82 DR GEORGE WILSON ON THE FINITE DIVISIBILITY OF MATTER. 



regions of the atmosphere, may be such at its boundary as to destroy the elasticity 

 of the air, and even to liquefy or solidify it.* DAUBENY,f Kane,]: and others, 

 have rephed to this, that the temperature of planetary space, according to Fourier, 

 ScnwANBERG, and others, is much higher than that to which ah- has been exposed 

 in experiments with solid carbonic acid and ether, without destroying its 

 elasticity. Dumas, in anticipation of such objections, has declared, that we are 

 not to consider the temperature which a thermometer would exhibit if placed in 

 the upper strata of the atmosphere, as necessarily identical with that of the air 

 around it.§ By which statement he means to enforce, if I understand him aright, 

 that non-elastic (liquid or solid ?) an- may, lilce other diathermanous bodies, trans- 

 mit heat without being thereby raised in temperatm-e itself, so that the outer 

 shell of air may be colder than the layers within it, or space beyond it. In allu- 

 sion to such a view, Professor James Fobbes has pointed out the difficulty of un- 

 derstanding " how it is possible that the higher strata of the atmosphere can 

 remain permanently colder than the strata beneath and the sky above them, 

 without admitting a paradox of the same kind with a mechanical perpetual 

 motion." il 



In reference to Dumas' mode of disposing of Wollaston's argument, I would 

 only further obseiwe, that natural philosophers are not at one as to the tempera- 

 ture, either of planetary space or of the upper strata of the atmosphere ; so that 

 it is impossible at present to say what is the exact value of the objection I have 

 been discussing. 



4:th, Finally, several physicists have denied the justness of Wollaston's con- 

 clusion, on the ground of its intrinsic invalidity. Among these are Professor James 

 Forbes^ and Dr Kane,** who have not, however, so far as I am aware, stated 

 in what way they dispose of the argument. Professor Whewell is Ukewise an 

 objector, and dissents from Wollaston's inference, on the plea that the latter was 

 not at Mberty to assume that the law which connects the density of the air with 

 the compressing force at the upper boundary of the atmosphere, is identical with 

 that which is Imown to prevail near the earth. His own words are — " We know 

 nothing of the law which connects the density with the compressing force in air 

 so extremely rare, as we must suppose it to be near the boundary of the atmo- 

 sphere. Now there are possible laws of dependence of the density upon the com- 



« Leyons, &c., p. 239. 



■)• Supplement to the Introduction to the Atomic Theory, p. 11. 



J Elements of Chemistry, p. 441. 



§ Lefons, &c., p. 241. 



II Report of British Association, 1841, p. 79. 



f Op. cit., p. 77. 



** Elements of Chemistry, pp. 15 and 358. 



