192 THE DUCTLESS GLANDS 



like substance obtained by these methods was precipitable 

 from alcoholic solution by means of ether. In the state of 

 solution preserved in sealed tubes it showed considerable 

 stability, and possessed a high degree of physiological activity. 

 A dose of 0-000025 gramme raised the blood-pressure of a rabbit 

 to nearly double its original height. At a later date Abel made 

 a comparison between a preparation obtained by the above 

 lead process and the crystalline adrenalin obtained by Taka- 

 mine's process (vide infra). The test was a double one. On 

 the one hand a colorimetric estimation of the iron compound 

 was made, and on the other hand the relative effect upon the 

 blood-pressure was noted, and in neither case was v. Furth's 

 substance shown to be weaker than that of Takamine. 1 Von 

 Fiirth called his substance " Suprarenin" 



Abel and Crawford converted the pyrocatechin-like substance 

 into a benzoyl compound, and observed after saponification 

 by addition of alkali a smell like that of coniine or pyridine. 

 Furthermore, they made the very important observation that, 

 by distillation of the product with zinc dust in a stream of 

 hydrogen, pyrrol was obtained, and they arrived finally at the 

 conclusion that the active principle of the adrenal medulla 

 belongs to the series of the pyridine bases. This has not been 

 confirmed by subsequent investigation. Moore came to the 

 same conclusion, since he observed that if some adrenal extract 

 be cautiously fused with caustic potash so as to avoid charring, 

 the peculiar odour of pyridine was at once obtained. But, as 

 pointed out by Moore in this relation, it is piperidine, and not 

 pyridine, which has a marked effect upon the blood-pressure. 

 Moore surmised, therefore, that the active substance is a 

 piperidine derivative i.e., that it contains a hydrogenated ring. 



V. Ftirth next proceeded to the formation of an iron com- 

 pound of the active principle. An extract of the glands was 

 made by boiling with acidulated water with the addition of 

 zinc dust. The extract was concentrated in vacua, the residue 

 extracted with methyl alcohol, and the solution, after getting 

 rid of inactive substances by means of zinc chloride and acetone, 

 decomposed with chloride of iron and ammonia. The iron 

 compound of the " suprarenin " separated out in the form of a 

 carmine-red flocculent precipitate. The substance was then 



1 In recognition of this fact the term " suprarenin " is still frequently used, 

 especially in Germany, for the active principle of the chromaphil tissues, 



