On the Hypothesis of Gaseous Repulsion. 2S 



sary wliich make it impossible such an hypothesis can be cor- 

 rect. For instance, there must be an attractive atmosphere 

 always ot" the same dimensions as the repulsive, otherwise the 

 law of repulsion would not at all places within the atmosphere 

 be inversely as the distance. The air also, if ever condensed 

 moi-e than eight times, will have its density and elasticity follow 

 different hiws ; and if rarefied more than eight times, the cubes 

 of the elasticity will be as the biquadrates ol the density. This 

 latter law wiU likewise take place if the temperature or calori- 

 fic atmosphei'e be so diminished as to place the particles, with- 

 out changing their distance, beyond that atmosphere. 



I know there are those who to meet the difficulties of caloric 

 will stir uj) their '' latent heat." But I have shown in the 

 Annals for December, that all the phajnomena, for which this 

 hypotliesis and that of capacity were created, can be truly and 

 mathematically explained without the assistance of either. To 

 press, therefore, into our service, for the explanation of one 

 thing, an hypothesis uselessly created for another, is a piece of 

 tyrannical obtrusion. Allowing however to philobophers the 

 entire powers of " latent caloric ;" and granting them the wide 

 field of" unrestrained imagination, I think I may venture to say, 

 there is not in Europe a philosopher, who could successfully ex- 

 plain, witli this doctrine, the simple developments of untram- 

 melled experiment. 



Viewed in this light, it is impossible that repulsion can exist 

 with caloric. And if we try to meet experiments by any altera- 

 tion in the homogeneity or extent oi'the atmospheres, we destroy 

 the law which nature observes, and plunge tlie hypothesis into 

 still greatei- difficulties. Under no circumstances, therefore, 

 will repulsion agree with caloric and phajnomena united. 



Repulsion is ecjually as unfortimate with the theory of heat 

 by motion, as with the doctrine of caloric. If in airs we con- 

 ceive a vibratory motion of the particles to be the cause of heat, 

 no increase or diminution of this motion could at all affect the 

 elasticity of the air, as experience jiroves an increase or dimi- 

 nution of heat does, unless the particles struck one another. 

 For, whatever may be imagined to be gained in action or elas- 

 ticity by an increase of celerity of any particles towards each 

 other, or by a further approximatio)i occasioned by a gieater 

 range of vibration, must be counterbalanced by the same in- 

 crease of velocity from each other, or by an ecjuivalent excess 

 of elongation ; so that the mean action or elasticity must be the 

 same under one temperature as under another. And if instead 

 of a vibratory we have recourse to a rotatory motion of the })ar- 

 ticles about their own axes, we have no physical principles, nay, 

 not even a fiict to my knowledge, that will enal)le us to enter- 

 tain merely the po-isibiliiy, to "-iiv iintliiiig of the probability, of 



a cliaiige 



