t no 3 



which the air poflerTes for the moft 

 part of the year in a country, and 

 thus to determine the advantages 

 which would arrive to our coniti^ 

 tution, in fpending our lives in one 

 country rather than in another, on 

 purpofe to preferve a good ftate of 

 health, to cure particular difeafes 

 which require a pure air, or to pro- 

 tract our exiftence in this world in 

 particular bodily difpoiitions. We 

 muft as yet content ourfelves with 

 the amufement of the experiment* 



The continual changes which I 

 obferved in the atmofphere daily , 

 by trying its conftitution, convinced 

 me of the too precipitate judgment 

 of fome philofophers, who, though 

 furnifhed with but indifferent in- 

 rtruments, have begun already to 

 aflert the degree of goodnefs of 

 certain places, by one or two obfer- 



vations 



