1815.] Royal Society. 69 
broad, joined together by straps of lead and plunged in a mixture 
of nitric and sulphuric acids, diluted with from 20 to 40 times 
their weight of water. By this battery metallic wires were ignited 
in the following order, beginning with the wire most easily ig- 
nited. 
Platinum Copper 
Tron Silver 
Gold Zinc. 
Tin and lead are so fusible, that with them the experiment could 
not be tried. Mr. Children considers the ignitability as the inverse 
of the conducting power of the metals; therefore platinum conducts 
worst and zinc best of the above six metals. When the two poles 
of the battery were connected by two parallel platinum wires of dif- 
ferent sizes, the thick wire was ignited and not the fine one; but 
when the two wires were tied one to the end of the other, the fine 
wire was ignited first. 
Iron wire was slit, some diamond powder put into the slit, and 
this powder surrounded by iron wire above and below. The wire 
was faintly ignited. The diamond powder disappeared and the iron 
was converted into steel and partly fused. This demonstrates the truth 
of Clouet’s original experiment, which was afterwards verified by 
Sir George Mackenzie. Iridium was fused by the battery and re- 
duced to a porous globule of the specific gravity 18°6. Oxide of 
tantalum was fused and reduced. ‘The metal was of a yellowish 
colour and brittle. Oxide of cerium was fused without being re- 
duced. This was the case also with oxide of titanium. Oxide of 
tungsten was reduced and fused. The metal was grey and very 
heavy. Oxides of molybdenum and uranium were likewise fused 
and reduced, and both metals were brittle. 
The titles of the following papers were read, in order to entitle 
them to insertion in the next volume of the Transactions ; want of 
att rendering it impossible to read the papers themselves at full 
ength. 
Considerations on the Solution of Bodies in Liquids, by Mr. 
Daniell. 
On the Dispersive Properties of the Air, by Mr. Stephen Lee. 
Considerations on the Vascular System of Animals, by Dr. Philips. 
The Polar Distances of 30 Circumpolar Stars, by John Pond, 
Esq. Astronomer Royal. 
The Society adjourned during the long vacation, 
N.B. In the last number ef the Annals of Philosophy, the numerical results of seye- 
ral of Mr. Porrett’s analyses of Prussic acid and its compounds were inaccurate, 
The following are the correct numbers, which Mr, Porrett has been so obliging as 
to communicate, 
100 Prussiate of mercury are composed of 
PING ACO tas cies opis ppendhepaeso.geee pide van aene 
