VI 



THE FOOD VALUE OF MILK 



There is no better way of presenting this subject than to quote 

 extracts from the testimony of Dr. E. V. McCollum who appeared as a 

 witness on behalf of the Committee at a public hearing held in the City 

 Hall, Rochester, September 18, 1919. 



Dr. McCollum is recognized as one of the leading food chemists of 

 America, and the chief exponent of the food value of milk. He has had 

 a most unusual training and experience in studies in the chemistry of 

 nutrition in Yale University, University of Wisconsin, and in Johns 

 Hopkins University. At the present time he occupies the position of 

 Professor of Chemical Hygiene in Johns Hopkins University. His testi- 

 mony in part was as follows : 



"At the time I left Wisconsin we had conducted approximately two 

 thousand feeding experiments, every one planned with a theory under 

 lying, and every one planned with an attempt to contributing to an answer 

 regarding a long series of questions of a technical nature on nutrition. 

 Those experiments in no case were under perhaps six weeks in length; 

 a considerable number of them at least four years in length ; and this 

 work involved the use of all the different types of animals that are avail- 

 able on an experiment station farm, together with such small animals as 

 are usable for laboratory study. Since going to Baltimore we have com- 

 pleted approximately fifteen hundred further experiments with animals, 

 each one contributing to an interpretation of the technical problems which 

 we have in view. 



'The first observation that we ever made that was of great import- 

 ance in perfecting our views regarding the whole subject of nutrition was 

 made in 1912. It consisted of a demonstration that it was possible to 

 make a certain diet which could be fed to a group of animals and would 

 lead to a failure of nutrition; that the same diet fed with such vegetable 

 fats as olive oil or cotton seed oil or lard or tallow or almond oil, would 

 still lead to prompt failure and always with one type of error in nutrition, 

 or rather pathological state. That pathological condition relates to the 

 eyes. This particular type of diet fed with any of the vegetable fats or 

 body fats of animals would lead to swelling of the tissues around the eyes 

 and inflammation of the eyeball, and total blindness, and ultimate death. 

 We produced blind rats, blind pigs, blind cows, blind pigeons, and there 

 is no question but what it applied to numerous species of animals. But 

 curiously enough this same diet which was so serious when fed with vege- 

 table fats, became nutritious for an animal when we introduced certain 

 other fats instead of the vegetable fats or body fats of animals ; when we 

 put butter fat or egg yolk fat into this diet and made no other change, no 



