72 The Founders of Geology LECT. 



investigation of the past history of the earth. They 

 showed how patient detailed research could solve some of 

 the most transcendently interesting problems in geology, 

 and how the minute and philosophical investigation of 

 one small area of the globe could furnish principles of 

 universal application. 



In one respect, perhaps, this far-seeing observer seems 

 to have been almost afraid to push his views of denuda- 

 tion to their logical conclusion. There occur in Central 

 France many flat, isolated areas of basalt capping de- 

 tached hills and fragments of plateaux, not apparently 

 connected with any visible lava-current or centre of erup- 

 tion. These patches were called by him culots, and he 

 explained their origin by supposing them to mark the 

 positions of volcanic vents up which the melted material 

 had risen without flowing out, and where it had solidified 

 within the crater, being retained by the encircling wall of 

 scoriae and cinders. The removal of the surrounding loose 

 material would, he thought, leave the lava as a cake with 

 steep scarped sides crowning the slopes below. Possibly 

 some of his culots originated in the way supposed, but 

 there can be little doubt that most of them are remnants 

 of lava-streams reduced to almost the last stage by the 

 progress of denudation. 



From the long intervals which he allowed to elapse 

 between the presentation of his papers to the Academy 

 and their final publication, it might be supposed that 

 Desmarest was probably of a procrastinating, possibly 

 even of an indolent, temperament. Yet, when we consider 

 the amount of work, official and scientific, which he 

 accomplished, we must acquit him of such an imputation. 



