The exhalants are developed preternaturally in many parts; it is especially in the cysts that this development is best seen. Their internal surface, ordinarily smooth, pours out very different fluids, according to the particular sensibility they possess. When we open these cysts, the exhalants furnish new fluids, and it is often necessary to remove them to prevent exhalation. Sometimes instead of the fluid that is ordinarily exhaled there, the blood is thrown out, as happens on the serous surfaces; for example, I have found very bloody serum in the encysted dropsies of the ovarium; latterly I have seen in them coagulated blood. I would observe that this is an essential difference to be added to those mentioned above, between the fluids that are exhaled and those that are secreted. These last are never preternaturally poured out in a cyst. We never find preternaturally a quantity of bile, of urine, saliva, serum, &c. whilst we often find serum, as in encysted dropsies, fat as in steatoma and other tumours which have a fatty liquid analogous to this fluid, synovia, as in the tumours called ganglions, when they are not dilatations of the synovial glands, which have cysts preternaturally produced, &c. Whence arises this difference? it would be necessary that the glands should be preternaturally developed in our parts, in order that the secreted fluids might be preternaturally separated from the blood, now the structure of these organs is too complicated, their organization supposes too many conditions, to admit of their preternatural development. On the contrary, the simple organization of the exhalant surfaces, which have only vessels continuous with the arteries, and without an intermediate organ, requires much less for them to grow preternaturally in parts, in which they were before unknown. Sometimes the fluids exhaled preternaturally do not collect in a cyst; they continually flow out; this is what takes place in fistulas, and other preternatural or artificial drains that are made in our organs. Then the cellular texture, constantly preserving the preternatural modification of sensibility that it has taken locally from a deposit, or any other circumstance, constantly continues to pour out a fluid different from the serum that is exhaled in a natural state. ABSORBENT SYSTEM. This system results from the union of a multitude of small vessels which arise from all the parts, and carry different fluids that are poured into the black blood, after having passed through certain peculiar swellings that are called lymphatic glands, and which make a part of the system with them. The whole of the absorbent system comprehends then two things, 1st, the vessels; 2d, the swellings or glands, an improper name, inasmuch as it assimilates them with organs which pour out fluids by the excretories that arise from them. ARTICLE FIRST. _Of the Absorbent Vessels._ We shall examine these vessels in their origin, their course and their termination.