44 PRESIDENTIAL ADDRESS— SECTION. B.- 



number of such compounds now actually described is some- 

 where about one hundred and fifty thousand, and new members 

 are beins:^ added to the list every day. The number theoretically 

 predictable is a question only of permutations. 



Since they are of extraordinary complexity, no chemist, 

 professed organic chemist though he be, makes the least attempt 

 to remember, or deal with, anythino- more than a mere fraction 

 of them : but contents himself with type compounds and a 

 study of the underlying principles involved in their i>reparation 

 or synthesis, the determination of their constitution, their sources, 

 properties, and the uses to which they can be put. To attempt 

 to. memorise the way in which the constitution of them all has 

 been determined would be as stupid as to attempt to memorise 

 a few thousand games of chess. Obviously, it is only possible 

 to learn the principles of the game. 



The domain of the organic chemist is so wide, and the 

 problems he may have to tackle are so intricate, that the modern 

 investigator usually finds it necessary to confine himself to a very 

 small section of his branch science ; ogle the amino-acids, give 

 his heart to a heterocyclic ring, or soak his brain in an aniline 

 -dye. But if he does any of these things he becomes a very 

 useful person. 



As an illustration of the significance of Organic Chemistry 

 in our daily affairs, the chemistry oi coal-tar may be taken. 



In the early days of coal-distillation the only products 

 arrived at were illuminating gas and coke, the bye-product, tar, 

 being regarded as of little value. Various chemists then took 

 up the study of coal-tar, at first in the spirit of " pure research," 

 and at the present day the commercial value of the tar products 

 far exceeds that of the illuminating gas itself. These products 

 are so numerous and so important that it is impossible to ofifer 

 even the briefest sketch of them here. Suffice it that huge 

 industries have arisen from the first academic researches, and 

 that the products go to feed all the other arts and sciences. To 

 the doctor go his anaesthetics, his hypnotics, his febrifuges, and 

 his specific drugs like salvarsan ; to the biologist his stains 

 and .solvents, and to the dyer his dyes; to the soldier his 

 explosives ; to ' the photographer his developers ; to everyone, 

 directly or indirectly, something. It would be difficult to 

 estimate the value to the community of the labours of the early 

 organic chemists, to whom the coal-tar industrv owes its origin, 

 though some idea of it may be obtained when it is considered 

 that before the war Germany exported over ten million pounds' 

 worth of coal-tar dyes alone per annum. It may not, perhaps, 

 come amiss to point out that the first step in the sequence of 

 development was made in Britain in 1856, when Sir W. H. 

 Perkin, then a boy of eighteen, was carrying out a research 

 with a totally dift'erent object in view — a research into Quinine. 

 In the course of his work he obtained a substance which 

 " seemed worthy of further investigation." Being a scientist 

 and not a utilitarian, he did not throw it away, but instituted 



