THE ADRENAL BODIES 197 



used in bottling the extract. Schultz narrates that in one 

 instance only 6 grammes of pure adrenalin could be obtained 

 from a sample supposed to contain 19 '4 grammes of natural 

 I- adrenalin base. He finds that the ratio of physiological 

 activity of the natural Z-base and the synthetic dZ-product are 

 to each other as 2 : 3 instead of 1 : 2, according to Cushny. 



The physiological activity of all adrenin-like bodies can be 

 assayed by the blood-pressure method and their efficiency 

 expressed in terms of pure adrenin base. Hence, if one has 

 two solutions, a known adrenin solution, 1 c.c. of which contains 

 a grammes of the base, and an unknown containing a certain 

 amount, y, of vasoconstrictor exciting substance, they can 

 readily be checked against each other by the blood-pressure 

 method. Whichever solution is the stronger can be diluted 

 until 1 c.c. injections of it cause the same rise of blood-pressure 

 as the other, and finally their relative activity calculated by 

 the following equation : 



a adrenin base 



. . . r: r = relative activity. 

 y vasoconstrictor excitant 



Folin, Cannon, and Denis have described a colorimetric 

 method for the determination of adrenin. Folin and Denis 

 had previously described a phospho-tungstic acid reagent 

 which gives a blue colour with uric acid, and also with poly- 

 phenol compounds. The method applied to adrenin in solution 

 reveals the presence of one part of adrenin in three millions of 

 water. Using a solution of uric acid of known strength for 

 the colour standard and accepting the proved observation that 

 adrenin has thrice the chromophoric value of uric acid, it 

 requires but a few minutes to assay a solution of adrenin. 



Schultz has investigated a series of specimens of adrenin sold 

 under different names by various firms. Of the seven different 

 brands of " epinephrin " examined, only three possessed an 

 activity that equalled the standard. The other solutions 

 varied from 3*75 to 71 per cent, of the required activity. Some 

 of the solutions were worthless, and perhaps even dangerous. 

 Certain solutions, though showing a high degree of activity 

 upon opening the original package, quickly deteriorated in 

 spite of the extra precautions taken to guard against conditions 

 known to further this process. This author remarks that, on 

 the other hand, some of the preparations now upon the market 

 are of the very highest quality. 



