Foreign Literature and Science. 349 
The following method-of producing pictures of metallic ve- 
— by M. Goldsmith, has been read before the French 
titute. Place a few grains of iron and copper filings on 
a glass plate at a certain distance from each other. Add to 
each parcel a few drops of nitrate of silver ; the silver is soon 
Seropitefed | ina metallic state, while the copper and the 
on are oxidated and coloured. Then with a small stick ar- 
range the ramifications of the silver, while the flame of a taper 
placed under the glass, promotes the evaporation of the flu- 
id, facilitates the reaction’of the materials, blackens the 
plat e, and thus forms the ground of the picture.—An. de 
Chimie, Mai 1820. 
Thenard has succeeded in causing pure water to absorb 
oxygen to the enormous extent of six hundred and 
‘times its volume. The process is complicated. The prin~ 
cipal agents he employs are barytes, and muriatic and sulphu- 
ric acid. The oxygenated water has a taste slightly astrin- 
gent and bitter. It whitens the epidermis and occasions 
very pungent sensations. A great number of the metallic 
oxids act upon it with such energy as to produce explosions. 
An. de Chimie. 
TNotices icated by aC Jent.1 
pireuce. Ps wv J 
Boracice Acid. 
bout two pr. ct. of Boracic Acid has been obtained by 
evaporating the waters of the lakes in Cherchaio, and it has 
en proposed to deliver this acid in Paris, in any quantity, 
at three frances the kilogram. The acid is in small greyish 
scales, taste slightly bittter, lrg solution reddens, litmus, 
Xe. Tilloch’s Phil. Mag. Dec. 1819. 
** M. Lucas, in a letter to M. Arago, sean the occur- 
rence of boracic acid in the water of cano. It is found 
on the surface, at the parts most nite = where vapors 
are continually rising. It occurs in a very white light state, 
though sometimes soiled, and sometimes mixed with sul- 
phur. The crusts are generally about three quarters of an 
inch in thickness, and sometimes above a foot in extent. It. 
Vou. H.iNe. 2 45 
