SECRETION AND EXCRETION 



351 



The length of time the milk was boiled, influenced the results. The 

 ultrafiltrate of woman's milk after 5 minutes' boiling still contained 

 about one-third, after 15 minutes one-tenth, of the original amount of 

 CaO. After boiling 30 minutes there were only traces of CaO. 



That there is hardly any difference between the freezing point 

 depression of raw and of boiled milk is, therefore, very remarkable. 



[McCoLLUM has shown by his feeding experiments on rats that 

 dried milk contains both of the essential food accessories, fat soluble 

 A and water soluble B. Tr,] 



