‘ 
a ae 
1875.1] Mineralogy. 395 
before the Tyne Chemical Society, by Mr. T. Gibb. has recently been published 
in the ‘‘ Chemical News ” (April 16). After describing the ordinary process of 
treating burnt pyrites by the wet way, he refers to Claudet’s method of ex- 
tracting the small proportion of silver, and then describes his own process for 
effecting this extraction as practised by the Bede Metal and Chemical Com- 
pany. This process consists in precipitating the greater proportion of the 
silver from the copper liquors by means of sulphuretted hydrogen, only a 
small proportion of copper being simultaneously thrown down. The sul- 
phuretted hydrogen is economically obtained by the action of dilute hydro- 
chloric acid on ‘‘tank waste.” This sulphuretted hydrogen, mixed with 
carbonic acid, and diluted with a large volume of atmospheric air, is blown 
through the copper liquors for about twenty minutes. The precipitated 
sulphide of silver is calcined at a low temperature, and then ground and 
lixiviated, first with water, to dissolve sulphate of copper, and afterwards with 
a hot solution of common salt, to dissolve out the chloride of silver which is 
present. The solution is mixed with milk of lime, and the precipitate, 
having been washed, is digested in dilute sulphuric acid, and again washed 
and dried. 
An improved method of preparing metallic barium has been devised by M. 
Sergius Kern, of St. Petersburg (‘‘ Chemical News,” June 4). He precipitates 
iodide of barium by the action of iodine on barium hydrate, and then decom- 
poses the iodide by heating it with metallic sodium. Barium is separated 
from the resulting mixture by means of mercury, and this metal is then 
distilled off from the amalgam, and the barium thus obtained in a free state. 
MINERALOGY. 
A short time ago a nickel ore from New Caledonia was described by Prof. 
Liversidge, of Sydney, under the name of Noumeite, after Noumea, the capital 
of the island. According to a paper since read before the Royal Society of 
New South Wales, it appears that the Rev. W. B. Clarke has suggested that 
the name of Garnierite should be bestowed on this mineral, since M. Garnier, 
a French geologist, some years ago obtained a similar mineral from New 
Caledonia. But the greater part of the nickel ore as shipped to Sydney con- 
sists of a similar mineral,—a hydrated silicate of nickel and magnesia,—but 
of a much darker apple-green colour than Garnierite, and to this second 
mineral Liversidge has now given the name of Noumeite, which he formerly 
applied to the paler variety. Both minerals are evidently products of decom- 
position, and Garnierite may perhaps be only a more highly altered form than 
Noumeite. 
Prof. Church has contributed to the ‘“*Chemical News” (April 9) some 
* Short Notices of some Cornish Minerals.” Specimens of a very pretty 
pink variety of soap-stone, resembling some of the Chinese figure-stones, 
were obtained from Mr. Talling, of Lostwi:hiel, and on analysis were found 
to consist of a hydrous silicate of magnesia, in which one-fourth of the mag- 
nesia is replaced by water: 3MgO.H20.4Si03. 
Some grains of gold from Ladock, in Cornwall, were found, by Prof. Church, 
to contain—Gold, 92°34; silver, 6:06; iron, a trace; silica and loss, 1:60. A 
fine specimen of filiform native silver, obtained many years ago from Huel 
Herland, in Cornwall, gave—Silver, 99°05; iron, 0°59. Neither gold nor 
copper was present, and the iron might be derived from traces of associated 
iron-pyrites. 
Under the name of Cossaite Prof. Gastaldi has described a mineral appa- 
rently identical with paragonite, from which it differs in the absence of mica- 
ceous cleavage. It was found first in an antique ring dug up near Turin, but 
has also been found in other localities. 
Several analyses of mineral phosphates extensively imported into Hamburg, 
from Estremadura, in Spain, have been contributed to a recent number of the 
‘Chemical News,” by Dr. B. C. Niederstadt. The average proportion of 
phosphoric anhydride is about 28 per cent. 
