12 SUPRARENAL GLANDS. 



COLOR TESTS. 



Adrenalin is described as a microcrystalline powder which possesses 

 basic properties and acts as a reducing agent. Strictly speaking, this 

 body can not be classed with the alkaloids. 



Freshly prepared solutions are colorless, but become rose colored 

 under the influence of light and air, especially in dilute solutions. 

 After long standing these solutions finally become brown and lose 

 their activity. This oxidation especially occurs in an alkaline medium, 

 so that commercial solutions are usually made acid. a 



The active principle when in solution gives a green color on the 

 addition of ferric chlorid. This green passes into a purple and finally 

 into a carmine on the addition of ammonia. A dilute solution of 

 iodin turns adrenalin solution to a rose color. 



This production of a green color with ferric chlorid has been utilized 

 by Battelli b as a method of estimating the amount of active principle 

 present. The formation of this color is, however, influenced by acidity 

 and appears badly in very acid solutions , c but the main difficulty 

 with this method is that the delicate green is hard to recognize in great 

 dilution. 



Cameron d states that this is a rough method for assaying solutions 

 of over 1-40,000 and that it fails for brown or solutions more dilute 

 than 1-40,000. 



Von Furth g has also proposed a color test with iron chlorid, sodium 

 carbonate, and potassium sodium-tartrate, but this does not offer any 

 advantages and is subject to the same criticism as other color reactions. 



Abelous, Soulie, and Toujan^ have proposed using the iodin reac- 

 tion for the same purpose, judging not by the amount of iodin used 

 but by the shade of rose color produced. This is ascertained by con- 



oLivon, C. Action des vieilles solutions d' adrenaline. Comp. Rend. Hebd. Soc. de 



Biol., vol. 1, p. 125, 1904. 

 Battelli, F. Transformation de l'adrenaline "in vitro." Comp. Rend. Hebd. Soc. 



deBiol., vol. 54, p. 1435, 1902. 

 b Battelli, F. Dosage colorimetrique de la substance active des capsules surrenales. 



Comp. Rend. Hebd. Soc. de Biol., vol. 54, p. 571, 1902. 

 c Boulud, R., and Fayol. Sur le dosage colorimetrique de l'adrenaline. Comp. 



Rend. Hebd. Soc. de Biol., vol. 55, p. 358, 1903. 

 d Cameron, 1. D. On the methods of standardising suprarenal preparations. Proc. 



Roy. Soc. Edinburgh, vol. 26, p. 157, 1906. 

 e Von Furth, O. Zur Kenntniss der brenzcatechinahnlich. Substanz d. Nebennieren. 



Zeits. f. Physiol. Chem., vol. 29, p. 115, 1900. 

 Zur Kenntniss des Suprarenins. Beitr. z. Chem. Physiol, u. Path., vol. 1, p. 244, 



1902. 

 /Abelous, J. E., Soulie, A., and Toujan, G. Dosage colorimetrique par l'iode de 



l'adrenaline. Comp. Rend. Hebd. Soc. de Biol., vol. 1, p. 301, 1905. 

 Sur un procede de controle des dosages chimique et physiologique de l'adrenaline. 



Comp. Rend. Hebd. Soc. de Biol., vol. 60, p. 174, 1906. 



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