MILK 



23 



secrete milk rich in fat while those whose offspring make rapid growth 

 secrete milk high in protein and mineral matter. 



In a sense every animal that is fed on the milk of another species is 

 given artificial food; in fact the only common substitution that is made 

 is that of the cow for that of the woman and even this is attended with 

 difficulties for there are marked differences in the two milks as Table 

 13 shows. To lessen the troubles that arise from feeding cow's milk 

 to babies it is often modified, or made to approach that of the woman in 

 character. 



TABLE 13. WOMAN'S MILK AND Cow's MILK CONTRASTED (ROTCH) 



Woman's milk 



Cow's milk 



1. Reaction 



2. Water.: 



3. Mineral matter.. . 



4. Total solids 



5. Fats.. 



6. Milk sugar . . . 



7. Proteins 



8. Caseinogen . . . 



9. Whey products 



10. Coagulable proteins 



11. Coagulation of protein 

 by acids and salts 



12. Coagulation of proteins 

 by rennet 



13. Action of gastric juice. 



Amphoteric (more alkaline 



than acid). 

 87-88 per cent. 

 0.2 per cent. 

 13 to 12 per cent. 

 4 per cent. ; relatively poor 



in volatile glycerides. 

 7 per cent. 

 1.5 per cent. 

 One-third to one-half of the 



total proteins. 

 Two-thirds to one-half of 



the total proteins. 

 Small proportionately. 

 With greater difficulty; 



curds small and Succulent. 



Does not coagulate readily. 

 Proteins precipitated but 



easily dissolved in excess 



of the gastric juice. 



Amphoteric (more acid than 



alkaline). 

 86-87 per cent. 

 0.7 per cent. 

 14-13 per cent. 

 4 per cent.; relatively rich 



in volatile glycerides. 

 4.75 per cent. 

 3.5 per cent. 

 2.66 per cent. 



0.84 per cent. 



Large proportionately. 

 With less difficulty; curds 

 large and tenacious. 



Coagulate readily. 

 Proteins precipitated 

 dissolved less readily. 



but 



Modified milk was first prepared for sale, by the Walker-Gordon 

 Laboratory Co. under the direction of Dr. T. M. Rotch, in Boston, Mass., 

 in 1891. 



It is manifestly impossible to so modify cow's milk that it will be 

 woman's milk; all that is feasible is to make the percentages of the 

 principal components of the two correspond and to replace the casein 

 with whey protein. The modifications of cow's milk that are commonly 

 made are, to reduce the protein and increase the sugar to correspond with 

 the respective percentages of these elements in human milk. In addi- 

 tion, 25 to 50 per cent, of lime water is often added to increase the alka- 

 linity of the milk and so to prevent or delay the formation of curds by 



