Native Copper of Lake Superior, &§c. 211 
through a stratum of red sand-stone, and covered by a very 
heavy deposit of alluvial soil full of water worn fragments 
of stones and pebbles, and imbedding occasional masses of 
native copper. Such is the character of the country in the 
immediate vicinity of the copper rock, and the latter is man- 
ifestly one of those imbedded substances, which has been 
fortuitously exposed to the powerful action of the river 
against an alluvial bank. , : 
During our continuance upon this stream we found, or- 
rather procured from the Indians, another mass of native 
copper weighing nine pounds (Troy) nearly ; which will be 
forwarded to the War Department. This specimen is par- 
tially enveloped by a crust of green carbonat of copper, 
which is in some places fibrous, and on the under side mix- 
ed with a small portion of adhering sand, and some angular 
fragments of quartz, upon which it appears. to Have tellen 
in a liquid state. There is also an appearance of ee 
ization upon one side of it, and a portion of adhering black 
oxyd, the nature of which it is difficult to determine by 
ocular inspection. Several smaller pieces, generally weigh- 
ing less than a pound, were also procured during our ex- 
cursion up the Ontonagon, and in the regions east of it, but 
all, excepting those cut from t rge mass, are somewhat 
pon the surface. The 
at other points along the river, between that and the lake, 
are also of a highly interesting character, but do not appear 
to me to demand a more particular consideration in this re- 
The discovery of masses of native copper is generally 
considered indicative of the existence of mines in the 
neighborhood. practised miner looks upon them as 
signs which point to larger bodies of the same metal ‘in the 
earth, and is often determined, by discoveries of this nature, 
in the choice of the spot for commencing his labours. The 
predictions drawn from such evidence, are also more san- 
guine in proportion to the extent of the discovery. It 
js not, however, an unerring indication, and appears liable 
to many exceptions. A detached mass of copper is some- 
times found at a great distance from any body of the met- 
al, or its ores; and these on the contrary, often oceur in the 
