— 308 — 



days. As the emanations from night soil contained in 

 the distillate I havQ, already described retained their 

 bad odour after being tortured by several chemical pro- 

 cesses, aTtd as this odour seems to be inseparably con- 

 nected with them, we have a perfect right to infer that 

 as all bad odour disappears when night-soil is mixed 

 with charcoal, these emanations cease to be evolved, 

 and all injurious action on the human system prevented ; 

 so that charcoal acts not merely as a deodoriser, but 

 also in the widest sense as a disinfectant. 



Experience in this island has sufficiently demons- 

 trated that powdered charcoal even when fully charged 

 with night soil, emits at most m^^re traces of a purely 

 ammoniacal odour, unaccompanied by the odour I have 

 described as characteristic of the distillate from night 

 soil ; and so little of ammonia is evolved that, as I have 

 ascertained by experience, a vessel containing a mix- 

 ture of several pounds of urine and foecal matter Avith 

 charcoal, may be kept in a chamber without rt ndering 

 the air of the chamber in the slightest degree offensive ; 

 and this, I may observe, is all that can be expected 

 or desired in a practical point of view, of any disin- 

 fectant. 



That the foetid emanation are completely decompos- 

 ed and destroyed is evidenced by the fact that the peat 

 charcoal, at present employed by Mr. Garbert retains 

 its disiafecling power after being dried in the open air, 

 and does not lose its power until after being repeatedly 

 saturated with night soil. The same charcoal has, as 

 Mr. Garb rt informs m'', been thus used ten or twelve 

 times, and, as I have myself seen, no offensive odour is 

 emitted during the process of drying even when the 

 mixed matter is brouht close to the nose. 



Not only does charcoal thus destroy the putrid ema- 

 nations, but it also possesses the power of preventing 

 and arresting putrefaction. " When we keep," says 

 Berzelius, " water mixed with powdered charcoal it 

 does not putrefy, or this occurs very rarely. For this 

 reason barrels previously well charred on the inside are 

 used at present with great advantage to preserve water 

 at sea. This happy discovery is due to BerthoUet. Here 

 the charcoal appears rather to present or arrest putre- 



