DISINFECTION, STERILIZATION AND ANTISEPSIS. 253 



A great many methods have been devised for using formalin 

 for room disinfection in the form of vapor. These vary all 

 the way from simply hanging up sheets wet with formalin to 

 more or less elaborate lamps for burning methyl alcohol and 

 converting it into formaldehyde. The two most important con- 

 ditions to fulfill in the use of formaldehyde as a gas are tempera- 

 ture and moisture. The room to be disinfected should be 

 warmed and the air saturated with moisture. 



Hill* finds an explanation of the discrepancy in results 

 obtained by different observers in the condition of the bacteria 

 as to dryness or moisture, and concludes that for practical dis- 

 infection the destruction of bacteria thrown off from the patient 

 in any way for some time before the disinfection of the premises 

 should be aimed at. 



Sanitary Construction Company's Lamp. — This lamp consists 

 of a tank to hold the formaldehyde solution, and a spiral tube 

 by which the solution is slowly conducted through a flame and 

 vaporized. The necessary amount of solution is placed in the 

 tank and the apparatus started, outside the room, the gas being 

 conducted through the keyhole by a suitable tube. 



Schering Lamp. — In this form of lamp formaldehyde is 

 generated by the decomposition of paraform or paraformalde- 

 hyde, a polymeric modification of formaldehyde, occurring as 

 a white salt. It is decomposed by heat, giving off formaldehyde 

 gas. It is placed on the market in the form of tablets, each 

 one of which yields a definite amount of gas. The lamp con- 

 sists of a small iron tray for the reception of tablets, and so 

 arranged above the heating apparatus that sufficient draught 



*Journ. Infectious Diseases. Supplement 2. Feb., igo6., p. 210. 



Other references to formaldehyde in disinfection are: 



Ravenel. Report of the American Public Health Association. Vol. XXVIII. , 



^Hill,' Eben. Vol. XXIX., p. 208. 



Rosenau. Disinfection and Disinfectants. Pub. Health and Mar. Hosp. 

 Ser. 



Evans. Journ. Injec. Diseases. Sup. No. 3, May, 1907. 



Herzog. Centralblatt f. Bakteriologie, etc. Orig. XXXIV., 2, 1903. 



