in the November and December Numbers of the Philosophical Magazine for 1861. Other notices by the same author were communicated and commented upon by Mr. R. P. Greg at the Manchester Meeting of the British Association. Meantime the Imperial Museum had received specimens of the Tula iron from Dr. Auerbach, and a rich collection of East-Indian meteorites through Dr. Thomas Oldham's kind intervention; and Messrs. Laurence Smith, B. V. Marsh, H. A. Newton, Baron Reichenbach, and others had published their theoretical views on meteorites. Dr. Buchner had lectured on the same subject at the thirty-sixth Meeting of German Naturalists at Spire, 1861. Another paper by von Haidinger had been communicated to the Academy of Paris by M. Elie de Beaumont*. The collections of meteorites have been greatly augmented since then. The Museum of Munich numbers (March 1, 1868) twenty-two localities of iron or of lithoid meteorites; the University Museum of Göttingen (July 1, 1868) 176 localities, 99 of lithoid meteorites, 77 of meteoric iron; the Museum of the Geological Survey of India in Calcutta (December 1867) 254 localities, 159 of lithoid meteorites, 95 of meteoric iron. XXXV. Contributions to the Mineralogy of Nova Scotia. By Professor How, D.C.L., University of King's College, Wind sor, N.S. [Continued from vol. xxxv. p. 41.] IV. Lignite-Semibituminous Coal-Cannel Coal-Turgite Delessite-Fahlunite-Silicoborocalcite. LIGNITE. In the eastern part of the province there are found in the carboniferous districts, but apart from the beds of coal, sulphides of metals associated with coaly matter having the characters of lignite. The sulphides are relatively large in quantity, and frequently consist of iron and copper pyrites, with a very rich sulphide of copper, apparently vitreous, though called grey. The enclosing rock of such specimens of these copper ores as I have seen is sandstone, and it is generally more or less impregnated with green carbonate. In one instance galena occurs with iron pyrites in a conglomerate of limestone and siliceous pebbles. The masses composed of the carbonaceous and metallic minerals generally exhibit the form of branches and trunks of trees; and Dr. Dawson points out that those containing copper result from the action of vegetable matter on waters containing sulphate of the metal. The formation of *See Comptes Rendus, vol. liii. (1861) pp. 456–461. † Acadian Geology, p. 327. galena would involve some secondary action. The deposits are not thought to be of mining-importance, except in two instances, in which the ores of copper are considered to exist in promising quantities: in one of these, indeed, lately discovered there is said to be a bed some feet thick; a sample of the ore sent me gave 29.5 per cent. metallic copper. I have not been able to find more than one complete ultimate analysis of a lignite; this is one of the fourteen analyses given by Dana*. In a minority only of the others is the existence of nitrogen mentioned; the quantity is given in no case but that referred to, the analysis of Vaux, who found 0.57 per cent. From this result and the following ultimate analysis of a lignite from one of the deposits above mentioned, for which I am indebted to Professor Anderson of Glasgow, it appears that the quantity of nitrogen is somewhat less in this mineral than in black coal. The lignite selected for examination occurs in the carboniferous district of Pictou county, with copper ore and common iron pyrites. It is nearly black, and retains on some faces a finegrained woody structure, not very obvious to the naked eye, but distinct under a glass: these surfaces are dull; those at right or oblique angles are black, of almost resinous lustre, and without structure it is sectile, and easily broken into angular fragments which receive polish under the burnisher. The mineral evidently belongs to the variety of brown coal called jet. Boiled in potash, it scarcely colours the fluid. Ignited, it gives a transient feeble yellow flame, and afterwards glows for a considerable time, evolving the greasy odour often observed with lignite; in a closed tube the product is chiefly water with a little yellowish matter; the vapours have an alkaline reaction. Ultimate analysis gave : It does not appear that any inquiry has been made as to whether lignites vary in composition according to their geological age. As the circumstances under which they were formed must have been analogous, the only differences to be expected at the corresponding stages of conversion are those depending on variations in the original material. Hence nothing like strict comparison can be made; the following, however, is not without interest. The large deposits of brown coal found in Germany * Mineralogy, 5th edit. p. 758. are of tertiary age; and Liebig has shown* that there is a notable difference among these in chemical composition. The more complete the obliteration of the woody structure, the greater the departure from the relative proportions of the organic elements in the original material. The wood-coal from Ringkuhl, near Cassel, is seldom found with the structure of wood, and is therefore more comparable with the Pictou lignite than any in which this is retained; its composition is given as is added as deduced from these numbers: for comparison' sake I have calculated a corresponding approximate formula from the analysis of the Pictou lignite; it is C32 H12 08. Hence, as compared with wood, for which Liebig gives the formula C36 H22 012, there is a further loss of one atom of water and two atoms of hydrogen, marking the difference between the carboniferous and the tertiary lignites in question. As I have before pointed out†, the true ratio of carbon to hydrogen, in such minerals as contain these elements together with oxygen, is only brought out after deducting the amount of hydrogen equal to that of the latter element present. In the case of the two lignites just spoken of, the ratio stands thus: Pictou. Ratio of C to H without deducting 100: 5.77 H=0 present Ratio of C to H after deducting H=0 present. Ringkuhl. 100: 7.52 }: The effect of this deduction is obvious enough; at the same time a very close accordance is exhibited in the ratio between the remaining elements. How much this differs from that existing in bituminous coals is seen by the following comparisons. While numerous coals of the province have been submitted to prismatic Agricultural Chemistry, 4th American edit. p. 368 et seq. † Mineralogy of Nova Scotia, p. 25. analysis*, one only has had its ultimate composition determined, that, namely, found at Springhill, Cumberland county. All the true coals of the province are bituminous, and they would, no doubt, give results comparable with those from the Springhill coal below and the bituminous coals now selected as representatives from among those analyzed by myself during the British Admiralty Coal-Inquiry†. Semibituminous Coal.-On the line of railway between Truro and Pictou, about twenty miles from the former town, a curious "vein" is found between slaty walls, consisting of black lustrous mineral formed into a sort of network by the intersection of numerous cross veins of fibrous ferriferous carbonate of lime, the whole being two or three inches thick. The black mineral looks something like graphite, is rather hard, H.=2·5, and very brittle; ignited, it gives a luminous white flame, exfoliates, smells strongly of sulphurous acid, and burns with some difficulty to a reddish ash. In a closed tube it does not melt, scarcely changes its form, gives but a small quantity of smoke and oil; the fumes are very acid. For the carbon- and hydrogen-determinations which follow I am indebted to Professor Anderson. Ultimate analysis gave: * Loc. cit. p. 33, and Dawson's 'Acadian Geology.' The residue, or "coke," consisted of a powder unchanged in appearance from that put into the crucible. The foregoing results indicate a semibituminous coal: the mineral differs widely from the bedded coals of the province, which, as before mentioned, are bituminous; some, indeed, are so in rather a high degree. The mode of occurrence of this coal (the only one I have met with here approaching anthracite) is curious, and worth further investigation. Cannel Coal.-A specimen "from an 18-inch seam at Little Glace Bay, Cape Breton," had the appearance of cannel coal, gave a brown powder and a brownish-black streak, burned alone when well heated in a flame, in a closed tube gave much volatile matter, and left a rounded swollen coke. Proximate analysis gave me : Moisture The amount of ash here, though considerable, is smaller than that in the well-known Scotch cannel from Capeldrae, which gives, according to Fyfe, 25-40 per cent. The volatile combustible matter is evidently high enough, in proportion to the fixed carbon, to mark the class of minerals to which the specimen belongs. This is the first example of Nova Scotian cannel coal yet examined, unless, as would be right according to some authorities, now perhaps diminishing in number, the remarkably rich oil-coal which I have called stellarite * is made to belong to the class. Turgite. This well-defined species may be recorded among the minerals of iron met with in the province. It occurs with brown hæmatite at Terry Cope, and at another locality, probably in the same county of Hants, according to my own examination of specimens sent me, and it will doubtless be found frequently elsewhere in the same association. Both the specimens in question afforded red powder, gave water on ignition, and decrepitated violently in the forceps before the blowpipe. The mineral from the last-mentioned locality was mixed with siliceous and calcareous matters; when these were deducted, the constituents of the air-dried substance were: Water Peroxide of iron 5.51 94.49 100.00 The formula of turgite, 2 Fe2O3 + HO, requires 5.32 per * Mineralogy of Nova Scotia, p. 24. |
