AMERICAN GEOLOGY DECADE OF 1840-1849. 373 



eruptions going on in a covert and languid manner under certain parts 

 of the range. But Daubeny, it must be remembered, carried his views 

 to an extreme, regarding the uplift of the chain itself as due to these 

 same volcanic forces. 



In 1842 there appeared in the Proceedings of the Boston Society of 

 Natural History a paper by J. P. Couthouy, one of the naturalists of the 

 Wilkes Exploring Expedition, in which an attempt was made to show 

 that the distribution of coral growth in the ocean was 

 Corai C arowth y i 8 n 42. limited by temperature. This paper brought forth 

 very promptly a reply from Dana, who, while agree- 

 ing as to the facts and theories, claimed that he (Couthouy) had simply 

 borrowed the idea from him; that the explanation "was originally 

 derived from my manuscript, which was laid open most confidentially 

 for his perusal while at the Sandwich Islands in 1840." The assertion 

 was, of course, denied by Couthouy with equal promptness, but it must 

 be confessed that the evidence, so far as it is available, favors Dana's 

 claim. 



Dana, it should be remarked, was led, from his observations while 

 on this expedition, to agree with Darwin as to the formation of atolls 

 (annular coral reefs), but could not agree with him regarding regions 

 of subsidence and elevation. He found nothing .which to him sup- 

 ported the idea that islands with barrier reefs were subsiding, while 

 those with fringing reefs were rising. 



In the summer of 1842 Dr. W. Byrd Powell, of Little Rock, passed, 

 of his own volition, some six weeks in a study of the geology of the 

 Fonrche Cove region, his results being published in a pamphlet of 23 

 Byrd Poweirs work P a » es ana " map, by the Antiquarian and Natural History 

 region of A^kaifsasf Society of Arkansas. The Doctor at the time of his 

 1842 - writing occupied the position of lecturer on phrenology 



and geology. Whatever may have been his qualification in the first- 

 named subject, as a geologist he was no whit above the majority of 

 workers of his day. The rocks of the cove and their association were 

 described in considerable detail, the prevailing syenite being called gran- 

 ite, although he noted that it contained no quartz. He differed with 

 Featherstonhaugh, however, in assuming, and wrongly, that the rock 

 was primitive and not intrusive. To a supposed transitional form of 

 greenstone into basalt he gave the name ( brnean. The other rocks 

 noted were basaltic clinkstone, amygdaloid, gneiss, etc. Some of his 

 observations are open to question. Less than a gill of mica from the 

 gneiss, he announced, yielded him half an ounce of metal, which he 

 considered as mostly iron. He further remarked that the hornblende 

 rocks of the region contained a large percentage of iron, which was 

 chiefly, if not wholly, native; also that they contained native lead and 

 a little silver. 



The organization of the geological survey of the State of New York 



