BLOOD 219 



binations and decompositions, which result from the 

 breaking down of muscle and nerve tissues. They 

 occur in very small amounts, being continually absorbed 

 from the tissues by the blood, but seldom accumulate, 

 as they are rapidly and continually passed off through 

 the kidneys, bowels, skin, etc. 



Inorganic Salts. Sodium and potassium chlorides, 

 phosphates and sulphates, calcium and magnesium 

 phosphates are found in the plasma. Sodium chloride 

 is the most important. The alkalinity of the blood is 

 due to the contained salts, some of which are alkaline 

 in reaction. 



The Red Cells. Red cells, corpuscles, or erythrocytes 

 are seen after a drop of freshly drawn blood is examined 

 under the microscope. They appear as disk-like 

 cells, floating or swimming about in the blood plasma. 

 After a few minutes they will be seen to group them- 

 selves in a number of columns of varying lengths, 

 resembling rolls of coins. Also a few white cells will 

 be seen floating about in the plasma. 



A single cell is slightly yellow or greenish. Numbers 

 when collected together appear fed. The color is due 

 to the presence within the cell of the coloring matter, 

 hemoglobin. The diameter of a red cell is -g^V o~ f an 

 inch or 0.0075 mm.; T2Toir or 0.0019 mm. in thickness. 

 The average number of red cells in one cubic milli- 

 meter of blood is 5,000,000 for the male; 4,500,000 

 for the female. 



Chemic Composition. The corpuscle consists of 

 hemoglobin, about 30 per cent, of total weight, the 

 rest, 70 per cent., contains 68 per cent, water, 2 per 

 cent, solid matter, e. g., cholestrin, lecithin, and 

 inorganic salts. 



The function of the red cell is to carry oxygen to 

 the tissues, where it enters into combination with 

 them (oxidation). This phenomenon is made possible 

 by the hemoglobin contained in the red corpuscle. 

 When the red cells in the blood come in contact, 



