170 LIFE OF BENJAMIN SILLIMAN. 



tions and overflows, I went to bathe in the cool ocean of 

 Werner ; and as both views were ably and eloquently sus- 

 tained, the exercise was to me a delightful recreation and 

 a most instructive study. I found time, also, to read Play- 

 fair's illustrations of the Huttonian theory, and Murray's 

 comparative view of both the conflicting theories ; and I 

 was not long in coming to the conclusion that both theories 

 were founded in truth, and that the crust of the earth had 

 been formed and greatly modified by the combined, or 

 sometimes antagonistic and conflicting powers of fire and 

 water. The two theories occupied to a considerable extent 

 a common ground as to the agency of water, but fire came 

 in to modify, or entirely transform, the materials which 

 water had deposited. The stratified rocks, the igneous 

 theory still conceded to the dominion of water ; but por- 

 phyry and all the trap family, and even granite, it claimed 

 as the products of fire. The strong analogy existing be- 

 tween the porphyries and traps and lithoid lava, both in 

 physical characters and composition, and frequently in posi- 

 tion, left no reasonable doubt that both are igneous. The 

 dykes and intrusive veins in rocks, go to the same account. 

 I felt greatly relieved when I was excused from attempting 

 to compel myself to believe that porphyry, trap in all its 

 varieties, and even granite, had ever been dissolved in 

 water. I became, therefore, to a certain extent, a Iluttonian, 

 and abating that part of the rocks which the igneous theory 

 reclaims as the production of fire, I remained as much of a 

 Wernerian as ever. But I held myself aloof from entire 

 committal to either theory, or to any theory except one 

 derived directly from the facts. Up to the time of my 

 leaving New Haven for England, (March 20, 1805,) I only 

 supposed that the east and west rocks of New Haven were 

 of the basaltic family, agreeably to a suggestion reported 

 from an English traveller many years before. Now I felt 

 assured of their igneous origin. New Haven resembled 

 Edinburgh, having trap rocks in its immediate vicinity. 



