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46 Examination of Minerals associated with Serpentine. 
To ascertain whether nickel was contained in the ore where 
it was not visible, as well as to determine the richness of the ore 
in chrome, I selected a specimen for analysis which had a slight 
coating of emerald nickel upon one side. This coating having 
been carefully removed, the rest was broken into minute pieces, 
and those rejected on which a trace of nickel was visible. The 
ore itself was jet black, shining and submetallic, very compact, 
rather brittle, with uneven fracture. Hardness 5:5; streak brown; 
specific gravity 4°568. : 
The specimen, having been finely pulverized, was analyzed in — 
the usual manner, by fusion first with bisulphate of potassa, and 
afterwards with a mixture of carbonate of soda and nitrate of 
potassa. ‘The chromic acid thus obtained in combination with 
the alkalies, was deoxydized by alcohol and . precipitated as 
chromic oxyd by ammonia. The nickel was separated from the 
iron by hydrosulphuret of ammonia and dilute hydrochloric acid. 
The several constituents were carefully reéxamined, and the ab- 
sence of alumina determined. The following was the result of 
the examination: ; 
Cr:Os3 ~ - - - 63:°384 
Fe:O3 - - - - 38°663 
NiO - - - - 2-282 
The analysis calculated into the formula RO, R2Os, excluding 
the nickel, gives FeO Cre Os 93:164+FeO Fe20; 5:298+ NiO. 
2°282=100-744. Ifthe nickel be included in the calculation it 
gives FeO Cr2O0: 93:164+ FeO Fe20s -591+NiO FezOs 7:150= 
100-905. ‘This specimen approaches nearer to the pure chromic 
iron (FeO Cr2Os) than is indicated by any analysis that I have 
yet seen. As the minute fragments exhibited not the slightest 
appearance of nickel, it is evident that the metal is either present 
as sesquioxyd, and therefore mechanically mingled with the ore, 
which is unlikely, or it belongs to the formula, as a replacement 
of protoxyd of iron, which I regard as the most probable view. 
Chrome Sand.—A large proportion of the chrome ore that 
is exported from this country, is obtained by washing the de- 
posits of sand which form in the beds of streams flowing from 
the serpentine. The method of washing employed is similar to 
that used for washing deposit gold, and depends upon the same 
principle, viz., that the metalliferous portions are much heavier 
than the siliceous, and consequently remain when the latter are 
washed away. The deposit being first sifted in water with 
hand sieves, to separate the coarse gravel, the finer sand is then — 
thrown into sloping troughs, through which a stream of water is — 
made to pass, and constantly raked up against the current until — 
all the lighter matter is removed.. The chrome sand on account 
of its superior gravity remains at the bottom of the trough. The 
