On Ihff Theory of Mixed Gases. 4U 



•* roborate mine, that his numbers are much 

 ** too large for air ot SO inches pressure. If 

 " you will examine the ditlerences of his 

 " numbers above and below 90% you will 

 ** find something wonderful in the quick tran- 

 " sition from 12,12, &c. to 115, 1 16, See; this 

 *' being the temperature at which, I calculate 

 ** he has changed his air from 15 to 7 or 8 

 " inches pressure." 



The objections contained in the foregoiijig 

 quotation, afej of a critical nature ; and a, 

 proper reply to them requires a mode of ex» 

 pression, to which I recur with reluctance : but 

 in controversy, the plain language of inquiry 

 will always supersede the punctilious style of 

 good breeding. I allow then a theory to be a 

 good one, which will , tell in all cases how a 

 man makes his experiments ; at the same time 

 it is equally certain, that if a theory invaria- 

 bly mislead the judgment in this particular, its 

 information is no proof of its correctness, la 

 order to rescue his hypothesis from the latter 

 imputation, my friend informs us he has found 

 by calculation, that Mr. Schmidt, in his ex- 

 periments upon air saturated with moisture, 

 changed the pressure of his apparatus, at 90 

 degrees of temperature, from 15 to 7 or 8 

 inches of Mercury. Now is not this begging 

 the question ? The procedure undoubtedly 

 3f 



