210 Mr. Herapath on True Temperature, and the [Sppt. 



as referred to equality of weight. In this sense aeriform bodies 

 have generally a much greater influence on temperatures than 

 solids and fluids. For instance, if a given weight of any body 

 be immersed in a given weight of any gas or air at a given differ- 

 ence of temperature, the effect on the temperature of the body 

 will be much greater than if an equal weight of any solid or fluid 

 with the same difference of temperature had been mixed with 

 the body, taking for granted, in both cases, that no chemical 

 action interferes. The reason of this will appear in the course of 

 our subsequent inquiries. In the mean time, however, it may 

 be anticipated, that even with aeriform and solid or fluid bodies, 

 there is no reason for believing it a universal, though it be a 

 pretty general rule, that the number of particles in a given weight 

 of air shall exceed the number of particles in an equal weight of 

 the solid or fluid from which it is derived. Thus in all those 

 bodies which explode with an increase of temperature, if there 

 be no solid or fluid residuum, 1 have no doubt experiment would 

 prove that what is called the capacity is less in the air than in an 

 equal weight of the solid or fluid. We shall, however, as we 

 proceed, have to develop our reasons for this more fully. 



We are now prepared, by the help of the principles here 

 developed and those given in my last paper, to carry our inquiries 

 to a much more interesting and extended length ; for as the 

 numeratoms of gaseous bodies may be determined by ascertain- 

 ing their " capacity," and since the ratio of these numeratoms 

 may also be found by our theory, p. 403 of the last volume of the 

 Annals, on the supposition of the homogeneity of the gases from, 

 their specific gravities, we can, by comparing these ratios, ascer- 

 tain the relative purity or impurity, or rather the relative homo- 

 geneity or unhomogeneity of the gases. And if we again 

 compare these numeratoms of the constituent gases with the 

 .numeratoms of the body they compose in the vapourous, fluid, 

 and solid states, determined in the manner hereafter described, 

 we may penetrate into the inmost recesses and operations of 

 nature ; we may unfold to the view the relative proportions of 

 the elementary parts to form a particle of the solid, and likewise 

 a particle of the fluid and vapour ; and again, by comparing 

 those with the like things of the same elements of another body, 

 and with other phenomena of the two bodies, as their relative 

 degrees of compactness, affinity, chemical effects, &c. it does 

 not seem impossible even to ascertain the very figures of the 

 constituent particles and atoms. Of such extensive and recon- 

 dite inquiries, however, philosophers will hardly expect of me in 

 the present instance any thing more than the hint. From those 

 who are better qualified for speculations of this kind, the world 

 asaay hereafter derive investigations suitable to the utility and 

 importance of the subject, and supported by all the evidence 

 and rigour of mathematical demonstration. 



Before I quit this part of the subject, it is necessary just to 



