1817.] during the Year 1816. 5 
1815, it vibrated 500 times in 4’ 32”; while on Oct. 3 of the same 
year it took 10’ 5” to make the same numberof vibrations, During 
the month of Sept. 500 vibrations usually occupied between 7’ and 
8’; during Oct. between 4’ and 6’ (Schiweigger’s Journal, xv. 
113). Schweigger aud Grindel have shown that Zamboni’s column 
always contains moisture when in a state of activity (Ibid. xv, 132, 
479). lager, of Stuttgard, has published an elaborate theory of 
this column (Gilbert’s Annalen, lii. 81), and important remarks on 
the same subject have appeared by Professor Piatf, of Kiel (Lbid. 
lii. 108). Bat as these papers, though well drawn up, do not 
appear to me to contain any thing essentially different from the ex- 
planations already given in this country, I do not consider it as 
necessary to enter into details respecting them. It is needless to 
notice the clocks that have been constructed by means of this 
column as a moving power both in this country and in Germany ; 
because it is obvious that the great irregularity in the motion of 
these pendulums must render such clocks of no real utility. 
From a paper on Zamboni’s column by Gay-Lussac (Ann. de 
Chim. et Phys. ii. 76), we learn that the first attempt to construct a 
dry galvanic column was made by Desormes and Hachette in 1803. 
But it would appear from his account that this attempt was not 
attended with success. Deluc was in reality the first successful con- 
structor of this column. His curious memoir was read to the Royal 
Society in 1809, and published in Nicholson’s Journal in 1810. 
Zamboni’s column was first constructed in 1812, and described by 
him in a memoir published in Verona, entitled, Della Pila Elec- 
trica a Secco, &c. I gave an account of it in the historical sketch 
for the preceding year. 
2. In the year 1814, Confiliacchi, who succeeded Volta as Pro- 
fessor of Natural Philosophy at Pavia, published a treatise on the 
Identity of Electricity and Galvanism. ‘This treatise was written by 
an anonymous friend and pupil of Volta, who had drawn it up, but 
had been prevented from publishing it by a premature death. It 
professes to give merely the theory and views of Volta. To judge 
from the account of it given in the Bibliotheque Britannique, 
(xxxviii. 305) and by Professor Gilbert (Annalen, li. 341), for I 
have not seen the original work, it seems to constitute the most 
complete treatise on galvanism which has hitherto appeared. The 
paper of Dr. Weber (Gilbert’s Annalen, li. 353) likewise deserves 
attention in a theoretical point of view, It contains a pretty full 
and clear exposition of the phenomena, arranged with the view of 
elucidating the theory of this obscure branch of electricity. 
3. Metallic Hydrurets.—I\t has been supposed that when different 
metallic wires are employed to complete the circuit of a galvanic 
battery by proceeding from the minus pole into a vessel of water, 
these metals combine with the hydrogen of the decomposed water, 
and form hydrurets. Several of these hydrurets have been long ago 
described by Ritter and by Brugnatelli. In Schweigger’s Journal, 
xy. 411, there is a paper by Ruhland, in which he describes a con- 
