218 PRACTICAL DIRECTIONS FOR DISINFECTION. 



rants, such as dry earth or pounded charcoal, or the chemical de- 

 odorants and antiseptics, such as chloride of zinc, sulphate of iron, 

 etc., will, under ordinar} 7 circumstances, prevent such places from 

 becoming offensive. Disinfection will be required only when it is 

 known or suspected that infectious material, such as the dejections 

 of patients with cholora, yellow fever, or typhoid fever, has been 

 thrown into the receptacles. 



In the Manual for the Medical Department of the United States 

 Army the following directions are given : 



92. When accumulations of organic material undergoing- decomposition 

 cannot be removed or buried, they may be treated with an antiseptic solu- 

 tion, or with freshly burned quicklime. Quicklime is also a valuable disin- 

 fectant, and may be substituted for the more expensive chloride of lime for 

 disinfection of typhoid and cholera excreta, etc. For this purpose freshly 

 prepared milk of lime should be used, containing about one part, by weight, 

 of hydrate of lime, to eight of water. 



93. During the prevalence of an epidemic, or when there is reason to 

 believe that infectious material has been introduced from any source, latrines 

 and cesspools may be treated with milk of lime, in the proportion of five 

 parts to one hundred parts of the contents of the vault, and the daily addi- 

 tion of ten parts for one hundred parts of daily increment of faeces. 



According to Behring, lime has about the same germicidal value 

 as the other caustic alkalies, and destroys the cholera spirillum and 

 the bacillus of typhoid fever, of diphtheria, and of glanders after 

 several hours' exposure, in the proportion of fifty cubic centimetres 

 normal-lauge per litre. Wood ashes or lye of the same alkaline 

 strength may therefore be substituted for quicklime. 



Finally, it must not be forgotten that we have a ready means of 

 disinfecting excreta in the sick-room or its vicinity by the application 

 of heat. Exact experiments, made by the writer and others, show 

 that the thermal death-point of the following pathogenic bacteria, 

 and of the kinds of virus mentioned, is below 60 C. (140 F.) : 

 Spirillum of cholera, bacillus of anthrax, bacillus of typhoid fever, 

 bacillus of diphtheria, bacillus of glanders, diplococcus of pneu- 

 monia (Micrococcus Pasteuri), streptococcus of erysipelas, staphylo- 

 cocci of pus, micrococcus of gonorrhoea, vaccine virus, sheep-pox 

 virus, hydrophobia virus. Ten minutes' exposure to the tempera- 

 ture mentioned may be relied upon for the disinfection of material 

 containing any of these pathogenic organisms, except the anthrax 

 bacillus when in the stage of spore formation. The use, therefore, 

 of boiling water in the proportion of three or four parts to one 

 part of the material to be disinfected may be safely recommended 

 for such material. Or, better still, a ten-per-cent solution of sulphate 

 of iron or of chloride of zinc at the boiling-point may be used in the 

 same way (three parts to one). 



