FIRST GEOLOGICAL EXPLORATION IN LOUISIANA. 679 
THE FIRST GEOLOGICAL EXPLORATION IN LOUISIANA. 
E. L. BERTHOUD, C. E. 
Among the concessions made by Law's company in Louisiana, in 1719-20, 
was that one made to Law, and embraced the lands on the Arkansas River, then 
known as "Arkansas Post," which was the point where Joutel, after La Salle's 
death, first reached the immediate valley of the Mississippi, and where he found 
two Frenchmen left there by Touti, La Salle's lieutenant, as a point of observa- 
tion or rally for that great explorer's benefit. 
In 1 721 Arkansas Post consisted of four or five palisaded houses, a little 
guard-house, and a cabin serving as a store-room. In that year, Dumont says 
that he went with its commander, Capt. De la Harpe, Lieut. Franchomme, Ser- 
geant Bessan and twenty-two men from that Post, to explore the Arkansas valleys in 
search of a reputed " Emerald rock " on that river. The party ascended the river 
250 leagues, and then struck off inland fifty leagues more; they passed through 
a beautiful country; vast prairies covered with buffalo, stags, deer, etc. They 
found jasper, marble, and also slate and talc (selenite), very fit for plaster. They 
also discovered, they thought, a little stream that rolled '■'■ gold dust" A salt 
spring also was found nearly 300 leagues from the sea. It is just possible De la 
Harpe reached into the country of the Big Bend of the Arkansas; if he did the 
Nescatunga Salt Plains and Salt Springs were visited by him. He may, perhaps, 
have been as far as the Wichita Mountains. But the emerald rock yet remains 
to be found, if it ever existed, — it was most probably carbonate of copper. 
This expedition might be called the first geological exploration of Louisiana. 
Morrison, III., Feb. 9, 1884. 
Ed. Kansas City Review of Science and Industry : 
Dear Sir, — I have just read Prof. G. C. Broadhead's article on "Flint 
Chips" in the current number of your valuable magazine, and it recalls to my 
mind a statement I once heard to the effect that there is no flint found in the United 
States. I have read the same statement in J. P. McLean's work on the " Mound 
Builders." Before I can accept this statement as true I would like more and 
better proof in its support. I have found specimens mingled with the drift over- 
lying beds of Niagara rock in this vicinity and also in the gravel on the shore of 
the Mississippi River at Lyons, Iowa, that corresponds exactly with the most 
precise definitions for the term flint. I have specimens of flint from the Dover 
Cliff's, England, which though black in color are translucent along the edges, 
though more so than some specimens found near this locality. 
The questions I would like to ask are : Is real flint found in this country or 
not, and if so, how can we tell flint from chert without chemical analysis ? 
