THE ADRENAL BODIES 193 



repeatedly dissolved in dilute ammonia, and precipitated by 

 means of acetone, and the final product was extremely active 

 physiologically, though not yet chemically pure. Analysis 

 indicated that the suprarenin probably contained C 8-9, 

 H 11-13, 3-4 per cent. 



Abel came td essentially different conclusions as to the 

 chemical nature of the active substance. This worker 

 benzoated adrenal extracts, saponified the purified benzoyl 

 product in the autoclave at a pressure of 3 to 5 atmospheres 

 with dilute sulphuric acid, and precipitated with dilute 

 ammonia or picric acid from the solution so obtained a 

 substance which he called " Epinephrin," which he considered 

 was the isolated active principle of the adrenal medulla. It 

 yields picrates and other salts, and is a substance of an 

 alkaloidal nature, having the elementary composition 

 17 H 15 N0 4 . V. Fiirth has shown that Abel's epinephrin is 

 quite a different substance from his own suprarenin, that the 

 former possesses in itself no physiological action, and that 

 whatever physiological effects may be induced by its adminis- 

 tration are due to admixture with suprarenin. Epinephrin is 

 also distinguished from suprarenin by its precipitation by 

 means of precipitants of alkaloids (phosphotungstic acid, picric 

 acid, tannic acid, etc.), by zinc chloride, by the absence of 

 reducing power, and the absence of the colour reaction with 

 perchloride of iron. Its separation from suprarenin can 

 conveniently be effected by careful neutralization of the acid 

 solution with very dilute ammonia, by which means the 

 epinephrin separates out as a dark flocculent precipitate easily 

 soluble in excess of ammonia. 



Abel has since shown that epinephrin is to be looked upon 

 as a derivative of suprarenin arising as a result of the treat- 

 ment with acid in the autoclave. The fact that a methylindol 

 is obtained by fusing epinephrin with potash must be regarded 

 as of importance in explaining the constitution of suprarenin. 

 Abel has suggested the possibility that by the autoclave 

 treatment a portion of the nitrogen is split off from the supra- 

 renin molecule. This view has been confirmed by v. Fiirth, 

 Afterwards, however, Abel was inclined to believe that by 

 treatment of the benzoyl product in the autoclave saponification 

 was not complete, and the resulting substance was still a 

 benzoyl product (C 17 H 15 N0 4 ) ; epinephrin would therefore 



13 



