72 E. V. COWDKY 



possible tha* we may be dealing with two substances, epinephrin itself 

 and some forerunner. 



(c) Silver Nitrate Reaction. Macallum has extended Laignel Lava- 

 stine's observation that certain granules in the medullary cells reduce sil- 

 ver nitrate, and has claimed that the reduction is probably due to the pres- 

 ence of an antecedent of epinephrin, which he believes to be tyrosin. It is 

 very interesting to note that Macallum has found that a similar reaction 

 is given only by nerve cells, indicating that they too may possess the 

 potentiality of epinephrin production, though in a much less marked 

 degree. 



(d) Osmic Acid Reaction. Cramer describes a simple method for the 

 demonstration of epinephrin within the cells through blackening with 

 osmic acid. The granules thus revealed may be distinguished from the 

 lipoid droplets by the solution of the latter in turpentine. He claims 

 that these "adrenalin granules" pass into the blood vessels in glands stim- 

 ulated by the injection of tetrahydronaphthylamin, and that they decrease 

 with exhaustion of secretion. He asserts also that "in the various con- 

 ditions demanding an increased functional activity of the suprarenals fine 

 black granules, similar to the adrenalin granules of the medulla, and not 

 dissolved by turpentine, appear in the cortex, especially in the layers of 

 cells nearest the medulla. Whether these granules are actually adrenalin, 

 or whether they are perhaps to be looked upon as precursors of adrenalin, 

 is at present not possible to say. This fact is, however, clear evidence that 

 the cortex participates in the functional activity of the medulla and that 

 these two parts of the gland are not physiologically independent organs." 



Secretory Changes. Secretory changes have been repeatedly de- 

 scribed. It has been found that following prolonged narcosis in man with 

 the accompanying discharge of epinephrin, the chromaffin reaction is re- 

 duced. Falta(t?) credits R. Kahn with the discovery that, after Claude 

 Bernard's "piqfire" of the medulla oblongata, "the tingibility of the 

 suprarenals to chrome salts in great part disappears and the contents of 

 adrenalin markedly diminish." It is also known that, in the compensatory 

 hypertrophy resultant upon the removal of one suprarenal gland, the 

 chromaphil reaction is also more intense. Cevidalli and Leoncini state 

 that the chromaphil reaction is less intense in the case of persons who 

 liaye died slowly, with exhaustion of the adrenalin content of the gland. 

 Their results, however, require confirmation. 



Discharge of Secretions. Many investigators have described the pres- 

 ence of material exhibiting the chromaphil reaction within the sinusoids 

 and veins of the medulla, which they consider to represent the adrenalin 

 secretion. Others, however, regard it as a simple coagulation of the 

 blood plasma. Its total absence in the cortex, and its restriction in the 

 medulla to the veins, arc advanced as evidence in favor of its secretory 



