Sillimarfs American Journal. 1 1 1 



The most important article in the present number is en- 

 titled, " Critical Notices of various Organic Remains hitherto 

 discovered in North America, by Richard Harlan, M. D." 

 The subject will be continued and completed in a subsequent 

 number; when we propose to take a review of the whole, 

 pointing out the remains which appear to be peculiar to the 

 American continent : we may also revert again to some other 

 articles in the present number. — B. 



Silliman, B, M.D. L L.D., &c. : The American Journal of 

 Science and Arts, No. LIX. Oct. 1835. O. Rich, Lon- 

 don. 



" Observations on the bituminous Coal Deposits of the 

 Valley of Ohio, and the accompanying Rock Strata: with Notices 

 of the Fossil Organic Remains and the Relics of Vegetable and 

 Animal Bodies ; illustrated by a geological map, by numerous 

 drawings of plants and shells, and views of interesting scenery. 

 By Dr. S. P. Hildredth, of Marietta, Ohio." 



This is, perhaps, the most important geological memoir that 

 has been recently published, if we take into the account the 

 amount and extent of the mineral treasures which it developes, 

 and their immense value to the rapidly increasing population 

 of the United States on the western side of the ranges of the 

 Alleghany Mountains. The memoir occupies the whole of 

 the last number (for Oct. 1835) of that valuable work " The 

 American Journal of Science and Arts, conducted by Professor 

 Silliman, of Yale College, Connecticut ■" The extent of the 

 region described comprises about five degrees of latitude, and 

 as many in longitude, on each side of the river Ohio. The 

 mineral treasures are precisely those which are most available 

 to the comfort and prosperity of an industrious and enter- 

 prising people : rock salt, or rather brine springs, containing 

 15 per cent, of salt; coal in numerous beds, some many yards 

 in thickness, and of an excellent quality ; ironstone of various 

 qualities ; lead ore, limestone, and millstone, &c. The 

 coal of this vast region occurs in regular strata, scarcely 

 troubled by the faults and dislocations which so much impede 

 mining operations in other districts. In general the strata 

 have very little inclination, and present great facilities for 

 working. The salt springs are bored for, in many situations, 

 to the depth of 600 ft., and even 900 ft. When the bed which 

 contains the salt water is first pierced, there is generally a 

 great rush of carburetted hydrogen gas emitted : it has, in 

 some instances, been so violent as tb blow up the boring rods. 

 The memoir is accompanied by explanatory sections, which 



