in the usual way by the hand after delivery of the child, lead me to support Matthews Duncan's view so far as to say that the main folding of the placenta, when it passes the os uteri, is generally on a longitudinal axis, though the presenting point is often further from the edge than is represented in Fig. 96. It is easily shown by experiments that the placenta will pass through a much smaller ring when thus folded than when the insertion of the funis comes first.

It is obvious that, the more the expulsion is effected by effusion of blood, the more nearly the mechanism approximates to Schultze's view; the more it is due to uterine contraction, the more nearly it approximates to Matthews Duncan's view. It will generally be agreed that the latter is preferable. The conclusion is that the usual mode of expulsion is intermediate, to a variable extent, between the two mechanisms; but approaches rather to that described by Matthews Duncan, and the more nearly so, the more judicious is the management of the third stage, and the more vigorous the uterine

action.

Separation and expulsion of membranes.—It has already been explained (see p. 153) that the membranes are separated from the lower segment of the uterus by its dilatation to form a canal for the fœtus, and that this separation is necessary for the formation of the bulging bag of membranes. By the retraction of the uterus, after delivery, the chorion is partially but not entirely detached, the line of separation passing through the ampullary layer of the decidua (see p. 57), so that the superficial layer of the decidua comes away with the chorion. The chorion is thrown into fine wrinkles, being detached along the ridges of the wrinkles, but remaining attached along the furrows. When the placenta is detached, the blood which escapes thereupon tends to detach also the membranes in the vicinity of the placenta It does not, however, separate the whole bag of membranes, partly because its quantity is insufficient, partly because it begins to escape externally as soon as it has cleared a way for itself to the os uteri. Then, when the placenta is expelled by the contraction of the uterus, it drags after it the membranes, completing their separation from above downwards, and usually inverting the bag of membranes. When there is sufficient effusion of blood behind the placenta to invert it, as in Fig. 97, this blood, driven down by the uterus, aids in the inversion, detachment, and expulsion of the bag of membranes. By the time the placenta and membranes escape from the vulva the membranes are inverted, the foetal surface of the amnion being external, and the placenta is often inverted also. If delivery of the placenta is aided by gentle traction on the edge which presents in the vagina, it generally comes down with the uterine surface outermost.

The large arteries and veins passing to the placenta are of course torn across as soon as detachment occurs, and some bleeding takes place from their open mouths. This is the source of the retroplacental hæmatoma, when such is produced. But, unless there is uterine inertia, the open mouths are quickly closed by further retraction of the placental site, the muscular fibres of the middle coat of the uterus interlacing irregularly around the vessels. After a time, the exact duration of which is unknown, permanent closure is secured by the formation of thrombi in the vessels beyond the constricted part, just as thrombi are formed in any other vessels the current through which is arrested by pressure or ligature. Champneys estimates the amount of blood escaping as six ounces before the delivery of the placenta, and six ounces enclosed in the placenta and membranes. As in his observations the uterus was unstimulated during the third stage of labour, the woman lying on her left side, the average quantity, when the uterus contracts well, is probably

less.

Occasionally the placenta is expelled into the vagina, or even externally, by the same pain which expels the foetus. More frequently there is a rest for a variable time-perhaps for from twenty minutes to an hour, or even longer, in the absence of external stimulus. During this time the uterus may be felt moderately hard, and still reaching up to some height in the abdomen, generally about up to the umbilicus. At this period, as well as at other times, rhythmic contractions, though not very marked, take place in addition to the tonic contraction, and therefore the uterus varies in hardness. After a time the contractions again become stronger, and are felt as pains, although slight as compared with those of the expulsive stage. With these pains a little blood may be expelled, and hence they have been called "dolores cruenti." They have the effect of gradually completing the detachment of the placenta, if that is not completed just after the birth of the child, or by subsequent effusion of blood behind the placenta, and at length of expelling it from the body of the uterus in the manner already described, so that it lies partly in the flaccid relaxed cervix and partly in the vagina. Its expulsion externally, in the absence of assistance, is effected by the expiratory muscles, aided by the muscular walls of the vagina and cervix.

After delivery of the placenta, the uterus may be felt in the hypogastrium as a comparatively small firm ball, varying, however, considerably in size in different women. The average level of the fundus may be taken as about five inches above the pubes, and more than half-way from pubes toward umbilicus; but, when the uterus is large or rests unusually high above the pelvis, it may

reach even up to the umbilicus. Rhythmic contractions, in addition to the tonic contraction, continue to take place in it, although not necessarily felt by the woman as pains. In all cases, therefore, it varies in hardness, and this variation must not be considered as indicating a risk of hæmorrhage, unless either the relaxation is too great in the intervals, or gushes of blood take place with the contractions, or between them.

Duration of labour.-Very wide differences are found between the duration of labour in different women, depending partly upon the vigour of the expulsive forces, partly upon the relation between the size of the fœtus and the canal of the bony pelvis and the soft parts, as well as upon the dilatability of these latter. The first stage generally occupies at least three or four times as long as the second, and in multiparæ the second stage may be completed by a very few pains. In primiparæ the length both of the first and of the second stage is very much greater: that of the first from the greater rigidity of the cervix; that of the expulsive stage, from the resistance offered first by the orifice of the vagina, formed by the ring of hymen so far as it still exists, which must inevitably be more or less lacerated; and secondly, by the perineum, which has never before undergone dilatation.

The average duration of labour, reckoning from the first manifest pains, may be taken as being about fifteen hours in primiparæ, and seven or eight hours in multiparæ. In primiparæ beyond the age of thirty-five years, the duration of labour is greater, and, on an average, exceeds twenty-four hours.

A greater number of labours take place during the night than during the day; the hours during which most commence being those from 9 to 12 P.M., and those during which most are terminated those from midnight to 3 A.M.

CHAPTER XIII.

MANAGEMENT OF NORMAL LABOUR.

It is a well-known rule that the accoucheur should always attend promptly to the first summons from a lying-in woman. It may be that she has deferred sending till the last moment, or labour may be extremely rapid. In such a case, if from any delay of the attendant the child is born before his arrival, the mother's life may be lost from post-partum hæmorrhage, or the child's in a case of pelvic presentation. Again the favourable moment for interference in a case of abnormal presentation may be lost. If, on the other hand the patient has sent unnecessarily early, the attendant, after ascertaining the exact state of affairs, and the probable duration of the labour, may confidently leave her for a time.

Requisites to be taken by the accoucheur.—The attendant should be provided with a stethoscope, a catheter (either a silver female catheter or a No. 10 or No. 12 gum-elastic male catheter), bottles containing chloroform, sulphuric ether, solution of chloral, tincture of opium or Battley's liquor opii sedativus, liquid extract of ergot, or liquor secalis ammoniatus, or some liquid preparation of ergotin, blunt-pointed scissors, a Higginson's syringe, which may with advantage be provided with a long vulcanite tube for intra-uterine injection, a hypodermic syringe, a chloroform inhaler, and either a small elastic catheter (No. 6), suitable for passing into the infant's larynx, or a tube specially made for that purpose. These may be carried in a simple leather bag with pockets at the sides for the bottles. There should also be in the bag suitable needles and sutures (silk-worm gut or silver wire) for stitching the perineum, and either iodoform gauze for plugging the uterus, or some preparation of perchloride of iron, either the liquor ferri perchloridi fortior, or the solid salt. The latter is somewhat less likely to rust the iron instruments in the bag; but even for this it is well to have a bottle with a cap over the stopper. A pair of forceps may also be carried in the bag, especially if the accoucheur is going far from home. These or any other obstetric instruments are most conveniently carried wrapped separately in chamois leather, which may be secured by indiarubber rings. There

should be provided in the room hot and cold water, thread for tying the funis, an abdominal binder, and a supply of diapers.

Certain antiseptics must either be carried in the obstetric bag, or provided beforehand at the house. These are perchloride or iodide of mercury for disinfection of hands and non-metallic instruments, and either carbolic acid, lysol, or permanganate of potash for metallic instruments; of these two, the two former are the more effective. Perchloride of mercury may be carried either in tabloids or in solution. If tabloids are used they should be tested with the water of the district in dilute solution, to make sure that no precipitate is formed by the hardness of the water. They should contain no powdery colouring matter, which would mask the slight milkiness caused by precipitation. I prefer to carry a concentrated solution according to the following formula :R. Hydrarg. Perchlor. gr. xx., Acid Hydrochlor. dil. 3ss., Glycerini Zi., Aq. ad zi. The acid increases the efficacy of the mercury in the presence of albuminous matter. A concentrated solution of mercuric iodide may be made according to the following formula : -R. Hydrarg. Iodid. Rubr. gr. xx., Potass. Iodid. gr. xv., Aq. zi. Pure carbolic acid may be carried, liquefied by 10 per cent. of water; permanganate of potash may be carried in crystals.

Antiseptic precautions. The reports of the RegistrarGeneral show that the mortality due to puerperal septicæmia throughout Great Britain considerably exceeds that due to all the difficulties and accidents of labour. Hence the most important thing of all, in the conduct of normal labour, is to take precautions against the occurrence of septicæmia. Of late years, by the improvement of antiseptic measures, and especially by the use of perchloride of mercury as an antiseptic, lying-in hospitals have been converted from the most dangerous places of all for delivery into the safest. There is therefore strong reason for believing that a universal adoption of stringent antiseptic precautions would considerably diminish the present mortality from puerperal septicemia.

I may so far here anticipate the subject of puerperal fever as to state the following facts. It is excessively difficult absolutely to sterilise the vagina by any antiseptic treatment, but the microbes or germs ordinarily present in it do no harm unless substances capable of decomposition, such as placenta, are retained. On the other hand, if virulent microbes are introduced, such as may be carried especially from puerperal or any other form of septicæmia, or from phlegmonous erysipelas, they may cause fatal septicæmia after perfectly normal labour. The most important element of antisepsis therefore consists in preventing the introduction of virulent germs into the genital canal, and this can be done without