2. Soak in bichlorid solution 1: 1000 for 6 hours. Then boil 3 minutes in sterile water. Place in alcohol, 50 per cent. TO STERILIZE CATGUT (FORMALDEHYD METHOD). Immerse in formaldehyd sol., 5 per cent., for 24 hours. Wash by soaking in sterile water for 24 hours, which must be changed every hour. Then boil in sterile water and basins about 10 minutes, according to size of the catgut. Lift out carefully, and place on a sterile towel until all moisture is absorbed. Prepare table, hands, and person as for an operation. Cut in required lengths, from 14 to 25 inches. Coil smoothly, and preserve in glass jars (which have been previously boiled for 20 minutes) containing the following solution: Corrosive sublimate, 1 part; Boiled glycerin, 200 parts; Alcohol, 95 per cent., 1000 “ . CHROMIC CATGUT. 1. Soak in ether 1 to 2 weeks, according to size. 2. Wind on glass spools. 3. Soak in chromic acid solution, 5 gr. to 1 pint water, 3 to 6 hours, according to size. 4. Dry in sun 3 days. 5. Boil in 95 per cent. alcohol 1 hour, under 15 pounds pressure, in autoclave. Use Mason fruit jars. Do not screw the top down when in sterilizer. TO STERILIZE LINEN THREAD. Wind several yards of thread into coils. Boil for 30 minutes in a 1 per cent. solution of bicarbonate of soda. Wash in fresh cold water, and allow to stand in cold distilled water for 6 hours. Then boil in fresh water for 30 minutes. Place in absolute alcohol for 48 hours, then in a solution of Schering’s celloidin with equal parts of alcohol and ether. The mixture must stand for 12 hours, or until dissolved; keep tightly corked. When ready for use add 1 per cent. of sterile oleum ricini, and immerse thread for 48 hours. Then wind upon a frame to dry. This will require from 1 to 3 days. When dry, cut into lengths and coil or wind on glass slides. Boil for 1 hour in normal salt solution. Preserve in Chinesol solution, 1: 500. =To Sterilize Glycerin or Any Kind of Oil.=—Place bottle uncorked in a vessel of boiling water for 2 hours. TO PREPARE RUBBER TUBING. Place different sizes in a deep dish of water. Add bicarbonate of soda to make a 10 per cent. solution. Let come to a boil over a slow fire, then with a stiff brush or cloth rub each piece well. This removes all sulphur, leaving a black surface. Rinse several times, then boil in clean water 15 minutes. Boil 15 minutes before immediate use. TO PREPARE SIX YARDS OF IODOFORM GAUZE. Prepare the following solution: Sterile iodoform, ℥iij; Sterile glycerin, ℥iij. Mix thoroughly, gradually add alcohol (95 per cent.), f℥iij, then very quickly, ether, f℥vij. Have gauze ready in desired lengths, and drop into solution. Press gauze uniformly to preserve evenness of color. Work rapidly. Prepare table, hands, and person as for an operation. Roll strips, and place in sterile glass jars. TO PREPARE IODOFORM GAUZE (GREEN-SOAP METHOD).