XIII. 



PRACTICAL DIRECTIONS FOR DISINFECTION. 



THE Committee on Disinfectants of the American Public Health 

 Association (appointed in 1884), after an extended investigation with 

 reference to the germicidal value of various agents, in a final report 

 submitted in 1887 submits the following " Conclusions": 



The experimental evidence recorded in this report seems to justify the 

 following conclusions : 



The most useful agents for the destruction of spore-containing infectious 

 material are 



1. Fire. Complete destruction by burning. 



2. Steam underpressure. 105 C. (221 F.) for ten minutes. 



3. Soiling in water for half an hour. 



4. Chloride of lime. 1 A four-per-cent solution. 



5. Mercuric chloride. A solution of 1 : 500. 



For the destruction of infectious material which owes its infecting power 

 to the presence of microorganisms not containing spores, the committee rec- 

 ommends 



1. Fire. Complete destruction by burning. 



2. Boiling in water for ten minutes. 



3. Dry heat. 110 C. (230 F ) for two hours. 



4. Chloride of lime. A two-per-cent solution. 



5. Solution of chlorinated soda.* A ten-per-cent solution. 



6. Mercuric chloride. A solution of 1 : 2,000. 



7. Carbolic acid. A nve-per-cent solution. 



8. Sulphate of copper. A ft ve-per-ceiit solution. 



9. Chloride of zinc. A ten-per-cent solution. 



10. Sulphur dioxide.* Exposure for twelve hours to an atmosphere con- 

 taining at least four volumes per cent of this gas in presence of 

 moisture. 



The committee would make the following recommendations with refe- 

 rence to the practical application of these agents for disinfecting purposes : 



FOR EXCRETA. 



(a) In the sick-room : 



1. Chloride of lime in solution, four per cent. 

 In the absence of spores : 



2. Carbolic acid in solution, five per cent. 



3. Sulphate of copper in solution, five per cent. 



1 Should contain at least twenty-five per cent of available chlorine. 

 8 Should contain at least three per cent of available chlorine. 

 3 This will require the combustion of between three and four pounds of sulphur 

 for every thousand cubic feet of air space. 



