There is a third sort of humors, which, like the second, are separated and retained in their respective reservoirs, not for the purpose of being, at least intirely, evacuated, but to acquire, in those reservoirs, a perfection that renders them fit for new, or other functions, when they return into the mass of humors. Such, among others, is the seminal liquid. Separated in the testicles, it passes thence, by a duct of some length, into the seminal vesicules, and being constantly repumped by the absorbent vessels, it is, successively, by little intervals, returned into the total mass of the humors. This is a truth demonstrable by many proofs. One alone may suffice. In a healthy man, the secretion of this liquid is continually formed in the testicles: it flows into these reservatories of which the capaciousness is very limited, not perhaps great enough for what is separated in one day; and yet there are men so continent as not to evacuate any for whole years. What would become of it, if it was not continually disposed of, by its re-entry through the vessels of circulation? A re-entry, that is extremely facilitated by the structure of all the organs that serve for the separation, the conveyance, and the preservation of this humor. The veins are there much more considerable than the arteries, and that in such a proportion as is observed no where else[59]. It is probable then that this resorption is not only made in the seminal vesicules, but that it has already taken place in the testicles, in the _epididymises_, which are a kind of first reservatory appendant to the testicles, and in the _vasa deferentia_, or chanel by which the seed is conveyed from the testicles to the seminal vesicules. It was not unknown to GALEN that the humors were inriched by the retained seed, though he was not apprized of the mechanism. “Every thing (says he) is full of it, with those who abstain from venery; but there is none of it to be found with those who abandon themselves to excesses of that sensuality.” He then labors hard to discover why a small quantity of that liquid can give so much strength to the body; at length he decides, “that it has an exquisite virtue, so that it can with surprising quickness communicate its energy to all parts of the body[60].” He proves afterwards, by various examples, that a small cause often produces great effects, and at length concludes thus: “Needs it be any wonder that the testicles furnish a liquid of a nature to diffuse fresh vigor over the whole body, when the brain produces motion and sensation, and the heart gives pulse to the arteries!” I shall wind up this Section with what one of the greatest men of the age (M. HALLER) says on the seminal humor.