102 THE STOCK owner's ADVISER. 



readily brought out by acetic acid. The white corpuscles are 

 present in the blood in the proportion of 1 per 300 red corpuscles 

 after a meal and 1 per 800 during fasting; they are much more 

 numerous in some diseases, as in leucocythaemia. 



The liquor sanguinis is a clear, yellow, alkaline fluid, in which 

 the corpuscles float. It is pale and clear, and consists of water, 

 fibrin, albumen, fatty compounds, extracts, odoriferous, and 

 saline matters. It may be obtained by allowing the slowly 

 coagulable blood of the horse to stand in a tall vessel surrounded 

 by ice. The temperature of 0° C. prevents coagulation, the 

 corpuscles subside, and the clear fluid may be removed by 

 pipette. Its composition may be described as serum plus the 

 elements of fibrin. The serum is a thin, transparent liquid, of a 

 pale straw or yellow color, consisting of the liquor sanguinis 

 deprived of fibrin. It contains nearly 90 per cent, of water, is 

 always slightly alkaline, and coagulates when heated, owing to 

 the large quantity of albumen it contains. Fibrin is a white, 

 stringy, elastic substance, which, when the blood is in circula- 

 tion, is in solution, and cannot be distinguished from the other 

 constituents of the plasma. It may be obtained by stirring some 

 freshly-drawn blood with a stick or bundle of twigs. It is in- 

 soluble in water or alcohol : soluble in alkalies, lactic phosphoric, 

 and acetic acids. 



THE CIRCULATION. 



The circulatory system of the horse, like that in the human 

 body, is carried on by means of the heart, arteries, capillaries, 

 and veins. The heart beats about thirty to forty per minute, 

 alternately receiving blood from the venous system and dis- 

 charging it into the pulmonary artery and aorta. The arteries, 

 with their elastic and muscular walls, form channels for the 

 blood to the system, assisting the heart in maintaining the cir- 

 culation and regulating the supply of blood to the different 

 parts. The capillaries are vessels of minute calibre, with thin, 

 permeable, elastic walls, allowing both liquor sanguinis and 

 white corpuscles to pass through tlieir walls into the surrounding 



