I. _Origin of the Absorbents._ The origin of the absorbents can hardly be demonstrated by inspection; it is like the termination of the exhalants. Such is in fact the extreme delicacy of these vessels at their origin, in most parts, that they cannot be seen with the best optical instruments. In some places we see pores; but it is difficult to distinguish their nature, whether they are exhalant or absorbent. Their origin then must be determined by the phenomena they produce in different places. Wherever absorption takes place, it is evident that there they begin. Now in examining attentively the phenomena of absorptions, we see that they are discoverable whenever there are exhalations; so that the same table may serve both for the absorbents and the exhalants; the following is the table for the first. ┌1st. exterior, arising ┌1st. mucous. │ from the systems └2d. dermoid. │ │ ┌1st. serous. │ │2d. cellular, ┌1st. fat. │ │ and taking │ │ │ up there, └2d. serum. ABSORBENTS.│2d. interior, │ │ arising from │ ┌1st. the short and flat │ the systems │ │ bones, and the extremities │ │3d. medullary │ of the long ones. │ │ │2d. the middle of the │ │ └ long bones. │ │ │ └4th. synovial.┌1st. the articulations. └3d. of nutrition. └2d. the tendinous grooves. Let us examine these different absorptions, of which I shall not give the proofs here in detail, because these proofs will be shown in each system from which the absorbents arise. 1st. The external absorptions do not correspond precisely with the exhalations of the same nature. In fact, neither the sweat nor insensible transpiration exhaled by the skin, are taken up by the cutaneous absorbents; these fluids are excrementitious. So the mucous absorbents allow the pulmonary transpiration to evaporate, and the other fluids exhaled upon their surface, to mix with the aliments and afterwards to pass off. It is the substances contained in the atmosphere, in the surrounding bodies, &c. that this kind of vessels takes up by a very irregular absorption, as we shall see, except however that of the chyle, which is not made in a continuous manner, which is subject to great intermissions, and which at other times takes place with remarkable activity.