¢ 
Foreign Literature and Science. 195 
day, during a specified time. No children are to be employ- 
ed in manufactories, under nine years of age. he wails 
and ceilings are to be white-washed once a year. The pen- 
alty for an infraction of the law, is a fine, in each case, not 
less than £10, nor exceeding £20 sterling. 
16. Refrigerating Compound.—I have analyzed, (says M. 
Vauquelin,) an English refrigerating salt, of which the fol- 
lowing is the composition: 
uriate of potash 57 
- Muriate of ammonia ~ 32 
ra Otas 10 
This salt, put into 4 parts of water, and agitated promptly, 
reduced the thermometer from 20 4-to—5° Reaumur’s scale, 
(=779+ to 21°+Fah.) Synthesis furnished a salt havi 
the same properties.— Bul. Univ. June, 1826. Hates 
17. Dry Voltaic Batteries. Extract froma Report made 
to the French Academy of Sciences, by M. AMP” RE, on the 
dry piles of M. ZamBont. We find in this memoir, besides 
we ; 
the description of some apparatus which the pi p in 
continual motion, the following results. 
Thee of the dry pile ceases at the end of two years. 
M. Zamboni has ascertained this by an experience of twelve 
years. The diminution in the two first years, varies accord- 
img to the manner in which the pile has been constructed. ~ 
The pile is more energetic in summer than in winter, in 
regard both to the tension which is produced, and the promp- 
titude with which it is manifested. ; 
he tinned paper, commonly called silvered paper, devel-_ 
with the black oxide of manganese an electric force ve- 
ry superior to that which is obtained when the paper is cov- 
ered with copper: this last is known by the name of gilt 
per. 
ae pile formed with disks of paper, tinned only on one 
- side, without any substance interposed, gives electrical effects 
which must arise from the mere circumstance of the metallic 
plate, which is pasted to the upper surface of the paper, touch- 
ing it more closely and rset Me ae it is aaa its 
turn by the inferior paper of the stratum placed above it. _ 
Zaraboni has ess. in these piles, which he calls bina- 
ry, whether the action of the elements takes place as in those 
which are composed of leaves of tin, covered with oxide ef 
