It was in 1661—rather more than two hundred years ago—that an Italian and a Dutchman discovered, each by himself in his own country, the microscopic population of the blood. The name of the Italian is not very difficult—Malpighi. As to the Dutchman's, you must pronounce it in the best way you can—he was called Leeuwenhock. You smile, but he was nevertheless one of the first men who really comprehended what a wonderful auxiliary human science had just got hold of in the microscope, and he has helped to open the eyes of the world to the marvels of miniature creation. So content yourself, young lady, with mis-pronouncing his name, and beware of laughing at it! Names are something like faces, one may live to be ashamed of ridiculing the wrong one.
This discovery of the globules of the blood, was destined to throw great light upon the way in which the nutrition of the organs was carried on. Modern chemists, who are always fond of investigation, have examined what they are made of, and can find little else in them but albumen. Out of our 127 ounces of globules, 125 are albumen; and these, with the 70 ounces which we found before in the serum, make up the 195 ounces (of albumen) which I told you were contained in the 1,000 ounces of blood. Forgive me all these ounces and figures. Exact accounts give exact information.
These globules, then, are composed almost entirely of albumen. Nearly two-thirds of all the albumen in the blood is concentrated in them; and you know now the use of albumen, viz., that it is the foundation of all the buildings of which the blood is the architect. Everything leads us to believe that the formation of globules in the blood is the last touch given by nature to that magical provision begun in thevegetable, continued in the stomach, and finished in the veins, to which, in combination with carbon, hydrogen, oxygen, and nitrogen, we are indebted for the subsistence of every portion of our body. Thus the blood-globules may be considered as albumen which has finished its education, and is ready to go into the world; while the albumen of the serum is, like our young friends, the generations in reserve, who are still at school awaiting their turn.
This is more than a mere supposition. Scientific men have taken to themselves, on their own authority, all sorts of rights over animals, and we profit basely enough by their crimes—I will not withdraw the word—in order to increase our knowledge. Accordingly, they conceived the idea of opening the veins of animals, and allowing the blood to flow until the victim was prostrate and motionless as a corpse. This done, they proceeded to fill the exhausted veins with blood, similar to that which had been withdrawn, and with the blood, life was seen gradually to return, till the animal rose from the ground, walked, and resumed its disturbed existence, as if nothing had happened. The interesting part of the experiment to us is, that if serum only, without globules, be restored to the unfortunate animal, it is of no use whatever, and the corpse does not revive.
It is evident, then, that all the power and virtue of the blood lies in the globules; and according as their number is great or small it is "rich" or "poor," as it is called; and where their number is not up to the mark, the blood acts more feebly on the organs, life is calmer, and people are no longer troubled with emotions—in other words, with violent heats of the blood. Hence the impassible character of lymphatic people, who often get on in the struggle of life better than others, because they are never in a hurry, and know how to wait for opportunities. You will occasionally hear the word lymphatic, for it has become the fashion, and it is time for me to explain it; but unluckily the explanation is not in its favor.
You remember those little scavengers we spoke about formerly, who came from the depths of all the organs, carrying away with them the worn-out building materials, and covering the surface of the body with an inextricable net work of tiny canals. These canals are called lymphatic vessels, in consequence of being filled with a liquid which is called lymph (water, in Latin), but why I cannot tell you, for it is, in fact, simple serum. There was a very simple way of ascertaining this by making out an inventory of the contents of the lymph liquid, and when this was done, they were found to consist of water, albumen, and the salts of serum; there was even a little fibrine; the only thing wanting was globules.
How the truant serum finds its way into the lymphatic vessels is probably as follows:—I have already mentioned the inconceivable delicacy of the capillary vessels, those last ramifications of our arteries and veins. It needs all the impulsive power of the heart to enable the blood to force its way through these narrow passages; and minute as are the globules, it would seem that they have but just room to pass, for in examining under the microscope a corner of the tongue of a live frog, the globules have been seen doubling themselves up to pass through the capillaries, resuming their natural form afterwards.
It was this, indeed, which made me tell you just now that their margins were elastic. During this momentary crush, part of the serum being forced on too fast, oozes through the wall of the over-filled capillaries, as water oozes through the leathern pipes of a fire-engine, and hence probably the appearance of serum or lymph in the organs, where it is immediately sucked up (i. e., absorbed) by the lymphatic vessels. Now, you will easily understand that the larger the proportion of serum in the blood, the greater will be the quantity to be expelled in passing through the capillaries, and the more will the lymphatic vessels swell. In such cases the temperament or constitution is said to be lymphatic. If, on the contrary, the globules are in excess, the lymphatic vessels receive less serum, and diminish in size. The temperament is then called sanguine, as if there were no serum in the blood. You shall be judge yourself, knowing what you now do, whether it would not be more reasonable to call such temperaments serous and globulous. At any rate those names would give people an idea of the real state of things, and teach them that there were such things as globules in the blood.
[Footnote: Here is a summary of the contents of 1000 oz. of blood:—
Ounces.
Water………………. 790
Serum. Albumen……………….70 870
Salts……………….. 10