PRACTICAL STERILIZATION AND DISINFECTION 153 



Surgical instruments may be sterilized by boiling in water 

 for fifteen minutes, provided they are' clean, as they should 

 be. If dried blood, pus, mucus, etc., are adherent, which 

 should never be the case, they should be boiled one-half 

 hour. The addition of sodium carbonate (0.5 to 1 per cent.) 

 prevents rusting. Surgeon's sterilizers are to be had at 

 reasonable prices and are very convenient. Whether the 

 instruments are boiled or subjected to streaming steam 

 depends on whether the supporting tray is covered with 

 water or not. The author finds it a good plan to keep the 

 needles of hypodermic syringes in a small wire basket in 

 an oil bath. The oil may be heated to 150° to 200° and the 

 needles sterilized in a very few minutes. The oil also prevents 

 rusting. 



Rooms, offices and all spaces which may be readily made 

 practically gas-tight are best disinfected by means of for- 

 maldehyde by any of the methods above described (Figs. 

 109 and 110). 



Stables and Barnyards (Mohler): "A preliminary cleaning 

 up of all litter is advisable together with the scraping of the 

 floor, mangers, and walls of the stable with hoes and the 

 removal of all dust and filth. All this material should be 

 burned since it probably contains the infective agent. Heat 

 may be applied to the surfaces, including barnyard, by means 

 of a 'cyclone oil burner.' When such burning is impracti- 

 cable, the walls may be disinfected with one of the following : 



"1. Whitewash 1 gallon + chloride of lime 6 ounces. 



"2. Whitewash 1 gallon + crude carbolic acid 7 oimces. 



"3. Whitewash 1 gallon + formalin 4 ounces. 

 The same may be applied with brushes or, more rapidly, 

 sprayed on with a pump; the surface soil of the yard and 

 surroundings should be removed to a depth of 5 or 6 inches, 

 placed in a heap and thoroughly mixed with quicklime. 

 The fresh surface of soil thus exposed may be sprinkled with 

 a solution of a chemical disinfectant as above described. 



"Portions of walls and ceiling not readily accessible may 

 be disinfected by chlorine gas liberated from chloride of 

 lime by crude carbolic acid. This is accomplished by mak- 

 ing a cone of 5 or 6 pounds of chloride of lime in the top of 



