[I]. Account of the absorbent system. [II]. The valves of the absorbent vessels may suffer their fluids to regurgitate in some diseases. [III]. Communication from the alimentary canal to the bladder by means of the absorbent vessels. [IV]. The phenomena of diabetes explained. [V]. [1]. The phenomena of dropsies explained. [2]. Cases of the use of foxglove. [VI]. Of cold sweats. [VII]. Translations of matter, of chyle, of milk, of urine, operation of purging drugs applied externally. [VIII]. Circumstances by which the fluids, that are effused by the retrograde motions of the absorbent vessels, are distinguished. [IX]. Retrograde motions of vegetable juices. [X]. Objections answered. [XI]. The causes, which induce the retrograde motions of animal vessels, and the medicines by which the natural motions are restored.
N.B. The following Section is a translation of a part of a Latin thesis written by the late Mr. Charles Darwin, which was printed with his prize-dissertation on a criterion between matter and mucus in 1780. Sold by Cadell, London.
[I]. Account of the Absorbent System.
[1]. The absorbent system of vessels in animal bodies consists of several branches, differing in respect to their situations, and to the fluids, which they absorb.
The intestinal absorbents open their mouths on the internal surfaces of the intestines; their office is to drink up the chyle and the other fluids from the alimentary canal; and they are termed lacteals, to distinguish them from the other absorbent vessels, which have been termed lymphatics.
Those, whose mouths are dispersed on the external skin, imbibe a great quantity of water from the atmosphere, and a part of the perspirable matter, which does not evaporate, and are termed cutaneous absorbents.
Those, which arise from the internal surface of the bronchia, and which imbibe moisture from the atmosphere, and a part of the bronchial mucus, are called pulmonary absorbents.
Those, which open their innumerable mouths into the cells of the whole cellular membrane; and whose use is to take up the fluid, which is poured into those cells, after it has done its office there; may be called cellular absorbents.
Those, which arise from the internal surfaces of the membranes, which line the larger cavities of the body, as the thorax, abdomen, scrotum, pericardium, take up the mucus poured into those cavities; and are distinguished by the names of their respective cavities.
Whilst those, which arise from the internal surfaces of the urinary bladder, gall-bladder, salivary ducts, or other receptacles of secreted fluids, may take their names from those fluids; the thinner parts of which it is their office to absorb: as urinary, bilious, or salivary absorbents.
[2]. Many of these absorbent vessels, both lacteals and lymphatics, like some of the veins, are replete with valves: which seem designed to assist the progress of their fluids, or at least to prevent their regurgitation; where they are subjected to the intermitted pressure of the muscular, or arterial actions in their neighbourhood.