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.