صور الصفحة
النشر الإلكتروني

P. S. The following list of the species of Paradoxurus cum Paguma, according to various authorities, may be useful.

[merged small][merged small][ocr errors][merged small][merged small][merged small][merged small][ocr errors][merged small][merged small][merged small][merged small][ocr errors][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][ocr errors][merged small][merged small][merged small][merged small][ocr errors][merged small][merged small][merged small][merged small][merged small][merged small][merged small][ocr errors][merged small][merged small][merged small][merged small][merged small][merged small][ocr errors][merged small][ocr errors][merged small][merged small][merged small][merged small][merged small][merged small][merged small]

Description and Analysis of the new Mineral NEWBOLDITE, sent from Southern India by Captain NEWBOLD, Madras N. I., Assistant to the Resident of Kurnool.-By H. PIDDINGTON, Curator Museum Economic Geology.

I had mislaid (that is, too carefully laid by) this specimen, and feared for a long time that I had lost it, but fortunately finding it, I have not again delayed to place it in our collection, and to give to our valued correspondent Captain Newbold the credit which he deserves for his discovery; which is that of adding not only a new mineral, but, as will be subsequently shown, establishing a new family of minerals, of which we may hope for more genera as our acquaintance with Indian mineralogy (perhaps we might say with mineralogy in general?) augments.

* General aspect of Bondar, but with four continuous dorsal lines and face marks as in Nipalensis. Habitat exclusively monticolous.

Our entire specimens are unfortunately very small, and thus I have been excessively cramped in my researches, for as will be seen, it is scarcely possible to obtain pure fragments even of a very small size.

I should describe it, as to external appearance and physical properties, as follows:-It is, where purest, and not weathered, of a clear apple-green, with considerable lustre on some of the facets of the numerous imperfect crystals of which it is formed, giving it the pearly glimmer of a green mica or of some of the green carbonates of Iron in a good light. Where weathered it is of a bluish grey-green, and the glauce is more minutely silvery or micaceous, or at times steel-like.

Minute fragments of the pure mineral are semi-translucent at the edges, like those of fine apple-green serpentine.

When powdered its colour is of a very light greenish buff or fawn colour, becoming a little darker, or greenish, when exposed to a very gentle heat to drive off the little water it contains. When pulverising, if smartly rubbed or struck it emits a very perceptible odour of sulphuretted hydrogen.

Its hardness is 3-4 scratching Calc-spar, but not Fluor.

The streak is of a dirty fawn coloured white, but always with a minute silvery line at the centre where the knife has cut.

It has a slight earthy smell when breathed upon. It is brittle and easily pulverised.

The fracture is hackly, and highly glistening; the fragments are at times laminar and angular, but in truth they are so small and the nests and veins of the mineral so diminutive that it is not fair to judge of these characters. It seems to cleave readily in certain directions, but what these are cannot be judged of yet; the larger fragments incline to cubical on rhomboidal prismatic forms.

It does not soil, or mark, or adhere to the tongue on the fresh fracture.

The crystals are too small, confused and imperfect to judge well of their form, which however appears to approach to that of rhomboidal prisms.

The mineral seems much subject to decay by the oxidation of the iron, which is distinctly seen in some parts, leaving in the quartz what are called in Cornwall vuggy cavities (i. e. rough, jagged, and full of irregular ridges) coated with the peroxide of iron.

It occurs in very small nests and veins in masses of milk quartz. With one of the specimens of milk quartz there occurs a mass of bluish sulphate of Baryta, and another specimen is in a bluish very fine granular mass of sulphate of lime.

Its specific gravity I should estimate at about 4.25, to 4.50, calculated from a piece which was about half matrix, but this is a mere approximation.

In the tube and bulb tube it decrepitates and flies to pieces with a complete explosion, sending the fragments sharply into the face and eyes when tried on platina foil, as soon as heated; these fragments are mostly imperfectly cubical or rhomboidal.

It was found to contain about 1 per cent. of water when reduced to powder.

Nothing sublimes from it at the red heat of glass; but when driving off the water a slight odour of sulphur seems apparent from the crucible.

BLOWPIPE.-Alone.-A small fragment is infusible, but becomes of a dirty yellowish white, and is not magnetic. This, apart from its sulphur (subsequently shown) at once distinguishes it from Spathose Iron, for some of the green semi-transparent varieties of which, from its colour and decrepitation, it might be mistaken on mere inspection.

With Borax it is not very fusible; the bead transparent, yellowish, and slightly tinged with green.

With Soda fuses to a dirty brownish opaque bead; nothing is reduced from it; when moistened and a little fresh Soda added, the bead gives out the smell of sulphuretted hydrogen common to all the sulphates and sulphurets when heated with Soda, and it discolours silver foil.

With phosphate of Soda.-On charcoal, and the cake transferred to platina wire, a dull milk-white semi-transparent bead.

The powder saturated with Nitrate of Cobalt, and heated on platina foil, is of a dull brown.

Via Humida.—It dissolves readily in the mineral acids. Acetic acid does not appear to affect it. With concentrated hydrochloric and sulphuric acids much sulphuretted hydrogen is evolved. Boiled in nitro-hydrochloric acid it dissolves rapidly without evolution of sulphuretted hydrogen in any considerable quantity, if at all, and leaves

a flaky white residuum which coagulates into a soft globule floating on the solution, which is pure sulphur.

If the boiling is gentle the sulphur is obtained in a light flake.

The solution of the pure mineral in nitro-hydrochloric acid when filtered from the sulphur is of a pale gold colour. When evaporated it crystallised largely in minute silky needles, which appear in mamillated or concretionary heaps if the evaporation is slow. They are apparently insoluble in water, and in the mouth, with a slight astringency, (probably from the muriate of iron) they are tasteless and lumpy like argillaceous earth, though without any decided taste except an earthy one. The muriate of iron gelatinises amongst them. The concretions are soluble in nitric acid. At a red heat on platina they become dull but do not otherwise alter.

To re-agents the solution gives as follows:-To Sulphide Ammonium a dirty greenish-brown precipitate with black grains, which becomes of a sooty black, soluble in muriatic acid.

Yellow Prussiate of Potass very pale bluish white.

Caustic Potass very pale amber-white precipitate, plentiful. Carbonate Potass, as Potass, but partly soluble in Ammonia. Ammonia.-Sparingly, the reddish precipitate of iron; and a white precipitate with excess.

Tinet: galls.-Brown colour, but no precipitate.

Oxalic Acid.-A precipitate, soluble when ammonia is added. Phosphate Soda.-White precipitate soluble in ammonia and in acids. Re appears with Potass.

Cyanide of Potassium.-A dirty amber-coloured precipitate.

By Wollaston's process (Carbonate of Ammonia and phosphate of Soda.)-A plentiful precipitate, like that of the Phosphate of Magnesia is obtained.


I have already adverted to the extreme difficulty of obtaining any portion of the mineral pure enough for an analysis. The process adopted was to pulverise the mineral and,

1. Dissolve it in nitro-hydrochloric acid, at a boiling heat.

2. Filter to separate the sulphur and silex.

3. Burn off the sulphur from the silex.

4. Precipitate the sulphuric acid formed in the solution by nitrate

of Barium, and add the equivalent weight of sulphur to that obtained in the solid state.

5. Precipitate by carbonate of potass in excess.

6. Digest again in nitric acid and precepitate the iron from the solution by Ferro-Prussiate of Potass, allowance being made for the Iron it contains. The solution evaporated is gelatinous, and this when calcined is the earth.

The results of the best of three analysis in which the assay was obtained by picking minute fragments with the forceps and examining them by the magnifier, but of which I could only collect 7.33 grains, gave—

[blocks in formation]

As the proportion of sulphur is so large, we may at once assume that the iron is a bi-sulphuret, in which case the 22.92 per cent. of iron would require 28.84 of sulphur ; leaving thus 22.59 per cent. of sulphur to combine with the 17.86 per cent. of the earth.

The earth is obtained in so very small a quantity that it is impossible to do more than describe it and its peculiar properties, so far as they can be ascertained with any degree of certainty, and wait till a better supply* of the mineral enables us to determine it.

This earth is of a pure white; of a granular appearance under the magnifier, light and powdery in the crucible, and not lumpy like Alumina.

BLOWPIPE. When heated to a white heat on Platina, no change : moistened and placed on Turmeric and litmus papers no effect, nor does it give any remarkable light.

* I have received an additional supply of the mineral, but unfortunately it is only very minute veins or nests, and this time in the red carbonate of Cerium, described in the Journal, Proceedings, July, 1846.

« السابقةمتابعة »