as deduced by himself and Dr. Suerman. 



343 



The accordance is here sufficient to justify the conclusion 

 that the specific heats, as far at least as respects their relative 

 values, are not materially affected by substituting my formula 

 for that of Gay-Lussac employed by Suerman, We may 

 therefore place, for the purpose of comparison, his mean re- 

 sults in juxtaposition with those at which I have arrived. 



A glance at this table is sufficient to show that, (oxygen 

 being excepted) the numbers of Suerman and mine are almost 

 identical. His number indeed for carbonic acid is somewhat 

 less than mine, but the difference is quite within the limits of 

 the probable errors of observation in such experiments. And 

 here I may observe that M. Suerman has given an erroneous 

 statement of my results, for which, however, I am myself to 

 blame. During the meeting of the British Association for 

 the Advancement of Science in Dublin, I laid before the che- 

 mical section some experiments which I had just concluded, 

 in reference to the subject under consideration, a brief account 

 of which was published in the succeeding number of the re- 

 ports of the Association*. The numbers given there are set 

 down as the specific heats under equal weights, whereas the 

 division by the specific gravities having accidentally been 

 omitted, they were in reality the specific heats of equal vo- 

 lumes. 



M. Suerman was aware of this omission, and has applied 

 the necessary correction. The numbers, however, at which 

 he has thus arrived do not still correctly represent my ex- 

 periments, and for the following reason. The gases operated 

 upon by me having all contained some atmospherical air, a 

 correction, as has been already explained, had to be applied 

 to the specific heats obtained from my hygrometric expression. 

 Now the formula used for this purpose affected the correction 

 upon the supposition of the numbers to which it was applied 

 being the specific heats of equal weights, whereas they were 

 in point of fact the specific heats of equal volumes. This cir- 



[» See Lond. and Edinb. Phil. Mag., vol. vii. p. 385.] 



