To the Editor:—In a paper previously published in this journal (Hamilton, B., and Schwartz, C.: Rickets and Hyperparathyroidism, Am. J. Dis. Child. 46:775 [Oct.] 1933), experiments were reported in which the administration of a soluble calcium salt by stomach tube to rachitic rabbits was followed in most cases by an immediate and marked rise of the serum calcium, while normal controls, of the same age as the rachitic animals and given the same dose of calcium, showed a much more moderate rise of the serum calcium.
In a personal communication, Dr. Richard H. McCoy has informed me of the results of experiments in which he failed to confirm the observations just cited. The experiments were then repeated by us, and it was found that in this new series of rachitic animals the marked rise in serum calcium previously obtained was not observed. As shown by Dr. McCoy, however,