_with acid_. The character of the marks was partly unintelligible. On each side, however, was a rude outline of a human figure. One of these held in one hand an object resembling a child, while the other was raised as if in the act of striking. The figure wore a head-dress, apparently made of quills. _Around the border were undecipherable hieroglyphics_. The figure on the opposite side extended only to the waist, and had also one hand upraised. This was furnished _with long tufts like mule's ears_. Around the border was another circle of hieroglyphics. On this side also was a rude outline of a quadruped. I exhibited this relic to the Geological Section of the American Association, at its meeting at Buffalo in 1876. The general impression seemed to be that its origin could not date from the epoch of the stratum in which it is represented to have been found. One person thought he could detect a rude representation of the signs of the zodiac around the border. Another fancied he could discover numerals, and even dates. No one could even offer any explanation of the objects or the circumstances of its discovery. The figures bear a close resemblance to rude drawings executed on birch-bark and rock surfaces by the American Indians. _But by what means were they etched_? And by what means was _the uniform thickness of the copper produced_? {p. 357} This object was sent by the owner to the Smithsonian Institution for examination, and Secretary Henry referred it to Mr. William E. Dubois, who presented the result of his investigation to the American Philosophical Society. _Mr. Dubois felt sure that the object had passed through a rolling-mill, and he thought the cut edges gave further evidence of the machine-shop_. 'All things considered,' he said, 'I can not regard this Illinois piece as _ancient_ nor _old_ (observing the usual distinction), nor yet recent; because the tooth of time is plainly visible.' He could suggest nothing to clear up the mystery. Professor J. P. Lesley thought it might be an astrological amulet. He detected upon it the signs of Pisces and Leo. He read the date 1572. He said, 'The piece was placed there as a practical joke.' He thought it might be Hispano-American or French-American in origin. the suggestion of 'a practical joke' is itself something which must be taken as a joke. No person in possession of this interesting object would willingly part with it; least of all would he throw so small an object into a hole where not one chance in a thousand existed that it would ever be seen again by any person.