THE RED BLOOD CORPUSCLES 181 



B. CHEMICAL PROPERTIES 



The Composition of the Red Corpuscles. — Different varieties of 

 red cells contain between 57 and 65 per cent, of water and between 

 35 and 43 per cent, of solids. It may be said in general that they 

 yield 65 per cent, of water and 35 per cent, of solids. The latter con- 

 sist of hemoglobin, 33 per cent., protein, 0.9 per cent., cholesterin and 

 lecithin, 0.46 per cent., and inorganic salts, such as potassium phos- 

 phate and chlorid and sodium chlorid, 1.4 per cent. Hence, the hemo- 

 globin forms by far the largest portion of the total solids, namely, 

 94 per cent. 



Each ^ red corpuscle is composed of a reticular network, or stroma, 

 and a fluid or semifluid portion. The former appears as a delicate 

 spongy and colorless ground substance, in the spaces of which is 

 deposited the hemoglobin, together with a small quantity of water and 

 salts. The hemoglobin exists here in a peculiar amorphous condition 

 and is not held in solution, nor is it deposited in crystalline form. 



Separation of the Stroma and Hemoglobin. Hemolysis. — The 

 procedures usually employed to isolate the hemoglobin are quite 

 simple. The blood may be frozen and thawed several times in suc- 

 cession, or it may be diluted with a small quantity of distilled water. 

 It also suffices to add to it a small amount of ether, chloroform, solanin, 

 saponin, alkalies or bile acids. Of special interest are those bodies 

 which are normally present in some animals, and plants and which, 

 when brought in contact with blood, cause a destruction of the red 

 cells and a liberation of their hemoglobin. This process is known as 

 hemolysis, while the agents concerned in it are designated as hemoly- 

 sins. These bodies are found in the products of bacteria, as well as in 

 the venoms and irritating secretions of snakes, toads, bees, and spiders. 

 They also exist in the normal blood-sera of the higher animals in which 

 they play an important part in the production of immunity. The 

 hemoglobin is liberated by them either by causing the corpuscles to 

 rupture or by abstracting this substance from them without marked 

 injury to their framework. The former change may be produced by 

 placing the corpuscles in water, and the latter by adding such solvents 

 as ether or chloroform to the medium in which they are kept. A very 

 rapid, almost explosive, destruction is had if they are brought in 

 contact with bile. When subjected to any one of these agents, the 

 blood gradually assumes a much darker color and becomes more 

 transparent, this change in its appearance being indicative of the 

 escape of the hemoglobin and its free dissemination through the plasma. 

 The stromatic remnants of the corpuscles are then designated as 

 "shadows," and the blood as a whole as "laked" blood. 



In order to retain the volume and shape of the red cells for a long period of time, 

 it is necessary to place them in a medium which is absolutely isotonic to them, or, 

 in other words, in a solution which possesses the same concentration and, therefore, 

 also the same osmotic pressure as the blood-serum. The fluid most commonly 



