The patient is usually in the third degree of narcotism when the operation is performed, and, in this degree, as was previously stated, there is not unfrequently a contracted and rigid state of the muscles. This state often affects the muscles of the jaws, and interferes with the opening of the mouth, if it be closed. I generally tell the patient to keep his mouth open whilst inhaling, and by that means it often remains open when he is insensible. Not unfrequently, however, he closes it on becoming insensible. One can generally open it by pressing on the chin; but as the chin does not afford a very favourable hold, there are a very few cases in which the mouth cannot be opened easily in this way, at least not unless the effects of the chloroform are carried further than is desirable for these operations. I therefore carry with me a little instrument of two blades, made to open by means of a screw. The ends of the blades are covered with leather, and, if introduced between the teeth, at the corner of the mouth on the side opposite to that on which the dentist is about to operate, the mouth can easily be opened.[149] The power of the instrument is only such that I can scarcely open it with one hand, when I hold the blades with the other. It would not enable one to open the mouth of an adult if he were closing it by voluntary power; but the spasm caused by chloroform is very much less powerful than the action of the muscles when influenced by the will. I never use the instrument for opening the mouth when the patient is closing it voluntarily under the influence of a disordered consciousness, but always wait till consciousness and volition are entirely suspended. When the mouth is once opened, it can generally be kept open with the fingers, and the instrument may be withdrawn. The bleeding during tooth-drawing is never so free as to interfere with the breathing; but when more than two or three teeth are extracted, and especially if they be in the back part of the mouth, some of the blood which escapes nearly always flows into the stomach; it flows down the fauces and œsophagus usually without any act of deglutition; but the evidence of its having gone into the stomach is obtained in those cases where the patient vomits. In consequence of the blood flowing into the stomach, vomiting cannot so generally be prevented by the precaution of not taking a meal before the operation in tooth-drawing as in other operations; but the sickness usually subsides as soon as the patient has emptied his stomach.