lar cows and the meat of tubercular animals. Wounds may open a gateway for infection.

Bacillus anthracis (Fig. 13), the cause of malignant pustule, or splenic fever.

Bacillus mallei, the cause of glanders.

Bacillus of syphilis (Lustgarten's bacillus). That syphilis is due to a micro-organism is highly probable, but that we have found the causative organism in Lustgarten's bacillus is by no means sure. A fact which points strongly against it as the cause is that it is found rather in non-contagious tertiary lesions than in contagious secondary lesions.

The bacillus coli communis, called also the bacterium coli commune or the bacillus of Escherich. Feces invariably

FIG. 16.-Tubercle bacilli in sputum (Ziegler).

contain this organism. It is believed by many observers to be the cause of appendicitis, peritonitis, and abscesses about the intestine. In cases of appendicitis we can rarely get a pure culture of Escherich's bacillus, but usually find also streptococci, staphylococci, or pneumococci.

The bacillus of malignant edema (the vibrione septique of Pasteur), found especially in stagnant water and certain varieties of soil.

The bacillus of typhoid fever (Eberth's bacillus) is responsible for some cases of gangrene, some of embolism, and not a few of bone and joint disease.

We may mention, in conclusion, as of occasional surgical importance, the bacillus of influenza, bacillus of diphtheria, bacillus of leprosy, bacillus of rhinoscleroma, bacillus of fetid ozena, bacillus of hemorrhagic septicemia, bacillus lactis aërogenes (an occasional cause of peritonitis).

Proteus vulgaris, or bacterium termo, induces putrefaction and is responsible for many septic intoxications.

II. ASEPSIS AND ANTISEPSIS.

Surgical cleanliness may be obtained by either the aseptic or the antiseptic method. In the aseptic method heat, chemical germicides, or both are used to cleanse the instruments, the field of operation, and the hands of the surgeon and his assistants, the surface being freed from the chemical germicide by washing with boiled water or with saline solution. After the incision has been made no chemical germicide is used, the wound being simply sponged with gauze sterilized by heat; if irrigation is necessary, boiled water or normal salt solution is used, and the wound is dressed with gauze which has been rendered sterile by heat. The effort of the surgeon is simply to prevent the entrance of microorganisms into the tissues. Some micro-organisms must enter, but the number will be so small that healthy tissues will destroy them. The aseptic method should be used only in non-infected areas. If chemical germicides are not used, the amount of wound-fluid will be small and the surgeon can often dispense with drainage. If a wound is to be closed without drainage, every point of bleeding must be ligated. It is often advisable to sew up the wound with Halsted's subcuticular stitch (Fig. 17). If this stitch is em

FIG. 17.-Halsted's subcuticular suture.

ployed, the skin staphylococcus does not obtain access to stitch-holes and stitch-abscesses cannot arise. This suture may consist of catgut, silk, or, preferably, silver wire, this latter agent being capable of certain sterilization by heat and exercising a powerful inhibitory action on micro-organisms. If a wound is closed without drainage, firm compression is applied over the wound to obliterate any cavity which may exist. In some regions of the body wounds are sealed with collodion or iodoform-collodion. If irrigation is not practised and the wound is dressed with dry gauze, the procedure is said to be by the "dry" aseptic method. In the antiseptic method the same preparations are made for the operation as in the aseptic method, but during the operation sponges impregnated with a chemical germicide are used,

and the wound is dressed with gauze containing corrosive sublimate or some other chemical germicide. If the wound is not flushed with a chemical germicide, and is dressed with dry gauze, the operation is said to be by the "dry" antiseptic method. The antiseptic method is preferred in infected areas. Dry dressings are usually preferable to moist dressings, because they are more absorbent and do not act as poultices, and dry dressings may be used even when the wound has been flushed. Year by year the aseptic method becomes more popular. Surgeons have learned that the most important factor in asepsis is mechanical cleansing by means of soap and water. The chemical germicide plays a secondary rather than a vital part. In many regions a strong chemical germicide must not be used (in the abdomen, in the brain, in joints, in the pleural sac, and in the bladder), and in other regions (mucous surfaces and fatty tissue) it is productive of harm rather than good.

Preparations for an Operation.-The surgeon and his assistants remove their coats, roll up their sleeves, and envelop their bodies in aseptic or antiseptic sheets to protect the patient and themselves. The hands and forearms are scrubbed with soap and hot sterile water. There is nothing equal to the ethereal soap of Johnston, which is a solution of castile soap in ether. Green soap or castile soap can be used. The brush employed is kept constantly in a I: 1000 solution of corrosive sublimate. The nails are cut short, are cleansed with a knife, and the hands are again scrubbed. The hands are dipped in a hot solution of corrosive sublimate, and with the forearms are scrubbed for at least a minute, the nails receiving especial care; they are then dipped for one minute into pure alcohol and are again. bathed with the mercurial solution. Kelly disinfects the hands by washing them with soap and water, dipping them in a solution of permanganate of potassium (a saturated solution in distilled water), and decolorizing them in a saturated solution of oxalic acid and washing off the oxalic acid in sterile water.

Weir has highly commended the following plan and Stimson is also pleased with it. Scrub the hands with a brush and green soap and in running hot water. Clean under the nails with a piece of soft wood. Place about a tablespoonful of chlorinated lime in the palm of the hand, place upon the lime an equal amount of washing-soda, add a little water, and rub the creamy mixture over the arms and hands until the rough granules of sodium carbonate are no longer felt. Place the paste under and around the nails by means of a

bit of sterile orange wood. Wash off the arms and hands in hot sterile water.1

Instruments are disinfected by boiling for fifteen minutes in a 1 per cent. solution of carbonate of sodium and then rinsing them in a 5 per cent. solution of carbolic acid. The carbonate of sodium prevents rusting. Boiling unfortunately destroys to some extent the keenness of the cutting instruments. They are kept in trays containing boiled water. Instruments can be disinfected satisfactorily by keeping them for fifteen minutes in a 5 per cent. solution of carbolic acid. Instruments with handles of wood must not be boiled. If such instruments are used, they can be disinfected by the use of carbolic acid, but they should not be used. After the completion of the operation the instruments should be scrubbed with soap and water, boiled, and dried. Marine sponges are rarely used, small pieces of sterilized or antiseptic gauze being preferred. In the abdomen Ashton's aseptic gauze pads are employed. These pads are about ten inches square, and are made of a number of folds of gauze stitched loosely at the edges.

Whenever possible, give the patient some days' rest in bed before a severe operation, and place him on a diet nutritious but not bulky. The night before the operation give a saline cathartic, and the morning of the operation employ an enema. Emptying the bowels lessens the danger of sepsis after operation. It is desirable that the rectum be empty, because in shock the stomach cannot absorb, and we may wish to utilize the absorbing power of the rectum and give stimulants by enema. Whenever possible, give a general warm bath the day before. The evening before the operation scrub the entire field of operation, and well clear of it, with soap and water; shave if necessary; wash with ether; scrub well with hot corrosive-sublimate solution. (1 1000); apply a layer of moist corrosive-sublimate gauze, and place over this dry antiseptic gauze, a rubber dam, and a bandage. On removing the dressings to perform the operation cleanse the part again exactly as before. In emergency cases disinfection can only be practised just previous to the operation. Disinfection can be thoroughly effected by the use of chlorinated lime (Weir, Stimson). Surround the field of operation with dry sterile sheets.

To clean the vagina or rectum, use a sponge soaked with creolin and Johnston's ethereal soap (1: 16), and subsequently irrigate with hot saline fluid or boric acid solution. 1 Medical Record, April 3, 1897.

To clean the mouth scrub the teeth with a brush and castile soap twice a day and rinse out the mouth with peroxide of hydrogen, or a solution of boracic acid every three hours for several days.

Irrigation is often practised in septic wounds, but is not required in aseptic wounds. Among irrigating fluids we may mention corrosive sublimate, carbolic acid, peroxid of hydrogen, boric acid solution, and normal salt solution. Hot normal salt solution is the best agent with which to irrigate the peritoneal cavity, the pleural sac, the interior of joints, and the surface of the brain. This solution contains 0.7 per cent. of sodium chloride.

Many surgeons employ Landerer's dry method in operating aseptically. No fluid is applied to the wound. As the wound is enlarged gauze sponges are packed in to arrest hemorrhage. On the completion of the operation the sponges are removed, any bleeding points are ligated, and the wound is closed without drainage.

The favorite ligature-material is catgut, which is well prepared by boiling in alcohol. Another method is to take raw catgut, keep it in ether for twenty-four hours, soak it for twentyfour hours in an alcoholic solution of corrosive sublimate (1 : 500), wind it on sterilized glass rods, and place it for keeping in ether or in alcohol. Fowler's catgut is prepared by boiling in alcohol, and is carried in hermetically sealed glass tubes containing alcohol, each tube holding twelve ligatures. Johnston's quick method of preparing catgut is as follows: place it for twenty-four hours in ether; at the end of this period place it in a solution containing 20 grains of corrosive sublimate, 100 grains of tartaric acid, and 6 ounces of alcohol. The small gut is kept in this for ten or fifteen minutes, the larger gut from twenty to thirty minutes, but never longer. It is placed for keeping in a mixture containing I drop of chlorid of palladium to 8 ounces of alcohol. This gut is strong and reliable. At the time of operation the gut is placed in a solution one-third of which is 5 per cent. carbolic-acid solution and two-thirds of which are alcohol. Chromicized gut will not be absorbed so readily as other gut.

It is prepared by adding 200 parts by weight of catgut to 200 parts of carbolic acid, 2000 parts of water, and I part of chromic acid. After remaining in this solution. twenty-four hours it is transferred for permanent keeping to ether or to alcohol. Kelly and Clark prepare catgut by boiling it in cumol. Senn uses gut prepared with formalin. The great advantage of formalin gut is that it can be boiled with