I answer, in the first place, that examples of this kind, and too frequent not to be generally known, ought to obviate such an objection. Who might not have observed, that an evacuation of milk (to go no further than that instance) though moderate and of no long duration, is capable of weakening a nurse that has not a strong constitution, to such a degree, that she may feel the influences of it for the rest of her life? And even the robustest would sink under it, if continued beyond a certain length of time. The reason is sensibly apparent. Upon evacuating too often the reservoirs appropriated to the reception of any liquid, the humors are, by a necessary consequence of the laws of the animal machine, determined to an afflux thither in the greater abundance. This secretion becomes excessive, all the others suffer by it, and especially nutrition, which is but a kind of secretion; the animal constitution falls into languor and debility. Secondly, There is an answer, relative to the seed which does not hold as to the milk, which is only a liquid simply nutritious, of which an over-abundant secretion does no detriment, but in so much as it diminishes the quantity of humors: whereas the seed is an active liquid, of which the presence produces effects necessary to the play of the organs, which ceases on its evacuation; a liquid, of which, for that very reason, the superfluous emission is detrimental, in a double view. This requires explanation. There are humors, such as those of the sweat and perspiration, which leave the body as soon as they are separated from the other humors, and thrown out by the vessels of circulation. There are others, such as the urine, which, after this separation and expulsion, are retained, for a certain time, in reservoirs appropriated for that purpose, and out of which they are not discharged, but when they are in a quantity great enough to excite, in those reservoirs, an irritation that mechanically forces them to void them.