Dubois. ] 226 [Dee. 1, 
Spanish America down to about 150 years past. (Tapping the edge with 
a hammer, was also in use): 
If the figures and characters were made with a tool, it must have been 
a very rude one, since a ‘‘flat-nosed ” graver would have left a smooth 
trough, while here it is rough and granular. This would suggest the 
greater likelihood of etching, were it not inconceivable that so advanced 
an art should have been practiced long ago on the Western prairies. The 
mineral acids, used for such work, were nowhere known until about the 
fourteenth century ; and in Illinois, while we might suppose agua ardiente, 
we cannot concede aqua fortis, longer ago than one century. On the 
whole, it has been worked out with a very crude instrument. 
As to the condition of the piece, and the discolorations; it is well known 
that copper, exposed to the air, acquires a superficial sub-oxide or dioxide, 
which protects it from further destruction. Very many ancient copper 
coins have been turned up by the spade or plough, which with a little 
cleaning up, look as if just out of the mint. I herewith show a specimen 
of Tetricus, a Roman usurper of the purple, in France, about A. D. 270; 
entirely free from corrosion. I also show a more interesting piece, which 
with many others, was ploughed up in the southern part of England, 
about 30 years ago. They were all so encrusted as to be illegible, and 
the owner gave me a choice at haphazard. On removing the coat of mail, 
and leaving only the mixture of brown and black oxides, it turned out to 
be a coin of Carausius, who established himself as a Roman Emperor in 
Britain, A. D., 287; as long before William the Conqueror, as William 
was before Victoria. This piece is rare and in perfect order, and forms a 
part of the Mint collection. ; 
Some ancient coins, especially those with a slight alloy of tin or cala- 
mine, making them bronze or brass, are beautifully coated and protected 
with the green carbonate, the same as that which formed on the Illinois 
piece before cleaning. I herewith show one of these patinated pieces, a 
coin of Augustus, also from the Mint Cabinet. They may have been in 
favorable hiding-places, such as cinerary urns, or columbaria. 
All things considered, I cannot regard this Illinois piece as ancient, nor 
old, (observing the usual distinction); nor yet recent; because the ‘tooth 
of time’’ is plainly visible. 
What the piece was made for, is a part of the inquiry. Not for current 
money, bevause it would take a long time to make a handful ; more likely 
a work of amusement, possibly to exercise the antiquarians. But how 
it got into such a deep place, supposing it a bona fide discovery which I 
eannot call in question, is a very perplexing point, and I gladly hand over 
the explanation to any one willing to undertake it. Certainly it seems, 
in connection with the finding of the copper ring, and other articles of 
iron and wood, at considerable depths, to form an item in the study of 
the formation of the superficial strata in that interesting section of our 
country. : 
Since the foregoing was written, I am favored with the suggestions (in 
writing) of Professor Lesley. He suspects that if anything, it is an 
astrological amulet. There are upon it the signs of Pisces and Leo. The 
