450 Transactions.— Geology. 
Rep., 1870-71, p. 5), is probably a misprint, no such mineral, as far as I am 
aware, being known. He also, page 148 of the same volume, without descrip- 
tion, mentions the occurrence of ‘ oxide of silver, and probably sulphate ot 
silver,” from the new Golden Crown Claim, but as neither of these minerals 
are mentioned in Dana’s mineralogy, I am unable to say to what he refers. 
Mercury. 
This metal has been found in New Zealand, both in the native state and 
also as Cinnabar, but only so far in small quantities. 
Native Mercury, Hg, occurs at Waipori, in the district of Otago, where 
it is found in the alluvial wash of the district as small globules, and also 
alloyed with gold to form amalgam (Hector, Jurors’ Rep., p. 404). Native 
mercury also occurs at the Ohaeawai Springs, near the Bay of Islands, but 
only in small quantities. It has been known since 1866, and in 1870 Captain 
Hutton described a visit to the locality (Trans. N.Z. Inst., vol. iii., p. 252), 
and the mode of occurrence has since been described by Dr. Hector (Geol. 
Rep., 1874-76, p. 5), as follows :—** The Ohaeawai Springs deposit a brown 
sandstone, which forms laminated beds 10 feet to 15 feet in thickness. This 
sand, which is an incoherent granular siliceous deposit, includes fragments 
of the surrounding vegetation, and thin layers of Cinnabar sand and globules 
of Metallic Mercury. The layer of sandstone containing mercury is only 4 
inches thick, and is confined to a very limited area, and the attempts made 
to collect the mercury have not, hitherto, been profitable.” 
Cinnabar, Hg’.—This mineral occurs as rounded grains in the alluvial 
deposits of the Obelisk Ranges, Potter’s Gully, Dunstan, Serpentine Valley, 
and Waipori, in Otago (Hector, Jurors’ Rep., pp. 264, 436), and also in the 
deposits of the Ohaeawai Springs previously mentioned. 
Art. LXXII.—On Crystalline Rocks. By W. D. Camesetn, F.G.S. 
[Read before the Auckland Institute, 11th July, 1881.} 
Crystaitine rocks occur as altered sedimentary deposits, and comprise most 
of the eruptive rocks; the latter are to a great extent crystalline at the time 
of their formation, while the former were originally loose accumulations of 
various particles for the most part. Both kinds of rocks are subject to 
changes of condition which are termed metamorphism, by which the 
internal texture and composition have been altseoa gradually by chemical, 
electric and crystallographic action, by the withdrawal of, or addition, oF 
substitution for some of the chemical elements, aided by heat and watery 
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