to one hundred single acts in the year.[394] Forel advises two or three times a week for a man in the prime of manhood, but he adds that for some healthy and vigorous men once a month appears to be excess.[395] Mantegazza, in his Hygiene of Love, also states that, for a man between twenty and thirty, two or three times a week represents the proper amount of intercourse, and between the ages of thirty and forty-five, twice a week.  Guyot recommends every three days.[396]

It seems, however, quite unnecessary to lay down any general rules regarding the frequency of coitus.  Individual desire and individual aptitude, even within the limits of health, vary enormously.  Moreover, if we recognize that the restraint of desire is sometimes desirable, and often necessary for prolonged periods, it is as well to refrain from any appearance of asserting the necessity of sexual intercourse at frequent and regular intervals.  The question is chiefly of importance in order to guard against excess, or even against the attempt to live habitually close to the threshold of excess.  Many authorities are, therefore, careful to point out that it is inadvisable to be too definite.  Thus Erb, while remarking that, for some, Luther’s dictum represents the extreme maximum, adds that others can go far beyond that amount with impunity, and he considers that such variations are congenital.[397] Ribbing, again, while expressing general agreement with Luther’s rule, protests against any attempt to lay down laws for everyone, and is inclined to say that as often as one likes is a safe rule, so long as there are no bad after-effects.[398]

It seems to be generally agreed that bad effects from excess in coitus, when they do occur, are rare in women (see, e.g., Hammond, Sexual Impotence, p. 127).  Occasionally, however, evil effects occur in women. (The case, possibly to be mentioned in this connection, has been recorded of a man whose three wives all became insane after marriage, Journal of Mental Science, Jan., 1879, p. 611.) In cases of sexual excess great physical exhaustion, with suspicion and delusions, is often observed.  Hutchinson has recorded three cases of temporary blindness, all in men, the result of sexual excess after marriage (Archives of Surgery, Jan., 1893).  The old medical authors attributed many evil results to excess in coitus.  Thus Schurig (Spermatologia, 1720, pp. 260 et seq.) brings together cases of insanity, apoplexy, syncope, epilepsy, loss of memory, blindness, baldness, unilateral perspiration, gout, and death attributed to this cause; of death many cases are given, some in women, but one may easily perceive that post was often mistaken for propter.

There is, however, another consideration which can scarcely escape the reader of the present work.  Nearly all the estimates of the desirable frequence of coitus are framed to suit the supposed physiological