USE OF THE RED CORPUSCLES. 709 



in sickly and ill-fed persons ; also in anaemia, in inflammations, and in 

 certain diseases of the spleen, probably because they do not then un- 

 dergo the usual change into red corpuscles, and so relatively accumu- 

 late in number. 



The red corpuscles, by virtue, as it would seem, of the coloring mat- 

 ter, or cruorin, are the great carriers into the system of oxygen, 

 which displaces carbonic acid from the blood during respiration, as 

 will be explained in the section on that subject. The substance usually 

 known as haamatin, is a product of the decomposition of cruorin, by 

 the action of acids or caustic alkalies. The haematin of Lecanu is a 

 highly-colored albuminoid substance, containing iron ; its chemical re- 

 lations with the myochrome of muscles, the pigment of the choroid 

 and iris, of the hairs and skin, in both the dark and fair races of man- 

 kind, and also with the coloring matters of the bile, the urine, and 

 the suprarenal bodies, may indicate some nutritive relations between 

 it and them ; it may, perhaps, be formed in the spleen, or in the lungs, 

 and may be dissolved, in minute quantity, in the nutritive plasma, and 

 so find its way chiefly to the muscles and hairs, in the coloring matter 

 of both of which iron is also found. The red corpuscles also probably 

 furnish, by their solution, continuous supplies of albuminoid matter to 

 the liquor sanguinis, the globulin of the corpuscles having a close re- 

 semblance to albumen and syntonin. The fact, however, that the red 

 corpuscles contain most of the potash, whilst the liquor sanguinis con- 

 tains most of the soda of the blood, may indicate that the muscular 

 tissue, w r hich also abounds in potash, may receive special nourishment 

 from these ; and, as they also contain a phosphorized fatty matter, 

 they may have special nutritive relations, direct or indirect, with the 

 nervous substance. The quantity of the red corpuscles in the blood, 

 is certainly greatest in healthy and vigorous persons. These corpus- 

 cles are also most abundant in the hot-blooded Birds, not quite so nu- 

 merous in the Mammalia, the temperature of which is not so high, and 

 much fewer in the cold-blooded Reptiles, Amphibia, and Fishes. Their 

 proportion in the blood is in direct relation, not only with the tempera- 

 ture of the body, but also with the general activity and energy of the 

 muscular and nervous apparatus. From this cause, the ratio of the 

 general solids to the water of the blood, shows similar proportions in 

 the different Vertebrate Classes. 



The special nutritive office of the liquor sanguinis, must be explained 

 by its composite chemical constitution. Its peculiar physical character 

 of smooth viscosity, due to the albumen, and particularly, it is said, 

 to the fluid fibrin which it contains, is highly favorable to the easy 

 passage of the blood along minute channels like the capillaries, with- 

 out its exuding too freely through their walls, and perhaps also to the 

 uniform suspension of the red particles in it. A tendency to exude 

 in undue quantity through the coats of the vessels, is probably favored 

 by a diminution in the amount of fibrin, as well as by like changes in 

 the proportions of the albumen and the salts. 



The uses of the particular chemical constituents of the blood as a 

 whole, require further consideration. The albuminoid principles of 

 the blood, its most abundant constituents, include the globulin of the 



