1 82 INTERNAL SECRETION 



progressive weakening of the liquid to be tested until a reaction 

 takes place, which, in regard to the intensity of the stain, is equal 

 to a standard adrenalin solution of i : 1,000,000. 



The amount of adrenalin in the suprarenal is ascertained by 

 cutting the organ into small pieces and reducing it to a paste 

 by means of quartz sand; ten times the bulk of a 2 per cent, 

 acetic acid solution is added, and the mixture is allowed to stand 

 for about twenty-four hours ; the filtrate is then twice treated, 

 each time with five parts of the same acetic acid solution, in a 

 water-bath at 70 C., and is again filtered. The filtrate, which 

 still retains its brown colour, is bleached with ammonium sulphate, 

 and is then ready for use. According to Zanfrognini, the adrenalin 

 present in the human suprarenal remains unchanged for several 

 days after death. 



S. Frankel and R. Allers describe a new and extremely 

 sensitive and characteristic adrenalin reaction. It depends upon 

 the fact that hydroidic-acid, or potassium biniodide and dilute 

 phosphoric acid, when added to adrenalin solution and heated, 

 change in such a manner as to produce an eosin pink colour in 

 weak solutions, and a splendid rose-red colour where stronger 

 solutions are used. On the further addition of ammonia, the 

 red colour changes to a rust-brown. The reaction is obtainable 

 with an n/ 50no - adrenalin solution, which is thus a .00365 per 

 cent, solution, or, in other words, contains i 1300,000. The 

 reaction is wholly specific to adrenalin, and none of the substances 

 for which adrenalin may be mistaken give a similar red stain. 

 The characteristic coloration is probably due to the formation of 

 an iodo- or an iodoso-combination on the part of the adrenalin. 



As G. Bayer has shown, the adrenalin colour reactions with 

 ferric chloride and with chromates, as well as with the Frankel- 

 Allers test, may be rendered more sensitive by the addition of 

 aromatic amidosulphonic acids (a-naphthylaminosulphonic acid, 

 p-amidobenzolsulphonic acid). The sulphanil acid modification 

 of the ferric chloride and chrome reactions ought to have a 

 distinct value in microscopic and histological work. The iodine 

 reaction of adrenalin is intensified by alanin and by phenylalanin, 

 and probably also by other products of the decomposition of 

 albumin. 



A method of testing the urine for adrenalin, recently 

 described by Schur, makes use of the red iodine reaction in the 

 following manner : an excess of tincture of iodine is added to the 

 liquid to be examined; the surplus iodine is then removed by 

 repeated shaking-up with ether, and this is continued until the 

 ether ceases to acquire a yellow tinge. Where adrenalin is 

 present the specimen stains pink, and though this colour is 

 permanent in pure adrenalin solutions, in urine it disappears after 

 some time. Adrenalin can be detected by this method in urine, in 

 a proportion of i : 200,000; in normal saline solution, in a proper- 



