120 



Scientific Proceedings (119). 



tioN fo the antiscorbutic, vitamin and account, in some degree, 

 for the varying content of this factor in heated milk. It is also 

 possible that the copper ingested with the food, especially in 

 infants whose diet consists mainly of milk, may exert an effect 

 within the animal body. 



58 (1805) 



The prevention of rickets in the rat by means of radiation with 

 the mercury vapor quartz lamp. 



By G. F. POWERS, E. A. PARK, P. G. SHIPLEY, E. V. MCCOLLUM and 



NINA SIMMONDS. 



[From the Department of Pediatrics, Yale University, New Haven, 

 Conn., the Department of Pediatrics, Johns Hopkins 

 University, Baltimore, Md., and the School of 

 Hygiene, Johns Hopkins University, 

 Baltimore, Md.] 



All the evidence as to the preventive and curative effects in 

 the rickets of human beings of the radiations from the mercury 

 vapor quartz lamp has been furnished by the X-ray. In order 

 to determine the protective action of these radiations in experi- 

 mental rickets in rats and also to examine the bones themselves 

 we performed the following experiments. 



Nineteen rats, mostly mixed black and white and about seven 

 weeks old, were placed on diet 3143 which, as previous experience 

 has shown, produces rickets comparable in every respect to the 

 rickets manifesting itself in human beings. 



Nine rats were kept as control animals under ordinary labora- 

 tory conditions in a room completely screened with windows of 

 ordinary glass (cage "R" animals). Ten rats were exposed to the 

 radiation from a Hanovia mercury vapor quartz lamp (Alpine 

 type) (cage "U-V" animals). One animal (16Y) in cage "R" 

 was found paralyzed thirty-eight days after being placed on diet 

 (age about eighty-eight days) and was killed. We have previously 

 pointed out that the "development of paralysis of the posterior 

 extremities not infrequently occurs in rats fed on diet 3143. 

 Another animal (26Y) was killed fifty-eight days after being 

 placed on the diet (age about one hundred and eight days); and 



