Man is every instant losing something of himself, and if he was not continually repairing that loss, he would soon necessarily fall into a weakness productive of death. This reparation is effected by aliments. But these aliments must undergo in the body different preparations, which are comprehended under the name of nutrition. But when that nutrition is either not performed, or deficiently so, all these aliments become useless, and do not hinder the falling into all the evils which are the consequence of atrophy or inanition. Of all the causes that may hinder nutrition, there is not perhaps a more common one than over-abundant evacuations. Such is the fabric of our machine, and in general of all human machines, that for aliments to acquire the degree of preparation necessary to repair the body, there must remain in it a certain quantity of humors well elaborated, and, if I may use the expression, naturalised to it. If this condition of them is defective, the digestion and coction of the aliments remains imperfect, and so much the more imperfect, as the humor that is needed requires the most elaboration, and is of the most importance.

A healthy robust nurse, from whom the taking some pounds of blood in twenty-four hours, would probably kill, would furnish to her child the same quantity of milk, for four or five days running, without any sensible inconvenience to her, because milk is, of all the humors, that which requires the least elaboration, being, a secretion almost distinct from the humors of the body; whereas blood is an essential of life. There is another humor, the seminal liquid, which has so great an influence over the forces of the body, and over the accomplishment of the digestions which repair them, that the Physicians of all ages have unanimously believed, that the loss of one ounce of this humor weakened more than the loss of forty ounces of blood.

Some idea may be gathered of its importance, from observing the effects which it operates on its first beginning to form itself: the voice, the aspect of the physiognomy, even the lineaments themselves of the face undergo an alteration: the beard appears, the whole body often takes another air, from the muscles acquiring a largeness and firmness that constitute a sensible difference between the body of an adult and, that of a young man who has not passed the season of pubescence. All these developements are stopped or hindered by the loss of the organ which serves for the separation of that liquid which produces them; very just observations having proved, that the amputation of the testicles, even in the age of virility, has occasioned the shedding of the beard, and the return of an infantine voice[3]. After that, can there be any doubt of the power of its action over the whole body? Does not it sensibly give reason for apprehending the multitude of evils which must arise from the waste or profusion of so pretious an humor? Its natural destination determines the only allowable means of its evacuation. Disorders will sometimes occasion its efflux. It may be involuntarily lost through the effect of lascivious dreams. The author of Genesis has left us the history of the crime of Onan, doubtless in order to transmit with it that of his punishment; and we learn from Galen, that Diogenes was guilty of the like pollution.

If the dangerous consequences of the over-abundant loss of this humor depended only on the quantity, or were the same, quantity for quantity, with the other humors, it would not, in a physical light, be of much importance, in which of the above ways the evacuation was made. But the manner or form here is as essential a point, as the substance of the thing itself, if I may be indulged this expression, my subject authorising such licence of language. Too considerable a quantity of the seminal humor, lost in the natural way, brings on very grievous disorders, but which are much worse when the same quantity has been wasted out of the course of nature. Those disorders, which such as exhaust themselves in the natural commerce of the sexes, bring upon themselves, are dreadful; but those are much more so which are produced by self-pollution. It is these last that are properly the objects of this work; but the intimate connexion which they have with the first, hinders the separation of them in the description. It is then the description common to both, that shall form the first Article. This shall be followed by the explanation of the Causes, a second Article, in which I shall state those that render the consequences from self-pollution the most dangerous: The Means of Cure, and Remarks on some Diseases that have an affinity to that cause, shall conclude the Work. I will add throughout, the Observations of the best Authors to those which I have myself made.