THE ADRENAL GLANDS. 435 



The extractives of the thyroid gland are represented by traces 

 of xaiithin, hypoxanthin, leucin, succinic acid, and paralactic acid. 

 In addition, notable quantities of kreatinin may be obtained. 



THE ADRENAL GLANDS. 



Of the function of the adrenal glands, nothing definite is known- 

 Their integrity, however, is essential to life, and, as in the case of the 

 thyroid, their removal leads to the death of the animal. It has been 

 noted, moreover, that the injection of blood from a dog which has 

 died as a result of the operation, into the circulation of a second 

 animal that lias been operated in the same manner, will hasten the 

 fatal end, while in normal dogs no deleterious results are observed. 

 It has hence been concluded that the glands normally furnish a 

 secretion which renders certain metabolic products innocuous, and 

 that the fatal result which follows the removal of the organs is the 

 result of an auto-intoxication. 



In man, disease of the adrenal glands leads to the complex of 

 symptoms which is commonly known as Addison's disease, and like- 

 wise results in death ; but as in the case of the thyroid gland, it has 

 been observed that the fatal issue may here also at least be retarded 

 by the administration of an aqueous extract of the organs. Experi- 

 ments with such extracts have further shown that the gland contains 

 a substance which has a very marked effect upon the blood-pressure, 

 raising this far beyond the normal. This substance is found in the 

 medullary portion of the glands. Further 'investigations have then 

 demonstrated the existence of a chromogen which on exposure to the 

 air in aqueous solution yields a beautiful carm in-colored pigment, 

 which, like its mother-substance, is soluble in water. The same 

 result is reached at once on treating with chlorine-, bromine-, or 

 iodine-water. This chromogen is present in the intracellular fluid of 

 the medullary portion of the gland. When this is extracted with a 

 dilute acid, a violet-red precipitate results on the addition of an 

 excess of ammonia, which suggests that the pigment is of a basic 

 nature. 



With a solution of ferric chloride the juice that can be expressed 

 from the glands gives a bright emerald-green color. This reaction 

 has been referred to the supposed presence of pyrocatechin, but thus 

 far this has never been isolated. 



Modern researches lead to the conclusion that the blood-pressure- 

 raisiuir constituent of the gland, as also the chromogen, which gives 

 rise to the carmin color and the pyrooatechin reaction, are identical 

 bodies. Abel, who claims to have isolated the blood-pressure-raising 

 principle of the glands, states that this must in all probability be 

 classed Avith the pyrrol compounds or with the pyridin bases or alka- 

 loids. He was unable, however, to obtain the substance, which he 

 terms epmephrin, in pure form. Pyrocatechin could not be split 

 off on boiling with an acid, but he states that a carmin-red pigment 



