The gauze sponges may be made of various sizes by sewing together about eighteen layers of plain absorbent gauze. The edges of the gauze should be folded in and hemmed to prevent the escape of loose threads in the peritoneum. Some operators use sponges made by wrapping absorbent cotton somewhat loosely in gauze. The number of sponges used should always be recorded before the operation. It is advisable to preserve the sponges in sets always of the same number, so that in every case the operator knows that this number, or some multiple of this number, of sponges has been used. The writer uses such sets of seven gauze sponges of the following sizes: one sponge 3 by 3 inches; one sponge 10 by 7 inches; five sponges 5 by 5 inches. Usually one such set of sponges is enough for an abdominal operation. In some cases, however, the first set of sponges may become soiled by the discharge from an abscess or a suppurating tumor, and it is advisable to discard these sponges and to complete the operation with a second clean set. The number of sponges should never be altered during an operation by cutting one in two. Sponges should never be removed from the operating-room until the abdomen has been closed and the sponges have been counted. If a sponge falls on the floor or in the vessel to receive slops, it should be put aside until the final counting is completed. When a set of sponges is used, they should always be carefully counted as they are placed in the basin, for the nurse who prepared and put up the set may have carelessly miscounted them. Accuracy in regard to the sponges is of the greatest importance. There are a number of recorded cases, and many unrecorded, in which sponges have been left in the abdomen. This accident is usually fatal, though there are several cases on record in which the sponge has made its way, by ulceration, into the intestine, and has been discharged from the anus, or has been removed by subsequent incision through the abdominal wall. =Discipline of the Operating-room.=--The discipline of the operating-room should be most rigid. Perfect personal asepsis can be obtained only by continuous watching and criticism. The work should be systematically divided among the assistants and nurses, and each should attend strictly to his or her own department, and to nothing else. The first assistant should assist the operator with sponges, etc. The second assistant should attend to the instruments, ligatures, and sutures. The first nurse should wash the sponges and place them in a basin of sterile water beside the first assistant. She should also attend to the towels and dressings. The second nurse, under direction of the first, should change soiled water in the sponge- and hand-basins, etc. No one should pick up anything that may have been dropped upon the floor, and no one, unless it is absolutely necessary, should touch anything that has not been sterilized.