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Scientific Proceedings (131) 



low phosphorus "rickets-producing" diet. It was found that 

 these rats were not refractory but developed rickets to the same 

 extent as the five other stocks that had been tested. Evidently 

 the alteration of the diet during the first four weeks of life was 

 the determining feature. It will be noted that the diet through- 

 out pregnancy was unchanged. 



After about the tenth day of life young rats not only suckle 

 but consume supplementary food. The acquired susceptibility 

 may, therefore, have resulted from an inadequacy of the food 

 consumed directly by the young, and not from an inadequacy 

 of the mother's milk. Experiments seem to confirm this point 

 of view. For example, a mother rat which was given 20 drops 

 of cod liver oil daily in addition to our laboratory diet, gave 

 birth to young which were not refractory to rickets. This would 

 lead us to believe that it is difficult to furnish the young with an 

 adequate amount of protective substance through the mother's 

 milk. It seems certain that in young rats the character of the 

 food during the first four weeks of life is of decisive importance 

 regarding their later susceptibility to rickets. This probably 

 indicates that protective anti-rachitic substances can be stored in 

 the body. A discussion of the constitution of the various 

 dietaries used in these tests is deferred until further experiments 

 are carried out. 



180 (2140) 



The various forms of phosphoric acid in the blood. 

 Findings in rickets. 



By T. F. ZUCKER and MARGARET GUTMAN. 



[From the Department of Pathology of the College of Physicians 

 and Surgeons and the Chemical Laboratory of the 

 Pediatrics Service, First Medical Division, Bel- 

 levue Hospital, New York City.] 



It is well known, that in rickets the inorganic phosphate in 

 the blood is low. We have shown previously that in rachitic 

 as well as in normal blood the inorganic phosphate is the same 

 in the cells and in the plasma, and we have also given evidence 



