1868.] SMALLWOOD — ON OZONE. 385 



dryness oi the atmosphere for July was .709, and for August, 

 .714 — taking saluration as 1.000 — with which number at 9 P.M. 

 on the 11th of August, the thermometer even stood at 76°. There 

 was a haze in the atmosphere, which led to the supposition of fires 

 in the woods being the cause ; the weather was calm, and the wind 

 north-westerly, but very light. There was a great thunderstorm 

 at Isle Jesus on the 6th of September, from 6 to 8 P.M., and a 

 slight frost occurred on the morning of the 11th, and snow fell at 

 Quebec on the 21st. The ozonometer, soon after these meteoro- 

 logical events, indicated its usual amount. On the other hand, 

 influenza and pulmonary diseases, when prevalent, are accompanied 

 by a high amount of Ozone, while all gastric diseases, diarrhoea 

 and its allies are accompanied by a decrease in the average amount. 

 The air coming from the sea shows a high amount of Ozone, and 

 it is presumed that, it is this property that makes the sea-breeze 

 so beneficial to health. It is a direct stimulant to animal and 

 vegetable life, and it must be borne in mind, that a 2000th part 

 of Ozone in the atmosphere would make it fatal to small animals, 

 and a little more than this would be fatal to man in an atmos- 

 phere which gives the maximum number 10 in the ozonoscope or 

 ozonometer; Ozone only exists iu the proportion of 1 to 10,000 

 parts of atmospheric air. When considering the source of Ozone 

 it would seem reasonable to suppose that there should be but 

 little of this agent manifested in the atmospheres of large and 

 crowded cities ; repeated experiments have proved this to be the 

 case. In such cities there is always a large consumption of Ozone 

 going on ; on the contrary, in the pure air of the country, and at 

 the sea-side, Ozone is generally abundant, and the consumption is 

 manifestly less. There is, indeed, a marked difference between the 

 amount observed at my own residence, which is not in a crowded 

 part of the city, and at the observatory in McGill College 

 grounds. Ozonometers placed in the wards and halls of hospitals 

 give no trace of Ozone, while at the exterior of these buildings a 

 reasonable amount is indicated, shewing that the atmosphere of 

 a city, where large numbers are dwelling together, tells largely 

 on the consumption of this peculiar body, and it must be self- 

 evident that any thing tending to its conservation, such as good 

 and efficient drainage, free currents of air and plenty of ventil- 

 ation, will directly contribute to the health of cities ; and the 

 removing of the causes of its consumption, if not destruction, is 

 the paramount duty of every citizen ; and it is thus to the interest of 



