302 PALEONTOLOGY. 



labours in which he has been, hitherto, almost unknown, but iu the 

 course of which he clearly recognized the great principle, that geological 

 investigations " had nothing to do with the original formation of the 

 earth, but had only a connexion with the changes on its surface." 



There was but one cognate contemporary mind, so far as I can dis- 

 cover, who, like Hunter, fully appreciated the true aim of the geologist. 

 I allude to Hutton, who, like Werner, was at work at the same time as 

 Hunter. 



In Hutton's ' Theory of the Earth,' published in the * Edinburgh Phi- 

 losophical Transactions ' for 1788, it was for the first time declared 

 that " Geology was in no way concerned about questions as to the 

 origins of things." 



" The ruins of an older world," writes Hutton, " are visible in the 

 present structure of our planet ; and the strata which now compose our 

 continents have been once beneath the sea, and were formed out of the 

 waste of pre-existing continents. The same forces are still destroying, 

 by chemical decomposition or mechanical violence, even the hardest 

 rocks, and transporting the materials to the sea, where they are spread 

 out and form strata analogous to those of more ancient date. Although 

 loosely deposited along the bottom of the ocean, they become after- 

 wards altered and consolidated by volcanic heat, and then heaved up, 

 fractured, and contorted." 



Evidence of all these operations, productive of geological change, 

 have since been abundantly made matter of observation. The cha- 

 racteristic feature of Hutton's mind was its freedom from any bias 

 towards hypothetical violent causes; its exclusion of all causes not 

 supposed to belong to the present order of nature ; and the aim of his 

 theory was to explain the former changes of the earth's crust by refer- 

 ence exclusively to natural agents. 



In precisely the same spirit Hunter writes, " Our mode of reasoning 

 on this subject may be termed retrograde ; it is by supposing, from the 

 state of the earth now, what must have taken place formerly." Now, 

 mark the importance of basing geology on a knowledge of the state of 

 the earth, as it is now : see the stimulus it gives to intellectual ac- 

 tivity in the right direction ; consider the nature and extent of observa- 

 tion in order to acquire that knowledge ! 



Most rapid, most unexpected, and at the same time most sure, has 

 been the progress made in geology since men, in place of inventing 

 causes and conditions unlike the present, have submitted themselves 

 to search after the nature of those that now are in operation, and of 

 whatever in the present state or inhabitants of the earth may be re- 

 lated to, or affected by, such operations. 



