188 Miscellanies. \ 
less with metallic copper, while oxygen continued to flow from the 
positive wire. He varied the experiment by trying other metallic so- 
lutions: silver and lead, and some others, presented the same phenom- 
ena, except that the silver and lead were transported in the metallic 
state, whilein other cases only the oxide was deposited. 
e must, in these cases, suppose, either that the hydrogen com- 
bines with the metal, or that the metal, separated in the state of ox- 
ide, is reduced by the hydrogen, which forms water by its combina- 
tion with the oxygen of the oxide. The latter supposition only is ad- 
missible. ‘To assure himself of its truth, he took a pile of two pairs, 
incapable of decomposing water slightly saline. A solution of nitrate 
of silver, cf much easier decomposition than water, was easily decom- 
posed, and it was observed that there was at first deposited, not me- 
tallic silver, as was common, but an olive coat of oxide of silver. 
Thus it is proved that the disengagement of hydrogen at the negative 
pole ceases, only because this gas is employed in reducing the oxides 
separated from their combination with acids, by the electric agent. 
Thus it appears that hydrogen, in its nascent state, is capable of 
decomposing oxides, a property it does not commonly possess, €X 
cept at elevated temperatures, 
In pursuing the investigation, the author took a pile of two pairs, 
charged with water very slightly saline, and which could not, of 
course, decompose even acidulated water. He placed the platina 
wires of this pile in a solution of chloride of copper, and observed, 
in the course of time, that the negative wire was acquiring a coating 
of metallic copper, while from the positive wire bubbles of gas wet? 
rising. Having changed the platina conductor for one of silver, the 
latter acquired a yellow coating, which soon became violet, and 
which led him to suspect the presence of chloride of silver. The ex- 
periment was repeated with iodide of zine and of iron; and scarcely ; 
were the platina wires plunged into these solutions, when the iodine 
appeared, distinctly, at the positive pole, and the metal was reduced 
at the negative pole. 
From these experiments the author thinks it may with certainty be 
affirmed, that these combinations, even when dissolved in wate?; do 
not change their nature, and are not converted, as chemists have of- 
ten imagined, into hydro-chlorates, hydriodates, &c., of oxides—~ 
Forli, 10 Sep. 1830.—Bib. Univ. Oct. 1830. 
10. The Black Sea.—Dr. P. C. Hepites, of Odessa, has analyzed 
the water of this sea, with the following results: Spec. grav- 1011. 
10,000 parts of the water being evaporated at a low heat, left 65 parts 
of a yellowish residue, which consisted of 
q 
‘ 
