_Extraction._ When once we have brought the feet into the vagina, the first part of the operation, viz. the changing the position of the child, is completed: it has now become a presentation of the feet, and as such ought to be treated, unless some source of danger be present which requires that the delivery should be hastened. The value of this practice in footling cases was first pointed out by Deleurye,[93] and particularly applied to the second act of turning by Wigand. "I have made it," says he, "a strict rule in turning, from the moment that I have brought a foot of the child as far into the vagina as I can without force, to do nothing beyond patiently waiting for the return of the pains, even if this did not take place for many hours, and leaving the rest of the labour entirely to nature. I have found by doing so that when the pains at length began to expel the child, they did it with so much force and activity as was not even seen in the most natural case of head presentation." (_Geburt des Menschen_, vol. ii. p. 130.) As the feet descend towards the os uteri, the presenting part, particularly if the arm has been prolapsed into the vagina, begins to recede, the hand externally will assist in moving the child round, and we should perform this step of the operation so gradually as to be assured that the presenting part has quitted the pelvis before the feet have entered. Without attention to this point, the child may easily be fixed across the upper part of the pelvis, or even the body brought down, while the head is wedged into the cavitas iliaca of the ilium, and produce a serious obstacle to its farther advance. This is a sort of mishap which can rarely happen except to young practitioners. If the process be slowly and carefully conducted, we doubt much if it be ever necessary to disengage the presenting part as has been so frequently recommended: the uterus in fact will move the child round with very little assistance on our part, and we shall find that after every pain the advance of the feet and recession of the part has increased considerably. From our own observations we would say that in all difficult cases, of turning especially, it is desirable for the patient to have several pains between the moment of gaining the feet and bringing them fairly into the vagina: very little force is required to bring them down, and the uterus does not appear to suffer; but where the position of the child has been rapidly changed, its contractile power seems to be injured, and it is ill able to make those exertions during the last stage, which will be required of it in order to save the child's life.