Foreign Literati Sivhitienn Cli, 183 
per bt enciiintione above a plate of m marble. 2 
112 over a stratum. an MOSSES. = lines thick. 
rae sp over a plate of Bismuth, 
= * *Jatina, - a - “6 
. 90 > ae” +) ROY, 
a 89 be: q, Lead, = By 8 hong 
SReie 1 050.9 « ~Gold, - - 2,9 * “ 
Bil oie - i ee “ 
SEE xs lB aise pad om & 
eee - - Brame, ~ iy AAD Ao canals 
62. - - ~~ Copper, x-5 odo 4, fen 
5. ne nears ot a se 
The author sscartenan by. experiment, “hal the metallic 
nature of the m ggoded pidge had the same. influence on 
b 
the metals, which, like 1 0m, witkel 2 nd cobalt, are magnetic, 
with others, w ich, ntimony, diminish. the magnetic 
force,—c —compounds are formed, which have no: influence on 
He. thus found 
suitable for compasses, and that that of | copper ed nickel 
deserves, the preference, get th iebene the most malleable. 
—Ferrussac’s Bull, Aout, 1 
29, Artificial Spider’s web for micrometers-—Dissolve, to 
a convenient extent very thin caoutchouc in very pure spiri 
of turpentine. By drawing out the solution, extremely fine 
and smooth threads are onaieas whieh when dried, are ve- 
ry goad for micrometers.—. 
30. Analysis of Potteries. _M. e Berthier has examined 
the composition of several kinds of pottery ware. He dis- 
ishes them into three sorts—Ist, porcelains, 2d, potte- 
ries, 3d, Fucibles: : 
