instead of being slightly broken, then the curve would, in its chief features, be geometrically symmetrical; and this symmetry appears to me to afford a convincing proof of the representative accuracy of the curve. We see that the month is divided into five periods; that the maxima occur on the following pairs of days: the 19th-20th, 13th-14th, 25th-26th, 1st-2d, 7th-8th; and that the minima occur at the beginning, end, and exact middle of the month. There have been many idle superstitions as to the influence of the moon upon the earth and its inhabitants, and some beliefs that—once deemed equally idle—have now been re-instated in the regard of science; but it would certainly seem to be a very fascinating and very curious fact if the influence of the moon upon men should be such as to regulate the spontaneous discharges of their sexual system. Certainly the lovers of all ages would then have "builded better than they knew," when they reared altars of devotional verse to that chaste goddess Artemis.
THE WEEKLY RHYTHM.
We now come to the third branch of our inquiry, and have to ask whether there be any weekly rhythm of the sexual activity. A priori it might be answered that to expect any such weekly rhythm were absurd, seeing that our week—unlike the lunar month of the year—is a purely artificial and conventional period; while, on the other hand, it might be retorted that the existence of an induced weekly periodicity is quite conceivable, such periodicity being induced by the habitual difference between our occupation, or mode of life, on one or two days of the week and that on the remaining days. In such an inquiry, however, a priori argument is futile, as the question can be answered only by an induction from observations, and the curves on Chart XI (Chart XIa and Chart XIb) prove conclusively that there is a notable weekly rhythm. The existence of this weekly rhythm being granted, it would naturally be assumed that either the maximum or the minimum would regularly occur on Saturday or Sunday; but an examination of the curves discloses the unexpected result that the day of maximum discharge varies from year to year. Thus it is[383]
| Sunday in | 1888, 1892, 1896. |
| Tuesday in | 1894. |
| Thursday in | 1886, 1897. |
| Friday in | 1887. |
| Saturday in | 1893 and 1895. |
Since, in Chart XI, the curves are drawn from Sunday to Sunday, it is obvious that the real symmetry of the curve is brought out in those years only which are characterized by a Sunday maximum; and, accordingly, in Chart 12 I have depicted the curves in a more suitable form.
Chart XII A is obtained by combining the data of 1888, 1892, and 1896: the years of a Sunday maximum. Curve 12 B represents the results of 1894, the year of a Tuesday maximum—multiplied throughout by three in order to render the curve strictly comparable with the former. Curve 12 C represents 1886 and 1897—the years of a Thursday maximum—similarly multiplied by 1.5. In Curve 12 D we have the results of 1887—the year of a Friday maximum—again multiplied by three; and in Curve 12 E those of 1893 and 1895—the years of a Saturday maximum—multiplied by 1.5. Finally, Curve 12 F represents the combined results of all nine years plus (the latter half of) 1891; and this curve shows that, on the whole period, there is a very strongly marked Sunday maximum.
I hardly think that these curves call for much comment. In their general character they display a notable concord among themselves; and it is significant that the most regular of the five curves are A and E, representing the combinations of three years and of two years, respectively, while the least regular is B, which is based upon the records of one year only. In every case we find that the maximum which opens the week is rapidly succeeded by a minimum, which is itself succeeded by a secondary maximum—usually very secondary, although in 1894 it nearly equals the primary maximum—followed again by a second minimum—usually nearly identical with the first minimum—after which there is a rapid rise to the original maximum. The study of these curves fortunately amplifies the conclusion drawn from our study of the annual rhythm, and suggests that, in at least part of the year, the physiological condition of man requires sexual union at least twice a week.
As to Curve 12F, its remarkable symmetry speaks for itself. The existence of two secondary maxima, however, has not the same significance as had that of our secondary maximum in the preceding curves; for one of these secondary maxima is due to the influence of the 1894 curve with its primary Tuesday maximum, and the other to the similar influence of Curve C with its primary Thursday maximum. Similarly, the veiled third secondary maximum is due to the influence of Curve E. Probably, any student of curves will concede that, on a still larger average, the two secondary maxima of Curve F would be replaced by a single one on Wednesday or Thursday.
One more question remains for consideration in connection with this weekly rhythm. Is it possible to trace any connection between the weekly and yearly rhythms of such a character that the weekly day of maximum discharge should vary from month to month in the year; in other words, does the greater frequency of a Sunday discharge characterize one part of the year, that of a Tuesday another, and so on? In order to answer this question I have re-calculated all my data, with results that are graphically represented in Chart XIII. These curves prove that the Sunday maxima discharges occur in March and September, and the minima in June; that the Monday maxima discharges occur in September, Friday in July, and so on. Thus, there is a regular rhythm, according to which the days of maximum discharge vary from one month of the year to another; and the existence of this final rhythm appears to me very remarkable. I would especially direct attention to the almost geometric symmetry of the Sunday curve, and to the only less complete symmetry of the Thursday and Friday curves. Certainly in these rhythms we have an ample field for farther study and speculation.
I have now concluded my study of this fascinating inquiry; a study that is necessarily incomplete, since it is based upon records furnished by one individual only. The fact, however, that, even with so few observations, and notwithstanding the consequently exaggerated disturbing influence of minor irregularities, such remarkable and unexpected symmetry is evidenced by these curves, only increases one's desire to have the opportunity of handling a series of observations sufficiently numerous to render the generalizations induced from them absolutely conclusive. I would again appeal[384] to heads of colleges to assist this inquiry by enlisting in its aid a band of students. If only one hundred students, living under similar conditions, could be induced to keep such records with scrupulous regularity for only twelve months, the results induced from such a series of observations would be more than ten times as valuable as those which have only been reached after ten years' observations on my part; and, if other centuries of students in foreign and colonial colleges—e.g., in Italy, India, Australia, and America—could be similarly enlisted in this work, we should quickly obtain a series of results exhibiting the sexual needs and sexual peculiarities of the male human animal in various climates. Obviously, however, the records of any such students would be worse than useless unless their care and accuracy, on the one hand, and their habitual chastity, on the other, could be implicitly guaranteed.
[373] First published in the University Magazine and Free Review of February, 1898, and since reprinted as a pamphlet. A preliminary communication appeared in Nature, May 14, 1891.
[374] [Later study (1906) has convinced me that my attempt to find a lunar-monthly period in the female