DISINFECTION B Y GASES 55 



of heat to an aqueous solution of the gas (formalin) 

 or by the oxidation of wood alcohol. 



In making practical use of this agent a suitable 

 apparatus will be required. For the disinfection of a 

 room with its contents, freely exposed for surface 

 disinfection, one pound of formalin should be volatil- 

 ised for each thousand cubic feet of air-space the 

 time of exposure to the disinfecting action of the gas 

 being not less than twelve hours. In the absence of 

 any apparatus satisfactory results have been obtained 

 by the Department of Health of the city of Chicago, 

 as follows : 



" Ordinary bed sheets were employed to secure an adequate 

 evaporatory surface, and these, suspended in the room, were 

 simply sprayed with a forty per cent, solution of formalin through 

 a common watering-pot rose-head. A sheet of the usual size 

 and quality will carry from one hundred and fifty to one hundred 

 and eighty cc. of the solution without dripping, and this quantity 

 has been found sufficient for the disinfection of one thousand 

 cubic feet of space. Of course, the sheets may be modified to 

 any necessary number. . . . Surface disinfection was thorough, 

 while a much greater degree of penetration was shown than that 

 secured by any other method." 



Formalin may also be used in the disinfection of 

 rooms and their contents by spraying all exposed 

 surfaces. 



Experiments made by Kinyoun and others show 

 that formaldehyd gas does not injure the colour or 

 textile strength of fabrics of wool, silk, cotton or linen 



