1 68 



Sterilization and Disinfection 



market. The original method of disinfection consisted of 

 the evolution of the gas from methyl alcohol by volatilizing 

 it in a steam apparatus, and passing the vapor over a heated 

 metal plate. At present many efficient forms of apparatus 

 are upon the market. 



The gas has enormous bactericidal powers, is not injurious 

 to man, and has no destructive effect upon furnishings. 



It is not always necessary to use a special apparatus in 

 order to disinfect with formaldehyd ; one can, in an emer- 

 gency, hang up a number of sheets saturated with the 40 per 

 cent, formaldehyd solution in the room to be disinfected. 



The number of sheets must vary 

 with the size of the room, as each is 

 able to evolve but a certain amount 

 of the gas, and the quantity neces- 

 sary for disinfection varies with 

 the size of the room. Care must 

 also be exercised that the hands 

 do not become wet with the con- 

 centrated formaldehyd solution, as 

 it hardens the skin and deadens 

 sensation. 



The "formalin," or 40 per cent, 

 solution of the gas, when fresh and 

 tightly corked, is fatal to most bac- 

 teria in dilutions of from i : 5000 to 

 i : 25,000. It can be employed 

 with advantage to spray the walls 

 and floors of rooms from a large 

 atomizer, though Rosenau* finds 

 that unless the spray discharged by 

 the atomizer be very fine its action 

 is uncertain. It cannot be em- 

 ployed upon the skin or mucous 

 membranes, because of its marked irritating effect. 



To disinfect with formaldehyd or any gaseous disinfectant, 

 the room must be carefully closed, the cracks of the windows 

 and doors being sealed by pasting strips of paper over them. 

 A carefully selected apparatus is set in action, and the dis- 

 charged vapor, entering the room through the keyhole or 

 some other convenient aperture, is allowed to act undis- 

 turbed for some hours, after which the windows and doors 

 are all thrown open to fresh air and sunlight. 



* "Disinfection and Disinfectants," Philadelphia, 1902. 



31. Trenner's for- 

 maldehyd gas regenera- 

 tor. 



