92 THE SIMPLER NATURAL BASES 



Colorimetric Estimation of Adrenaline. The green coloration with 

 ferric chloride has been employed by Batelli [1902] who found by 

 this means 0*174 P 61 " cent, in fresh bullock's glands. Von Fiirth [1901] 

 has used the carmin red coloration produced by ferric chloride in the 

 presence of sodium carbonate and sodium potassium tartrate. The 

 ferric chloride reaction is, however, not very suitable for quantitative 

 work (cf. Cameron [1906]) and the same applies, according to the 

 author's experience, to the iodine-thiosulphate method of Abelous, 

 Soulie and Toujan [1905]. Comessatti [1909] has employed 

 the mercuric chloride reaction a good deal for quantitative purposes, 

 and Cevidalli [1908] and Zanfrognini [1909] have used their re- 

 actions in the same way ; their methods have been adversely criticised 

 by Borberg [1912]. Ewins [1910] found a distinct parallelism 

 between the depth of colour produced by potassium persulphate and 

 the pressor activity of supra-renal extracts. This physiological control 

 has not been applied sufficiently to most other colorimetric methods. 



A notable exception is found in a recent paper by Folin, Cannon, 

 and Denis [1913] and the colorimetric method of these authors based 

 on the reaction described above (under E) appears to be almost or quite 

 as accurate as the blood pressure method with which its results agree 

 within a few per cent, of the total adrenaline present. The method 

 is even sufficiently sensitive to demonstrate the increase of adrenaline 

 in the supra-renal vein by stimulation of the splanchnic nerve (cf. 

 p. 95). It is not necessary to have pure adrenaline as a standard, for 

 uric acid gives an identical coloration with one-third of the intensity. 



Amount of Adrenaline in the Supra-renal Gland ; Yield ; 

 Distribution in other Organs ; Origin. 



By the physiological blood pressure method, which is probably the 

 most accurate, Elliott finds that the adult human gland in health con- 

 tains about O'l per cent, (unpublished observation, referred to below). 



By the same method Elliott [1912] has found that the normal 

 cats supra-renal, weighing 0*2 grm., contains on the average 0*22 mg. 

 of adrenaline, or OTI per cent. Folin, Cannon and Denis [1913] 

 found in the gland of young cats 0-122-0-152, of the dog and monkey 

 0*2-0-25, of the calf 0-25-0-35, of sheep, cattle, rabbits, 0-3 per cent. 



Houghton [1902] found Takamine's original adrenaline to be 600 to 800 times as 

 active as fresh bullock's gland ; according to Takamine [1901, 4] the specimen contained 

 mineral impurities and pure adrenaline is probably 1000 times as active >as the fresh gland, 

 which would therefore contain o - i per cent, of the base. 



For the horse we have Bertrand's statement [1904, l] that 118 kilos, of the fresh gland 

 yielded 125 grm. of adrenaline or o'io6 per cent. 



