'H.AB.'DMAi^i— Zinc for Magnesium in Minerals. 537 
tion of hydrogen in a barely acid solution of hydrochloric acid ; the 
solution evaporated, moistened with nitrate of cobalt, and heated be- 
fore the blowpipe, gave the characteristic green reaction. 
4. jSerpentine {?). — A green, soft, steatitic rock, from Garrarus 
strand, near Tramore, Co. "Waterford. This rock occurs among silurian 
limestones and slates, near masses and dykes of felstone, &c. Some of 
the limestone can be seen to pass into serpentine. 
Examined qualitatively for zinc : found it present in fair quantity. 
The rock contains about eight per cent, of water, and eleven per cent, of 
carbonic acid,"^' being evidently a passage rock. 
5. Basalt, Ho. 2, from Curglasson ; already described. 
6. Black Mica, in a gneissose or granitic rock. Locality unknown. 
Specimen from Geological Survey collection. I The mica is perfectly 
black, and occurs in quantity, in small flakes thickly massed together. 
About four grains were treated at a time, before the blowpipe, with 
carbonate of soda; After fusion, the mass yielded a notable quantity 
of copper, a very appreciable amount of zinc, and a trace of a metal 
supposed to be lead. All the characteristic tests for zinc were answered 
very distinctly, 
7. Chlorite Schist (? Talc Schist), from Geological Survey collec- 
tion, with enclosed grains of glauconite. — The examination with the 
blowpipe gave two metals, copper and zinc, both in very appreciable 
quantity. The zinc reactions were very pronounced. 
8. "Mountain Leather,^^ Ya,vietj of asbestos; from Portlock's col- 
lection, Geological Survey Museum. Locality unknown, but associated 
with basaltic minerals from Antrim. Zinc very apparent, all the re- 
actions being most distinct. A trace of lead also observed. 
9. Augite.% — Yery large crystals in a trappean ash. Locality un- 
known. Geological Survey collection. About four or five grains of the 
powdered mineral, fused with carbonate of soda on charcoal, yielded a 
sufficiency of metal to identify with certainty. Besides zinc, copper 
was present. The zinc reactions were most distinct. 
These rocks and minerals are not selected from a number contain- 
ing specimens in which no zinc was found, but comprise all that I have 
as yet examined for it. They were for the most part chosen on account 
of containing, or being themselves, magnesian compounds; and they 
are numbered in the order in which they were tested, none proving 
blank. In many cases the examination by the blowpipe and its imme- 
diately-connected wet tests were found to be amply sufficient to prove 
* Carbonic anhydride, C O2. 
t The specimens from the Geological Survey Museum were obtained by the kind 
permission of Prof. E. Hull, F.R.S., Director of the Geological Survey of Ireland. 
J Zinc is recorded as occurring in Augite in one instance ; JefFersonite ; a lime- 
iron ; Manganese ; Zinc pyroxene; in Dana's Manual of Mineralogy (1854). As only 
the same specimen is given in the new edition (1874), I conclude that no account of 
any other has been published. The analysis itself was published in 1822. [Added in 
Fress.] 
