Peculiar Conditions of Metals 111

and also by Dr. Mitchell of Philadelphia 2 in 1830. It
seems very probable that if such a substance as spongy platina
were used, another law for the diffusion of gases under the
circumstances would come out than that obtained by the use
of plaster of Paris.

396. I intended to have followed this section by one on the
secondary piles of Ritter, and the peculiar properties of the
poles of the pile, or of metals through which electricity has
passed, which have been observed by Ritter, Van Marum;
Yelin, De la Rive, Marianini, Berzelius, and others. It appears
to me that all these phenomena bear a satisfactory explanation
on known principles, connected with the investigation just
terminated, and do not require the assumption of any new state
or new property. But as the experiments advanced, especially
those of Marianini, require very careful repetition and examina-
tion, the necessity of pursuing the subject of electro-chemical
decomposition obliges me for a time to defer the researches to
which I have just referred.

November 30, 1833.

V3

§ 5. ON ELECTRO-CHEMICAL DECOMPOSITION, CONTINUED.4 ^f iv.
ON SOME GENERAL CONDITIONS OF ELECTRO-DECOMPOSITION.
^[ V. ON A NEW MEASURER OF VOLTA-ELECTRICITY. ^f VI.
ON THE PRIMARY OR SECONDARY CHARACTER OF BODIES
EVOLVED IN ELECTRO-DECOMPOSITION. ^j vii. ON THE
DEFINITE NATURE AND EXTENT OF ELECTRO-CHEMICAL
DECOMPOSITIONS. § 7. ON THE ABSOLUTE QUANTITY OF
ELECTRICITY ASSOCIATED WITH THE PARTICLES OR ATOMS
OF MATTER

Preliminary

397. THE theory which I believe to be a true expression of the
facts of electro-chemical decomposition, and which I have there-
fore detailed in a former part of these Researches, is so much
at variance with those previously advanced, that I find the

t * Quarterly Journal of Science, vol. xxviii. p. 74, and Edinburgh Transac-
tions, 1831.

2 Journal of the Royal Institution for 1831, p. 101.

3 Seventh Series, original edition, vol. i. p. 195.

1 Refer to the note after 783, Part VI.—December 1838. probably be found