For dysmenorrhoea or sterility due to flexion or stenosis the method of operation is as follows: A suppository containing a grain of the aqueous extract of opium is introduced into the rectum, the patient etherized, and the uterus exposed by Sims's speculum. The cervix is held by a tenaculum, and the smaller dilator is introduced as far as it will go. Upon gently stretching open that portion of the uterine canal which it occupies, the stricture above so yields that when the blades are closed they will pass higher. By repeating this manoeuvre a cervical canal is tunnelled out which before would not admit the finest probe. Should the os {180} externum or cervical canal be too small to admit the instrument, a pair of pointed scissors may be substituted, and by the same opening and closing motions the canal may be prepared for the introduction of the smaller dilator. As soon as the cavity of the uterus has been entered the handles are brought together. This dilator is then withdrawn, the larger one introduced, and its handles slowly screwed together. If the flexure be very marked, the larger instrument after being withdrawn should be introduced with its curve in the opposite direction to that of the flexure, and the final dilatation made with the dilator in this position. But in reversing the curve the operator should take care not to rotate the organ upon its own axis, and not to mistake a twist thus made for a reversal of the flexure; the ether is then withheld, and the instrument allowed to remain in place until the patient begins to flinch, when it is removed. The best time for the dilatation is midway between the monthly periods. In the majority of cases the dilatation should be carried to about one and a quarter inches. The infantile uterus which has failed to develop at puberty has thin, unyielding walls, and should therefore not be dilated more than three-fourths of an inch or an inch. In using the larger instrument it is usually necessary to have the assistant make decided counter-traction with the vulsella forceps to prevent the blades of the dilator from slipping out. The cervix is sometimes lacerated, but not sufficiently to produce unpleasant results. Goodell's statistics include one hundred and fifty operations of full dilatation under ether, with no fatal result and without serious inflammatory disturbance. As precautions against cellulitis, peritonitis, and metritis the patient should be fortified for the operation with moderate doses of opium and full doses of quinine, and for two or three days after the dilatation this should be continued and supplemented by the application of an ice-bladder over the abdomen.