Progress of Forevgn Science. 139 
that these two metals, when of the same thickness, acted equally 
well. 
The oxide of carbon and oxygen combine, and nitrous gas is 
decomposed by hydrogen at the ordinary temperature, when they 
are in contact of the sponge of platinum. Olefiant gas mixed with 
a proper quantity of oxygen, is completely transformed into water 
and carbonie acid by the sponge of platinum, but only at a tem- 
perature above 300° cent. 
M. Thenard long ago shewed that iron, copper, gold, silver, and 
platinum, had the property of decomposing ammonia at a certain 
temperature, without absolving any of the principles of this alkali; 
and that this property seemed to be inexhaustible. Iron possesses 
it ina higher degree than copper, and copper more than silver ; 
gold and platinum under equal surfaces. Ten grammes of iron 
wire are sufficient to decompose, within a few hundred parts, a 
current of ammoniacal gas pretty rapid, and kept up for eight or 
ten hours, without the temperature exceeding the point at which 
ammonia completely resists decomposition. A tripple quantity of 
platinum wire, of the same size, does not produce a nearly similar 
effect, even at a higher temperature. 
Palladium, in a spongy mass, inflames a stream of hydrogen, as 
well as platinum. Iridium under this form becomes very hot, with 
the production of water; nickel and cobalt, in mass, determine at 
about 300° cent. the union of hydrogen and oxygen ; lastly, the 
sponge of platinum forms, in the cold, water and ammonia, with 
nitrous gas and hydrogen, and acts also on a mixture of hydrogen 
and protoxide of azote. M. Gay-Lussac’s hydrogen lamp answers 
well for the experiment of ascension, as the hydrogen would issue 
in a very small stream. By holding a very light bit of platinum 
sponge, about three quarters of an inch, before the orifice, the efflu- 
ent gas is instantly kindled. This is more convenient than the 
trophorus plate.—Ann. de Chim. et de Phys. xxiii. 440, 
On the Preparation of Oxide of Uranium. By MM. Lecanu and 
Serbat. 
The authors of this process, after having fused the pulverized 
mineral (pech-blende,) with one half of its weight of nitre, washed 
the mass which results from the operation, treated the residiuum 
with nitric acid, evaporated the solution to dryness, and re-dis~ 
solved in water acidulated with the same acid, add to the solution 
an excess of carbonate of ammonia, which, while it is sufficient to 
re-dissolye the whole oxide of uranium, has no action on the car- 
bonates of lead and lime. M. Laugier, in commenting on the 
above process, recommends the use of one part and a half of nitre, 
instead of half a part. ‘The solution containing the nitrate of am- 
monia, and the carbonate of uranium is to be evaporated to dryness 
