PARATHYROID GLANDS 



657 



They admit the possibility of the calcium being "precipitated" as ex- 

 tremely minute particles that are held in solution by the colloids of the 

 serum, in which event it might not be removable by the centrifuge. In 



to 2o 3o 4o So loo Jo 2o 3o 4o ' So 2 



Fig. 14. Graph of experiment showing the synchronous changes in the alveolar 

 air, the blood and the urine during the forced respiration leading to manifest tetany 

 in a human subject. (After S. B. Grant and A. Goldman, Am. J. Physiol., Bait., 1920, 

 Hi, 209.) 



their opinion, the alkalosis they observed probably caused the tetany by 

 heightening the excitability of the nerves. Since tetany occurs under many 

 circumstances, they think it improbable that it can be attributed in all 

 cases to a single etiological factor; on the contrary, any condition that 



