sulphuric acid until it has become of tarry consistency. It is then ex- 

 hausted with ether, acetone and absolute alcohol in succession. 



The residue is physiologically very active, and it gives all the reac- 

 tions characteristic of an aqueous solution of the gland— a beautiful 

 rose color on the addition of an alkali, a green color with ferric chlo- 

 ride, reducing silver nitrate, etc. 



However, we are not yet dealing with a pure substance. If we neu- 

 tralize an aqueous solution of the product thus obtained with a free 

 alkali or with a carbonate of the alkalies, an overpowering odor much 

 like that of coniine is perceived. As this odor passes that of pyridine 

 seems to take its place. The basic substance thus liberated fumes in the 

 air or when a glass rod moistened with hydrochloric acid is brought 

 into its neighborhood. To remove this basic substance we made an 

 aqueous solution of the active principle as above isolated, rendered 

 it faintly alkaline with sodium carbonate and shook out ether sev- 

 eral times in succession. But this method does not remove all of the 

 coniine-like substance. To effect this we were obliged to make the 

 active principle strongly alkaline with sodium hydrate before shaking 

 out with ether. The acjueous solution, in consequence of the addition 

 of the free alkali, takes on a deep red color, and carmine red flocks are 

 thrown out. After the removal of the coniine-like substance with 

 ether, the fluid containing the red flocks was acidulated with sul- 

 phuric acid and the carmine-red substance was filtered off. The clear 

 filtrate, which was a pale straw color, was concentrated in vacuo, and 

 the active principle taken up in weak alcohol. On account of the in- 

 solubility of the sulphate of the active principle in absolute alcohol 

 it is difficult to obtain this entirely free of sodium sulphate. We hope 

 in future to remove both the coniine-like substance and the pig- 

 ment ^vith the help of ammonia. The presence of pyridine in our 

 ammonia prevented our using it for this purpose. 



This volatile base of a coniine-like odor has not hitherto been de- 

 scribed as a constituent of the suprarenal capsule. The beautiful 

 carmine-red pigment we take to be identical with the red substance 

 which many other observers have found to be thrown out as a pre- 

 cipitate when ammonia is added to a concentrated aqueous solution 

 of the gland, or when a solution is evaporated in the presence of lead 

 acetate.* Others have believed this red precipitate to be the oxidation 

 product of the active principle of the gland, but we shall presently 

 see that the active principle is still present in the filtrate from the 



* Holm, Journ. f. prakt. Chemie, c (1867), 150. 



49 



