THYROID GLAND. 373 



formation of uric acid. This relation has been studied by HORBAO 

 ZEWSKI. He has shown that when the spleen-pulp and blood of calves 

 are allowed to act on each other, under certain conditions and certain tem- 

 perature, in the presence of air, large quantities of uric acid are formed, 

 and he has also shown that the uric acid originates from the nucleins of 

 the spleen. 1 This behavior is explained by the above-mentioned inves- 

 tigations of BURIAN, SCHITTENHELM, JONES, and others on the enzymotic 

 formation of uric acid, and the deamidization of the purine bodies, and a 

 relation between the spleen and uric-acid formation is indisputable. 

 Still we cannot say that the spleen shows a special relation to the uric-acid 

 formation as compared with other organs (see Chapter XIV). 



The spleen has the same property as the liver of retaining foreign 

 bodies, metals and metalloids. 



The Thyroid Gland. The nature of the different protein substances 

 occurring in the thyroid gland has not been sufficiently studied, but at 

 present, through the researches of OSWALD, there are known at least two 

 bodies which are constituents of the so-called secretion of the glands, 

 the colloids. One of these, iodothyreoglobulin, behaves like a globulin, while 

 the other is a nucleoprotein (see also GouRLAY 2 ). The iodine present 

 in the gland occurs chiefly in the firct body, while the arsenic, which has 

 been shown to be a normal constituent by GAUTIER and BERTRAND, ; * 

 seems to be related to the nuclein substances. 



According to OSWALD the iodothyreoglobulin occurs only in those 

 glands which contain colloid, while the colloid-free glands, the parenchyma- 

 tous goitre, and the glands of the new-born contain thyreoglobulin free 

 from iodine. The thyreoglobulin first becomes iodized into iodothyreo- 

 globulin on passing from the follicle-cells. Besides these mentioned 

 bodies leucine, xanthine, hypoxanthine, choline, iodothyrine, lactic and 

 sucdnic acids occur in the thyreoidea. Like certain other organs, sub- 

 stances also occur in the thyroid which act upon the blood pressure and 

 indeed partly as vasodilator and partly depressing but whose chemical 

 nature has not been positively established. Among the enzymes we 

 find lipases and catalases which, according to JuscHTSCHENKO, 4 are 

 related to the corresponding enzymes of the blood. MAGNUS-LEVY 5 

 found 757 parts water, 243 parts solids, 43.8 parts fat, 26.8 parts nitrogen, 

 and 0.058 parts iron in 1000 parts of the human thyroid gland. 



1 Monatshefte f. Chem., 10, and Wein. Sitzungsber. Math. Nat. Klasse, 100, Abt. 3. 



2 Gourlay, Journ. of Physiol., 16; Oswald, Zeitschr. f. physiol. Chem., 32, and 

 Biochem. Centralbl., 1, 249. 



3 Gautier, Compt. Rend., 129. See also ibid., 130, 131, 134, 135; Bertrand, ibid., 

 134, 135. 



4 Juschtschenko, Bioch. Zeitschr., 25 and Arch, scienc. biol. de St. Petersbourg, 15. 



5 Bioch. Zeitschr., 24. 



