September 12, 1912] 



NATURE 



43 



SECTION B. 



CHEMISTRY. 



Opening Address by Prof. A. Senier, Ph.D., M.D., 

 D.Sc, President of the Section. 



1 .\.\l sure it will be agreeable to the feelings of the 

 members of this section that, before beginning my 

 address, I should refer to the great losses we have 

 sustained by death since our gathering last year at 

 Portsmouth. 



An active member and past-president has passed 

 away in the death of Edward Divers, after a serious 

 operation, undergone at his advanced age with char- 

 acteristic fortitude. His devotion of his long life, in 

 this country and Japan, to the advancement and dif- 

 fusion of science is indelibly inscribed in its records. 

 But Divers was more than an investigator and 

 teacher ; he was a beloved centre of our social life, and 

 was particularly happy when he could bridge over the 

 distance between the young beginner in research and 

 the older experienced master. Me understood and had 

 the sympathy of both. 



In Henry Forbes Julian, one of the victims of the 

 awful disaster to the Titanic, we have lost a valued 

 contributor to our proceedings ; though he was best 

 known as a geologist and metallurgical engineer. It 

 was, however, by chemistry, under the inspiring in- 

 fluence of Sir Henry Roscoe, that his first enthusiasm 

 for science was aroused. Forbes Julian was a leading 

 technical adviser in mining undertakings, and his 

 advice was much sought after, especially in South 

 Africa, and even in Germany. 



Another tragedy, from the shock of which we have 

 not yet recovered, has deprived science of the young 

 and promising inquirer, Humphrey Owen Jones. We 

 know the dreadful details — he and his young wife — 

 how they became sacrifices to the treacherous crags 

 and snows of Mont Blanc. 



.And this, alas, is not all. On the very day of the 

 fatal accident to Humphrey Jones, another young and 

 promising chemi^st — John Wade — passed from us from 

 the effects of a cycling accident. He was an inquirer 

 of singular ability, and found time also to give us 

 one of our deservedly most popular manuals of organic 

 chemistrv. 



Part I. 



The Nature and Method of Chcmisiry. 

 Perhaps there is no intellectual occupation which 

 demands more of the faculty of imagination than the 

 pursuit of chemistry, and perhaps also there is none 

 which i-esponds more generously to the yearnings of 

 the inquirer. It is surely no commonplace occurrence 

 that in experimental laboratories day by day the mys- 

 terious recesses of Nature are disclosed and facts 

 previously quite unknown are brought to light. T"he 

 late Sir Michael Foster, in his presidential address at 

 the Dover meeting, said: — "Nature is ever making 

 signs to us, she is ever whispering the beginnings of 

 her secrets." The facts disclosed may have general 

 importance, and necessitate at once changes in the 

 general body of theory ; and happily, also, they may 

 at once find useful application in the hands of the 

 technologist. Recent examples are the discoveries in 

 radio-activity, which have found an important place 

 as an aid to medical and surgical diagnosis and as a 

 method of treatment, and have also led to the neces- 

 sity of our revising one of the fundamental doctrines 

 of the theory of chemistry — the indivisibility of atoms. 

 But the facts disclosed may not be general or even 

 seem important ; they may appear isolated and to have 

 no appreciable bearing on theorv or practice — our 

 journals are crowded with such — but he would be a 

 bold man who would venture to predict that the future 

 will not find use for them in both respects. To be the 

 NO. 2237, VOL. go] 



recipient of the confidences of Nature; to realise in all 

 their virgin freshness new facts recognised as positive 

 additions to knowledge, is certainly a great and 

 wonderful privilege, one capable of inspiring 

 enthusiasm as few other things can. 



While the method of discovery in chemistry may 

 be described, generally, as inductive, still all the modes 

 of inference which have come down to us from 

 Aristotle, analogical, inductive and deductive, are 

 freely made use of. A hypothesis is framed which is 

 then tested, directly or indirectly, bv observation and 

 experiment. All the skill, all the resource the inquirer 

 can command, is brought into his service ; his work 

 must be accurate ; and with unqualified devotion to 

 truth he abides by the result, and the hypothesis is 

 established, and becomes part of the theory of science, 

 or is rejected or modified. In framing or modifying 

 hypotheses imagination is indispensable. It may be 

 that the power of imagination is necessarily limited 

 by what is previously in experience— that imagination 

 cannot transcend experience ; but it does not follow, 

 therefore, that it cannot construct hypotheses capable 

 of leading research. I take it that what imagination 

 actually does is — it rearranges experience and puts it 

 into new relations, and with each successive discovery 

 it gains in material for this process. In this respect 

 the framing of a hypothesis is like experimenting, 

 wherein the operator brings matter and energy 

 already existing in Nature into new relations, new 

 circumstances, with the object of getting new results. 

 The stronger the imaginative power, the greater must 

 be the chance of success. The Times, in a recent leading 

 article on .Science and Imagination, says : — " It has 

 often been said that the great scientific discoverers 

 . . . see a new truth before they prove it, and the 

 process of proof is only a demonstration of the truth 

 to others and a confirmation of it to their own reason." 

 While never forgetting the essentially tentative nature 

 of a hypothesis, still, until it has been tested and 

 found wanting, there should be some confidence or 

 faith in its truthfulness ; for nothing but a belief in 

 its eventual success can serve to sustain an inquirer's 

 ardour when, as so often happens, he is met by diffi- 

 culties well-nigh insuperable. In a well-known pas- 

 sage Faraday says : — " The world little knows how- 

 many of the thoughts and theories which have passed 

 through the mind of a scientific investigator have been 

 crushed in silence and secrecy by his own severe 

 criticism and adverse examination ; that in the most 

 successful instances not a tenth of the suggestions, 

 the hopes, the wishes, the preliminary conclusions 

 have been realised." 



But a hypothesis to be useful, to be admitted as a 

 candidate for rank as a scientific theory, must^ be 

 capable of immediate, or at least of possible, verifica- 

 tion. Many years ago, in the old Berlin laboratory in 

 the Georgenstrasse, when our imaginations were wont, 

 as sometimes happened, to soar too far above the 

 working benches, our great leader used to say : — " I 

 will listen readily to any suggested hypothesis, but 

 on one condition — that you show me a method by 

 which it can be tested." As a rule, I confess we had 

 to return to the workaday world, to our bench experi- 

 ments. No one felt the importance of the careful and 

 correct employment of hypotheses more than Liebig. 

 In his Faraday lecture Hofmann says of Liebig : — 

 '■ If he finds his speculation to be in contradiction with 

 recognised facts, he endeavours to set these facts 

 aside by new experiments, and failing to do so he 

 drops the speculation." -Again, he gives an illustra- 

 tion of how on one occasion, not being able to divest 

 himself of a hypothesis, he missed the discovery of 

 the element bromine. While at Kreuznach he made 

 an investigation of the mother-liquor of the well- 

 known salt, and obtained a considerable quantity of 



