297 

 OZONEJAT HAT. 



By J. EVANS SMITH, Eaq. 

 From March ith, 1863, to March 3rd, 1866. 



With respect to thia report and the tables I herewith lay before yon, I 

 will briefly st^te that, having kept a record of Ozone at Hay for rather more 

 than a year with Dr. Clarke's ozone cage, I thought it advisable to preserve 

 the results, by reducing them to order and depositing them in the archives of 

 our club, where they could be made use of whenever required. 



The chief results that I have derived from these observations are the 

 following 1 — 



That the least amount of ozone occurs with easterly winds, especially 

 from the northern side. "When a north-east wind prevails, there is often no 

 ozone for days together. 



The greatest amount of ozone occurs with westerly winds, especially 

 from the south-west, and during a tempest or stoim from the S.W. the 

 highest numbers are invariably recorded. So regularly do the above phenomena 

 occur, that I generally know the direction of the wind by examinirg the state 

 of the ozone paper that has been exposed for twelve hours previously. 



Unfortunately I did not keep a constant record of the direction of the 

 wind, but I can often supply the omission l^y other means, except during the 

 months of July and August, January and February. 



The winter and spring quarters show the greatest amount registered. 

 The autumn and summer show the least amount. Of the months January 

 shows the highest, September the lowest. 



With respect to the prevalence of illness, I have not sufficient facts to 

 lead me to any useful conclusions, but it should be observed that the absence 

 of ozone may produce a greater prevalence of disease, and yet the chief part 

 may be brought under the notice of the medical man when the period of 

 minimum ozone has passed away, and the papers may show an increased 

 amount. Hence it is very difficult to ascertain correctly the effect of ozone on 

 its absence on health. In epidemics I have observed that on a change of wind 

 to N. or N.W,, and an increased supply of ozone, the disease has diminished 

 in virulence, and if the state of the weather continues a long time the disease 

 dies out. 



