^ Mr Sankey on the action of Caloric 



Thus knowing the modulus, and obtaining by observation a, 

 'S', ^, g, we can find Q for the same temperature that gives g in 

 the other body. In this way we may verify the calculations by 

 experiment. 



We may also observe, that, if this view be correct, we shall 

 arrive at the same value for m from the comparison of the 

 cubes of any two solid bodies in respect to their specific gra- 

 vity and expansion, since the modulus of gravity must be con- 

 stant. Therefore, finding the law of expansion for given tem- 

 peratures in any one solid, we can calculate the law for all 

 other solids. 



Further, we have seen above, that a = jY(P-f T) — T, and 

 also that a = n {p-{-t)--t .\ N(P -^ T)'—T=n(p + t)^t; there- 



1 J 1 1 



gS ^~S ;S^ gS 



fore, putting for N, w their values — — - *— 7— ' — 1 1 — j— T 



m^P TTT p m^ m^ P 



— T~ 4- ?-_^—/, or multiplying by m*,'S'i+^ T—m^T 



= 2^ -j t — m^ t. We have seen also that t=:.a -, there- 



P m^ 



— 1 



1 J I 



5 7H^ f) CI ^— 2^D 



fore, putting for n its value ^— , t = — ^ ^-^ which, 



m^p 2^ — m^p^ 



taking t as general for the distance between the particles, and p 

 as general for the diameter of the minute particles, &c. will 

 give us a general formula for the distance between the minute 

 particles, in terms of the side of the square of the cube, the 

 weight of the given body, the modulus of gravity, and the 

 diameter of the minute particles. Applying it, however, in 

 the present instance to the comparison of two solids, we find 



that, as t = '»\P--^"P. so T= "'^P--sip ^^^^^^ 



25 — jn5 p ^3 — ^sp 



then, as the elastic force of caloric may be considered as 

 equal in all solids at the same temperature, therefore it is pro- 



