1872.] Mineralogy. | 261 
by which they are made to yield the greatest amount of sulphur, and are then 
converted into chlorides. The pyrites is first roasted in a series of tall vertical 
retorts, so arranged that each becomes in turn the first, intermediate, and last 
vessel of the set, with respe& to the passage of air or gas through the series. 
A current of chlorine or of hydrochloric acid gas is passed through the spent 
pyrites contained in these retorts and maintained at a high temperature. 
Other improvements in roasting pyrites have been patented by Messrs. 
Perret Brothers and Olivier, of Paris. The heat generated in the furnace in 
which the crude pyrites is roasted is conducted into another furnace, where it 
is utilised in further roasting the ore, so as to drive off the sulphur more com- 
pletely. The operations may be conducted in a single furnace, built with 
several floors, through which the heat circulates. 
From Mr. Hunt’s volume of ‘* Mineral Statistics’? for 1870 we are able to 
extract the following table, showing the quantities and value of the metals 
obtained from the ores raised in the United Kingdom during that year :— 
Pig-iron .. a < ee 5,903,515 tons. 14,908,787 
Tin. Se wa as Sc 10,200 ,, 1,299,505 
Copper... aie ic ic GPG [le fe 551,309 
Lead es te +e er 735420 55 1,452,715 
Zine Sic xe oe ote 3,936 ,, 74,096 
Silver ee 5c we ae 784,562 ozs. 196,140 
Gold Sic TOL 5; 750 
Other metals (estimated) a — 3,500 
£ 18,486,802 
MINERALOGY. 
Among a number of “ Mineralogical Communications” recently made by 
Prof. Vom Rath to “ Poggendorff’s Annalen,” perhaps the most interesting 
are those which relate to the constitution of the felspars. Several lime-soda 
felspars have been carefully examined, including specimens of andesine from 
Vesuvius, Frejus, and Predazzo; of oligoclase from Nieder-mendig and 
Veltlin ; and of labradorite from Iceland. These studies confirm Tschermak’s 
views regarding the composition of the lime-soda series, and tend to show that 
these so-called species may all be represented as isomorphous mixtures of 
albite, or pure soda felspar, and anorthite, or pure lime felspar. Hence we can 
never expect to find an oligoclase quite free from lime, or a labradorite free 
from soda. It has indeed been supposed that the mineral called Evrsbyite 
represents a labradorite without soda, but Vom Rath’s investigations show 
that this species cannot be referred to labradorite, but should rather be placed 
with scapolite. 
In a former number of this Journal allusion was made to the discovery 
of crystals of boracite in the salt-mines of Stassfurt, in Prussian Saxony. 
These crystals have since been described by Dr. Schultze, from whom we learn 
that they were found among the residual matters obtained from the treatment 
of salts which had been raised from the upper beds of these great deposits, 
and had been lixiviated in the chloride of potassium works at Stassfurt. The 
author offers some theoretical views on the probable origin of this boracite, 
and the formation of certain nodules containing alternating layers of boracite 
and other minerals. The double sulphate of soda and magnesia, termed 
Simonyite, has been found in the Anhalt portion of these salt-mines. Simo- 
nyite contains NaO.SO; + MgO.SO3+4HO; and the sulphate of soda present 
in the salt may render it of economic value in the manufacture of carbonate 
of soda. 
Fulianite is the name proposed by Prof. Websky for a new species some- 
what resembling fahlerz, but possessing isomorphous relations with buntkup- 
fererz. It occurs in small groups of cubic crystals, presenting a dark grey 
colour, and containing AszCu3S¢, part of the arsenic being replaced by anti- 
