Researches in the Theory and Calculus of Operations. 259 



they are simultaneously destroyed by mutual and equal 

 antagonism, to be continually renewed while the universe 

 remains in existence. All the time a constant emanation of 

 ethereal force, arising out of the difference of action between 

 the substance of the iron and that of the medium surround- 

 ing it, proceeds outward into space. A blow directed per- 

 pendicularly upon the upper force destroys at once the upper 

 and lower tier of atomic forces of the bar, reducing its length 

 to the dimension represented by B. In the immediately fol- 

 lowing instant, these two tiers are regenerated and appear 

 outside of the extremities of the now compressed substance; 

 and if the blow is not repeated, the substance will directly 

 retake, by the reaction of the expelled forces, its former 

 dimension in A. But if this return is prevented by a repeti- 

 tion of the blow, a second tier of atomic forces will be libe- 

 rated and unite with the first tier; so that the amount of 

 liberated atomic force will increase with the continuance 

 of the operation, until a certain limit is reached. 



Force liberated by this method of operation, or by strong 

 friction, has the spheroidal form of vibration, alternately 

 swelling and condensing, and constitutes the matter of heat 

 termed caloric. By its repeated impulsions, it enlarges the 

 radii of the atomic forces of most material substances, causing 

 their increase in three dimensions. In metallic substances 

 the atomic range is great, and heat is transmitted with ra- 

 pidity; but in compounds or complex substances, wood, 

 stone, etc., the transfer takes place by conduction, each par- 

 ticle handing over to its next neighbor. Like as in electri- 

 city, there are more and less perfect and imperfect conductors 

 of heat, distinguished as diathermanous and athermanous sub- 

 stances. In liquids, the particles being freely movable 

 * among each other, their own movement takes the place of 

 the movement of the forces in solids : the heat being applied 

 at the bottom of the vessel containing the fluid, the first 

 stratum of particles swell and ascend by virtue of their re- 



