THE SUPRARENAL SYSTEM 247 



as Henle proved, stains brown in watery solutions of chromic acid 

 and the chromates. Oliver and Schafer next discovered that the 

 specific action of suprarenal extract is obtained exclusively with 

 the extract of the medulla, extract of the cortical substance being 

 negative. It was shown by both Langlois and S. Vincent, that 

 blood-pressure is raised by those extracts only which are obtained 

 from animals, the suprarenals of which are composed of medullary 

 and cortical portions. Vincent found that extracts of the so- 

 called suprarenal bodies (Balfour) of Selachii, were physiologically 

 active and, in combination with Moore, he succeeded in obtaining 

 with these substances the chemical reactions characteristic of the 

 chromogen of the suprarenal medulla. Extracts of the interrenal 

 bodies were partially active owing, Vincent believes, to the 

 inclusion of a proportion of medullary substance; extracts of the 

 bodies of Stannius of Teleosteii were completely inactive. These 

 tests were only employed to prove toxicity. 



I next found that extracts obtained from the adrenal organs 

 of Selachii possess all the physiological properties of adrenalin. 

 It is a noteworthy fact that, if adrenal organic extract is injected 

 into the branchial arteries of rays or torpedoes, a rise in blood- 

 pressure takes place similar to that which follows the injection 

 of adrenalin. Finally, it was shown by Biedl and Wiesel, 

 that extracts of the extracapsular chromaffine tissue, more par- 

 ticularly extract of the accessory sympathetic organs in the 

 neighbourhood of the abdominal aorta of children (Zuckerkandl), 

 produce contraction of the peripheral vessels and increased cardiac 

 activity, by which a rise in arterial tension is effected. These 

 authors also discovered that the substances exercise a transitory 

 injurious effect, first upon the right heart, and afterwards upon 

 the left, which is manifested by the occurrence of arhythmic beats. 

 They emphasize the fact, and in this they are supported by A. 

 Kohn, that the physiological reaction which is regarded as the 

 specific effect of suprarenal extract, is a property of the extract 

 of the chromaffine cell-group. In view^ of these results, it is 

 hardly possible to doubt that adrenalin is a chemical component 

 of that tissue which is distinguished, histologically, by the chrom- 

 affinity of its cells, and which has received the name of adrenal 

 tissue. 



A certain amount of information as to the quantity of adren- 

 alin present in the suprarenal and in the free portions of the 

 adrenal system, is supplied by histological investigation. The 

 chromaffinity of the adrenal cells, that is to say, the property which 

 their cytoplasm has of staining brown or yellow-brown with 

 chromium salts after suitable fixation, is the measure of their 

 adrenalin contents. 



The most suitable fixing fluids are mixtures of potassium 

 bichromate and formalin (Kohn, Wiesel). The objects must be 

 as fresh as possible when put into the fixing fluid, for the chrome 

 reaction disappears with remarkable rapidity after death, the cells 



