Recent Progress in Sanitary Science. 275 



affections which present themselves. MM. Houzeau and 

 Leudet, jr., have shown that there is no agreement between 

 the prevalence of respiratory affections at Rouen, and the 

 depth of ozonic reaction as presented by true ozone tests. 

 These diseases are most numerous during the winter, when 

 the amount of ozone, as distinguished from the other air 

 purifiers, would seem from the researches of the former gen- 

 tleman to be comparatively small. Mr. Harris,, of Worthing, 

 has always remarked during the prevalence of N. E. and E. 

 winds, when no ozone is present in the air, the great fre- 

 quency of irritative affections of the mucous membrane of 

 the throat and air passages. The results arrived at by M. 

 Behard, of Havre, are : 



"1. That the number of cases of pulmonary disease is 

 probably in direct relation with the amount of ozone in the 

 air, and in inverse relation with the temperature : and, 2. 

 That atmospheric ozone appears to exert a certain influence 

 on rheumatismal affections." Dr. Clemens, of Frankfort, 

 states "that eleven saddle-horses contracted inflammation of 

 the lungs in consequence of being run against a south wind, 

 very powerful and very rich in ozone, and that the greater 

 number died." 



A similar wide difference of opinion exists concerning the 

 connection between the prevalence of ozone and malaria, 

 various descriptions of fever, and other diseases ; and it is 

 difficult to see how these discrepancies will be reconciled, 

 except by systematic observations carried on by a number of 

 competent observers. In this respect a great deal is being 

 done in Great Britain and on the Continent. In the United 

 States, isolated inquirers have pursued researches, some 

 account of which, from time to time, has appeared in our 

 scientific literature. The contradictory results hitherto ob- 

 tained, however, have discouraged many who need the stimu- 

 lus of united effort, and the certainty that their observations 

 will be carefully preserved and collated, to continue this 

 very valuable work. 



