228 Proceedings of the Royal Physical Society. 



fact that Werner had made a statement on any subject was 

 cited as a sufficient answer to any objection or argument. At 

 the same time it is amusing to read the ill-suppressed contempt 

 which these writers express for theorists. " We should form," 

 says one of them, " a very false conception of the Wernerian 

 geognosy were we to believe it to have any resemblance to 

 those monstrosities known under the name of Theories of the 

 Earth." It seems never to have occurred to them that under 

 the belief that they were making nature her own interpreter, 

 they were themselves so blinded by theory as to be incapable 

 of realising some of the most simple and obvious facts in 

 geological structure. 



Looking back from the present stand point of science we 

 cannot but wonder on what chemical principles the Wer- 

 nerians satisfied themselves that the rocks of the earth's crust 

 could have been precipitated from aqueous solution, and by 

 what physical principles they explained the retirement of the 

 ocean. They would admit of no subterranean movement. 

 They asserted that the original ocean must have reached at 

 least as high as the highest mountain peak. Whither did 

 the retiring waters escape ? Some Wernerian writers sup- 

 posed them to have found their way into subterranean 

 cavities. This absurd notion was ridiculed by others who 

 frankly confessed that they could not solve the difficulty. 

 " But," says Jameson very naively, " although we cannot give 

 any very satisfactory answer to the question " [he prudently 

 gave no answer at all] "it is evident that the theory of the 

 diminution of the waters remains equally proiaUe. We may 

 be fully convinced of its truth, and are so, although we may 

 not be able to explain it. To know from observation that a 

 great phenomenon took place is a very difi'erent thing from 

 ascertaining how it happened." * A very different thing 

 indeed! Yet one would suppose that the impossibility of 

 explaining the "theory" might have suggested doubts whether 

 the "observation" on which it was based could really be 

 reliable. 



But besides the difficulty of accounting for the progressive 

 retirement of the ocean still greater complication was intro- 

 * 0}}. cit., vol. iii., p. 82, 



