Note.-A few of the names in the preceding list have been purposely inserted twice. By that means, the varities of Garnet can either be kept together as a distinct group; or they can be inserted in the places they would more properly occupy, if arranged strictly according to the chemical composition of each individual member.

The names printed in smaller type are those of varieties of the mineral which they immediately follow.

GEOLOGY, LONDON.

The plan of the Museum of Practical Geology, on the opposite page, is borrowed, with some alterations, from that published in Mr. Hunt's Descriptive Guide. It will be of use by indicating the position and numbers of the Cases referred to in the Glossary. The Wall-cases which contain the collections of British and Foreign ores and metallic minerals, are those situated at the outer margin of the Plan, and the Horse-shoe Case is that surrounding the central area, which forms the glass roof of the Lecture Room.

The following is a general list of the contents of the various compartments into which the Horse-shoe Case is divided, commencing at the southeast end.

a. CARBON (and its natural compounds): - Diamond, Graphite.

Coal, Coke, Bitumen, Lignite, Mellite, Amber, Ozocerite, Hatchettine, &c.

c. SULPHUR, and its compounds.

d. HALOIDS and SALTS.

Common or Rock Salt, Boracic acid, Alum, Cryolite, Nitrate of potash.

Calc Spar, Marble, Stalagmite, or Oriental Alabaster, Ara-
gonite, Dolomite, Fire Marble, &c.

Rock Crystal (and its varieties):-Amethyst, Cairngorm, False Topaz,
Citrine, Morion, Rose Quartz, Ferruginous Quartz, Aventurine, Cat's-
Eye, Chrysoprase, &c.

Amorphous Silica- Quartz, Chalcedony, Carnelian, Mocha-stone,
Agate, Sard, Sardonyx, Onyx, Jasper, Heliotrope or Bloodstone.
Amorphous Silica- Flint, Sandstone, Silicified Wood, &c.
Hydrous Silica- Opal, Hyalite, &c.

Ruby, Sapphire, Schorl, Tourmaline, Emerald, Chrysoberyl, Cymo-
phane, Zircon (Jacinth, Hyacinth), &c.

Garnets (Almandine, Cinnamon stone, Romanzowite, Uwarowite,
Grossular, Dimanthoid), &c.

Idocrase, Topaz, Pycnite, Chrysolite or Peridot, Chondrodite, Spinel.
Felspar (Adularia, Orthoclase, Labradorite), Lapis Lazuli, Mica,
Lepidolite, Gilbertite, Hayne, Jude, Leucite, Rhodonite, Antho-
phyllite, Augite, Epidote, Hornblende, Chlorite, Tremolite, &c.
Serpentine, Steatite, Diallage, Websterite, Cimolite, Bole, Turquois,
Asbestos, Amianthus, Prehnite, Chabazite, &c.

Harmotome, Poonahlite, Heulandite, Apophyllite, Phacolite, Thom-
sonite, Cluthalite, Analcime, Pectolite, Stilbite, Talc, Meers-
chaum, &c.

The British Ores are contained in the Wall-cases numbered 1 to 14, 24 to 36, and 43 to 56; the Colonial Minerals in Wall-cases 37 to 42, and the Foreign Ores in Wall-cases 15 to 23.

The remaining numbers in the square compartments indicate the positions of TableCases, Models, and other objects.