LEWELLYS F. BAKKEK 



sible for tetany and for death. He asserts that all salts that act as diuretics 

 aid in the excretion of the tetany toxin and that the especially beneficial 

 effect of calcium is due to the additional influence of its sedative or de- 

 pressing effect upon nervous excitability. According to Koch's theory, 

 tetany is simply an intoxication; the toxin is subdued by diuresis or by 

 neutralization, and it cannot exert its effects in the presence of the normal 

 secretion of the parathyroid glands. 



These studies of Koch assume an especial interest in the light of the 

 investigations of Paton and Findlay (c). In researches directed toward 

 the etiology of tetania parathyropriva and its relationship to guanidin and 

 methylguanidin intoxication, these authors, after concluding that there is 

 no direct interrelationship between the parathyroids and the thyroid, assert, 

 (1) that there is no evidence that the parathyroids exercise a direct con- 

 trolling influence on the central nervous system, (2) that the symptoms of 

 tetania parathyropriva are not primarily due to any decrease in any constit- 

 uent of the body such as calcium ions nor are they due to any increase in 

 ammonia, xanthin or beta-imid-azolyl-ethylamin, but (3) the symptoms of 

 tetany are identical with those producible by the administration of salts of 

 guanidin and methylguanidin. These assertions are supported by the 

 findings of several of Paton's coworkers. Burns and Sharpe found a 

 marked increase in the amount of guanidin and methylguanidin in the 

 blood of dogs after parathyroidectomy and in the urine of children suffer- 

 ing from idiopathic tetany. G. M. Wishart observed that the serum of 

 parathyroidectomized dogs acts upon the muscles of the frog in the same 

 way as do dilute solutions of guanidin and methylguanidin. D. A. Burns 

 found that the administration of guanidin hydrochlorid to dogs caused 

 similar metabolic phenomena to those observable after parathyroidectomy 

 in dogs, and concludes that the two states are probably identical. Paton 

 and Findlay, summarizing the results of the investigations, concluded (1) 

 that the parathyroids regulate the metabolism of guanidin in the body and 

 by so doing probably exercise a controlling influence on the tone of the 

 muscles., and (2) that, since tetania parathyropriva and idiopathic tetany 

 are identical as regards their character and metabolism, the parathyroids 

 are, in nil probability, implicated in the latter as well as in the former, 

 despite the fact that the histological evidence therefor is not yet conclusive. 



As to the part that ferments play in the production of the tetany poison, 

 but little is as yet known. When discussing the metabolism of tetany (vide 

 xuj/ni ) I have expressed the conviction that parathyroid insufficiency may 

 mean a ferment insufficiency and experiments in this direction should cer- 

 tainly he undertaken. 



The vagueness and obscurity of these various conceptions of the etiol- 

 ogy and pathogenesis of tetany prove that, as yet, our knowledge of the 

 subject is too immature to permit of a clear portrayal. The facts and 

 ideas that have been brought forward are like a pack of scattered cards. 



