156 Mr H. Meikle's Refutation of Mr Ivory's New Law of 



The absurdity of the new lazv of condensation is therefore ren- 

 dered evident to demonstration ; and, indeed, if we reflect for a 

 moment on its illegitimate origin, we shall cease to wonder at its 

 untimely fate. 



The result clearly proves what I formerly stated, that it 

 is impossible, in the very nature of things, for the change of the 

 quantity of heat in air to follow the change of volume under a 

 constant pressure, if we admit the law of Boyle, and that the 

 specific heat of air under a constant pressure, has to its specific 

 heat under a constant volume an invariable ratio. So that, in 

 spite of all Mr Ivory's analytical skill, he has allowed his pre- 

 judices to run him into a most untenable delusion ; but having 

 virtually renounced his former tenets, it is not very obvious 

 what he can next embrace. 



Postscript. — It will be found on examining Mr Ivory's pa- 

 pers in Phil. Mag. for February and March last, which treat 

 expressly on his new law, that no intelligible reason is given 

 for such a radical reform. This excited in me, and proba- 

 bly in many others, no small degree of surprise. For every one 

 would have naturally expected, that a most satisfactory reason 

 for the change should have prefaced his first paper ; and since 

 his article on Sound, in the Number for April, did not profess 

 to treat of the new law, but is styled an " application" of it, I 

 never thought of searching there for what ought to have ap- 

 peared so long before, and was foreign to the title. But since 

 my paper on Mr Ivory's articles was sent away, I happened to 

 look into his article on sound, and found a very brief and ob- 

 scure hint that something of his in Phil. Mag. for June 1825 

 was liable to objection. At first, I thought it should be June 

 1824, but afterwards saw that it must mean July 1825, and 

 then perceived that such was all the explanation or admission of 

 incorrectness we were to expect on this mysterious transaction. 

 But this, after all, was an admission of error in a point where 

 he was most correct ; and therefore really worse than no ad- 

 mission. Before, however, making this tardy and useless con- 

 fession, our author tries to have MM. Laplace and Poisson first 

 in the scrape, and prefers a charge against them, which, I have 

 no dcfubt, he will discover to.be without foundation, when once 



