The os uteri ought always if possible to be fully dilated: this however is not so essential as with the forceps, for when once it has reached the size of a crown piece, it mostly yields easily to the introduction of the hand. Where turning is indicated in malposition of the child we may safely await its full dilatation so long as the membranes remain unruptured. Where the membranes have been ruptured some hours and the os uteri hard, thin, and rigid, it will be impossible to turn until, either spontaneously or by proper treatment, it becomes soft, cushiony, and dilatable. In cases which require turning as a means of hastening labour, as for instance in flooding from placenta prævia and other causes, the hæmorrhage is seldom so severe as to demand it without at the same time rendering the os uteri so relaxed as to present little or no obstruction to the hand. Where convulsions indicate turning, the bleeding and other depleting measures, which are necessary to control them, will have a similar effect in preparing the os uteri for this purpose. In ordinary cases of turning there will be no need to change the patient's position, as it will be just as easy to perform it as she lies upon her left side, merely bringing her pelvis nearer to the side of the bed in order to reach her with greater facility. Where, however, from the position of the child or from the state of the uterus, the introduction of the hand and searching for the feet will probably be attended with considerable difficulty, it may be advisable to place her across the bed, sitting upon its edge, her back supported by pillows, her feet resting on two chairs, in the same way as it is used by the Continental practitioners for applying the forceps; or if it be really a case of very unusual difficulty, it will be better to put her upon her knees and elbows, for in this position we gain the upper and anterior parts of the uterus with greater ease. In choosing which is the best hand for performing the operation, the practitioner must not only be guided by the position of the child, but also by the hand with which he possesses most strength and dexterity: many always use the left hand for turning when the patient lies upon her left side; for our own part we have always used the right, and have never failed except in one or two cases of great difficulty, where we judged it more prudent to put the patient on her knees and elbows than risk any injury by using too much force. In introducing the hand into the vagina as the patient lies on her left side, the right is moreover preferable, as we can pass it more completely in the axis of the vagina, than we can the left.[88]