PART V. 



THE USE OF MILK FOR INFANTS 



The advantages of milk as a general food for man 

 are so well known that no further discussion is neces- 

 sary; but the special use of milk for infants, as a sub- 

 stitute for mother's milk, offers certain points of inter- 

 est which merit further consideration. Tt is logical first 

 to review the behavior of milk and the changes that 

 (iccur in it during digestion. 



Tender the influence of the gastric juice, the i)roteids 

 undergo a jirocess of splitting up in the stomach. The 

 albumin and globulin are fii-st changcil into syii- 

 tonin and then se])arated into albumoscs and, })robably, 

 pejjtone. Casein behaves somewhat differently. Tt is 

 transformed by the hydrochloric acid of the gastric juice 

 into an acid calcium salt and then, under the influence of 

 ronilii. it undergoes a change, during which whey all)u- 

 min is formed, into calcic paracasein, which separates as 

 a curd. The calcic paracasein is then split by jtepsin into 

 albumin and i)aranuclein (pseudoneuclein) which is pre- 

 cipitated but which is afterwards dissolved by the pro- 

 longed action of the gastric juice, being broken up into 

 an albumin-like material and phosphoric acid. The albu- 

 mins that are formed by splitting of the casein are later 

 changed into albumoses (caseoses) and peptone. Ac- 

 cording to i-ct'ent investigations it appears that these 

 substances may undergo still other changes before they 

 are absorbed. Through the action of rennin, an albu- 

 min-like substance (plastein) is formed and through the 



147 



