APPENDIX B. 251 



As Ft = when t = 0, B is 0; thus 



that is, the motive power produced would be found 

 to be exactly proportional to the fall of the caloric. 

 This is the analytical translation of what was 

 stated on page 98. 



NOTE F. M. Dalton believed that he had dis- 

 covered that the vapors of different liquids at equal 

 thermometric distances from the boiling-point 

 possess equal tensions; but this law is not pre- 

 cisely exact; it is only approximate. It is the 

 same with the law of the proportionality of the 

 latent heat of vapors with their densities (see Ex- 

 tracts from a Memoire of M. C. Despretz, Annales 

 de CMmie et de Physique, t. xvi. p. 105, and t. 

 xxiv. p. 323). Questions of this nature are closely 

 connected with those of the motive power of heat. 

 Quite recently MM. H. Davy and Faraday, after 

 having conducted a series of elegant experiments 

 on the liquefaction of gases by means of consider- 

 able pressure, have tried to observe the changes of 

 tension of these liquefied gases on account of slight 

 changes of temperature. They have in view the 

 application of the new liquids to the production 

 of motive power (see Annales de CMmie et de 

 Physique, January, 1824, p. 80). 



