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XIV. On the Specific Heat of the Gases. By W. T. HAYCRA FT, 



ESQ. 



(Read November 3. 1823J 



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 THE experiments which I now submit to the Royal Society are 

 repetitions of those I made- many months ago, for the purpose of 

 ascertaining the Specific Heats of the Gases. The importance of 

 the subject so impressed my mind, that I determined to spare 

 no pains in the prosecution of the inquiry, and therefore I will- 

 ingly withheld my first experiments from the public eye, until, 

 by a fresh series, I might present them with the greater confi- 

 dence. The apparatus employed in these experiments was cal- 

 culated to operate upon greater quantities of the Gases than the 

 former one, and as every precaution which had been suggested 

 was adopted, they have, perhaps, given even more decisive re- 

 sults than the last. The results themselves, however, are in 

 every important particular exactly the same. It is also but jus- 

 tice to myself to state, that the conclusions which the former ex- 

 periments led to, were exactly the reverse of what I had antici- 

 pated, and that they seemed at the time totally opposed to the 

 doctrines of BLACK and CRAWFORD, which I am still disposed to 

 credit to a limited degree. 



j i j 



Before I enter into the detail, it will be necessary to take no- 

 tice of the modes in which former experimenters have proceeded 

 in these inquiries, and to point out what I conceive to have been 

 the sources of fallacy in some of their conclusions. Of all these 

 modes, none were more elegant than that adopted by Professor 

 LESLIE ; but as he himself states, that their results were discor- 

 dant with each other, it seems unnecessary to enter into a de- 



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