24 



A MANUAL OF VETERINARY PHYSIOLOGY 



cells is potassium phosphate. The following table from Bunge 

 bears on the question of the salts of the blood in different animals : 



Horse - 

 Ox 

 Pig - 



Water free from salts is destructive to protoplasm ; no doubt, 

 therefore, one important function of the salts in the blood is to 

 maintain the vitality of the tissues. Sodium chloride is here 

 especially valuable, and its extensive presence in blood (60 per 

 cent, to 90 per cent, of the total amount of ash) corresponds to 

 its importance. As the blood is simply the carrier of the salts, 

 and the only channel by which the tissues can obtain them, it 

 by no means follows that all the mineral matter found in i M is 

 essential to its own repair and constitution. 



The Temperature of the Blood in the different domestic animals 

 varies from 37-8° C. to 40-54° C. (ioo° to 105° F.), the warmest 

 blood in the body being found in the hepatic veins. 



The Quantity of Blood in the Body cannot be determined by 

 mere direct bleeding alone. After all the blood is drained off, 

 the vessels require to be washed out, and the quantity of blood 

 in the water estimated by the colour present ; the body has then 

 to be minced and macerated, and the quantity of blood in this 

 estimated by the colour test, comparison being made with a 

 standard solution of blood. 



By Haldane and Lorrain Smith's carbon monoxide process the 

 amount of blood in the living animal may be calculated. The 

 essential steps in this process are to estimate first colorimetrically 

 the percentage of haemoglobin in the blood, and then the extent 

 to which this is saturated by breathing a measured volume of 

 carbon monoxide. In this way the total capacity of the blood 

 for carbon monoxide may be ascertained, and the carbon mon- 

 oxide capacity being the same as the oxygen capacity, the 

 volume of the blood may be readily calculated. 



Sussdorf * puts the proportion which the weight of the blood 

 bears to the body weight as follows : 



Horse - ^ = 66 per cent, of the body weight. 



Ox - t 1 s = 7 , 7 i 



Sheep - T ^ = 8-oi „ „ ,, 



pi g " ^=4' 6 



D°g - iV = to ^ = 5- 5 to 9- 1 per cent . of the body weight . 



* Ellenberger's ' Physiologie der Haussaugethiere. 



