664 LEWELLYS F. BARKER 



acidosis, it is not surprising that Morel, finding that the severity and dura- 

 tion of the signs of tetany correspond to the degree of acidosis existing, 

 should have emphasized the importance of acid poisoning in the etiology of 

 the symptoms. By the administration of betaoxybutyric acid, he asserted 

 that he could shorten the lives of animals suffering from tetany following 

 parathyroidectomy by at least two days, and he found further that he could 

 prolong their lives, if .he diminished the acidosis by administering sodium 

 bicarbonate. 



On the other hand, alkalosis rather than acidosis seems sometimes to 

 exist in tetany. Wilson, Stearns and Thurlow (1915), and Wilson, 

 Stearns and Janney (1015) observed a period of alkalosis in parathy- 

 roidectomized dogs just before an attack of tetany, though this alkalosis 

 was neutralized by acid substances produced during the attack. Injections 

 of acid and also of calcium salts relieved the tetany. They suggested that 

 the calcium salts may have acted, in part at least, by causing a relative 

 increase in acid radicals (formation of Ca 3 (PO 4 ) 2 from the carbonates, 

 thus liberating HC1). 



The experiments of McCann (1918) also point to alkalosis rather than 

 to acidosis as a cause of tetany, this alkalosis being due, perhaps, to a dis- 

 proportion between the rates of secretion of acids and alkalies by the gastro- 

 intestinal tract. He found a marked increase in the CO 2 combining power 

 of the plasma of the blood, coincident with the development of tetany after 

 parathyroidectomy, and also following gastric operations that prevented 

 the entrance of acid into the duodenum. He suggested that tetany follow- 

 ing pyloric obstruction may be explicable by an alkalosis similarly condi- 

 tioned. 



In 1920, MacCallum and his collaborators observed that, when pyloric 

 occlusion was experimentally produced in dogs and distilled water only 

 was injected into the duodenum, the stomach continued to secrete HC1, the 

 alkalinity of the blood increased, and symptoms like those of tetany 

 appeared, though they could be prevented by injecting a solution of sodium 

 chloride into the duodenum, or, after the symptoms had developed, they 

 could be made to disappear by injection of the same substance into the, 

 blood. The calcium content of the blood plasma was not changed. They 

 suggested that the tetany-like symptoms in these dogs might be due to a dis- 

 turbance of the acid base equilibrium. 



Even a temporary alkalosis produced by the therapeutic administration 

 of alkalies may, apparently, call forth tetany. Thus, Howland and Mar- 

 riott (19 1H) mentioned three cases of tetany in children following admin- 

 istration of sodium bicarbonate; in all three the calcium content of the 

 serum was diminished. Ilarrop (11)19) saw tetany appear in an adult 

 after injection of sixty grains of N"aIICO ;t intravenously. Binger (1917), 

 by intravenous injection of sodium phosphate, had produced tetany in dogs 

 and decrease of the calcium content of the serum, though, if the solution 



