As a supplement to the collection of simple Minerals, is arranged, in case 41, a group of natural substances which either belong or are closely related to the Mineral Kingdom, although, in the formation of most, organised matter has played a very important part. The most important of these are Coal and Amber. Coal (41a), in most of its varieties, gives structural evidence of its vegetable origin: its chemical composition depends on the amount of change which has taken place, and thus is less definite than in the preceding minerals. In the variety called Anthracite all traces of the original organised structure have disappeared. Amber (41c), in ancient times regarded as one of the precious stones, is likewise of vegetable origin. It is fossil resin, chiefly derived from trees allied to the pines; its originally sticky condition is proved by the insects sometimes found enclosed. [Sidenote: Larger Mineral Specimens.] In the pavilion at the east end of the gallery the visitor will find many mineral specimens which, owing to their size, cannot be satisfactorily exhibited in the table-cases. Among these, attention may be directed to the magnificent series of Minerals in the wall-cases, and to the large specimen of Gypsum, or Selenite, presented by H.R.H. the late Prince Consort, which, with some fine masses of Iceland Spar, is exhibited in a special case. Of the four table-cases in the windows of the pavilion, the first three contain a series illustrating the various kinds of Pseudomorphs, or minerals in which the original constituent has been altered and replaced by a new substance which preserves the crystalline form of the first. The fourth displays a set of specimens selected by the late Professor Ruskin to illustrate varieties of Silica.[24] [Sidenote: Meteorites.] The most important feature of the pavilion is the collection of Meteorites,[25] of which the smaller specimens are shown in the four central cases. The fall of masses of stone and iron from the sky, though observed again and again since the most remote ages, was very rarely credited by anyone beside the spectators themselves; and till the beginning of the nineteenth century no attempt was made to collect such specimens for examination and comparison. In the special guide it is shown how evidence of the actual fall of such bodies at length became irresistible, and a description is given of the circumstances attending their fall, of their general characters, and their chemical composition: illustrative specimens, collected together for easy reference, will be found in one of the cases. It is also shown that meteorites are closely related, not only to shooting stars, but also to comets, and probably to nebulæ and fixed stars. SECOND FLOOR. [Sidenote: Botanical Gallery.] The upper floor of the East wing is devoted to the Department of Botany.