Bar veil — Growth of Knowledge of Earth Structure. 143 



1S30 and 1831; by Edward Hitchcock, Prof, of Chemistry and 

 Natural History in Amherst College. 



A footnote adds that this is "published in this Journal by 

 consent of the Government of Massachusetts, and intended to 

 appear also in a separate form, and to be distributed among the 

 members of the Legislature of the same State, about the time 

 of its appearance in this work. It is, we believe, the first exam- 

 ple in this country, of the geological survey of an entire State." 



This article includes a geological map of the state and 

 covers the subject of economic geology. The report 

 brought forth the following remarks from a French 

 reviewer in the Revue Encyclopedique, Aug. 1832, quoted 

 In the Journal (23, 389, 1833) : 



"A single glance at this report, is sufficient to convince any 

 one of the utility of such a work, to the state which has under- 

 taken it ; and to regret that there is so very small a part of the 

 French territory, whose geological constitution is as well known 

 to the public, as is now the state of Massachusetts. France has 

 the greater cause to regret her being distanced in this race by 

 America, from her having a corps of mining engineers, who 

 if they had the means, would, in a very short time furnish a 

 work of the same kind, still more complete, of each of the 

 departments. ' ' 



The complete report published in 1833 is a work of 700 

 pages. Pages 465 to 517 are devoted to the subject of 

 granite. Numerous detailed sketches are given showing 

 contact relations. Nine pages are given to theoretical 

 considerations and many lines of proof are given that 

 granite is an igneous rock, molten from the internal heat 

 of the earth, and intruded into the sedimentary strata. 

 His statement is the clearest published in the world, so 

 far as the writer is aware, up to that date, and marks 

 Edward Hitchcock as one of the leading geologists of his 

 generation in Europe as well as America. Unfortu- 

 nately his views were largely lost to sight during the fol- 

 lowing generation. 



In 1840 the first American edition of Mantell's "Won- 

 ders of Geology gave currency to the idea that granite is 

 proved to be of all geological ages up to the Tertiarv 

 (39, 6, 1840). In 1843 J. D. Dana pointed out (45, 104) 

 that schistosity was no evidence of sedimentary origin. 

 He regarded most granites as igneous as shown by their 

 structural relations, but considers that some may have 

 had a sedimentary origin. 



