2 , ' '■'', ; ; •* A }&AN V^L OF; VET ERIN A RY PH YSIOLOG Y 



obtained with litmus is not a true reaction, but due to the litmus 

 acid driving out the sodium from the weaker carbonic acid. 



Excepting in the herbivora, considerable amounts of acid may 

 be administered by the mouth or formed in the tissues without 

 affecting the neutral reaction of the blood, the acid being neutral- 

 ised by the ammonia split off from proteins. Proteins may, in 

 fact, act in a dual capacity, either as bases neutralising acidity, or 

 as acids neutralising alkalinity. 



The carbon dioxide of the blood is in the main united with 

 bases, especially soda, and the total carbonic acid content of a 

 sample of blood is a measure not only of its capacity for carrying 

 carbonic acid, but also for maintaining the neutral reaction of the 

 blood. With the herbivora the carbonic acid content is readily re- 

 duced under the influence of acids administered by the mouth or 

 formed in the body, and this protective mechanism is thus reduced. 



The recently-drawn blood of the cat and dog has a peculiar 

 and decidedly disagreeable smell ; this is not observed in the 

 blood of the horse and ox. The taste of blood is saltish, due to 

 the amount of sodium chloride it contains. 



The specific gravity varies in different animals : in the horse, 

 ox, and pig, 1060 ; sheep, 1050-1058 ; dog, 1050 (Colin). Accord- 

 ing to Hoppe-Seyler, the specific gravity of the liquor sanguinis 

 of the horse is 1027 to 1028, and the specific gravity of the cells 

 1 105. This considerable difference between the specific gravity 

 of the cells and the liquor sanguinis in the horse accounts for the 

 rapid manner in which the cells sink in horse's blood when drawn 

 from the body, producing during the process of clotting the so- 

 called ' buffy coat.' 



Composition of the Blood. — Blood consists of a fluid portion or 

 plasma in which the blood cells or corpuscles are suspended. 



Plasma, or liquor sanguinis, is a yellow-coloured, somewhat 

 viscid, fluid, containing in solution — 



Protein. 

 Extractives. 

 Mineral matter. 

 Enzymes. 



Unknown substances (i.e., immune bodies). 

 (See p. 8.) 



The corpuscles are — 



Red corpuscles, or erythrocytes. 

 White corpuscles, or leucocytes. 

 Platelets. 



So far as the presence of the various constituents is concerned, 

 the blood of any one animal presents a very uniform character, 

 but their amount in the blood of different animals is liable to 



