Sil8 Mr. Meikle's Reply to Mr. Ivory. 



temperature, to have its volume instantly enlarged or restored 

 to what it was at first. Then it is manifest that, if the quan- 

 tity of heat in the air have all the vv^hile undergone no change, 

 such air will just be restored to the first temperature, t. An 

 expression for the diminution of temperature caused by this 

 enlargement of volume, may obviously be obtained with the 

 same values of the symbols, by making p' and p to change 

 places in the above general formula, and likewise using, in it, 



the augmented, temperature t + — M48 + t\ x ^-^ in 



place of r. By this means we obtain, for the fall of tempe- 

 rature due to restoring the original bulk, 



£ [448 + . + 4(4*8 + .)x^']xt^^ 

 "which, with its sign changed, must just equal 



(448 + r\ xtzl 



the rise of temperature due to the previous condensation. 

 From the equation so formed, we obtain, by reduction, /> = §'; 

 that is, there has been no change of density, which is absurd, 

 because directly contrary to the main supposition with which 

 we set out. 



Hence, because / and p are any densities, and t any tempe- 

 rature, the universal inconsistency of the rule is manifest. It 

 cannot, therefore, be the law of nature, even within a limited 

 range. Indeed, human genius could scarcely have devised a 

 rule which would set reason and experience more completely 

 at defiance. Thus, in place of compression causing an inde- 

 finite rise of temperature, the rise is confined under a ridicu- 

 lously-contracted range ; while, instead of an impassable limit 

 of cold (which is inseparable from the scale Mr. Ivory defends), 

 we have one which is bottomless and unfathomable ! 



Whether, then, shall we adopt a rule which is full of extra- 

 vagant inconsistency, and palpably at variance with the facts 

 best known, merely to accommodate Mr. Ivory, because he 

 has run himself into a labyrinth from which he is unable and 

 even loth to come out, or shall we venture on the more 

 rational alternative of adopting the formula 



