CHEMICAL CONSTITUTION AND PHARMACOLOGICAL ACTION. 407 



will apply to the study of the relation between constitution and 

 action, we find that the results are still very meagre. 

 In the main they are as follows : 



1. The discovery that the antipyretic action of the anilin and 

 amidophenol derivatives (phenacetin) is proportional, within cer- 

 tain limits, to the amount of p-amidophenol split off in the organism 

 (Hinsberg). Hence all such combinations in which, through im- 

 proper substitution of the amido group or of the main group (p- 

 amidoacetophenon, NH 2 -C 6 H 4 -CO-CH 3 ) ? the liberation of p-amido- 

 phenol is prevented cannot be used as antipyretics. 



2. The discovery by Kendrick, Dewar, Filehne, that in the pyri- 

 din series the hydrated products act more strongly than the parent 

 substance. Thus piperidin, C 5 H 10 NH, is a much stronger poison 

 than pyridin, C5H 5 X. In this the transformation of the tertiary 

 nitrogen atom in the imin group plays a certain role, as is shown 

 especially by the observations of Filehne on the tetra-hydro-chinolm 

 series. According to these the replacement of the imid's hydrogen 

 atom by alcohol radicals reduces the irritant action. 



3. The demonstration that the antipyretic power of antipyretics 

 is destroyed by the introduction of salt-forming acid radicals, such 

 as SO 3 H, CO 2 H (Ehrlich, Aronson, Nencki, Penzoldt). Hence 

 so far as this action is concerned acetanilido-acetic acid, 

 C 6 H 5 X(COCH3)CH 2 CO2H, is inert. So also are acetanilin sulfonic 

 acid, C 6 H 5 XH CO CH 2 SO3H, the carbonic and sulfonic acids of 

 phenacetin, and the ethoxy-phenylglycin which is similar to 

 phenacetin. 



C 6 H 4 



/OC 2 H 5 

 \XH-CH 2 .CO 2 H. 



4. The demonstration by Filehne, Einhorn, Ehrlich, and Poulson, 

 of the ansesthesiophore character of the benzoyl radical. Homo- 

 logues of cocaine, such as are obtained when other acid radicals, 

 such as succinic acid, phenylacetic acid ; cinnamic acid, are intro- 

 duced into the ecgoninmethylester, lack these anaesthetic properties. 

 This discovery resulted in the production of new potent anaesthetics 

 containing the benzoyl group as the active agent, e.g. eucain (Merling) 

 and orthoform and nirvanin (Einhorn). 



5. The function of the ethyl group. This has been brought out 

 very clearly by Baumann's discovery that the hypnotic action of 

 certain disulfons is due exclusively to the presence of ethyl groups 



