left to dangle about freely. He-Dr. Goodell-claimed for this method, that the cord dried up without any bad smell, or process of putrefaction, and fell off like a ripe fruit without leaving a raw stump. He stated that formerly two astringent lotions of tannin and zinc were kept at the Preston Retreat, which were in constant demand for the sore navels; but that, since adopting this new method, out of more than two hundred infants not a single one had had a pouting, angry-looking, or purulent umbilicus; nor had any one suffered from fungoid vegetations or umbilical hernia. That, since anatomists had pointed out the existence of muscular fibre in the cord, he believed its ligation to be unnecessary; for if hemorrhage did not take place immediately after cutting and "stripping" it, it was very unlikely to occur at a later period. That he had once successfully dispensed with the ligature, but had suffered so much anxiety of mind lest a regurgitation of blood should occur during his absence, that he had ever since invariably applied it, although he was ashamed of this cowardice, and considered it the result of early prejudice. That the fact of a second, and even third ligature being occasionally required to arrest subsequent hemorrhage-as in Dr. Pepper's typical case -so far from being an argument in favor of ligation, was to him rather an argument against its use. For, if the cord were tied before being thoroughly emptied, and allowed to collapse, the blood imprisoned in it by the knot, being out of the circulation, would not only keep the vessels patulous, but would also necessarily undergo a process of putrefaction. DR. DUER stated that he had been induced by Dr. Goodell to try this method in a case occurring in his own private practice which they saw together, and so gratified was he with the result that he was now introducing it in the lying-in wards of the Philadelphia Hospital. MEETING OF JUNE 2D, 1870. ABORTION WITH RETAINED PLACENTA. DR. ROBERT P. HARRIS said that he had recently been called to attend a lady in her second pregnancy. She fell in premature labor at about the eighth month, in spite of every effort at prevention. After the foetus was expelled the uterus failed to contract, and after waiting for some time for the spontaneous expulsion of the secundines, Dr. Harris passed his hand into the uterus and found the placenta firmly adherent around the right cornu, while the uterine tissue at this point was perfectly flaccid and relaxed. A portion of the amniotic sac had become inverted, forming a large pocket in which a mass of coagulated blood was contained, thus giving rise to much the appearance of a large polypus. Dr. H. readily removed the coagula, and afterwards the placenta. He only alluded to the case as presenting interesting points in relation to diagnosis. DR. WM. GOODELL, in commenting upon the case, said that he could explain it in no other way than by supposing that the membranes had formed abnormal adhesions to the uterine walls. This condition he believed was much more common than was generally received, and in this way he explained those cases where the placenta was inverted and the membranes torn cleanly off, and subsequently removed with very great difficulty. Dr. Goodell believed that those delicate adhesions existed as a normal condition, and it was by their abnormal development that such cases as the above were produced. He also thought that these adhesions might become abnormally developed as the result of inflammatory disease around blood clots, or from the failure to separate of some of the natural submucous adhesions when the decidua vera atrophied and became continuous with the decidua reflexa. Other members made remarks on the subject substantially to the same effect. DYSMENORRHEA INDUCED BY A PESSARY. DR. ROBT. P. HARRIS related the history of a case which he had received by letter from a medical friend. A young girl who had suffered from profuse menorrhagia, unaccompanied by pain or other evidence of uterine disease, had, for some uterine malposition, a pessary introduced. The succeeding menstrual periods became exceedingly painful,--the pain and disturbance subsiding, however, upon the removal of the instrument. The dysmenorrhoea induced was of the mechanical expulsive character. DR. HARRIS believed that the symptoms arose from the posterior bar of the instrument (a Hodge pessary) pressing upon the os uteri, thus occluding the calibre of the canal. DR. G. PEPPER had seen much the same train of symptoms induced as well by the introduction as the withdrawal of pessaries, and in certain cases was inclined to attribute the suffering experienced to the altered position and circulation of the uterus, and could scarcely believe that an instrument exercising sufficient pressure to close the cervical canal or os uteri externum could be worn in the intermenstrual periods without any evidence of disturbance. DR. F. G. SMITH had noticed the same condition particularly well marked in a case recently under his care. QUARTERLY REPORT ON OBSTETRICS, DISEASES OF WOMEN AND DISEASES OF CHILDREN. ON THE MUSCULAR FORCES EMPLOYED IN PARTURITION, THEIR AMOUNT AND MODE OF APPLICATION. By the REV. SAMUEL HAUGHTON, M.D., Dublin, D. C. L. Oxon.; Fellow of Trinity College, Dublin. (Dublin Quar. Jour. Med. Sciences, May, 1870.) IN the first stage of natural labor, the involuntary muscles of the uterus contract upon the fluid contents of this organ, and possess sufficient force to dilate the mouth of the womb, and generally to rupture the membranes. I shall endeavor to show that the uterine muscles are sufficient, and not much more than sufficient, to complete the first stage of labor, and that they do not possess an amount of force adequate to rupture, in any case, the uterine wall itself. In the second stage of labor, the irritation of the fetal head upon the wall of the vagina, provokes the reflex action of the voluntary abdominal muscles, which aid powerfully the uterine muscles to complete the second stage, by expelling the foetus. The amount of available additional force given out by the abdominal muscles admits of calculation, and will be found much greater than the force produced by the involuntary contractions of the womb itself. The mechanical problem to be solved for both cases is one of much interest and some difficulty, as it is the celebrated problem of the equilibrium of a flexible membrane subjected to the action of given forces. It has been solved by Lagrange (Mecanique Analytique, p. 147). In the most general case of the problem, the following beautiful theorem can be demonstrated. Let T denote the tensile strain acting in the tangential plane of the membrane, applied to rupture a band of the membrane one inch broad; let P denote the pressure resulting from all the forces in action, perpendicular to the surface of the membrane, and acting on a surface of one square inch; and let 1 and 2 denote the two radii of principal curvature of the membrane, at the point considered. Then we have the following equa tion If the surface, or a portion of it, become spherical, the two principal curvatures become equal, and the equation becomes— In the case of the uterus and its membranes, the force P arises from hydrostatical pressure only, and is therefore easily measured, and the supposition of spherical curvature is approximately admissible. In the first stage of labor, the contraction of the muscular walls of the uterus compresses its liquid contents, and the membranes are pushed through the mouth of the womb, bulging out into the segment of a sphere, and are in most cases ruptured by the pressure of the liquor amnii contained in them. It is evident from the form of the gravid uterus that its curvature is greatest near its mouth, and equation (2) shows that for a given hydrostatical pressure, the tensile strain is proportional to the radius of curvature; hence this strain will be greatest at the fundus of the uterus. If we assume the shape of the uterus to be that of a prolate ellipsoid, whose longer diameter is 12 inches, and shorter diameter 8 inches, its mean curvature will be that of a sphere whose diameter is 9.158 inches. The volume of the gravid uterus is found from the expression. Volume = 4 3 * ab2; (3) in which a and b are the semiaxes, and is the ratio of the circumference of a circle to its diameter; substituting for a and b their numerical values, we find the contents of the uterus to be 402-13 cubic inches. The surface of the gravid uterus may be found from the equa tion Surface = 2*ab(Sin 'e + e√2 = e (4) in which e is the eccentricity of the generating ellipse. If the numerical values be substituted in this expression, it will be found that the surface of the uterus is 270-66 square inches* * Levret estimates the contents of the gravid uterus at 407 cub. in.and its surface at 339 sq. inches. Poppel estimates the contents at 300 cub. in., and the surface at 210 sq. inches. Some highly interesting conclusions may be drawn from the preceding calculations, combined with the weight of the total muscular tissue of the uterus. Heschl estimates the weight of the uterine muscles at from 1 lb. to 1.5 lb. Montgomery found the muscles of the gravid uterus to weigh 15 lbs.; and Levret estimates them at 51 cubic inches, which, with a specific gravity of 1.052, I find to be equivalent to 1.93 lb. Taking the mean of these estimates, we have Weight of Muscular Fibres of Gravid Womb. If we now suppose this quantity of muscle to be spread over the entire surface of the uterus, we find Mean thickness of muscular wall of uterus, = 1.56 × 7000 × 1000 252.5 × 270·66 × 1052 =0.1519 inch. If we suppose a ribbon, one inch in width, to be formed from the wall of the uterus, its thickness will be 0.1519 inch; and as each square inch of cross section of muscular fibre is capable of lifting 102.55 lbs., we find for the greatest tensile force produced by the contraction of the uterine muscles. Tensile strain of uterine 102.55 x 0.1519 102-550-1519 = Substituting this value of T, in the equation (2)— 15.577. lbs. and for its mean value 9.158 in., we obtain the maximum hydrostatical pressure inside the gravid uterus producible by the contraction of its muscular fibres. Maximum hydrostatical pressure 2 x 15.577 produced by uterine contraction = 9.158 3'402 lbs. One hundred experiments were made by Duncan and Tait, upon the hydrostatical pressure necessary to rupture the membranes which contain the liquor amnii, which are recorded in Dr. Duncan's book* (p. 306-311.) The greatest pressure observed was 3.10 lbs., and the least was 0.26 lb. ; and I find that * Researches in Obstetrics. Edinburgh, 1868. |