492 



SCIENCE. 



[N. S. Vol. XX. No. 511. 



istry: The discovery of isomerism, the dis- 

 covery of radicals, the older radical theory, 

 the theory of types, the establishment of 

 true molecular weights, the discovery of 

 the fact of valence, the determination of 

 structure. 



I think that all workers in organic chem- 

 istry will accept the following as a con- 

 servative statement of our present knowl- 

 edge: (1) That in organic compounds, at 

 least, each atom is attached directly to only 

 a limited, small number of other atoms; 

 (2) that in the sense of the order of the 

 successive direct attachments the structure 

 of a very large number of compounds is 

 known with a degree of probability that 

 amounts to practical certainty. 



This brings me to the task which has been 

 set, an attempt to outline the problems 

 which lie before us in the further develop- 

 ment of our science. 



In the first place, there is still much to 

 be done to extend our knowledge of com- 

 pounds found in nature. This field is 

 much less cultivated, relatively, than was 

 the case sixty years ago. There has been 

 good reason for this because of the prob- 

 lems of absorbing interest which have 

 arisen in the preparation and study of 

 new compounds and in the extension of 

 our knowledge of old ones. But there must 

 still remain many compounds to discover 

 among both animal and vegetable products. 

 On this side organic chemistry resembles 

 the descriptive sciences of botany, zoology 

 and mineralogy. And just as botanists 

 think it worth their while to secure as com- 

 plete a description as possible of the plants 

 to be found on the earth, so it lies in our 

 province to isolate and identify the carbon 

 compounds of the animal and vegetable 

 worlds— with the difference that in our 

 case each compound, new or old, may be 

 the starting point for the preparation of 

 an almost endless number of others. But 

 here most of us recognize that unless a com- 



pound has some further interest than that 

 it is new it is not worth the time taken in 

 its preparation. I am afraid, however, as 

 we look over the pages of our journals, there 

 is too much evidence that not every one 

 lives up to this view. Our ever-increasing 

 army of nascent doctors must needs have 

 something to do, and it is so easy to make 

 new .compounds and so difficult to find 

 something new of larger scope and really 

 worth the doing. 



There still remains much to do in the 

 determination of the structure of com- 

 pounds which have long been known. The 

 study of a single compound often involves 

 an incredible amount of work. Baeyer 

 worked with indigo for fifteen years be- 

 fpre his labors were crowned with a suc- 

 cessful synthesis, and twenty years more 

 and the work of very many chemists were 

 needed before the scientific achievement 

 could become a commercial success. 



It was nearly twenty-five years after the 

 first structural formula was proposed for 

 camphor before Bredt was fortunate 

 enough to suggest the true arrangement of 

 its atoms, and it was ten years longer and 

 required in all the work of more than fifty 

 chemists before Bredt 's suggestion was con- 

 firmed by Komppa's beautiful synthesis. 



More than thirty formulae were proposed 

 for camphor, and those who think little of 

 organic chemistry have some reason if they 

 say that we jump at conclusions too hastily 

 and propose too many formula that are 

 mere guesses. Some might even say that 

 the last formula isn't worth much, but 

 those who have followed the matter know 

 that step by step we have arrived at an 

 almost positive certainty even in this com- 

 plex problem. 



The final solution of a problem with re- 

 gard to the structure of a compound of 

 natural origin is not usually considered to 

 have been satisfactorily attained until its 

 sjmthesis has been effected. Those who 



