Cure of Infantile Rickets by Sunlight. 



3i 



Falk and others upon different material. If we assume that the 

 alkalinity of the tissue is slowly changed to acid reaction, it is 

 difficult to see how low hydrogen ion concentration can operate 

 to render the tissues more digestible, whereas a high degree of 

 acid, such as we have found developed in the liver in the present 

 study, may well be imagined to exert a profound influence upon the 

 character of the proteins of the liver, for this concentration re- 

 sembles that of gastric juice, especially that of the young subject, 1 

 where proteins are digested rapidly. 



Since the above statements were written, the electrometric 

 method has been checked by the Sorensen colorimetric method 

 supplemented by the indicators of Clark and Lubs. Practically 

 identical results have been obtained with both liver and kidney. 

 The details of the method, with results and discussion, will be 

 given in another place under the following title: "Further Studies 

 on the Reaction of Dying Tissues," by Wi throw Morse and R. 

 Goldberg. The question will be raised therein, whether the sug- 

 gestion made by Paul Erlich ("Die Aenaemie") that the reaction 

 of the nucleus is acid, is applicable here. 



16 (1763) 



The cure of infantile rickets by sunlight as demonstrated by a 

 chemical alteration of the blood. 



By ALFRED F. HESS and P. GUTMAW. 



[From the Department of Pathology, College of Physicians and 

 Surgeons, Columbia University, New York City.] 



It has been shown by one of us (A. F. H.) that the rickets of 

 infants can be cured merely by frequent exposures to the sun's 

 rays. 2 Animal experiments carried out in this laboratory con- 

 firmed these clinical observations. They clearly demonstrated 

 that rickets could be either prevented or brought about in rats fed 

 a standard diet, according to whether they were subjected for 



1 McClendon, J. F., Amer. J. Physiol., 1915, xxxviii, 191. 



2 Hess, A. F., and Unger, L. J., Proc. Soc. Exper. Biol, and Med., 1921, 

 xviii, 298. 



Hess, A. F., and Unger, L. J., J. A. M. A., 1921, Ixxvii, 39. 



