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THE POPULAR SCIENCE MONTHLY 



from particles of the burning element flying around the room, and, 

 settling on articles of copper and iron, covering them with a sulphur- 

 ous coating. 



" The process of using liquid anhydrous sulphurous acid in siphons 

 is free from these inconveniences. The siphons contain 750 grammes 

 of the acid, and one of them is efficient for the disinfection of twenty 

 cubic metres of space. In using the siphons a vessel is set in the mid- 

 dle of the room, and is put in communication with the outside by 

 means of an India-rubber tube passing through a hole in the door. 

 The door having been closed, the orifice of the siphon is inserted into 

 the India-rubber tube, and, the liquid being let in through it, is freely 

 evaporated in the air of the room. This process is very convenient ; 

 it avoids the danger of fire, and does not affect metallic objects ; and 

 the penetrative force of sulphurous acid thus administered appears to 

 be greater than that of the acid obtained by bui-ning sulphur. The 

 only drawback to its use is the high cost. The siphons are sold to 

 the general public for a dollar each, but can be bought in large quan- 



Fig. 2. M. Ckiandi Bet's Burner fob Bisulphide of Carbon. 



tities for half that price. Thus the expense of disinfecting a room of 

 one hundred cubic metres with this preparation would be from two 

 and a half to five dollars." 



The process of the combustion of bisulphide of carbon was sug- 



