46 HUMAN PHYSIOLOGY. 



Water acts as a solvent for the inorganic matters and holds in suspension 

 the corpuscular elements. 



Albumin is the nutritious principle of the blood ; it is absorbed by the 

 tissues to repair their waste and is transformed into the organic basis 

 characteristic of each structure. 



Paraglobulin Q? fibrinoplastin is a soft amorphous substance precipitated 

 by sodium chloride in excess, or by passing a stream of carbonic acid 

 through dilute serum. 



Fibrinogen can also be obtained by strongly diluting the serum and 

 passing carbonic acid through it for a long time, when it is precipitated as 

 a viscous deposit. 



Fatty matter exists in small proportion, except in pathological conditions 

 and after the ingestion of food rich in oleaginous matters ; it soon disap- 

 pears, undergoing oxidation, generating heat and force, or is deposited as 

 adipose tissue. 



Sztgar is represented by glucose, a product of the digestion of saccharine 

 matter and starches in the alimentary canal ; glycogenic matter is derived 

 from the liver. 



The Saline constititents aid the process of osmosis, give alkalinity to 

 the blood, promote the absorption of carbonic acid from the tissues into 

 the blood, and hold other substances in solution; the most important 

 are the sodium and potassium chlorides, the calcium and magnesium 

 phosphates. 



Excrementitious matters are represented by carbonic acid, urea, creatin, 

 creatinin, urates, oxalates, etc. ; they are absorbed from the tissues by the 

 blood and conveyed to the excretory organs, lungs, kidneys, etc. 



Gases. Oxygen, nitrogen and carbonic acid exist in varying proportions. 



BLOOD CORPUSCLES. 



The corpuscular elements of the blood occur under two distinct forms, 

 which, from their color, are known as the red and white corpuscles. 



The Red Corpuscles, as they float in a thin layer of the Liquor 

 Sanguinis, are of a pale straw color ; it is only when aggregated in 

 masses that they assume the bright red color. In form they are circu- 

 lar and biconcave; they have an average diameter of the ^^W ^ 

 an inch. 



In mammals, birds, reptiles, amphibia and fish the corpuscles vary in 

 size and number, gradually becoming larger and less numerous as the scale 

 of animal life is descended, e.g. : 



