Sometimes, when the os uteri is half dilated, there is an interval of freedom from pain for several hours after the rupture of the membranes, and partial escape of the liquor amnii. Here it is advisable to turn without delay; and the hand can be passed up into the uterus and the feet brought down with little more difficulty than if the membranes had not been ruptured." The operation of turning is however beset with many difficulties, and unless the conditions for it are very favorable, and the operator skillful, it may cause greater mischief than it is intended to remedy. The probability is, as in the case of other operations, that it would seldom or never be needed if proper means were used in time, and perseveringly; and it is yet a question whether the prospect, for both mother and child, would not be more favorable if the delivery was always left to nature, in those cases where version is now attempted. Dr. Collins says, "As to turning, the risk to the mother is, in the majority of cases, so great as to forbid its employment, nor do I think the practitioner justified by the circumstances in so greatly hazarding his patient's life." PART II. THE DISEASES OF WOMEN DURING PREGNANCY, AND IN CHILD-BED. Women are liable during pregnancy, and after childbirth, to most of the diseases which afflict them at other times, and also to many derangements peculiar to those periods. As a general rule either of those conditions somewhat modifies the disease, and also necessitates certain differences in its treatment. My former work on the _Diseases of Women_ having treated on all those affections common to every other period, I shall in this confine myself chiefly to those peculiar to the two conditions referred to; giving their causes, symptoms, and treatment, with practical hints for their prevention. SECTION IX. THE DISEASES OF PREGNANCY. The diseases which are found during pregnancy are of two kinds; the first kind called _Sympathetic_, or nervous, consist of various derangements of different parts of the system, produced chiefly by nervous sympathy with the Womb. The second kind, called _Idiopathic_, are real primary derangements of the Generative Organs themselves, or of those intimately connected with them. Each of these kinds will be treated of separately. CHAPTER XXVI. SYMPATHETIC DISEASES OCCURRING DURING PREGNANCY. SICKNESS AND VOMITING.