640 LEWELLYS F. BARKEE 



cord with the studies of Erdheim and those of Leopold and von Reuss. 

 Erdheim's Itudies of rats after parathyroid extirpation had revealed, as 

 we have already seen, hypoplasias of the enamel that indicate an anomaly 

 of the calcium metabolism. Leopold and von Reuss (1908) found no 

 marked diminution in the total calcium in parathyroidectomized rats, hut 

 the total amount of calcium in the hodies of growing rats suffering from 

 tetany was definitely less than in the bodies of healthy animals, and, fur- 

 thermore, the relation between the bone calcium and the calcium of the 

 soft parts was always lower than in control animals, for the soft parts were 

 richer in calcium, the bones poorer in calcium than normal, an observa- 

 tion that seemed to be in accord with the histological findings in the bones 

 and in the teeth. These authors conclude, therefore, that there is, in 

 tetany, a diminution of active calcium in the body. 



Since the papers of A. Netter and of MacCallum and Voegtlin, many 

 authors have reported success in the 'treatment of tetany by the adminis- 

 tration of calcium salts (Berkeley and Beebe, Ott, Bell and Martin, Stone, 

 Roger Morris, Howland and Marriott), though most admit, however, that 

 in many cases the .calcium salts have only a, temporary effect. If the para- 

 thyroid insufficiency does not become compensated for, the tetany 

 continues and may be fatal. Biedl could not prolong the lives of cats by 

 the administration of calcium after removal of the thyroid and parathy- 

 roid glands. 



Moreover, the salts of calcium possess no monopoly of favorable in- 

 fluence, for the salts of magnesium and the salts of strontium exert a very 

 similar effect upon the symptoms of tetany (Canestro). Even the salts 

 of lanthanum and of thorium- are said to diminish the number and intensity 

 of the attacks of muscle spasm in tetany (Frouin). And Joseph and 

 Meltzer (1011) found that the intravenous injection of a sodium chlorid 

 solution in molecular concentration in amounts of from 10 to 20 c.c. per 

 kilogram, stopped the hyperkinetic symptoms of tetany immediately and 

 permanently in parathyroidectomized dogs ; but the animals died, 

 nevertheless, within two weeks, of cachexia (without spasms). Meltzer's 

 studies are of great interest when we consider the views of Sabbatani 

 and of Loeb regarding the influence of disturbances of the kation balance 

 in the body. 



In recent years a number of studies of calcium metabolism in human 

 and in experimental tetany have been undertaken by American investi- 

 gators. Thus, J. V. Oooke, influenced by the publications of MacCallum 

 and Voeiitlin and of Underbill and Saiki, undertook to determine (1) 

 whether or not an increased excretion of calcium during tetany would be- 

 come more apparent if animals were kept on a calcium-poor diet for long 

 }>eriods, and (2) whether the increased salt elimination described is con- 

 fined to salts of calcium or includes also salts of magnesium. Cooke ob- 

 served, therefore, (1) the excretion of calcium and magnesium in normal 



