CHEMISTRY OF THE SUPRARENAL GLANDS 81 



of the benzoyl product presumably had occurred. This solution gave the 

 iodin reaction and yielded a precipitate with picric acid which was physi- 

 ologically active. In a dog (6.8 kgm.) with cut vagi, the intravenous in- 

 jection of 0.0011 g. of this impure picric acid precipitate cause a rise 

 in blood pressure of 46 mm. Hg, while 0.0042 g. produced a rise 

 of 88 mm. Hg. 



Using Abel's method, von Fiirth could not obtain a physiologically 

 active picrate and there may be some question whether Abel's precipi- 

 tate might not have been a picrate of a modified epinephrin to which 

 was absorbed some unchanged active compound; but, however this may 

 be, Abel(fr), from this precipitate, obtained very active preparations, i. e., 

 sulphate (C 17 H 15 NO 4 ) 2 H 2 SO 4 , an impure bisulphate, etc. The bisul- 

 phate (0.00013 g.) raised the blood pressure of a dog with cut vagi 14 mm. 

 Hg, while 0.00043 g, raised it 60 mm. This activity would correspond to 

 0.000019 g. of the salt per kilo or to 0.000013 g. of free base. A sulphate 

 made from the bisulphate was tested by Reid Hunt(c), who found that 

 0.083 millionths of a gram per kilo body weight raised the blood pressure 

 of an atropinized dog 5 mm. Hg, while 5.7 millionths of a gram per kilo 

 raised it 66 mm. 



Abel did not obtain the active compound in the form of a free base, 

 because, as is well known, the autoclave treatment destroys much of the 

 active compound and NH 4 OH will not precipitate it save from concen- 

 trated solutions. 



Abel called his active product epinephrin hydrate or native epineph- 

 rin. In connection with the subject of two possible forms of epinephrin 

 it may be remembered that Halle suggested that in the suprarenals there 

 might be a series of closely related compounds. 



Abel(<i) made a mistake in naming the inactive product epinephrin and 

 the active form epinephrin hydrate. If he had named his active prepara- 

 tion epinephrin and his inactive form epinephrin anhydrid much con- 

 fusion would have been avoided, as anhydrids are often inactive. Further 

 confusion resulted from his early failure to reduce Fehling's solution 

 with his active preparations, but the physiological tests made by Hunt 

 and by himself showed that he had a product with marked physiological 

 activity. (Compare Abel and Macht.) 



As one of its decomposition products Abel(#) (k) obtained pyrrol and 

 at first believed the pressor compound to contain this nucleus. Abel's 

 method was too involved and required the use of too expensive chemicals 

 for commercial purposes, but Takamine soon isolated the pressor com- 

 pound in a form which was commercially feasible. 



Von Fiirth (a), at first, used a method somewhat like that of Holm, i.e., 

 he extracted with alcohol at low temperature, removed inactive sub- 

 stances with Pb acetate and precipitated the filtrate with Pb acetate and 

 NH 4 OH. This precipitate was decomposed with H 2 S, evaporated in an 



