The chief causes of flooding are, the too early or violent, separation of the placenta; insertion of the placenta over the mouth or on the neck of the womb; laceration of the womb or vagina; the bursting of a swelled vein; rupture of one or more of the blood vessels of the uterus; and breaking of the cord. Probably the most frequent of these causes are the premature or violent separation of the cord, and the bursting of the blood vessels. The insertion of the placenta over the mouth of the womb, instead of on the fundus, occurs very seldom, but when it does severe flooding is nearly certain to follow, because the placenta has then to be torn, by the expansion of the parts, at the very commencement of the labor, and probably continues to pour out blood for a long time before the child is delivered, and it can be expelled. In fact this occurrence, unless the labor terminates very speedily, is nearly always fatal to the mother, and frequently to the child also. In most cases there is more or less hemorrhage from this cause during gestation, particularly after the sixth month, when the neck of the uterus begins to enlarge more than the placenta, and consequently tears away from it. Abortion frequently results also, if the flooding be not stopped. Madame Boivin tells us that in _twenty thousand three hundred and fifty-seven_ deliveries there were but _eight_ cases in which the placenta grew over the mouth of the womb; which is equal to _one_ case in every _two thousand five hundred and fifty-four_. Dr. Churchill has collected the accounts of _one hundred and seventy-four cases_ of this kind, and he finds that out of these forty-eight terminated fatally; or nearly _one out of every three_. The rupture of the blood vessels may occur when they are too much engorged with blood, or when their coats are weakened and corroded by disease. Shortness of the cord may also produce a rupture of the vessels, by the strain it causes on them and on the membranes. In many cases the flooding comes on suddenly, without any warning whatever, though most usually it is preceded by a sensation of weight, heat, and fluttering in the pelvis, pains in the thighs and back, flushed face, headache, and dizziness. The pulse also becomes irregular, the hands and feet grow cold, and the ears often ring, or buzz. The only certain sign that the hemorrhage has really commenced is the appearance of the blood itself, and this often occurs, as previously remarked, without any premonitory sign whatever.