and have always been able to separate subsequently an active material. 

 After such treatment with alkalies, care must be taken in the sub- 

 sequent evaporation of the alcohol with which the active principle 

 is removed, to keep an acid reaction, as otherwise the greater part, if 

 not all of it, will be destroyed by oxidation. And unless all evaporations 

 are carried on under reduced pressure, much material will be lost, 

 even with the above precaution. 



Although somewhat contaminated with its own decomposition 

 products, this final sulphate has all the characteristics of an active 

 substance. As shown by repeated experiments, it promptly raises the 

 blood pressure, it constricts the vessels of an inflamed eye, and when 

 injected into the dorsal lymph sac of the frog it acts like a narcotic 

 or cerebrospinal poison. 



As freed of the red substance the sulphate of the active principle 

 behaves as follows: It is very soluble in water, fairly soluble in weak 

 alcohol (50 per cent), almost insoluble in absolute alcohol, and quite 

 insoluble in ether, acetone, ligroine and chloroform. Its aqueous solu- 

 tion, even when freed from adherent sulphuric acid, has a slightly 

 acid reaction. The addition of iodine water to a neutral solution does 

 not give a rose-red color. Alkalies added to a strong solution give a 

 brown color which deepens on heating. Ferric chloride gives a pur- 

 plish brown, almost black in concentrated solution, which on the ad- 

 dition of tartaric acid and an alkali passes into a deep red color. Before 

 the removal of the carmine-red substance the addition of ferric chlo- 

 ride gives the well-known emerald green color, w^hich passes into red 

 on the addition of an alkali. 



It is evident that our sulphate gives Vulpian's ferric chloride re- 

 action, though somewhat changed by the removal of what we take to 

 be the chromogenic substance which gave his iodine reaction. It also 

 promptly reduces silver nitrate in alkaline solution, but does not re- 

 duce Fehling's solution even on boiling. 



Probable Relation to the Alkaloids 



More than a year ago, during our first studies with suprarenal ex- 

 tract, we were struck with the fact that every extract entirely free of 

 proteids and physiologically active gave a fine pyrrol reaction when 

 subjected to dry distillation. This is evidenced both by the odor and 

 by the pine sliver reaction. A small quantity of the isolated sulphate 

 also gives the pyrrol reaction when heated either alone or with zinc 

 dust. 



We attach considerable importance to this reaction. As is well 



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