_Description of the straight and curved forceps.--Mode of action.-- Indications.--Rules for applying the forceps.--History of the forceps._ Before describing the various species of dystocia, or faulty labour, it will be necessary to consider the different means with which the increasing experience of years has furnished us, of giving artificial assistance in such cases. These may be brought under two heads, first, where delivery can be effected with safety to the mother and her child; secondly, where this can only be effected at the expense of the infant's life. Under the first head come the forceps, turning, the Cæsarean operation, and artificial premature labour; under the second are craniotomy or perforation, and embryotomy. Of these the forceps is by far the simplest and safest means of artificial delivery, and is therefore an operation which should always be had recourse to in preference to any of the others wherever it is possible. The forceps is the simplest imitation of nature, for in fact it is nothing more than a pair of artificial hands introduced one on each side the head. It is impossible to define any precise limits of pelvic contraction, within which the forceps can, or beyond which it cannot, be safely applied, for the difference in the size and hardness of the child's head, and in the condition of the soft parts, will greatly modify the degree of resistance to the progress of the labour: hence the attempt to fix the exact degree of contraction beyond which the forceps becomes inapplicable is quite impracticable, as in some cases we might be led to make a trial of it where it would be quite improper, and in others have recourse to the perforator where a cautious application of the forceps would have been attended with success. For the farther consideration of this subject we must refer to the chapter on DYSTOCIA PELVICA. The forceps consists of three parts--the blades, the lock, and the handles. The blades of the present forceps are not solid, but are merely elongated bows of polished metal, by which they are not only rendered much lighter, but allow the most prominent parts of the head to project between them, and thereby take up no additional room when introduced into the pelvis. In the simplest form, viz. the straight forceps, the blades have only one curvature for adapting them to the convexity of the head. The degree of curve varies a good deal in different instruments: the greater the curve the more firmly will the blades hold, because they act more or less as blunt hooks, and do not require much pressure upon the head for the purpose, but on the other hand, they are more difficult to introduce; whereas, blades which are slightly curved can be applied with greater ease, but require much more pressure upon the head in order to hold fast.