228 THE CANADIAN NATURALIST. [June 



Thus nitrous oxide from saltpetre or nitric acid — chloric acid 

 from chlorate of potash — chlorine from hypo-chlorite of lime- 

 Ozone from permanganate of potash — (Condy's fluid.) 



These are true disinfectants — that is, removers of smell, de- 

 odorizers, and destroyers of decaying matter, but not antiseptics, 

 that is preservers of organic substances. 



De-oxidizers have a similar ofiice, and sulphur fumigation is 

 one of the most ancient forms of purification. In Cowper's 

 translation of Homer's Odyssey, book xxii., line 492, we have : — 



" Bright blast-averting sulphur, nurse, bring fire ! 

 That I may fumigate my walls ; then bid 

 Penelope with her attendants down. 

 And summon all the women of her train. 

 But Euryclea thus his nurse replied. 

 My sou! thou hast well said; yet will I first 



^ :i; :f: :^< ^ 



Not SO. Bring fire for fumigation first. 

 He said : Nor Euryclea, his loved nurse. 

 Longer delayed, but sulphur brought, and fire. 

 While he, with purifying streams, himself 

 Visited every part, the banquet room. 

 The vestibule, the court." 



Grlauber, in 1689, part 3, p. 2, says: — "Whoever shall 

 attempt to describe sulphur in a most accurate manner, will have 

 need of abundance of paper. But he that knows nothing of 

 sulphur, knows nothing at all.'' 



The gas (sulphurous acid gas) is very valuable in arresting- 

 fermentation and cryptoganic growth. It de-odorizes putrid 

 matter, while it disinfects. Chlorine may act either as an 

 oxidizing agent. It destroys putrid smells as if by magic, and 

 thoroughly destroys animal matter. 



Heat and cold are nature's own disinfectants, acting by des- 

 sication and condensation. The tar acids ai*e among the most 

 valuable disinfectants, chiefly because they retain their power 

 under circumstances of extreme dilution. The available forms 

 of these compounds — viz., carbonic acid and carbonate of lime — 

 are highly recommended as antiseptics as well as disinfectants. 

 But the subject of comparative values of these disinfectants we 

 will reserve for a subsequent notice, as our space is exhausted. 



J. B. E. 



(To be continued.) 



