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Show 106 Conclusion of the First Part. Conclusion (film First Part. lymphatics may also arise from the eittremities of arteries ; and tli; power lost by throwing the absorbed fluids into the cells of glands may e compensated by some impulse given to the cliyle and lymph, .111 the lacteals and lymphatics, from the fluid of arteries, though I suspet‘t it is not so. Though in the former edition of this work, Iliave said, that Idid not know the use ofthe lymphatic glands, I think it probable that they divide'th‘e work of absoiption amongst a great number ofdiii‘ercnt vessels: the vas interens, for example, takes tip ehyle from the cavity of the Intestines, and propels it into the nearest lymphatic gland, this becomes a temporary reservotr, and to; secreted through the whole ofthe internal surfaces of the intestines. The urine bears some proportion to our drink; but the faces are in a small proportion to our food, the cliyle, and to these fluids. Boerhaave sup- poses that all the secreted fluids, except those of the kidnies and skin, are returned to the blood by the absorbents. A very great part, I believe, is returned, but changed into lymph. Dr. Fordyee believes that a living body has a power of destroying animal and vegetable matter, and convert- ing it into water, in a manner not yet understood. Perspiration may then That the glands also produce some change in the cliyle and carry it ofi-But the proper discussion of this subject would require a vo- lume of itself. In the third place, there cannot be a doubt but that the lymphatics ab- sorb on the surface of the body, and on an analogous surface, the internal surface of the trachea, and air-cells of the lungs. Erasistratus taught lymph, is extremely probable, perhaps gives them a greater disposition to that the arteries absorbed air: and Galen says that the veins absorb, xx lie converted into blood; but I am not certain that this is their function. Mi'yzy ,umpaw aspisxoy£y©4 n‘mz; izsp©a That these glands serve to mix animal spirits with the cliyle, by means of the nerves, is an idle supposition, since we have no proof ofany such spi- crates alluded to in part, when he said, " Emryaov m: sic-moor my -ro a'pmz." --Dr. Hales found, in distilling blood, that a thirty-third part of the whole was air. Haller, alluding to those experiments, says, " Utique fere trigesima tertia pars totius sanguinis verus est aer."--\Vliatevei‘ happens from distillation of blood out of the body, I am perfectly certain, that there are no loose masses of air in the blood. I have tied up the trunks both of arteries and veins, when they were turgid with blood, in the living ani- mal; on opening them under water, not a particle of air shewed itself. I even tied up the eava superior, and the interior, as far as the diaphragm; and, removing them with the heart and lungs entire, under which circum- stances, from the lungs being collapsed, they remained turgid and un- may be considered as entirely passive; the vas efferens absorbs the-cliyle From the cells of the gland, and, as larger in size, propels it With additional force towards the next gland; and thus in succession, till it comes to the thoracic duct. rits; and the nerves entering these glands are scarce demonstrable, as we have said : that they serve to form the central particles of the globules of blood, as Mr. Hewson and Falconar contended, is as improbable, since these central particles have not been seen by the first microscopic observers in the world; I never have seen them; Haller says he once saw it, but supposes it a morbid appearance. The diluting the cliyle and lymph, by mixing some secretion of the ar- teries in the glands with it, is also another idle supposition, supported by not even the shadow of a proof, since it supposes the chyle too thick, which has never been proved, and since the fluid of the glandS, to every inierosco- pic observation, is not more dilute than the cliyle or lymph themselves. Besides the fluid which moistens the cavities ofthe hollow viscera in commen with all other cavities, there are great quantities of other fluids poured into them : the drink taken into the stomach may be two pounds in twen- ty-four hours ; the saliva swallowed may be one pound in the same period, the gastric juice another, the pancreaticjuiee another. The bile poured into the intestines Haller supposes about twenty ounces, besides the fluid secreted And says, that this was what Hippo- changed, as well as the right auricle and ventricle, I placed them in the receiver of an air-pump, and exhausted it; but neither these veins, nor the right auricle and ventricle, did swell, nor Show any symptoms of con- taining air.-Thc Chevalier Roza, in Italy, has endeavoured to confirm the opinion of Erasistratus by experiments, by tying up the trunks of arte- ries when they appeared to be turgid with blood. On opening these arte- ries, an elastic vapour, he says, escaped, and they contained btit very little real blood. Harvey, in his experiments, found nothing but blood in arP 2 terics. |