THE PAKATHYKOID GLANDS 539 



withdrawn and replaced by normal saline solution, the symptoms are 

 promptly relieved. If the calcium depletion theory were correct, this 

 treatment should make matters worse. Joseph and Meltzer showed that 

 the injection of sodium chloride solution without previous bleeding will 

 allay the neuromuscular symptoms. 



In order to ascertain whether calcium were specific in its action, 

 Berkeley and Beebe (a-) tried strontium and barium salts, as well as cal- 

 cium. They found that a, comparatively large dose of strontium may be 

 given (ten cubic centimeters of a ten per cent solution of strontium chloride 

 to a ten kilogram dog) without any evidence of poisoning. They tried 

 the effect of the injection of strontium salts into ten animals suffering 

 from tetany, and found it scarcely possible to decide whether calcium or 

 strontium gave the better results. The effects of calcium seemed to ap- 

 pear a little earlier than those of strontium, but they are not more com- 

 plete or lasting. They also tried soluble salts of barium, but, as these 

 have poisonous qualities, they had difficulty in determining the effective 

 and, at the same time, non-lethal dose. Nevertheless, they found it pos- 

 sible to give an intramuscular injection of barium chloride and get fairly 

 prompt relief from the symptoms of tetany. "All four of the metals in 

 this group are effective in relieving the symptoms of tetany. Strontium 

 and calcium salts are comparatively harmless agents and may be given 

 intravenously with perfect safety. Magnesium at one end of the scale is 

 a powerful depressant, while barium at the other is a powerful stimulant; 

 and they are both dangerous to life when given in a dose sufficient to 

 control the symptoms of tetany. Calcium and strontium occupy a com- 

 paratively neutral position. It need hardly be said that barium salts 

 should never be given as a therapeutic measure for the relief of tetany/' 



With the hypothesis before them that the symptoms of tetany are 

 due to the action of some toxin, which, like strychnin, caffein, ammonia, 

 or xanthin, stimulates the central nervous system, they induced muscular 

 spasms by the injection of these substances and then tried the effect of 

 calcium and strontium in subduing them. With strychnin and caffein 

 the results were unsatisfactory, but they showed that the toxic effects of 

 ammonia and xanthin were promptly relieved by both calcium and stron- 

 tium. They conclude from this series of experiments that the symptoms 

 which follow thyroparathyroidectomy are caused by some toxin produced 

 by the deranged metabolism, and not essentially by any deficiency of 

 calcium, which may itself be due to the starvation cachexia that ensues 

 after the operation. They are inclined to believe that the function of 

 the parathyroids is essentially to produce enzymes, which are of prime 

 importance in the intermediary metabolism of nitrogen. 



In 1910 Cooke (&), repeating to a large extent the work of MacCallum 

 and Voegtlin, was not able in some respects to confirm their results. His 

 observations with regard to calcium and magnesium excretion extended 



