1914-15.] Influence of Feeding on Composition of Milk. 
195 
XIX. — On the Composition of Milk as affected by Increase of the 
Amount of Calcium Phosphate in the Rations of Cows. 
By A. Lauder, D.Sc., and T. W. Fagan, M.A. 
(MS. received May 11, 1915. Read June 21, 1915.) 
The various factors which are supposed to influence the composition of milk 
have already been the subject of numerous investigations. The general 
result of these has been to show that within very wide limits the com- 
position of milk is very little affected by the nature of the food supplied. 
As regards the mineral constituents the results of some of the investi- 
gations are rather conflicting, and while there is a general consensus of 
opinion that the composition and amount of the mineral constituents 
are independent of the food-supply, certain investigators claim to have 
been able to increase both the calcium and phosphoric acid in the milk 
by slight amounts. 
Duclaux'*^' in 1893 investigated the preparation of the so-called ‘‘phos- 
phate milk,” in which the phosphates are supposed to have been in- 
creased by feeding calcium phosphate to the cows. He found, however, 
no more than the normal percentage of phosphates in milk obtained in 
this way. 
Somewhat later J. Neumann]* investigated the same question, and 
came to the conclusion that he had been able to increase both the 
calcium and the phosphoric acid. He suggests that the negative results 
obtained by other workers are due to their not having continued the 
experiment long enough, as the results became apparent only after three 
or four weeks. His average figures are ; — 
CaO. P2O5. 
Without calcium phosphate . . 0T479 0T960 
With „ „ . . 0T592 0-2132 
The differences are slight, and, as will be seen later, appear to be 
within the limits of natural variation. He concludes, however, that the 
production of the so-called phosphate milk by special feeding is im- 
possible. 
In 1894 H. WeiskeJ attacked a somewhat different side of the problem. 
* Ann. Inst. Pastern^ 1893, 2-17 ; Chem. Soc. Jour.., Ixiv (1893), ii, 582. 
t Milch Zez7.,xxii, 701-704 ; Ghem. Soc. Jour., 1894, ii, 246. 
I Landw. Versuchs-Stat., 1894, xlv, 242-245 ; Chem. Soc. Jour., Ixviii (1895), ii, 121. 
