294 Kojima 



water and dilute hydrochloric acid, but soluble in dilute alkalies. It is 

 advocated as a substitute for alkaline iodides.^ 



One tablet of thyro-protein, or an equivalent weight of iodo-protein, per 

 diem was ground up in a mortar with rusks, and a paste of the mixture 

 was administered in the usual way to rats Nos. 56 and 57 (thyro-protein) 

 and Nos. 58 and 59 (iodo-protein) during five days. During this period the 

 animals exhibited no special symptoms ; the appetite was normal, and there 

 was no appreciable change in weight. 



On microscopic examination the usual effects of thyroid ad- 

 ministration are seen in the pancreas of rats Nos. 56 and 57, 

 which were fed on thyro-protein. A few cells show mitosis, but 

 not as many as with the administration of whole thyroid. 

 Zymogen is plentiful, and the granules are coarse. Some of the cells 

 show vacuoles. No change is observable in the islets. The pancreas 

 of Nos. 58 and 59, fed with iodo-protein, has practically a normal 

 appearance. There are no mitoses, and the cells contain abundance 

 of zymogen granules. 



Summary. — An artificial combination of iodine with protein does not 

 cause the changes in the pancreas which are produced by thyroid, although 

 these are produced by a natural combination of iodine with protein which 

 is extracted from the thyroid. The efi"ect is, however, less marked than 

 when thyroid itself is used. 



What is the Effect upon the Pancreas of Iodides and 



OTHER Salts ? 



Sodium Iodide. 



(a) Administration of Sodium Iodide to Normal Rats. — A small 

 amount of sodium iodide dissolved in water was mixed with the food 

 given to two full-grown male rats (Nos. 60 and 61), O'l grm. per rat per 

 diem being administered in this way for five days. The appetite was 

 somewhat afiected, and diarrhoea was produced from the third day. The 

 weights of the animals were respectively 145 grm. and 190 grm. at the 

 commencement, and 135 grm, and 180 grm. at the end of the period, when 

 they were killed. 



(b) Sodium Iodide Administration, with a Period of Inter- 

 mission. — The same dose of sodium iodide was given each day for a 

 week to two other full-grown male rats (Nos. 62 and 63 : see Table XV.). 

 Afterwards it was intermitted for seven days, and was then repeated 

 during the succeeding week. From the fifth da}^ of the first week the 

 animals suffered from diarrhoea and appeared inactive. During the 

 intermission they recovered. Throughout the second administration 

 there were no symptoms to record. In all these experiments with sodium 

 iodide there was an intensive iodine reaction in the urine, and this 



1 See W. H. Martindale and W. W. Westcott, The Extra Pharmacopceia, 1915, 

 vol. i. p. 462. 



