One of the points which has been most hotly contested in technical as well as in popular physiology is the use and functions of the _spleen_. This organ, as most readers are aware, is a gland, of somewhat oval shape, lying close to the left side or extremity of the stomach. It is one of the so-called ‘ductless’ glands of the body—that is, it possesses no duct or outlet, as do the liver, sweetbread, and other glands concerned with the formation of special fluids used in digestion and other functions. In olden times philosophers puzzled themselves over this mysterious organ; nor was its nature rendered any clearer by the discovery of the fact that it may be removed from the bodies of the higher animals without causing any great or subsequent inconvenience, and without affecting in any perceptible degree the health of the subject operated upon. One classical authority went so far as to allege that he could find no use whatever for the organ; whilst another maintained that possibly it was intended to serve as a kind of packing for the other organs around it, and that it kept them from getting out of their places in the movements of the body. The idea, however, which obtained most credence was that which regarded the spleen as the fountain and origin of all the vile ‘humours’ which rankled the blood and soured the disposition of man. We can still trace in the metaphorical expressions of our literature this ancient belief; so that what at first were regarded as literal and true ideas of the spleen and its use, have come in modern days to do duty simply as metaphors.
Modern science, in dispelling those antiquated notions, has now assigned to the spleen a very important part in our internal mechanism. The part it plays may be thus described. The blood, as every one who has looked at a thin film of that substance through a microscope will know, is in reality a fluid as clear as water, and derives its colour from the immense number of little red bodies the ‘corpuscles,’ which float in it. These red corpuscles of human blood do not attain a greater size than the 1/3500th part of an inch—that is, three thousand five hundred of these little bodies placed in a line would make up an inch in length. In addition to the red bodies, there exist in the blood a much smaller number of ‘white corpuscles,’ each containing a little central particle which the red ones want. From the results of the most recent researches it would appear that the red corpuscles are produced by the partial destruction of the white ones; and that the little central particles of the white globules, when coloured, appear before us as the red corpuscles of the blood. Now the spleen is to be regarded as the great manufactory or _depôt_ in which the red corpuscles are thus produced from the white ones, and in which also many of the white corpuscles are themselves developed. And it would also appear highly probable, that when the red globules of the blood have served their turn in the economy of the body they are broken down in the spleen; their material being doubtless used for some wise purpose in the maintenance of our complicated frame.