BIOLOGICAL CLASSIFICATIOX OF FOODS 53 



supph- this dietary factor (fat-sdluhlc- A I in tire food of cliildrt-n 

 except in the form of milk-lat, and mill; is therefore an indis- 

 pensalile food for the young." 



Attention should be called to one other point. It has been 

 suggested by s(jme that possibly pasteurization of milk: or cream 

 destroys the growth-ijromoting qualities nf the " fat-soluble A "' 

 in the fat. Osbourne and Mendel found that i)assing li\X' steam 

 through milk-fat for two hours did not affect it, and INIcCollum 

 and Davis found that it was not alTected by being heated to 

 the boiling-point of water, 'bhis should Ix- satisfactory e\idence 

 tliat pasteurization of milk or cream in no way ati'ects the growth- 

 promoting qualities of the milk-fat. 



