DESTRUCTION OF BACTERIA. 25 



It is a surface disinfectant having very little pene- 

 trating power, and is not as reliable as it was once 

 thought to be. It is liable to corrode fabrics and 

 destroy colors. It tarnishes metals and leaves a dis- 

 agreeable odor for some time after it is used. 



Formaldehyde gas is made in a variety of ways. 

 For use in hospitals and by boards of health an auto- 

 clave is used, which generates the gas under pressure. 

 After the room has been sealed to prevent the gas 

 from escaping, the gas from the autoclave is forced 

 into the room through the keyhole of the door. A 

 much simpler way that is practical for home disin- 

 fection is the burning of paraform candles in the pres- 

 ence of moisture. The disinfectant action is strongest 

 when the temperature of the room, is between 90 and 

 100 F. The gas is a surface disinfectant; conse- 

 quently, articles to be disinfected should be hung up 

 or so arranged as to allow the free circulation of the 

 gas about them. It is the most efficient disinfectant 

 known when properly used, and is also a deodorant. 

 It has no harmful action on clothing or other house- 

 hold goods. The vapor is very irritating to the eyes 

 and upper air-passages. Although the gas is very 

 destructive to bacteria and their spores, it will not 

 kill vermin. 



In disinfecting during or after illness of con- 

 tagious or infectious nature, it is necessary to render 

 all discharges, excreta, and so on, non-infectious and, 

 at the conclusion of the illness, to render the apart- 

 ment in which the patient has been sick safe for others 



