Should there be fever combined with the hydrops or an imposthume, or if it be caused by stoppage of the menses or of haemorrhoidal flux, a little blood may be let occasionally, for the wasting of blood cools the liver, and carries off the nourishment from the members. Avicenna says when there is much evil in the body, and little good, the letting of a vein steals the good with it, and leaves the evil in its own dominion, where it was at first; or understand what he says thus; when the good blood is thin, and the humours dense and viscous, and far off from the place where the vein is let, then the vein steals the good blood, and leaves the bad within.