216 Letters of Mr. Brongniart with remarks. 
draulic works to any extent; while the surrounding coun- 
wry is =e as to admit of an ‘agricultural settlement. 
mpany this report with a geological chart of a ver- 
soaks auth of the left bank of the Mississippi: at St. Peters, 
embracing a formation of native copper, and in which the 
superposition of the layers of rock, and the several subde- 
posites forming the alluvial stratum, exhibit a remarkable 
orde e curvatures in the lines of the alluvial stratum, 
represent a, patil mound or hillock recumbent upon the 
. of the river, which has partially fallen in, thus expo+ 
dag its internal structure. The formation was first noticed 
by the garrison who quarried stone for quicklime, and for the 
purpose of building chimneys, at this spot. The masses of 
copper found are all small, none exceeding a pound in weight. 
T have the honour to be sir, 
with great respect, and regard, 
your most obedient servant, 
HENRY 
(Copy) a : R. SCHOOLCRAFT. “ 
- 
Tue observations of Mr. Brongniart, especially on some 
American localities will probably be interesting and instruc- 
tive to others in this country, as they have been to us; this 
has induced us to give publicity to remarks which although 
not forwarded for this purpose, cannot fail to do honour to 
their respectable author. 
His first letter, oe Oct. 9, 1819, is a reply to one ac- 
companying American specimens transmitted to him, and 
-. about some fe {which his mpiaion was asked. ‘Mr. Brongn 
art observ 
met rani yea to-day through the intervention of Mr 
« oo) A collection sufficiently complete, of substances 
dapted to the manufacture of p: and ii 
the principal changes and processes which diene substances 
