III. _Purges._ The efficacy of this remedy, in the cure of dropsies, has been acknowledged by physicians in all ages and countries. Jalap, calomel, scammony, and gamboge, are often preferred for this purpose; but I have heard of two cases of ascites being cured by a table spoonful of sweet oil taken every day. It probably acted only as a gentle laxative. The cream of tartar, so highly commended by Dr. Home, seems to act _chiefly_ in the same way. Gherlius, from whom Dr. Home learned the use of this medicine, says, that all the persons whom he cured by it were in the vigour of life, and that their diseases had been only of a few months continuance. From these two circumstances, it is most probable they were dropsies of great morbid action in the arterial system. He adds further, that the persons who were cured by this medicine, were reduced very low by the use of it. Dr. Home says that it produced the same effect upon the patients whom he cured by it, in the infirmary of Edinburgh. Dr. Sydenham prefers gentle to drastic purges, and recommends the exhibition of them every day. Both drastic and gentle purges act by diminishing the action of the arterial system, and thereby promote the absorption and discharge of water. That purges promote absorption, we learn not only from their effects in dropsies, but from an experiment related by Mr. Cruikshank[40], of a man who acquired several ounces of weight after the operation of a purge. The absorption in this case was from the atmosphere. So great is the effect of purges in promoting absorption, that Mr. Hunter supposes the matter of a gonorrh[oe]a, or of topical venereal ulcers to be conveyed by them in some instances into every part of the body. [40] Letter to Mr. Clare, p. 117. IV. _Certain medicines_, which, by lessening the _action of the arterial system_, favour the absorption and evacuation of water. The only medicines of this class which I shall name are _nitre_, _cream of tartar_, and _foxglove_.