68 THE BLOOD. 



a clear liquid. The liquor sanguinis has, however, the pale 

 corpuscles mixed with it, which are found to collect at the 

 top, and this clear liquid which is found at the top after co- 

 agulation, when inflammation has been present, is styled 

 the bujfy coat, and is found to separate into fibrin and serum. 



The liquor sanguinis shows under the microscope numer- 

 ous fine filaments variously interwoven. 



The fibrin may be separated from the blood by stirring it 

 with a stick roughly notched, and its proportion is supposed 

 not to exceed two and one-half parts in the thousand. Its 

 quantity is regarded as greater in arterial than venous blood. 



The color of the blood is the first physical property we 

 notice. This is a beautiful red or vermilion in the arteries, 

 modena or purple in the veins, and still darker in the vena 

 portae. 



Its quantity has been variously estimated by differe'nt 

 physiologists the extremes being 8 pounds for the lowest 

 and 100 pounds for the highest. 



The calculations of Hoffman and Valentin are regarded as / 

 coming nearest the truth. Hoffman makes the weight of 

 the blood to the whole body as 1 to 5 hence, an individual 

 weighing 150 pounds, has 30 pounds of blood or nearly 4 

 gallons. 



Its smell is faint and peculiar, and has been compared to a 

 fragrant garlic odor. 



The taste is slightly saline and peculiar. 



To the touch it is viscid. It is also coagulable, has a tem- 

 perature of about 98 or 100 Fahrenheit, and a specific 

 gravity, when compared with water, of 1.0527 to 1.0800. 



In reference to the property of coagulation in the blood, 

 M. Magendie remarks that it is a " fundamental point in 

 the theory of the blood, that in order to support life it must 

 be coagulable/ 7 and that where it loses this property, life 

 must cease and death is inevitable; and this is what is 

 believed to occur in all those destructive epidemics, as the 

 cholera, plague, and yellow fever, the blood in each being 

 in a fluid state and not capable of coagulation. 



A variety of agents are found to destroy this property in 



