Nocturnal Emissions.—In civilized man such difficulties are opposed to marriage, that he replaces it by prostitution, or by more or less unnatural means, as soon as his sexual appetite becomes strong. In those who abstain, the images produced by sexual excitation, combined with erections, act more strongly during sleep than waking and produce ejaculations of semen called nocturnal emissions or pollutions. These generally occur during erotic dreams, and as the dreams produce the illusion of real perception, in quality as well as in intensity, it is not surprising that they are followed by an orgasm and ejaculation of semen.
Masturbation.—In the waking state the unsatisfied sexual appetite may produce such excitation that the boy applies friction to the glans penis, which cause voluptuous sensations. As soon as he has made this discovery he repeats the act and provokes ejaculation of semen artificially. Thus arises the bad habit of masturbation or onanism, a habit which is both depressing and exhausting, which takes an increasing hold on those who practice it. Although from the purely mechanical point of view masturbation causes a more normal ejaculation than nocturnal emissions, which are often interrupted by awakening and the vanishing of the dream which produced them, it has a much more harmful effect, by its frequency and especially by its depressing action on sentiment and will. We shall return to this subject in Chapter VIII.
The accumulation of semen in the seminal vesicles strongly excites the sexual appetite of man, and he is momentarily satisfied by their evacuation. But we shall soon see that this purely organic or mechanical excitation, which seems at first to be only adapted for natural wants, does not in man play the principal role. We can easily understand that it cannot be the principal moving power of the sexual act. In fact, for any of the animals in which copulation occurs, the possibility of accomplishing this is not connected solely with the accumulation of semen, for it depends on obtaining a female. It is necessary, therefore, for the accumulated semen to wait, and for the perception of the female by the aid of the senses to excite the male to coitus.
External Signs of the Sexual Appetite.—Like every other desire the sexual appetite betrays itself by the physionomy. This consists in the play of cerebral activity, that is the thoughts, sentiments and resolutions, on the muscles by means of motor nerves and nerve centers. It is not limited to the face but extends to the whole body. The abdomen, the hands and even the feet have their physionomy; that of the muscles of the face and eyes is, however, the most active and most expressive. Sexual desire betrays itself in looks, by the expression of the face and by certain movements in the presence of the female sex. Men differ greatly in the way in which they betray or hide their sentiments and thoughts by the play of their muscles, so that the inner self is not always reflected without. Moreover, the expression of sexual desire by the play of the physionomy may be confounded with that of other sentiments, so that one who appears libidinous is not always so in reality, and inversely.
Continence in Man.—Abstinence or sexual continence is by no means impracticable for a normal young man of average constitution, assiduous in intellectual and physical work, abstaining from all artificial excitations, especially from all narcotics and alcohol in particular, for these substances paralyze the judgment and will. When sexual maturity is complete, that is after about twenty years, continence is usually facilitated by nocturnal emissions accompanied by corresponding dreams. The health does not suffer from these in any way. However, in the long run this state cannot be considered as normal, especially when there is no hope of it coming to an end in a reasonable time. What is much more abnormal are the numerous artificial sexual excitations that civilization brings with it.
Sexual Power.—The individual variations in the sexual instinct are enormous, and may be said to vary from zero to an intense and perpetual excitation called Satyriasis. By sexual power is understood the faculty of accomplishing coitus. This power in the first place requires strong and complete erections, as well as the faculty of following them by frequent seminal ejaculations, without being precipitate. Impotence or incapacity for coitus belongs to pathology and consists usually in the absence or defectiveness of erections. Sexual power and appetite generally go together, but not always, for it is possible to be powerful with feeble sexual appetite, and intense appetite sometimes goes with impotence; the latter condition, it is true, is pathological. Sexual power also varies so much in individuals that it is hardly possible to fix a limit between the normal and the pathological.
The sexual power and appetite in man are strongest on the average between 20 and 40 years, especially between 25 and 35. But, while young men of 18 to 20 years or more may be still tranquil, without having had seminal ejaculations, one often finds, among races who mature earlier, boys of 12 or 16 who are fully developed both in sexual power and appetite. In our Aryan races, however, when this occurs before the age of 14, it is a case of pathological precocity. The late appearance of sexual power and appetite is rather a sign of strength and health.
After the age of 40, the sexual power slowly diminishes, and after the seventieth year, or even before this, becomes extinct. Exceptionally one finds old men of 80 who are still capable. Normally the sexual appetite diminishes with age; often, however, especially when it is artificially excited, it lasts longer than sexual power.
As regards sexual power we must distinguish between that of copulation and that of fecundation. The power may exist without the latter, when the testicles have ceased to functionate, while the other glands, in particular the prostate, second the venereal orgasm by their secretion, when the power of erection is still preserved. Inversely, the testicles may contain healthy spermatozoa in the impotent. In this case artificial fecundation by the syringe is practicable.
Individual Variations in Sexual Power.—The fact that there are men who for several years can copulate several times a day proves to what extent sexual power varies in man. Sexual excitation and desire may sometimes attain such a degree that they are repeated a few minutes after ejaculation. It is not rare for a man to perform coitus ten or fifteen times in a single night, in brothels and elsewhere, although such excess borders on the domain of pathology. I know a case in which coitus was performed thirty times. I was once consulted by an old woman of 65 who complained of the insatiable sexual appetite of her husband, aged 73! He awakened her every morning at three o'clock to have connection, before going to work. Not content with this, he repeated the performance every evening and often also after the mid-day meal. Inversely, I have seen healthy looking husbands, at the age of greatest sexual power, accuse themselves of excess for having cohabited with their wives once a month or less. The reformer, Luther, who was a practical man, laid down the average rule of two or three connections a week in marriage, at the time of highest sexual power. I may say that my numerous observations as a physician have generally confirmed this rule, which seems to me to conform very well to the normal state to which man has become gradually adapted during thousands of years.