Studies on the Endocrine Glands 



281 



I'^ffect of Tliyroid Fi-edincr on the Anionnt and (^)uality 



of the L'rine. 



The animals took a considerable amount of water durin<jj the j)eriods of 

 thyroid ft-t-diiii;, so that the amount of urine was thus increased; but when 

 the feeding was intermittent it was not much diminished in the intervals. 

 No trace of sugar or albumen was at any time found in the urine of the 

 thyroid-fed animals. The most striking effect upon the urine is 

 that during and for some time after thyroid feeding iodine 

 is always present, whereas in the normal animal fed on rusks alone 

 iodine can never be detected in the urine. One rat (No. 20, B group) 



Fig. 14. — Photograjili.s (natural size) of the iiaiicieas of three rats showing the effect 

 upon the general ap])earance of the gland of thyroid feeding. (1) Pancreas from 

 rat No. 19 ; (2) pancreas from rat No. 20 ; (3) pancreas from rat No. 17 (control). 

 Both No. 19 and No. 20 received thyroid in addition to their ordinary food 

 during two jieriods with a few days' intermission. No. 19 was killed a week 

 after the second period liad ceased, and No. 20 twenty-five days afterwards. 

 In all the figures the splenic end of the pancreas is placed uppermost. Both 

 (1) and (2) are larger and heavier than (3). 



which was killed twenty-five days after thyroid feeding had ceased still 

 showed slight evidence of iodine in the urine. 



The following method was employed^: — 10 c.c. of the urine to 

 be examined is evaporated to dryness on the sand-bath, and about 

 twnce its weight of pure NaOH, prepared from metallic sodium, is 

 added to the residue ; the mixture is heated gradually : at short 

 intervals potassium nitrate is added. The heating is continued until 

 the mass, at first charred, just becomes white. After being allowed 

 to cool, it is extracted with hot water. The extract is filtered into 

 a test tube, cooled, acidified with sulphuric acid, and an equal quantity 

 of chloroform added. On shaking up the mixture, any iodine 



1 This method is described in Milroy's Practical Physiological Chemistry, 1904, p. 3. 



