The functions of the blood.

  • Heaton, C.W.
Date:
[1867]
Catalogue details

Licence: Public Domain Mark

Credit: The functions of the blood. Source: Wellcome Collection.

Provider: This material has been provided by The Royal College of Surgeons of England. The original may be consulted at The Royal College of Surgeons of England.

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    r ‘ ) ' ft* . r1 ’• / jf . THE FUNCTIONS OF THE BL BY ,C. IT. HEATON, Professor of Chemistry to Charing Cross Hospital College. Every one who lias looked through, a microscope at a drop of bloody knows that the red or purple colour is confined to certain minute discs, which resemble pieces of money in form, and which float in a clear yellow liquid. The discs are known to physiologists as the blood-corpuscles, and the liquid as liquor- sanguinis. Both these constituents of the blood have their own specific functions to fulfil in the operations of life, and both have been the subject of numberless researches. Very- much still remains to be done; but it is not too much to as- sert that this most wonderful of liquids is slowly yielding up its secrets to the patient workers who have so long sought for them in vain, and that “the blood; which is the life” of the animal; is no longer the utter, hopeless mystery which it has for ages remained. Careful microscopic measurements have been made of the size of the corpuscles in the blood of different animals; and it is now generally agreed that in the human subject their average length is J -3200th of an inch; and their thickness 1-12400th of an inch. Hence it would be possible; if they were packed close together; for 8;126;464 to lie in the compass of one cubic millimetre—a space not larger than a good-sized pho/s head. How the corpuscles occupy; in the aggregate; about one half of the volume of the blood,* and we are, there- fore, able to form a good guess at their probable number. Vierordt and Welker have, indeed, gone through the laborious process of counting them • and the former fixes their number at 5,069,000, and the latter at 4,600,000, in the cubic milli- metre. It will be seen that these figures agree tolerably well with the rough calculation founded on the size of the corpuscles, and we are, therefore, forced to admit that the tiny red drop obtained from the fiuger by the prick of a needle, may contain four or five millions of these curious bodies. Such figures, however, give but vague ideas to the mind. A more distinct one is, perhaps, conveyed in the fact, that a room sixty feet long, thirty feet wide, and fifteen feet high, could not contain as many grains of corn as there are corpuscles in a single tea- spoonful of human blood, the number being, approximately, eighteen thousand millions ! * This is, of course, only a rough approximation. Their quantity varies extremely in different parts of the body, and even at different times of the day.