French National Institute. 28S 



vibrations of the particles of bodies, and not to a particular 

 »Mbstance, or to caloric, as admitted by several cheniists, 

 A very strong objection has been made to bini ; which is, 

 that bodies are heated when they are condensed, as if the 

 condensation pressed out the caloric conlained in them, and 

 which, no longer finding any room, manifests its departure by 

 its effects. Thus waier and alcohol, when mixed, lose a 

 fortieth part of their volume, and gain several degrees in the 

 thermometer. Pieces of money come out quite hot from 

 the die under which they are stamped. 



Count Runjford has answered these objections by experi- 

 ments which are not less certain, and in which condensation is 

 ;iccompanied with cold. Thus, some solutions of salts in 

 pure water lose both in volume and in heat. We know 

 well, that salts on dissolving often produce cold, and we 

 explain this phcenomcnon by the necessity of a solid sub^ 

 stance absorbing caloric when it becomes liquid : but this 

 explanation does nor appear applicable when a solution 

 already conipletely effected is simply diluted with a fresh 

 quantity of water. 



We know thai steam when confined is susceptible of ac- 

 quiring a heat far superior to that of boiling water ; and 

 count Rumford, long ago, invented a speedy and oeconomi- 

 cal method of heating liquids, by introducing into them tins 

 steam in a state of extrenie heat, 



He has made an extremely fortunate application of this 

 discovery in the art of soap-making, and has succeeded in 

 boiling this article completely in six hours, while sixty were 

 requisite in the usual way. The kind of percussion which 

 heated steam gives to the mixture of oil and ley, by penetra- 

 ting into it, and suddenly condensing, contributes, accord- 

 ing to count Rumford, to the acceleration of the process. 



This learned chemist has also succeeded in adding new 

 perfection to cauldrons destined for heating' liquids, by ap- 

 plying to their bottoms several tubes which descend into the 

 flame, and by thus multiplying the surface of the bottoul 

 without increasing its diameter. By these means we not 

 «nly save fuel, but abo the cauldron ; because the latter, re- 



jistiug 



