THE THYROID APPARATUS 57 



soda. When the same subjects were treated with this salt in 

 combination with a soluble calcium salt, symptoms of tetany did 

 not follow. 



THE PARATHYROID GLANDS AND THE 

 METABOLISM OF CALCIUM. 



In the first part of this book reference was made to J. Loeb's 

 discoveries in connection with the physiological significance of 

 the kathions, especially of the effect which calcium salts have in 

 reducing neuro-muscular irritability. These discoveries have 

 some bearing upon the pathogenic aspects of tetany and they 

 have led the way to other experiments, undertaken with the object 

 of determining the connection between the parathyroid glands and 

 the metabolism of calcium. Quest (1905) induced a condition of 

 electric hypersensibility of the peripheral nerves in young dogs, 

 by means of a diet from which lime was excluded. He attributed 

 a genetic significance in infantile tetany to the scarcity of calcium 

 in the organism, and his view is confirmed by the fact that the 

 brains of children who die of tetany contain a smaller proportion 

 of calcium than those of normal children. Oddo and Sarles found 

 that the urine of tetanous children contained an increased amount 

 of calcium salts. Quest's results, however, were not confirmed by 

 those of either M. Cohn, or Leopold and v. Reuss. 



Netter found that the convulsions of infantile tetany were 

 favourably influenced by the exhibition of calcium chloride, but 

 Stoeltzner obtained only an increased sensibility to electric 

 stimulus by this means. Unlike Quest, Stoeltzner explains the 

 spasmophilia as the result of calcium poisoning. He assumes 

 that the galvanic irritability of the peripheral nerves depends on 

 the calcium concentration in the tissues, and believes that an 

 excess of calcium inhibits convulsions. 



The relationship which the quantity of calcium in the urine 

 and faeces bears to the general metabolism of calcium, has also 

 formed the subject of investigation. Experiments conducted with 

 dogs suffering from tetany, and similar clinical experiments, have 

 not, however, yielded conclusive results. Czybulski found that, 

 in a child of 7 months with tetanic symptoms, there was a far 

 smaller retention of calcium at the time of the seizures than in 

 the intervals between the attacks. In dogs from which the para- 

 thyroids had been removed and which were either starved or 

 kept on a uniform diet, MacCallum and Vogtlin found a con- 

 spicuous increase in the amount of calcium in the urine and fasces 

 as compared with the control animal. V. Reuss and Welde found 

 that, after partial parathyroidectomy, a dog showed increased 

 retention of calcium. 



The contradictory nature of these results induced v. Reuss 

 and Leopold to try other methods to obtain more definite data 



