January 10, 1919] 



SCIENCE 



35 



lems of medicine, which should be emphasized, 

 is that which has found its most convincing 

 expression in Ehrlieh's great work on salvar- 

 san and neo-salvarsan, now kjiown to us by 

 their American official names as arsphenamine 

 and neo-arsphenamine. This is the most con- 

 vincing instance of the wonderful opportuni- 

 ties in developing the specific agent that will 

 kill a specific invading germ without perman- 

 ent injury to its host. Quinine was, I believe, 

 the first specific of this kind, and it would 

 seem that it would have been only a single 

 self -understood step from the use of a natural 

 chemical compound to the development of syn- 

 thetic chemicals for similar purposes — but it 

 took an Ehrlich to take the first great and 

 successful step in that direction. Ehrlich, 

 like Pasteur, was a chemist before he became 

 interested in medicine and it is important to 

 know that in developing arsphenamine he used 

 all the resources of pure organic chemistry, 

 his special field, changing the structure of the 

 molecule he was developing, here a little, there 

 a little, putting an apparently slight but es- 

 sential finishing touch here and there, just as 

 a sculptor would handle his clay and his 

 marble.- Finally after six hundred and five 

 preliminar.y studies the product needed to 

 produce the desired effect was perfected! In 

 arsphenamine the ordinary path of synthesis 

 was abandoned, that is, the ordinary path of 

 taking a natural product like indigo, cocaine, 

 or atropine and finding out the secret of the 

 constellation nature had constructed. Ehrlich 

 struck out to build his own cunning molecular 

 contrivance to kill the invading germ without 

 harm to the host and he succeeded brilliantly ! 

 For many other diseases due to bacterial in- 

 vasion medicine is now using specific anti- 

 toxins and vaccines, manufactured in some 

 host or medium by the germs themselves. 

 With the curative agency we find inevitabl.y 

 substances poured into our systems which are 

 not needed for the effect desired and which 

 ma.v indeed be harmful. For instance, a 

 child unfortunate enough to have received a 

 prophylactic dose of diphtheria antitoxin is 

 exposed to the dangers of anaphylactic shock 

 if later an actual attack of diphtheria develops 



and the treatment with antitoxin is indicated 

 in an effort to save its life. Surely, physicians 

 would prefer to use some pure specific if chem- 

 istry could prepare one, equally efficient, 

 equally potent. The effort to prepare such 

 chemical specifics has been blazed by the dis- 

 covery of arsphenamine and invites untiring 

 research efforts on the part of chemists. Some 

 of the other synthetic drugs which have al- 

 ready been prepared are specifics, if not in the 

 sense of completely curative agents, at least as 

 alleviating remedies of the highest value. The 

 demands for luminal for the relief of epileptics, 

 which have come in since its importation was 

 stopped bj' the war have been pathetic in 

 the extreme, and the gouty sufferer on the 

 other hand has been grateful that almost with- 

 out any delay American chemists were able 

 to produce phenyl cinehoninic acid or atophan, 

 which clears the system of the ache-producing 

 uric acid! 



We now come to the third and last field of 

 effort of pure chemical research in the service 

 of medicine which I should like to include in 

 this short sketch — -the study of the chemistry 

 of life itself, of protoplasmic agencies and 

 activities. Such a study is clearly so funda- 

 mental that it must ultimately give the world 

 the rational basis both for preventive and for 

 curative medicine. The problem obviously is 

 a tremendous one that must be attacked by 

 many workers from many sides and it will 

 take generations of toilers to complete the 

 great undertaking. That complete knowledge 

 will come no one can doubt who has followed 

 the brilliant advances made in the last sixty 

 years. At this time I can refer only to a very 

 few phases of this slow but triumphant march 

 of our science to the knowledge of the chem- 

 istry of life — a few phases which illustrate 

 different lines of attack and which at the 

 present moment hold out the greatest promise 

 of success. 



First, let me recall the fact that Pasteur's 

 first great contribution to science, as a young 

 chemist of twenty-six, was the discovery in a 

 study of the crj-stallinc character of tartaric 

 acid, that matter may be arranged in molecules 

 in space in an unsymmetric fashion, yielding 



