162 SCIENTIFIC THOUGHT. 



generally attributed to gases. Andrews l in the 'sixties 

 carried on his important experiments on the transition of 

 bodies from the liquid to the gaseous state, and came to 

 the conclusion " that the gaseous and liquid states are 

 only remote stages of the same condition of matter, and 

 are capable of passing into one another by a process 

 of continuous change." 2 He also referred to the " pos- 

 sible continuity of the liquid and solid states of matter." 

 Another important step by which our conceptions of 

 the nature of the liquid condition of matter were con- 

 siderably enlarged and altered motion being introduced 

 where a former view had seen only rest was taken by 

 Clausius, who, following Joule and Kronig, had about the 

 \ same time given its modern form to the kinetic theory 

 of gases. What suggested this step was the pheno- 

 menon of electrolysis. The older view looked upon the 

 action of the electric current, which, passing through 

 substances in a state of fusion or solution, liberated the 

 constituents out of which they were composed, as an 

 exertion of a force contrary to the forces of chemical 

 / affinity, by which the chemical constituents were sup- 

 | posed to be held together. In this case energy would 

 have to be spent in doing work against chemical forces. 

 It was, however, very soon found that the decomposi- 

 tion, or as Sainte Claire Deville first called it 3 the 



1 See vol. i. p. 316, note, of this 

 History. 



2 See 'The Scientific Papers of 

 Thomas Andrews,' with a Memoir 



series of original investigations, first 

 iu organic then in metallurgical 

 chemistry, entered upon his re- 

 markable work in thermal chem- 



by Tait and Crum Brown, London, | istry at the time when Clausius in 



1889, p. 316. Germany was being led from an 



3 Sainte Claire Deville (1818-81) entirely different point of view to 



approached chemical research from | the same subject. He introduced 



the side of medicine, &nd after a the term dissociation to denote the 



