On the Relation between Muriatic Acid and Chlorine. 101 
The Report from the mint is in these words : . 
From every appearance, the piece of copper seems to have 
been taken from a mass that has undergone fusion. The melting 
was, however, not an operation of art, but anatural effect, caused 
by a voleanic eruption. 
The stream of lava probably carried along, in its course, the 
aforesaid body of copper that had formed into one collection, as 
fast as it was heated enough to run, from all parts of the mine. 
The united mass was probably borne in this manner to the 
place where it now rests in the soil. 
The crystallized form observable every where on the original 
surface of the metal that has been left untouched or undisturbed, 
leads me to presume that the fusion it has sustained was by 
a process of nature ; since this crystallized surface can only be 
- supposed to have been produced by a slow and gradual cooling, 
whereby the copper assumed regular figures as its heat passed 
into other substances, and the metal itself lay exposed to 
the air. 
As to the properties of the copper itself, it may be observed 
that its colour is a clear red; that it is peculiarly qualified for 
rolling and forging; and that its excellence is indicated by its 
resemblance to the copper usually employed by the English for 
plating. 
The dealers in copper call this sort Peruvian copper, to distin- 
guish it from that ef Sweden, which is much less malleable. The 
specimen under consideration is incomparably better than 
Swedish copper, as well on account of its brilliant colour, as 
for the fineness of its pores, and its extreme ductility. 
Notwithstanding, before it is used in manufactures, or for the 
coining of money, it ought to be melted anew, for the purpose 
of purifying it from such earthy particles as it may contain. 
The examination of the North American copper, in the sam- 
ple received from his excellency the minister, by the operations 
of the cupel and the test by fire, has proved that it does not con- 
tain the smallest particle of silver, gold, or ides other metal. 
XVI. Experiments on the Relation between Muriatic Acid and 
Chlorine. By Axpruw Urn, M.D. Professor of the Anden- 
sonian Institution, and Memler of the Geological Society.* 
Tue Chloridie theory, though more limited in its application ” 
to chemical phenomena than the Antiphlogistic, may justly be 
* From the Transactions of the Royal Society of Edinburgh. 
G3 regarded 
