457 



the measures recommended for adoption to meet the evil 

 are, speaking generally, such as are comprehended in a 

 well devised national scheme of sanitary improvement. But 

 to particularize, more especially in reference to the imme- 

 diate subject before us, I shall confine my remaining ob- 

 servations to a brief review of the popular means which 

 from time to time have been suggested to clear the air and 

 other bodies of stench, putrid emanations, the matter of 

 contagion, and the like supposed agents or vehicles of in- 

 fection. 



The means resorted to may be comprised under six sec- 

 tions, viz. first, the prompt removal of all surrounding 

 impurities, refuse, and other sources of obvious pollution ; 

 secondly, correction, by thorough ventilation, within and 

 without infected localities ; thirdly, by the admixture of 

 certain gaseous fluids with the tainted atmosphere when 

 confined to limited spaces ; fourthly, by the aid of sundry 

 chemical agents possessed of exhalent or absorbent pro- 

 perties, by the action of which affinities are brought into 

 force capable of divesting the air or other matters of their 

 offensive odour and noxious qualities ; fifthly, by the addition 

 of antiseptics to decomposing materials ; and sixthly, by 

 washing, cleansing, and otherwise purifying by exposure to 

 the sun's rays and atmospheric dilution. 



On the two first and last of these divisions, though by 

 far the most important, and those upon which, par excellence^ 

 all other measures should be based, I must forbear to enter 

 as somewhat foreign to my present object, and lest I should 

 be tempted to inflict upon your patience a very long paper 

 on the sanitary question. In limine, however, I would 

 observe, that I do not propose to consider disinfecting gases 

 and deodorizing fluids as in substitution of, but as sub- 

 sidiary to, sanitary measures generally. Their application 

 is necessarily limited, for no prevailing pestilential constitu- 

 tion of the general atmosphere of a district can be materially 



