zio THE POPULAR SCIENCE MONTHLY. 



And now comes a further surprise. After having given these 

 superfluous stabs to the slain body of the preacher's argument, my 

 good ally remarks, with magnificent calmness, " So far, then, the 

 preacher and the professor are at one. . . . Let them smoke the calu- 

 met." By all means : smoke would be the most appropriate symbol 

 of this wonderful attempt to cover a retreat. After all, the duke has 

 come to bury the preacher, not to praise him ; only he makes the 

 funeral obsequies look as much like a triumphal procession as possible. 



So far as the questions between the preacher and myself are con- 

 cerned, then, I may feel happy. The authority of the Duke of Argyll 

 is ranged on my side. But the duke has raised a number of other 

 questions, with respect to which I fear I shall have to dispense with 

 his support nay even be compelled to differ from him as much as or 

 more than I have done about his Grace's new rendering of the " bene- 

 fit of clergy." 



In discussing catastrophes, the duke indulges in statements, partly 

 scientific, partly anecdotic, which appear to me to be somewhat mis- 

 leading. We are told, to begin with, that Sir Charles Lyell's doctrine 

 respecting the proper mode of interpreting the facts of geology (which 

 is commonly called uniformitarianism) " does not hold its head quite 

 so high as it once did." That is great news indeed. But is it true ? 

 All I can say is that I am aware of nothing that has happened of late 

 that can in any way justify it ; and my opinion is, that the body of 

 Lyell's doctrine, as laid down in that great work, " The Principles of 

 Geology," whatever may have happened to its head, is a chief and 

 permanent constituent of the foundations of geological science. 



But this question can not be advantageously discussed, unless we 

 take some pains to discriminate between the essential part of the uni- 

 formitarian doctrine and its accessories ; and it does not appear that 

 the Duke of Argyll has carried his studies of geological philosophy so 

 far as this point. For he defines uniformitarianism to be the assump- 

 tion of the " extreme slowness and perfect continuity of all geological 

 changes." 



What " perfect continuity " may mean in this definition, I am by 

 no means sure ; but I can only imagine that it signifies the absence of 

 any break in the course of natural order during the millions of years, 

 the lapse of which is recorded by geological phenomena. 



Is the Duke of Argyll prepared to say that any geologist of author- 

 ity, at the present day, believes that there is the slightest evidence of 

 the occurrence of supernatural intervention, during the long ages of 

 which the monuments are preserved to us in the crust of the earth ? 

 And if he is not, in what sense has this part of the uniformitarian doc- 

 trine, as he defines it, lowered its pretensions to represent scientific 

 truth ? 



As to the " extreme slowness of all geological changes," it is simply 

 a popular error to regard that as, in any wise, a fundamental and 



