1st. Whenever a tight ligature applied to a limb makes the lower part swell, whenever too long standing, a perpendicular position of the superior extremities, &c. produce the same effect, it is to be presumed that the effusion depends upon the compression of the lymphatics, and takes place then like venous dilatations in similar circumstances, because the lymph finds it difficult to circulate. Here then is a case in which the exhalants have nothing to do with the dropsy, which takes place because the absorbents do not take up what the exhalants furnish. If other causes, as a bruise, a wound, &c. diminish the activity of the part, the absorbents directly weakened, are not able to take up their fluids. So if their weakness is sympathetic, that is to say, if it arises from the injury of another viscus, the same phenomenon will be the result of it. In all these cases we find the absorbents much dilated in the dead body: often they are even full of fluids. 2d. But in the organic affections to which dropsy succeeds, the exhalants certainly in the greatest number of cases, pour out more fluids than usual. The pleura is filled in phthisis, the skin is then covered with night sweats, blood is raised, &c. These are the exhalations which I have called passive. They are so abundant on the serous surfaces, that if a puncture is made, the peritoneum often fills again with such rapidity, that as much water is collected in a day, as there would be in a month, if the exhalation was natural. I do not say that the absorbents are not also affected in these cases; but the principal cause of the dropsical effusions is certainly then in the increased action of the exhalants. I could cite other examples, but this is sufficient. Four years since I was engaged upon the absorbents; I observed then that these vessels are not always very evident in dropsical patients, notwithstanding what has been said by many authors, and that very often we see them more easily in very thin subjects. I had not then thought of this difference of dropsies; but in working again upon this system for my Descriptive Anatomy, I think of comparing the cases in which it is dilated and those in which it is not, with the cause of the death. III. _Termination of the Absorbents._ All the known absorbents unite into two principal trunks. One of these, which is the thoracic duct, receives all those from the lower extremities, abdomen, the greater part of the thorax, and those of the left side of the superior parts. The other is formed by the union of the absorbents of the right side of the superior parts, as well of the head, as the extremities, and of some of those of the thorax. These two principal trunks go into the vena cava superior; around them, many smaller branches also terminate there.