MILK. 299 



milk as at first produced is in very large flakes. The two 

 caseins have different contents of sulphur and phosphorus and 

 give up their nitrogen in digestion experiments in different 

 ways. It has been recently suggested that the product coagu- 

 lated as casein from human milk may contain other proteins 

 in sufficient amount to give it the peculiar properties noticed. 

 Modified Milk. From all this it is evident that attempts 

 to modify cow's milk so as to make it resemble mother's milk 

 must be more or less abortive, as we are not able to duplicate 

 the unknown proteins in the human secretion. However, 

 many suggestions have been made in this direction and the 

 line followed is essentially this : Cow's milk is first diluted 

 with an equal volume of water or whey to reduce the proteins 

 to the proper percentage amount. Then a certain volume of 

 cream is added to restore the fat, and enough milk sugar or 

 cane sugar to bring that constituent up to about 6 per cent. 

 Unfortunately, the addition of fat is uncertain because of the 

 great variations in market cream. Good cream should con- 

 tain at least 20 per cent of fat, but is usually much inferior 

 to this standard. The cream sold in cities often contains from 

 5 to 10 per cent of fat only. Assuming, however, a cream 

 containing 20 per cent of fat, 3.5 per cent of casein and 3.5 

 per cent of sugar, and taking the gram and cubic centimeter 

 as equivalent for our purpose, the following illustration will 

 serve as an example of such a modification. Starting with 

 average market milk of the composition given some pages 

 back, 500 cc. may be mixed with water, cream and sugar to 

 give a result as follows : 



Iln 500 cc. of Market IOO cc - Contains, approximately, after addition 

 of 400 cc. of Water, 100 cc. of Cream, 

 35 gm. of iMlk Sugar. 



Fat 17.5 gm. 37.5 gm. 3.8 per cent. 



Sugar 22.5 61.0 6.1 



Proteins 19.5 23.0 2.3 



Salts 3.5 4.0 0.4 



This mixture has a percentage composition pretty close to that 

 of mother's milk. Sometimes the dilution is made with whey 



