Quantity.— The quantity of the menstrual fluid vs hich escapes at each period has been so variously estiniated at different times and by different observers, as to render it obvious that the calculations could not have pro ceetled upon any common data. Thus Hip pocrates, and afterwards Galen who quotes him, states the quantity as two Attic hernina, equal to about eighteen ounces. In recent times it has been estimated by Magendie at several pounds, and IIaller gives the average amount as varying from six to tw elve ounces. But all these estimates are too high. Dehaen, who employed an ingenious method of mea surement, calculated that some women lost three, others five ounces, and very few half a pound ; but that it was exceedingly rare for a woman who had no malady to lose a,s much as ten ounces.f Probably the only proceed ing by which any definite result can be ob tained, is that of observing the rate of escape of the discharge from the uterine orifice. According to the observations of Mr. White head, this is generally so slow that no more than from ten to twelve grains could be pro cured during the time that the patient was able to endure the irksomeness of the pro ceeding. From these, and similar observations of my own, as well as from other estimates, I conclude that two to three ounces is probably the full extent of the natural flow, and that a discharge amounting to six or more ounces in the aggregate will generally produce for the time sensible effects upon the constitution, such as general pallor, and some feebleness of the muscular systeni.
Nature of the catanuidal discharge. — There is no foundation for the belief once so preva lent, and even partially still retained, that the menstrual fluid contains materials of a noxious or poisonous nature, nor yet that it serves as a vehicle for the depuration of the blood of the female. The occasional fcetid odour of the discharge, and sometimes also of the breath of women during menstruation, arises from the decomposition of the fluid, as it slowly collects in the vagina, and doubtless also from its partial resorption into the system, producing in such cases a heavy or fcetid odour of the breath, the cause of w hich was pointed out more than two centuries ago by De Graaf.t The menstrual fluid has always, even in health, a peculiar and somewhat heavy' odour which is as characteristic of it, as is the gravis odor puerperii of the lochial and other discharoes in childbed.* But these circumstances agrd no evidence that the excretion is, when first formed, necessarily unhealthy.
The menstrual fluid, when first formed, ap pears to consist almost entirely of pure blood ; but, in its course through the vagina, it re ceives in addition the secretions of that canal, whereby both its physical condition and chemical constitution are materially altered. Hence the differences of opinion which have so long prevailed regarding the real nature of this fluid, and the extent to which it differs from pure blood. These differences have been
maintained chiefly by the well-known fact that menstrual blood seldom coag,ulates, and also by the difficulty of discovering fibrine in it. But a solution of this difficulty is found in the fact that the mucus of the vagina has always an acid reaction, and that in this acid the fibrine of the blood is so readily dissolved, that not only is its coagulation prevented, but chemical analysis fails usually to reproduce more than a trace of it.
The menstrual fluid, therefore, as escaping from the vaginal orifice, and that collected from the os uteri, are essentially two different products, and this distinction should be ob served in all examinations having reference to its chemical or physical composition. But it would be perhaps arbitrary to designate either of these alone the menstrual fluid. Probably this term is most suitable to the first. Both the vagina and uterus are concerned in the production of this fluid in the form in which it is most familiarly known, and in this form it may first be examined, the pure and un mixed product of the uterus being reserved for subsequent consideration.
Composition of menstrual fluid according to M. Denis.
Water - - 82-50 Fibrine - - 0.05 Hematosine - - 6-34 Mucus - - 4-53 Albumen - 4.83 Oxide of iron - - 0.05 Osmazome and cruorine, of each - 0-11 Salts and fatty matter - - 1-59 Microscopic exandnotion. —The menstrual flux exhibits three periods or stages; viz. the periods of invasion, stasis, and decline. In the first the discharg,e is of a paler colour, and sometimes consists mainly or entirely of rime LI S - menstrua aMa. But this stage is not always observed, the discharge often commencing at once of the deep red colour characteristic of the middle stage. This con tinues durino the greater part of the period, and is succeeded by the third stage or that of decline, when the discharge loses its deep red colour and assumes the hue of water in which raw flesh has been washed. This is very com monly the condition of the discharge during the last day or two of each period, especially in those women in whom the flow is of long continuance.
M. Pouchet* has examined with great care the menstrual discharge at each of these periods. The following are the results of his observations : 1st invasion. A very few blood globules mixed with mucus may be observed, together with mucous-corpuscles and scales of epithelium, mostly entire, floating in an abun dance of limpid fluid. Almost all the mucous corpuscles contain smaller globules or granules which form in them a central nucleus. 2. Stasis. Menstruation havingreached its apogee, the blood•globules are much more numerous than at the onset. The plates of epithelium usually remain entire. 3. Decline. The fluid contains the same substances, and presents nearly the same appearances as at the time of commencement of the flow.