Studies on Experimental Rickets. 277 



generation in a family confined to this diet showed no signs of 

 physical deterioration. Without the calcium addition, but with 

 3 per cent, of butter fat, very little growth can take place. 



The striking differences between the nutritive properties of 

 cod liver oil as contrasted with butter fat we have up to the present 

 time been able to demonstrate in so satisfactory a manner only 

 with diets in which the phosphorus content is approximately the 

 optimum, and with the calcium content distinctly below the 

 optimum. The results of feeding these two fats with a diet similar 

 to that described but in which the phosphorus content is low and 

 the calcium varies from low to high, we shall discuss in a forth- 

 coming paper. 



140 (1722) 



Studies on experimental rickets, V. 

 The production of rickets by means of a diet 

 faulty in only two respects. 



By P. G. SHIPLEY, E. A. PARK, E. V. McCOLLUM and 

 NINA SIMMONDS. 



[From the Department of Pediatrics, and from the Laboratory of the 

 Department of Chemical Hygiene, School of Hygiene and 

 Public Health, Johns Hopkins University, Baltimore.] 



The following diet, when fed to the young rat, in a com- 

 paratively short time (three to five weeks) produces rickets. The 

 diet is composed of : 



Rolled oats 40.0 



Gelatin 10.0 



Wheat glutin 7.0 



Sodium chloride 1.0 



Potassium chloride 1.0 



Calcium carbonate 2.0 



Dextrin 39.0 



This diet is extremely poor in fat-soluble A, the anti-xerophthalmic 

 substance. Young rats develop xerophthalmia when placed upon 

 it in from four to five weeks. Its proteins are of good quality and 

 are supplied in abundance (2 1 per cent.) . The phosphorus content 

 is relatively low (0.209 gms. per 100 gms. of the food mixture). 

 The calcium content is approximately the optimum. 



