352 Mr. Emmett on the [Nov. 



chemical action demonstrate that caloric is attracted by, and 

 enters into union or combination with, the ultimate particles of 

 matter. Let concentrated sulphuric acid be dropped into a satu- 

 rated solution of ammonia in water, intense heat, accompanied 

 with an explosive ebullition, immediately succeeds, and solid 

 matter is produced. Let now a solution of the carbonate of 

 ammonia, containing: the same proportion of the alkali, be em- 

 ployed ; the heat will be less intense, and a large quantity of 

 elastic matter will be liberated. In these experiments, since the 

 materials employed were originally cold, the heat which is libe- 

 rated must previously have existed in them ; and since its pre- 

 sence was not indicated by the thermometer, its action, when in 

 the materials before mixture, must have been suspended as much 

 as that of the sulphuric acid is when it exists in combination 

 with lime ; and we know of no power or force capable of produc- 

 ing such an effect, except that which is called attraction ; and 

 besides in the latter experiment we have an example of the heat 

 passing from one state of combination to another without ever 

 being so far free and disengaged from the operation of this cen- 

 tripetal force as to affect the thermometer. Caloric is, therefore, 

 attracted by the ultimate atoms of ponderable matter ; were fur- 

 ther proof wanting, its refrangibility would be sufficient. 



Prop. 6. — If a mass or particle of matter be placed in a 

 medium of uniformly diffused caloric, it will be surrounded by 

 an atmosphere of heat, of which the density will be reciprocally 

 as some power of the distance. 



Let D H M (PI. CIX) fig. 1, be a sphere, or particle of matter, 

 placed in a medium of uniformly diffused caloric, of which the 

 density is represented by the line A a, through a draw the fine 

 a g, parallel to the radius produced, S A, and let S A be the 

 greatest distance at which the caloric is attracted by the sphere ; 

 divide the distance D A into innumerable equal evanescent por- 

 tions A B, B C, See. the stratum A B tends towards S, by reason 

 of its own gravitation only, with this force then it compresses all 

 the inferior strata ; the density of the next stratum, B C, is, there- 

 fore, increased, and may be represented by B c, which tends 

 towards the centre S, by its own gravitation; in hke manner the 

 next stratum sustains the pressure of these two, and also tends 

 towards S ; its density is C d ; let now the number of strata be 

 increased, and the altitude of each be reduced indefinitely ; then 

 since A o,B c, C d, &c. represent the densities at their respect- 

 ive distances, the ordinates of the curve that passes through the 

 innumerable points, a, c, d, Sec. will represent the density of the 

 calorific atmosphere at the distances represented by their 

 abscissas ; and since the centripetal force is equal at all equal 

 distances from s, and the surrounding caloric has uniform density, 

 the density of the several spherical strata will be uniform, and 

 that of the inferior, greater than that of the superior strata. 

 Cor. 1 . — Hence the elastic or repulsive force of this atmosphere 



