In rare cases, in which the excision of tissue has been carried high up in the lateral vaginal fornices, it may be necessary to ligate the uterine arteries in order to control the hemorrhage. This may be done by passing around the vessel, close to the cervix, a curved needle carrying a heavy ligature. Bleeding from the circular artery may readily be controlled in a similar way, the ligature being passed like the first suture in trachelorrhaphy. If the operation has been thoroughly performed, there will be left a large crater or conical cavity in the vaginal vault. This cavity may then be packed with sterile gauze, or, if there is much bleeding, with gauze saturated with Monsel’s solution. Some surgeons sew together the walls of the cavity to diminish as much as possible the raw surface. Others char the walls with the actual cautery, in order to carry the destruction of tissue still farther than has been done with the knife. If the removal with the curette and knife has been thorough, it is not necessary to make a caustic application. If, however, the cavity is walled by obviously cancerous tissue, the use of the caustic is advisable. This is usually the case. Chloride of zinc is a valuable caustic in cancer of the cervix. It should be applied as follows: After the cancerous tissue has been removed as thoroughly as possible with the knife, the scissors, and the curette, bleeding from the walls of the cavity should be checked by packing with gauze, dry or saturated with a 5 per cent. solution of antipyrine. The bleeding may very often be checked in this way in a few minutes, and in this case the caustic may be immediately applied. In case, however, the bleeding is not so quickly controlled, the packing must be left in the cavity for twenty-four hours, at the end of which time it may be removed, without anesthesia, and the caustic application may be made. Before introducing the caustic the vagina and the vulva should be protected by thorough greasing with an ointment composed of 1 part of bicarbonate of soda to 3 parts of vaseline. The strength of the caustic should depend somewhat upon the thickness of the tissue that separates the cavity from the peritoneum or other important structures. The thickness may be approximately determined by palpation. Usually a 100 per cent. solution of chloride of zinc may be safely employed. If the walls of the cavity appear very thin--less than a quarter of an inch--the caustic may be reduced to a 50 per cent. solution. Small balls of cotton, about half an inch in diameter, should be saturated with the caustic and carefully packed in the cavity. The operator should be careful to remove quickly with the sponge any excess of caustic that may be expressed from the cotton. Much unnecessary pain may be experienced if the caustic comes in contact with the vagina or the vulva.