82 ALBEET C. CRAWFORD 



atmosphere t>f CO 2 , and finally extracted with alcohol "and precipitated 

 with ether. From 2000 pig suprarenals he obtained about 0.4 g. of a 

 nitrogenous compound, but he did not feel sure of its purity. 



From a study of an impure acetyl product von Flirth at first argued 

 that the pressor compound was either tetra-hydro : dihydroxy-pyridin 

 (C 5 H 7 NO 2 ) or di-hydro-dihydroxy-pyridin (C 5 H 7 NO 2 ), but he soon 

 abandoned this view. 



Von Fiirth (a) then started out from Hofmeister's observation that the 

 chromogen is very resistant to reduction with zinc dust in acid solution. 

 He extracted the glands with a dilute solution of ZnSO 4 , removed heat- 

 coagulable proteins, precipitated with NH 4 OH, and then purified by an 

 elaborate method. However, it is difficult to see how all zinc would be 

 removed by this method. From 200 beef glands he obtained 0.5 g. of 

 material. The intravenous injection of 0.00005 g. of this preparation 

 raised the blood pressure of a rabbit 74 mm. Hg. 



Later he extracted with acidulated water in the presence of zinc dust, 

 concentrated, extracted with methyl alcohol, then removed some inert 

 materials with ZnCl 2 and acetone, precipitated with FeCl 3 and am- 

 monia, but his purified product was not uniform in composition. He 

 named the pressor compound, suprarenin, although he only obtained it 

 as his iron suprarenin compound. Of this iron compound, 0.000075 g. 

 raised the blood pressure 24 mm. Hg in a rabbit weighing 2 kilograms. 

 In a dog (6 kilo.) the intravenous injection of 0.0001 g. caused a rise of 

 4.6 mm. Hg. Five millionths of a gram of this iron compound, which 

 equals about four millionths of a gram of free suprarenin, raised the 

 blood pressure of a dog (7 kilo.) 14 mm. Hg (von Fiirth (&)). Von 

 Fiirth estimated the glands to contain from 0.1 to 0.17 per cent suprarenin 

 (ImrayO)). 



After the papers of Takamine and Aldrich had appeared, von Fiirth (c) 

 (d] decomposed his iron compound with H 2 S and heated the solution with 

 NH 4 OH and thus obtained a product which corresponded to that of 

 Aldrich. He admitted that his iron method was likely to be attended 

 with oxidation (Radziejewski). 



Takamine extracted the glands with water, or acidulated water, cov- 

 ering the surface with fat to lessen oxidation, coagulated the proteins 

 by heat, then concentrated in vacuo and precipitated with NH 4 OH or 

 XaOII. This crude product was then dissolved in acid and precipitated 

 with alcohol and ether. On reprecipitation, it appeared as a white, 

 microcrystalline substance, which yielded five different crystal forms. 

 This substance, which he named adrenalin, produces a slightly bitter 

 taste and reacts alkaline. To neutralize 100 parts of adrenalin required 

 27.38 parts H 2 SO 4 or 19 parts HC1. It is soluble with difficulty in 

 cold water. 



Takamine pointed out that colorless solutions of adrenalin readily 



