Commissioner, M. Odernheimer.

The most valuable and interesting series in this collection to the geologist and metal manufacturer is the verycomplete group of ores and minerals exhibited by the Government Mining Engineers. The specimens ofhsematite, of nickel ore, of copper and of manganese ore, are particularly deserving of notice, together with theinformation given as to their locality and production. Specimens of clay are exhibited also. These, withsome samples of ultramarine, some miscellaneous articles, and manufactures in ivory, complete the number.The exhibitors amount to thirteen: under the first numeral, however, a considerable number must beincluded.—B. E.

1 The Government Engineers of Mines —in Hiename of the Mining Proprietors ,

Grey copper ore (Fahlerz), containing from 4 to 16ounces of silver in tlie cwt.

[The grey copper ore is found united with lead ore ingreater or less quantity, on which partly depends thequantity of silver contained in the smelted lead.]

Specimens of lead ore; sulphuret of lead, containingfrom 1 to 2 oimces of silver in the cwt.; by the admixtureof grey copper ore, a larger quantity of silver is obtained.

[The mines of lead ore in Nassau are in general of olddate, but many veins have yet to be tried, or to be openedto a greater depth.]

Carbonate of lead, the result of oxidation in the upperand middle parts of the veins, containing sulphuretof lead. The quantity of silver in this carbonate of leadis not inconsiderable. The mines are near Oberlahnstein

and Ems.

Phosphate of lead, found in combination with carbonate°f lead. Remarkable for its crystallization. From thelead mine near Ems.

Specimens of copper ore; from Dillenburg, copperPyrites , containing 30 per cent, of copper.

[The copper of Nassau is of the best quality, but thequantity produced is, at present, small. Engines fordraining the deeper mines are about being erected.]

. Specimen of Kupferinclig (sulphuret of copper, contain-lll g 66 per cent, of copper) ; found associated with copperPyrites . Ferruginous red oxide of copper with malachite(green carbonate of copper); the produce of oxidation inthe upper part of the copper veins.

, Zinc ore, sulphuret of zinc. This ore fills part of theead veins, and has been used of late years for producingMetallic zinc.

Manganese ore, pyrolusite (the greatest part) and psilo-^lane, peroxide of manganese. District of the Lalm.

[The mines of manganese ore in Nassau have been openedUicfly within the last 15 years, and yield a vast produce.

[Official Ili.ustr.

The quantity raised every year is above 20,000 tonsEnglish , and the ore is exported to all quarters of the world.1,200 persons are employed in the mines and washing-mills. Manganese ore is used for extracting chlorinein the manufacture of soda from common salt; for glazingin potteries; for whitening glass, &c.]

Specimens of iron ores, red haematite, red oxide of iron.

[The red haematite is raised in numerous mines, in verygreat quantity: it yields iron of superior quality, in thefurnaces of Nassau , worked with charcoal. This iron oreis also exported to the coal districts of Germany and toFrance , for the purpose of improving iron. From 1,500,000to 2,000,000 cwts. of iron ore are raised every year, ofwhich the half is smelted in Nassau . Part of the iron orecontains ealespar, and is used in that state as the bestadmixturo for smelting. Magnetic iron ore, oxydulatediron. This ore is found united with red haematite. Hy-drous oxide of iron, brown haematite— stilxuosiderite. Thisore is found in Nassau in great quantities: it is chieflyworked for exportation, and is used especially for pro-ducing hard steel. Spathose iron; from Haclienburg.There are only a few mines of spathose iron in Nassau ,near the Prussian country of Siegen; the ore, and the steelproduced from it, are much esteemed.]

Specimens of bituminous coal or lignite—of remarkablewood-like character, covering a space of about 100 English square miles; used in Nassau and the neighbouringcountries as the principal household fuel. For technicalpurposes the lignite is valuable. -A.t present the yearlyproduce amounts to 1,200,000 cwts., but the quantitywhich can be raised is incalculable.

Slate. The mines of slates in Nassau near the Rhine and Lahn are of good quality.

Heavy spar, sulphate of barytes.

[This spar was formerly not worked in great quantities,but new discoveries of rich veins promise a considerable

iatf.d Catalogue.]

4 M