12 Improvements in Physical Science (JAN. 
A bar of platinum + of an inch square, and 2-25 inches long, 
was also heated red, and fused at the end. ‘* 
A round bar of platinum, 0°276 inch* in diameter, and 2:5 
inches in length, was heated bright red throughout. 
The chemical effects of this battery were as follows :— 
(1.) Box-wood charcoal intensely ignited in chlorine produced no 
effect ; nor was any effect produced in azotic gas. 
(2.) Oxide of tungsten fused, and was partly reduced. The 
metal greyish white, heavy, brilliant, and very brittle. 
(3.) Oxide of tantalum. A very small portion fused. The grains 
have a reddish yellow colour, and are extremely brittle. 
(4.) Oxide of uranium. Fused, but not reduced. 
(5.) Oxide of titanium. Fused, but not reduced. When in- 
tensely heated, it burnt, throwing off brilliant sparks like iron. 
(6.) Oxide of cerium. Fused; and when intensely heated, burnt 
with a large vivid white flame, and was partly volatilized. The 
fused oxide, when exposed to the air, fell to powder in a few hours. 
(7.) Oxide of molybdenum. Easily fused and reduced. The 
metal is brittle, steel-grey, and is soon covered with a thin coat of 
purple oxide. 
(8.) Compound ore of iridium and osmium, fused intoa globule. 
(9.) Iridium, fused into an imperfect globule not free from cavi- 
ties. The metal was white, very brilliant, and its specific gravity 
was 18°68. 
(10.) Ruby and sapphire were not melted. 
11.) Blue spinell ran into a slag. 
(12.) Gadolinite fused into a globule. 
(13.) Magnesia was agglutinated. 
(14.) Zircon from Norway was imperfectly fused. 
(15.) Quartz, silex, and plumbago, were not affected. 
(16.) Iron containing diamond was converted into steel, and the 
diamond disappeared. 
VI. MAGNETISM. 
1. The magnetometer of Lampadius, described in the Annals of 
Philosophy (vol. iv, p. 434) may be of some use; and might 
perhaps be improved so as to renderit a tolerably correct instru- 
ment. 
2. It is well known that a magnetic needle, if it be poised 
exactly on a pivot before it receives the magnetic touch, will not 
retain the horizontal position after it has become a magnet. One 
end will incline more towards the earth than the other end. This 
is called the dip of the needle. It has been observed, that the 
end of the needle which is turned to the nearest pole is the one that 
dips, and the dip increases as we approach the pole, and diminishes 
as we approach the equator. The dip changes much more slowly 
* There must be a mistake in this number., It represents the bar as smaller 
than the wire, of which eight feet six inches were heated red-hot, 
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