1816.) Scientific Intelligence. 47h 
That it ought not to be rejected in the analysis of your new ore, 
which, in my humble opinion, affords a strong proof of the truth of 
the electro-chemical theory, I trust you will not he displeased at 
receiving, or in my submitting to your serious consideration, the 
following application of your analysis to that theory. 
61 gr. of silex = 25°31 gr. per cent. of silex = 37°87 gr. of 
oxide of silex. 
10°5 gr. of copper = 43°57 gr. per cent. of copper = 52°22 or. 
peroxide of copper. 
Now adopting your experiment (the particulars of which are not 
stated) that the carbonate of copper is composed of one atom of 
acid and one atom of oxide; and if it shall appear probable that 
sufficient carbonic acid did not exist in the mineral to unite with 
the whole, but only half, the peroxide of copper, namely, 26-11 gr., 
che conclusion must be that the remainder of the copper is united to 
the silex. 
26°11 gr. of peroxide of copper = 36°21 gr. of carbonate of 
copper. 
Hence the ore is composed of 
Oxide of stlex..:s:selvssn eid 374 
Peroxide of copper unite 
to silex 
Peroxide of copper united 
to carbonic acid- 
Carbonic acid ........e.06 1 
UU _. --— 
*BAxo sureyu0d 
ah. 
100°20 
So that the contents of silex or copper area little too great, 
owing probably to the whole of the oxygen not being liberated 
before weighing. 
Hence the mineral is Cu O* + Cu S°. 
Berzelius’s tables have been adhered to, which seem to differ 
from yours. lam, &c. 
April 2, 1816. An Evecrro-Cuzmica, Tueorist. 
I mast have expressed myself inaccurately, otherwise this inge- 
nious Correspondent would not have supposed that I was of opinion 
that the silica in the ore was only accidental ; for I considered it as 
an essential ingredient, founding my opinion upon the different way 
in which nitric acid acts upon this ore, and upon common carbonate 
of copper. I did not venture to apply the atomic theory, because 
my analysis was made upon too small a quantity of the ore to warrant 
perfect confidence in the numerical results. But the statement in 
the preceding letter deserves atteution, and there are strong reasons 
for considering it as accurate. 
There is a considerable difference between the external characters 
of dioptase and of this mineral. The specific gravity of dioptase is 
