192 EQUINE PHYSIOLOGY. 



Casein, | . . i 6j 



Albumin, J •■ 



Butter 6.87 



Milksugar, ^ g_^ 



Inorganic salts, j -' 



17.16 



The gases of milk (Pfluger) are carbonic anhydride, oxygen 

 and nitrogen. 



Colostrum is the milk secreted a short time after parturition. 

 It is yellow in color, of a higher specific gravity, slightly acid, 

 contains large oil globules covered with casein, and has purgative 

 properties. 



The mammae at the time of gestation become enlarged, pend- 

 ent, soft. I'he epithelium becomes rounded, and contains a large 

 amount of fat. 



Milk can be coagulated by acids, tannin and mineral salts by 

 coagulating the casein. 



Mare's milk contains a large amount of sugar, which, by the 

 addition of an acid, takes on a lactic acid fermentation, as in the 

 preparation of koumiss. 



The rapidity and amount of the mammary secretion are de- 

 pendent on arterial pressure. Certain drugs have more or less 

 action upon it. 



URINE. 



Urine, the excretion of the kidneys, is a watery, yellowish fluid, 

 holding in suspension many sohds, which are excreted in this 

 form. It is alkahne in reaction when the animal feeds on vege- 

 table food, and its specific gravity varies from 1016 to 1060, 

 usually about 1050. Its composition is (Smith, from Boussin- 

 gault) : 



Urea 31. 



Potass, hippurate 4.7 



Alkaline lactates 20. 1 



Potass, bicarb 15.5 



Magn. carb 4.2 



Calcium carb 10.8 



Potass, sulph 4.2 



Sodium chloride 0.7 



Silica i.o 



Water 9io-o 



1 000.0 



