M Mr, lierapath on True Tem-perature, and the [Jan. 



ries into the atomic theory ; namely, that hydrogen, oxygen, 

 aqueous vapour, and in fact all pure gases, are very nearly, if 

 not accurately, homogeneous. Hence the theorem which I have 

 given, p. 454 of the last volume, for finding the baromerin of 

 homogoneous airs, is, as I suspected, very nearly, or, perhaps, 

 perfectly correct in all pure gases and vapours, whether they be 

 simple or compound. 



Ihis theorem for practice will be more convenient in this 



form "Tj V G ; in which G represents the specific gravity of the 



gas, that of hydrogen being unity, and the baromerin of water 

 iso unity. 



In an early part of the present paper, I had hinted my inten- 

 tion to undertake the refutations of the modern doctrines of 

 ** capacity and latent heat." This I have still in contempla- 

 tion to do ; but as the present communication has already been 

 extended to a very unusual length, it has appeared advisable to 

 defer the execution of this intention to a future period, and to 

 close the ))resent paper with a brief recapitulation of the things I 

 have in the course of the two papers developed and demonstrated, 

 w^ith the authority of the pha^nomena annexed. By this recapitu- 

 lation, I shall give a kind of index to the papers, and at the same 

 time afford philosophers an opportunity of seeing by a glance of 

 the eye the great variety of phsenomena I have succeeded in 

 developing; by ?vhich means they will be the better able to 

 judge of the merits of the theory 1 have embraced. I shall say 

 nothing of the theory of collision, because it relates to perfectly 

 hard bodies, and does not, therefore, properly speaking, come 

 under the class of ordinary phaeaiomena. 



ANNALS, VOL. I. {New Series.) 



Phenomena 



Developed. Covfinned by 



1. P. 343. — The elasticity of a given This is generally admitted, but I do 

 portion of gas is the same whatever be the not know that it has ever been made the 

 figure of the vessel in which it is contained, subject of direct experiment. 



pfrovide<l the capacity and temperature be 

 the same. 



2. P. 344. — Other things being alike. By Boyle in air. and in other gases by 

 Ae elasticity of any gas is directly as the others. 



compression, or reciprocally as the space. 



3. P. 345 — The elasticity is as the The law of Boyle united to the experi- 

 square of the temperature directly and sim- ments of De Luc and myself. 



pie of the space inversely. 



4. P. 346. — Elasticities being equal, De Luc and myself, 

 the spaces are as the squares of the temper- 

 atures. 



5. Ibid. — Equal changes of tempera- Dalton and Gay-Lussac. 

 ture equally affect equal volumes of all 



other tliing» being alike. 



