CO WS> MILK. 



129 



The gases of human milk. In five experiments, 100 c.c. of milk 

 yielded 1/07 to 1*44 c.c. of oxygen, 2*35 to 2-87 c.c. of carbonic anhydride, 

 and 3-37 and 3*81 c.c. of nitrogen. The method of collecting the milk 

 could riot have obviated admixture with small quantities of air ; hence, 

 no doubt, the higher percentage of oxygen and nitrogen than previous 

 observers have found in the milk of lower animals. 1 



Cows' milk. Colostrum. This has a high specific gravity (1046- 

 1080). Its fat has a higher melting point than that of normal milk, 

 being poorer in the lower fatty acids. 2 It contains more lecithin, 

 cholesterin, and proteid coagulable by heat than normal milk. 3 The 

 following are some analyses that have been made : 



Normal cows' milk. The following are averages of numerous 

 analyses, in the first column of those collected by Gorup-Besanez, 7 in the 

 second, by Hoppe-Seyler. 8 



I. II. 



Water .... 84'28 85-86 



Solids .... 15-72 15-18 



Caseinogen . . . 3 -5 7 3-4 



Albumin . . . 0'75 0'3-0'5 



Fat .... 6-47 4 



Lactose .... 4 -34 4 -5-5 

 Salts ..... 0-63 



Hammarsten 9 gives the following tables (from Konig) of normal 

 milk and the averages of various preparations from milk as follows : 



Tatlock 10 gives the average composition of skimmed milk as follows (1) 



1 E. Kiilz, Ztschr.f. Biol., Miinchen, 1895, Bd. xxxii. S. 180. 



2 Nilson, Jahresb.'ii. d. Fortschr. d. Thier-Chem,, Wiesbaden, Bd. xvii. S. 169. 



3 Ibid., Bd. xviii. S. 102. 



4 "Das Molkereivvesen," S. 39. 5 "Chem. d. Mensch. Nahrungsmittel. " 



6 Journ. de pharm. et chim., Paris, 1894, Ser. 5, tome xxx. p. 337. 



7 " Lehrbuch," 1878, S. 424. 8 " Physiol. Chem." 

 "Physiol. Chem.," 3rd German edition, S. 388, 390. 



10 "Produce of the Dairy," Glasgow, 1888. Numerous milk analyses will be found in 

 this book. 



VOL. I. 9 



