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ent, especially of carbonic acid, much of its chemical efficacy 

 depends. In larger quantities lime has been much employed 

 in correcting the disagreeable smell from cesspools. 



Charcoal, too, is not destitute of virtue, and formed pro- 

 bably the base of Salomon's powder noir animalise, as of 

 the pastilles and water filters much used some years ago. 



The preference over other disinfectants I have always 

 given to chlorine has hitherto been undisturbed, although 

 it has been my practice to make trials from time to time 

 of newly recommended agents. Its ordinary evolution in 

 the aeriform state, and its marked affinity for one of the 

 elements of the most common and the most offensive of 

 septic gases, and its applicability in the form of Labarr- 

 hague's liquid within the chambers of the sick, in my mind 

 give it a pre-eminence over all its rivals. Although sul- 

 phuretted hydrogen, hydrosulphate of ammonia, carburetted 

 hydrogen, and carbonic acid, be not really the matter of 

 infection, these gases in towns are its frequent associates, 

 and chlorine readily decomposes the three first, and, when 

 combined as in this fluid with lime, is replaced by the last. 

 Daily experience attests its efficacy in promptly correcting 

 the stench of infected apartments, ami its value in remedying 

 the nuisance of bad odours in water-closets is familiar to you 

 all. When properly used, it does not permanently leave its 

 own peculiar smell for the original one which it removes. 

 It does not act on the principle of a substitute disguising 

 the first smell, but chemically to annihilate it. And the 

 objection sometimes raised as to its employment in the 

 wards of the sick is not valid ; for except in some cases of 

 disease affecting the respiratory organs, in which, as a dis_ 

 infectant, it is less required, chlorine may, when suitably 

 diluted, in all other instances be harmlessly inhaled. It is 

 respirable in the preparation of bleaching powder, I under- 

 stand, when present in the proportion of about 7 per cent., 



