1868.] SMALLWOOD — ON OZONE. 383 



Ozone, the bad odour is destroyed as long as the ozonometer 

 gives evidence of the presence of Ozone, but as soon as the 

 ozonometer ceases its indications, the odour immediately returns. 

 Schonbien's experiments proved that air containing one-6000th part 

 of Ozone can disinfect 540 times its volume of air from putrid 

 meat. Apartments are now being purified by means of Ozone ; 

 and during the visitation of cholera, last summer, in Lon- 

 don, Ozone was extensively used as a disinfectant. Pieces 

 of phosphorus were also suspended over the gratings of the 

 sewers, so as to generate Ozone and neutralize the spread of the 

 choleraic-contagion. It is here necessary to remark that the 

 phosphorus must be luminous to produce Ozone, and the height 

 of the barometer and the degree of temperature must be taken 

 into account ; even the direction of the wind has some influence on 

 its development. 



It is a matter of history that, in 1854, cholera visited many 

 cities of the old world and of the new. It has been asserted, and 

 that by numerous observers, that during this visitation, there 

 was always indicated a deficiency of Ozone in the air ; and fur- 

 ther, that the increase or decrease of cholera coincided strictly 

 with the development or absence of this mysterious substance. 



Below is a table shewing for seven years the comparative day 

 of precipitation (rain or snow) each year, and the amount of Ozone 

 indicated, in quantity more than five-tenths of the scale. 



1850 there were 106 days of precipitation and 110 days of ozone in more than uf 



1851 do. 123 do. 136 do. 



Shewing the comparatively small amount of ozone in the year 

 1854, the year this cholera was prevalent. 



A commission of the members of the Medical Society of Stras- 

 burgh, during the visitation of cholera" in 1854, was named for 

 testing the subject, and their united report was: — That during 

 the days that Ozone was deficient in the atmosphere, cholera was 

 at its greatest rate of mortality. From observations taken at 

 Isle Jesus observatory and carefully compared with the death 

 rates in Montreal, and the country parts visited by the epidemic 

 in 1854, this opinion was certainly confirmed. At Newcastle, in 

 England, during the prevalence of cholera, in 1854, Ozone was at 

 its minimum ; in London, in the same year, from the 24th of 

 August until the 11th of September, Ozone was only present 



