D,—No. 14

ANNUAL REPORT ON THE

16

Regarding the modifications which Brown Coals may undergo by natural processes, specimens submitted by Dr. Haast, P.R.S., for analysis of coal altered by contact with doleritic lava, from the Rakaia Gorge, aro very suggestive. Prom the composition of these altered coals, it will" be obvious that the lava, although it has expelled the hydro-carbon, has not affected the coal as in the process of coking, but has changed it into a close compact anthracite, difficult to distinguish from true anthracite in appearance, having a high specific gravity, and altogether so changed that, if it had been found under less clear geological circumstances, it might easily have led to a belief in the occurrence of coal in that locality of high geological antiquity. Analysis of Coal from Rakaia Gorge. Water ... ... 6-76 ... Combustible ... 8578 Pixed carbon ... 64-51 ... Water ... ... 676 Hydro-carbon ... 2T27 ... Ash ... ... 746 Ash ... ... 7-46 ... 100-00 100-00 Coke, per ton... 14cwt. lqr. 151bs. Inquiries having been addressed to the Department as to the most favourable localities for the construction of saltworks, among other information obtained in reply was the composition of the water from the ocean adjacent to New Zealand, as compared with the sea in the Northern Hemisphere ; and Table No. 111., on the following page, gives the results of the analyses performed, which have considerable interest beyond their mere novelty. The thermal and mineral waters from various parts of tho Colony, which have been analyzed, show very curious results, but which having more of a scientific than practical bearing will appear elsewhere. Of the metallic ores analyzed, the most interesting is Dufrenoysite, found by Captain Hutton, at the Great Barrier Island, of which the following is an analysis : — Sulphur ... ... 221 Formula?: Arsenic... ■■■ -■ jjO-J PS -t. A S 3S3 Lead ... ... ... at & —-— , z 100-0 lii addition to which the mineral contains a little antimony, and traces of copper, silver, and iron. Several very interesting metallic minerals have been found at the Thames Gold Pields, such as Native arsenic, sulphide of antimony, copper, and lead. The specimens of supposed auriferous quartz, brought from the Wairarapa by Mr. Groves, although they showed no sign of gold, were found to contain, in addition to sulphide of iron and copper, distinct traces of malachite or carbonate of copper; and Mr. Skey has determined that a very tough description of rock, found as a boulder, by Mr. Bidwill, in the Wairarapa gravels, has the chemical composition of epidote, a mineral usually associated with tin. The great majority of the soils transmitted to the Laboratory, in reply to the circular which was issued last year, have now been analyzed, and the special Report on them is appended hereto. Specimens of the various rocks passed through in excavating the Lyttelton Tunnel, 258 in number, have also been examined, and Table No. IV. gives the composition of the principal^ varieties, as determined by analysis of all the samples which presented a marked mineralogical difference. The results have been reported at length to Dr. Haast, who will apply them to tho elucidation of the geology of the sections which the tunnel affords. Many very interesting chemical points have been determined by Mr. Skey, and contributed a s Papers either to the Wellington Philosophical Society, or to the London Chemical News. In continuation of the list of several papers given last year, I enumerate tho following :— Published in London Chemical Netos. 13. Continuation of No. .11, on certain new Metallic Sulpho-cyanides. 14. Presence of Phosphoric Acid in Opal, Mint, &c. 15. Solubility of Anhydrous Silica in Ammonia. 16. On the coagulation and precipitation of Clay from suspension by Salts generally. 17. On the formation of a series of double Sulpho-cyanides of certain of the Metals with the Alkaloids generally. 18. Absorption of Arsenic, Arsenious and Tungstic Acid, by Charcoal. 19. Continuation of No. 17. 20. Production of a fragrant volatile substance from Eesins by oxidation. 21. New test for Molybdena. 22. On a Sulpho-eyanide of Chromium. Communicated to Meetings of the Wellington Philosophical Society. 23. Solubility of various Alkaloids in Benzone and Kerosine, and their proposed isolation thereby. 24. Notes on a new process for the prevention of the flowering of Mercury when used as a gold solvent in quartz crushing. 25. Continuation of No. 2, showing the solubility of Mercury, Silver, and Gold in Cyanide of Potassium. 26. Solubility of Silver in Bi-ehromate of Potash, and the proposed application of this to tho separation of silver from argentiferous gold.