These observations agree generally with my own, and also with those of Donne, who found the menstrual fluid to consist of, 1. Ordinary blood-globules of the proper character, and in great abundance. 2. Mucus from the vagina mixed with epithelial scales. 3. Mucous corpuscles from the cervix uteri.
The unmixed menstrualfluid.—But in order to determine the nature of the menstrual fluid as it issues from the uterine orifice, unmixed with the secretions of the vagina, it must be collected by a speculun1 accurately fitting the uterine neck. The fluid so obtained possesses properties very different from those of the flux already described. Its sensible characters, as observed in more than a dozen specimens, are well described by Mr. Whitehead. Thus procured, the fluid is never so dark in colour as ordinary menstrual blood, so called, nor so fluid always as that of the arteries. Its colour varies slightly, but whatever is its tint, this is not subsequently affected by intermixture with the vaginal mucus. It appears usually rather more viscid than systemic blood, pro bably on account of its slow exudation. When thus collected it invariably coagulates, the separation into clot and serum being complete in three or four minutes. It sometimes passes off in a continued stream as pure blood, but more often as a thin coloured serum mixed with small flattened clots, the size of orange seeds, which, becoming broken down and, as it were, dissolved in the vaginal mucus, appear at the external orifice in the usual uncoagulable fluid form. It is invariably alkaline.
In menorrhagia the discharge is as fluid as arterial blood, and not being delayed on ac count of the greater rapidity of escape, it trickles in drops along the tube.
On account of the great difficulty which is experienced in obtaining the pure fluid from the uterus in quantities sufficient for chemical analysis, the following results by Bouchardat are the more valuable. The woman, a multi para, was thirty-five years of age. To explain the large proportion of water Bouchardat states that she had subsisted chiefly on a vegetable and milk diet.
Bouclzardat's analysis of pure nzenstrual blood. Water - - - - 90.08 Solid matter - - - 6.92 The solids were composed of— Fibrine, albumen, colouring matter - 75.27 Extractive matter - - - 0.42
Fatty matter - - - 2.21 Salts - - - 5.31 _ Mucus - - - - 16-79 It will be observed that the proportion of fibrine is here much larger than in the former example. But chemical analysis is not needed to show that this element of the blood con• stitntes a part of the fluid exuded from the uterus. For in women who have died men struating fibrinous clots have been found in the uterine cavity ; coagula have also just been described as forming at the os uteri and mixing with the fluid collected by the specu lum, and it cannot have escaped observation that clots sometimes form about the vulva, at times of menstruation, especially when the discharge is freer than usual.
But the notion that the menstrual discharge differs from ordinary blood "in containing only a very small quantity of fibrine, or none at all,"* which view has gained general cur rency of late, and in support of which the in vestigations of Brande or Lavagna are usually quoted, appears to be altogether a modern one. For the older writers considered the menstrual discharge as identical with blood. Hippocrates says in reference to it, " procedit autem sanguis velut victima, et cito coagu latur, si sana fuerit niulier." Mauriceaut says that menstrual blood does not ordinarily differ in any way from that which remains in the woman's body. So also Haller and Hunter, both of whom regarded menstruation as a natural evacuation of blood.
The results of these careful investigations therefore warrant the conclusion that the men strual fluid, at the moment of its effusion, con sists of pure blood, mixed only with the small quantity of mucus and epithelium which it receives in passing through the body and neck of the uterus, and that at this point it always has an alkaline reaction. But that in the course of its passage through the vagina the original fluid becomes mixed with the mucus of' that canal, vvhich there exists in increased quantities, and that in the acid of that mucus the fibrinous portion is so far dissolved as to render the detection, by chemical means, of fibrine, as a constituent of the secretion, diffi cult or impossible. So much, however, of fibrine as belongs to the blood-corpuscles must always be present, for these bodies exist in large quantities in every instance of a healthy menstrual flux.