22 



Scientific Proceedings (125) 



of variation in hydrogen ion concentration through the varying 

 growth, we will see what the significance of these experiments 

 may be. In the first place, it is well known that the hydrogen ion 

 secretion of digestive juices and also possibly through bacterial 

 concentration of the gastric juice of infants on a milk diet is only 

 a small fraction of that of older children and adults on mixed 

 diet. Therefore, it is quite possible that through a still further 

 reduction of acid in the digestive tract a significant lack of ab- 

 sorption of calcium and phosphorus may take place. We report- 

 ed experiments in these Proceedings 3 some time ago on the effect 

 of varying intake of acid and base on the partition of calcium 

 and phosphorus between urine and feces, and interpreted the 

 effect of greater urinary excretion under a more acid regime as 

 a greater absorption from the intestine. Data supplied by 

 Scheer 4 in the meantime further substantiate this, and show that 

 in children there is concomitant with a greater absorption under 

 the influence of acid, also a greater retention of calcium and 

 phosphorus. 



We come to the conclusion, therefore, that on a diet which 

 from the point of view of balance between calcium and phos- 

 phorus should not lead to rickets, it may be possible that with a 

 change in the intestinal tract in the sense of a lessening acidity, 

 rickets may be produced. Here we have, then, a factor which 

 resides in the individual and not in the diet, and may lead to at 

 least a partial explanation of the occurrence of rickets in infants 

 on a diet which is perfect from a dietetic point of view. 



In the course of this winter we are planning to investigate the 

 application of this hypothesis to infantile rickets. 



■ Zuckcr, T. F., Peoc. Soc. Exp. Biol, and Med., 1921, xviii, 272. 

 4 Scheer, Jahrb. f. Kindcrh., 1922, xcvii. 



