O PROOFS THAT CALORIC IS 



3. That it modifies the forms, properties, and 

 conditions of all other bodies, in an endless 

 variety of ways : * 



4. That it passes by radiation through the 

 most perfect vacuum that can be formed by 

 means of the air pump, in which it produces the 

 same effects on the thermometer as in the atmos- 

 phere : 



5. That it exerts mechanical and chemical 

 forces which nothing can restrain, as in volcanos, 

 the explosion of gunpowder and other fulmina- 

 ting compounds : 



* It was first ascertained by Dr. Black, that on mixing a 

 pound of water at 172 F. with a pound of ice or snow at 32, 

 the latter was melted, when the temperature of the mixture stood 

 at 32 ; showing that 140 of caloric had been transferred to the 

 ice, and intimately combined with its particles. Since then it has 

 been found, as predicted by Black, that definite measures of 

 caloric are required to convert all other solids into the liquid and 

 gaseous states : that when a pound of steam at 212, is mixed 

 with 7 pounds of ice at 32, the latter is converted into water 

 of the same temperature; showing that 7 X 140, or 980 are 

 thus transferred from the steam to the ice, and employed in 

 melting it, without producing in it any elevation of tempera- 

 ture. This is what Black called the latent heat of water and 

 steam. It has also been discovered, that a cubic inch of water 

 at 212, is expanded to the dimensions of a cubic foot, or about 

 1720-fold on passing into the gaseous state, proving that 1719 

 parts by volume of steam at the same temperature, are occupied 

 by the caloric which surrounds its particles. The same fact is 

 still more remarkably illustrated in hydrogen gas, the volume of 

 which is nine times greater than that of the same weight of 

 steam, ceteris paribus : so that above 15,000 parts of the space 

 occupied by hydrogen, must be filled by that subtile form of 

 matter called heat. 



