488 CHEMICAL PATHOLOGY OF THE DUCTLESS G LANDS 



thyroids (a view still held by some l ), but they are now gener- 

 ally believed to be independent organs of fully as great impor- 

 tance as the thyroid. To their removal are ascribed by many 

 investigators the acute manifestations of athyreosis, while the 

 more chronic changes of myxedema are attributed to the loss of 

 the thyroid. 2 



MacCallum's studies support this view, for he found the 

 results of parathyroidectomy in dogs very different from the 

 results of thyroidectomy. The most prominent symptoms were 

 muscular twitchings, gradually passing into tetanic spasms, and 

 due to nervous impulse rather than to muscular changes, since 

 they did not appear in muscles from which the nerve-supply had 

 been cut off. Trismus, protrusion of the eyes, and rapid 

 respiration without cyanosis (i. e., air hunger) were also 

 observed, and death usually resulted from exhaustion. Appar- 

 ently these symptoms are due to some toxic substance which 

 accumulates on account of the absence of the parathyroids, for it 

 was found that simply diluting the dog's blood by withdrawing 

 part of it, and injecting a corresponding amount of salt solu- 

 tion, caused a temporary cessation of the tetanic symptoms ; 

 and injections of emulsions of parathyroid checked the symp- 

 toms for some time, presumably through neutralizing the hypo- 

 thetical poisons. Degenerative changes that were observed in 

 the cerebral ganglion-cells also favor the view that some unneu- 

 tralized toxin is responsible for the symptoms following para- 

 thyroidectomy. Of particular importance is the demonstra- 

 tion by MacCallum and Slemons that parathyroidectomy has 

 practically no effect upon proteid metabolism, in marked con- 

 trast to the effect of thyroidectomy. 



CHEMISTRY OF GOITER 



In connection with his earliest studies of thyroiodin, Bau- 

 mann observed a great difference in the amount of iodin in 

 the thyroid glands of normal individuals living in goitrous dis- 

 tricts, as compared with those living in non-goitrous districts. 

 Thus in Freiburg, a goitrous district, the average weight of the 

 dried thyroid was 8.2 grams, each gram containing 0.33 mg. 

 of iodin, a total of 2.5 mg. of iodin to each gland. Glands 

 from Hamburg averaged 4.6 gm. in weight, containing 0.83 mg. 

 of iodin per gram, a total of 3.83 mg. per gland. Berlin 

 glands weighed 7.4 grams, and contained 0.9 mg. of iodin 



1 Kishi, Virchow's Arch., 1904 (176), 260. 



2 Full discussion by Kichardson, " The Thyroid and Parathyroid Glands," 

 Philadelphia, 1905, pp. 29-40; and MacCallmn, Med. News, 1903 (83), 820. 



