PRACTICAL DISINFECTION OF ROOMS 359 



The disinfection of sewers and street-gullies is useless for 

 the same reason, and if bad gases are given off it is because 

 proper ventilation has not been provided, or because of the 

 stagnation of the sewage. These remarks do not apply to 

 the flushing of sewers, which is essential to their main- 

 tenance in proper condition. 



Practical Disinfection of Rooms. — It is utterly useless to 

 attempt the disinfection of the air of rooms, which seems 

 to be sought after by some, but the floor, walls, ceiling, 

 hangings, furniture, etc., should be dealt with. The steps 

 to be taken depend on whether the room may be stripped 

 of its paper or not. 



As by far the greater number of bacteria must be on the 

 floor, it is important to destroy them first, and not to 

 allow them to be stirred up into the air by the movement 

 of those engaged in the subsequent operations. To ensure 

 this, the floor and carpet should be liberally sprinkled with 

 sawdust mixed with 10 per cent, by weight of crude carbolic 

 acid (Calvert's No. 5), or with a solution of mercuric 

 chloride (about 1 in 1,000). 



A fire should then be lighted in the room, both to cause 

 the air in the room to leave it by the chimney, and to be 

 available for burning anything that is sufficiently valueless 

 to be destroyed. 



All hangings, bedding and clothes should then be removed 

 to a steam disinfector, and the walls and ceiling washed 

 down by means of a whitewashing brush and a solution of 

 mercuric chloride (1 in 2,000) or bleaching-powder (6 ounces 

 to the gallon) ; the furniture should be taken out of doors 

 and scrubbed. The wall-paper is stripped and burned 

 without being taken out of the room, and the carpet taken 

 up, and (if in the country) thoroughly sprayed with formic 

 aldehyde solution 5 per cent., or if in town sent to the 

 disinfector. 



