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fpeculative, it may be anfwered, that no one fcience 15 

 io little connected with the reft as not to afford many 

 principles whofe ufe may extend conliderably beyond 

 the fcience to which they primarily belong, and that no 

 proportion is fo purely theoretical as to be totally inca- 

 pable of being applied to praftical purpofes. There is 

 no apparent connedtion between duration and the cycloi- 

 dal arch, the properties of which duly attended to 

 have furnifhed us with our beft regulated methods of 

 meafuring time : and he who has made himfelf mafter 

 of the nature and affe6llons of the logarithmic curve, is 

 not aware that he has advanced conliderably towards 

 afcertaining the proportionable denfity of the air at its 

 various diftances from the furface of the earth. The 

 refearches of the mathematician are the only fure ground 

 on which we can reafon from experiments ; and how far 

 experimental fcience may aflift the commercial interefts 

 of a ftate, is clearly evinced by the fuccefs of thofe fe- 

 veral manufactures in the neighbouring countries of 

 England and France, where the hand of the artificer 

 has taken its diredion from the philofopher. Every 

 manufacture is in reality but a chemical procefs, and 

 the machinery requifite for carrying it on but the right 

 application of certain propofitions in rational mechanics. 

 If chemiftry and natural hiftory then have never yet 

 employed themfelves in enquiring into the ftate of this 

 country, if its minerals have never yet been explored, 



nor 



