254 



NORMAL PARTURITION. 



coagulable by heat, and it may be said that the albumen takes the place 

 of casein ; but soon after parturition the former disappears and the latter 

 is present. Towards the end of lactation, however, if the animal is preg- 

 nant, the milk again loses its casein, and becomes very albuminous ; 

 consequently, coagulable by heat. Its sugar also diminishes or disap- 

 pears altogether. The leucocytes seem to be increased in number in 

 the colostrum, as the animal is disturbed or its health deranged ; and as 

 the young creatures are often attacked by diarrhoea, this is ascribed to 

 the presence of these particles. 



Milk. — Towards the fifth or sixth day, or even longer, after parturition 

 in the Cow and Mare, earlier with some of the other animals, the colos- 

 trum disappears, and then we have the ordinary milk. This is an opaque, 

 pure white, or slightly yellowish fluid, possessing a sweet taste, and a 

 faint odor somewhat resembling that of the animal from which it is 

 obtained ; it is unctuous to the touch, has an average density of 1032 to 

 1 041, according to the species and other circumstances;* and is com- 

 posed of three essential parts — water, butter, and casein. We hav^e in 

 addition albumen, milk-sugar, and mineral matters. 



The three principal constituents are easily separated — the fat or cream 

 by allowing the fluid to stand at rest for some time ; by pressure the 

 casein is separated in a solid mass ; and the remaining portion contains 

 the water. 



The milk varies considerabl}'-, as has been said, according to species, 

 breed, age, food, the period of lactation and milking, climate, state of 

 health, etc. In herbivorous animals it is generally alkaline ; in carnivo- 

 rous, acid. 



Vernois and Becquerel give a comparative table of the composition of 

 the milk of various animals, as below : — 



Specific Gravity 

 Weight of Water - 

 Weight of Solid Parts 

 Fat ----- - 



Casein and Extractive 



Matters . - - . 

 Milk-sugar - - - ■ 

 Salts (by incineration) 



Camel. 



1033-74 

 904-30 

 134-00 95-70 

 36-00 24*36 



40-00 

 58-00 



33-35 

 32-76 



5-23 



Bitch. 



1041-62 



772-08 



227-92 



87-95 



116-88 

 15-29 



7-80 



Doyere furnishes us with another interesting analysis, which we cannot 

 omit publishing here : — * 



* Cow's milk of good quality, according to Voelcker, has a specific gravity of about 1030 ; Woman's 

 lilk, 1020 ; Goat's and Eve's milk, 1035 ; Ass's milk, 1019. 



