154 French National Institute. 
Natural Philosophy in the University of Edinburgh.—Mr. 
Allan communicated a letter from Dr. Henry, of Manches- 
ter, describing the position of some singular masses of a 
substance apparently composed of wax and rosin, which 
had been laid bare by a late overflow of the river Mersey, 
alittle below Stockport, about three feet under the soil,—and 
supposed to be the refuse of some manufactory, of which 
no other vestige or recollection now remains. 
FRENCH NATIONAL INSTITUTE. 
The following is a brief abstract of the Report of the 
National Institute at Paris for the year 1810. 
Messrs. Gay-Lussac and Thenard have directed their 
attention to compare the relative powers and energies of 
different Galvanic piles. They have discovered that the 
force of the pile is not increased in proportion to the num- 
ber of plates. To produce a double effect, the number of 
plates must be increased eight times. In general, it was 
found that the quantity of gas the piles will produce, is 
nearly in proportion to the cube root of the number of 
plates employed.—Amongst the discoveries to which the 
Galvanic pile has given rise, there are few more interesting 
to general chemistry than the transformation of the alkalies 
into combustible substances of metallic splendour. 
This transformation, first discovered by Mr. Davy, was 
afterwards doubted by Messrs. Lussac and Thenard. In 
their former report they were disposed to consider potassium 
and sodium as combinations of the alkalies with hydrogen, 
and to class them amongst the compound substances called 
hydrurets: subsequent experiments have led them to in- 
cline to the opinion of Mr. Davy, and to regard potassium 
and sodium as simple metallic substances. vis 
M. Berthollet has communicated a process for making 
the muriate of mercury, called mercurius dulcis or calomel, 
by passing oxygenated: muriatic gas through mercury; it 
coinbines rapidly with the metal, and forms with it the 
muriate of mercury; and as this metallic salt has a perfect 
analogy with other mercurial salts produced by other acids 
and mercury at the minimum of oxidation, he concludes 
that the mercury, in forming this combinafion, has been 
reduced to an oxide by the oxygen of the acid, and not by 
that of the water. 
M. Guyton has directed his attention to the mode of 
giving a permanent red colour to glass, by means of copper, 
which by accident he first discovered. might be done. 
; M. Sage 
