CHAPTER III 

 BLOOD 



When blood is centiifugalised, means having been taken 

 to prevent it clotting, it separates into three layers : the 

 lowest layer composed of the red corpuscles in an almost 

 soUd mass ; above this a thin layer consisting of the 

 leucocytes; above this, again, a clear fluid, the blood- 

 plasma. 



THE PLASMA 



Blood-plasma has a specific gravity of 1'06. 



Its saline constituents amount to 0-85 per cent. Of 

 these, the most abundant is sodium chloride ; potassium, 

 calcium, magnesium, phosphates, carbonates and sulphates 

 also occur. 



Plasma contains the following proteins — 



1. Fibrinogen, belonging to the class of globuhns. 



2. Serum-albumin. 



3. Serum-globuhns {p^f^aogbbuhn. 



4. ( ? ) Thrombogen. 



Besides the above substances, plasma contains dextrose 

 fats, cholesterin, lecithin, urea and other nitrogenous sub- 

 stances, amino acids and innumerable substances of un- 

 known composition such as antitoxins. 



THE RED BLOOD CORPUSCLES 



Structure and Composition 



The Red Blood Corpuscles, of which there are about 

 5,000,000 to every c.mm. in men and rather less in women, 



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