

 than Goethe, once an enthusiastic votary of Geology, was 

 now, in his play of " Faust," holding up its teachers to 

 ridicule. The theories " evolved from the inner conscious- 

 ness " of Continental Neptunists and Plutonists were to 

 Goethe excellent subjects for caricature. It was then the 

 Englishman, Greenough, founded a society to turn Geology 

 from the pursuit of fleeting fancies and lead her to the 

 study of sober but enduring facts. The members of this 

 society were to abandon the quest of scientific chimajras ; 

 thev were to leave to later generations the attempt to 

 solve the universe as a whole. 



The Geological Society has owed its influence to its 

 bold, original purpose. It was not founded as a drifting 

 social union of men, with a common interest in a single 



