DISINFECTION AND STERILIZATION. 191 
vacuum of fifteen inches can be obtained in the cham- 
ber. The steam should be thrown into the chamber in 
large amount, both above and below the goods, and the 
excess should escape through an opening in the bottom 
of the chamber, so as to more readily carry off with it 
any air still remaining. The live steam in the cham- 
ber should be under a pressure of two to three pounds, 
so as to increase its action. , 
To disinfect the goods, we place them in the chamber, 
close tight the doors, and turn the steam into the jacket. 
After about ten minutes, when the goods have become 
heated, a vacuum of ten to fifteen inches is produced, 
and then the live steam is thrown in for twenty min- 
utes. The steam is now turned off, a vacuum is again 
formed, and the chamber again superheated. The 
goods are now thoroughly disinfected and dry. In 
order to test the thoroughness of any disinfection, or any 
new chamber maximum, thermometers are placed, some 
free in the chamber and others surrounded by the 
heaviest goods. It will be found that, even under a 
pressure of three pounds, live steam will require ten 
minutes to penetrate heavy goods. 
The Disinfection of Hands, Instruments, Ligatures, and 
Dressings for Surgical Operations. 
Instruments. All instruments, except knives, after 
having been thoroughly cleansed, are boiled for three 
minutes in a 1 per cent. solution of washing soda. 
Knives, after having been thoroughly cleansed, are 
washed in sterile alcohol and wiped with sterile gauze 
and then put into boiling soda solution for one minute. 
This will not injure their edges to any great extent. 
Gauze. Gauze is sterilized by moist heat either in 
