GENERALIZE TION. 267 



and assert that, under adequate pressure, every liquid 

 might be made to pass into a gas without any breach of 

 continuity*. 



The liquid state, again, is considered by Professor 

 Andrews to be but an intermediate step between the 

 solid and gaseous conditions. There are various indica- 

 tions that the process of melting is not perfectly abrupt ; 

 and could the experiments be made under adequate 

 pressures, it is believed that every solid could be made 

 to pass by insensible degrees into the state of liquid, and 

 subsequently into that of gas. 



These discoveries appear to open the way to most im- 

 portant and fundamental generalizations, but it is probable 

 that in many other cases phenomena now regarded as dis- 

 crete may be shown to be different degrees of the same 

 process. The late Professor Graham was of opinion that 

 chemical affinity differed but in degree from the ordinary- 

 attraction which holds different particles of a body together. 

 He found that sulphuric acid continued to evolve heat 

 when mixed even with the fiftieth equivalent of water 

 that is added to it, so that there seemed to be no distinct 

 limit to chemical affinity. He concludes * There is reason 

 to believe that chemical affinity passes in its lowest degree 

 into the attraction of aggregation'". 



The atomic theory is well established, but its limits are 

 not marked out. As Mr. Justice Grove suggests, we may 

 by selecting sufficiently high multipliers express any com- 

 bination or mixture whatever of elements in terms of their 

 equivalent weights x . Sir W. Thompson has suggested 

 that the power which vegetable fibre, oatmeal, and many 

 other substances possess of attracting and condensing 

 aqueous vapour is probably continuous, or, in fact, iden- 



* 'Nature/ vol. ii. p. 278. 



u 'Journal of the Chemical Society,' vol. viii. p. 51. 



x 'Correlation of Physical Forces/ 3rd edit. p. 184. 



