January 1, 1897.] 



SCIENCE. 



as observed, but this is not always conclu- 

 sive of the age of the rock viewed at a given 

 point, for it is known that these relics are 

 never uniformly distributed throughout the 

 substance of the rocks, even of the newest 

 formations. Its position would indicate 

 a near alliance to the old red sandstone. 

 Werner has considered this rock in all situa- 

 tions as secondary. Bakewell places it in a 

 class of transition rocks, in which he is fol- 

 lowed by Maclure and Eaton. I am not 

 prepared to decide upon the point * * *, and 

 shall content myself in the present instance 

 with a bare recital of the facts." 



After the examination of the famous 

 mass of native copper, variously estimated 

 to weigh from one to five tons, which was 

 the attraction of all travelers to the Lake 

 Superior region, he says, in the course of 

 his reflections upon its probable manner 

 of occurrence, " there is reason to presume 

 that the precious metals may be found in 

 the northern regions of the American con- 

 tinent. Nothing appears more improbable 

 than that the veins of silver ore that are so 

 abundant in Mexico and the province of 

 Texas are checked in their progress north- 

 ward into Arkansas and Missouri by the 

 effect of climate. This metal is known 

 to be found in association only with certain 

 limestones, schists and other rocks, and 

 when these cease it is in vain to be sought. 

 Other metals and minerals have their par- 

 ticular associations serving as a geognostic 

 matrix, and hence rock strata may be con- 

 sidered as indexes to particular metals, 

 minerals and ores, and the geologist is thus 

 enabled to predict with considerable cer- 

 tainty from an examination of the exterior 

 of the country whether it is metalliferous 

 or not." In his ' Lead Mines of Missouri' 

 he had mentioned the occurrence of chalk 

 with flints, at Little Chain of Rocks, on 

 the Mississippi Eiver, which he says was 

 worked commercially and found equal to 

 foreign chalk. This was probably a bed of 



white pipe clay described by Shumard in 

 1871 (Missouri Geological Survey). He 

 mentions the fluorspar of southern Illinois, 

 the novaculite of the Arkansas Hot Springs, 

 the red pipe stone of the upper Mississippi, 

 coal in western Pennsylvania, Ohio, Vir- 

 ginia, Kentucky, Illinois and Missouri; 

 also hydrogen gas or carburetted hydrogen 

 at the Burning Spring on the Licking 

 River. Pumice, he says, is brought down 

 the Missouri River in the June floods, 

 and probably comes from some volcanic 

 mountain at the head of the river. A 

 pseudo-pumice is also brought down which 

 he supposes to have originated from the 

 burning of beds of coal. He speaks of amass 

 of native iron, upwards of 3,000 pounds 

 in weight, discovered on the banks of the 

 Red River, and now (1819) in the collection 

 of the New York Historical Society. " Its 

 shape is irregular, inclining to oval form, 

 its surface deeply indented and covered 

 with oxide of iron. It is said to contain 

 nickel, etc," 



1821. In 1821 Schoolcraft made another 

 expedition with General Cass from Toledo 

 across Ohio and Indiana, past the fluor- 

 spar deposits of southern Illinois, to St. 

 Louis, returning by way of Chicago, an ac- 

 count of which was published as ' Travels 

 in the Central Portions of the Mississippi 

 Valley.' 



1823. In 1823 a second expedition under 

 Major Long was sent out by the War De- 

 partment, which followed the Mississippi 

 and Red River of the North to Lake Winni- 

 peg, returning along the northern shore of 

 Lake Superior, To this expedition Prof. 

 William H. Keating, of Philadelphia, was 

 attached as geologist, and published a nar- 

 rative in two volumes in 1823 (George B. 

 Whittaker, London). Keating in his nar- 

 rative of the expedition, which started at 

 Philadelphia, notes the evidences of old 

 copper mining at South Mountain, in Mary- 

 land; the fact that coal mining is being 



