360 A TEXTBOOK OF PHYSIOLOGY 



It will be seen that, in addition to the qualitative difference - 

 mentioned above, the quantitative composition of human milk is 

 markedly different from that of cow's milk. Woman's milk is poorer 

 in proteins, richer in sugar, poorer in salts. Human milk is also richer 

 in lecithin. In regard to the salts, it is to be noted also that they are 

 present in quite different proportions to those of cow's milk. The 

 following figures represent the content in 1,000 parts of mi k: 



K Z O. Na_O. CaO. MgO. Fe_O 3 . P. 2 5 . <'l. 



Human .. 0-884 0-357 0-378 0-053 0-002 0-310 0-591 

 Cow's .. 1-72 0-51 1-98 0-20 0-0035 1-82 0-98 



It will be seen that human milk is much poorer (six times) in cal- 

 cium ^salts and in inorganic phosphorus, as well as being generally 

 poorer in all salts. It is obvious, therefore, that, besides being im- 

 possible to make cow's milk qualitatively like human milk, it Js quite 

 out of the question to make it quantitatively the same. In the past, 

 much has been written about humanizing cow's milk. To effect 

 such is out of the question. If the old rule be followed, by 

 which it was sought to bring about a correct human proportion 

 of proteins, fats, and carbohydrates, in cow's milk naniety, to dilute 

 with water and then add cream and sugar it is obvious that the 

 proportion of salts is disregarded. " Humanizing " is therefore a 

 very rough process at the best, and it is never worth while putting a 

 patient to expense to buy so-called humanized milk. 



Artificial Feeding. Artificial feeding is sometimes necessary, and 

 the question then arises as to what food an infant should be given. 

 The principles to be borne in mind in artificial feeding are that the 

 food and receptacles shall be clean, and not teeming with micro- 

 organisms; and that the food shall be easily digestible by the child, 

 and contain the essential vi bricks " necessary for its growth. Cow's 

 milk is obviously the most handy substitute; as shown above, it- 

 is not possible to humanize it; but it must be acknowledged that- 

 some of these attempts at humanizing have succeeded in rendering 

 the cow's milk more easily digestible by the child. Some authorities 

 recommend the addition of barley-water, others of sodium citrate. 

 In the table (p. 359) is set forth a method of feeding proved success- 

 ful. It should be noticed that there is no need to use expensive 

 lactose, and if the parent be too poor to purchase cream, a vegetable 

 oil may te used. The large quantity of fat serves a double purpose: 

 it nourishes the child, and at the same time ensures that the infant 

 is not constipated. The addition of the lime-water insurer, that the 

 clot of casein is light and easily digestible. 



Generally speaking, the patent infant foods by no means approxi- 

 mate to the correct proportions of the constitu?nts of human milk; 

 many contain starch, wh'ch a very young child cannot digest. The 

 proteins are not readily soluble in water, and there is also a deficiency 

 in fats. If milk is boiled, the anti-scurvy vita mines require to be 

 replaced by the giving of orange or swede juice. 



