down to that of the finest powder; and is a porous lava, light, tender, and somewhat resembling an argillaceous substance, which is astringent to the tongue; some of the grains are hard lava, heavy, ferruginous, and in round particles. Nearly half of this first volcanic rain consisted of very fine powders; these, seen through a microscope, appear to be composed, 1. of crystals of black schorl*, which partially retain their prismatic shape, and are partially eaten by rust; 2. vitreous grains of similar schorl; 3. grains of lava which have undergone alteration, and are reddened or whitened by vapour; 4. crystals of felspar, detached, and although somewhat decomposed, preserving their rhomboidal form; 5. other crystals of felspar adhering to lava, changed and covered with farina externally, but internally untouched; 6. fragments of lava with small crystals, similar to the arsenical ruby; 7. others incrusted with flowers of sulphur; 8. vitrifactions of no regular figure, porous vitrifactions, and a species of black glass or obsidian, transparent at the edges and of a dark green colour.

"The matter here analysed was collected on the snows of the crater at Trifoglietto.

• Schorl was then a name for siderite, or hornblende.-P.

"No. II. Heavy drosses of nearly an oval shape, and weighing from six to eight and nine pounds; such were projected the distance of four miles from the crater; superficially they are vitrified, their pores are glossy, and are five or six lines in diameter. The centre of these drosses has rounded and pretty regular pores; it contains crystals of white felspar confusedly dispersed, and some volcanic chrysolites. The crystals of felspar preserve their transparency, and are merely a little glazed, while the chrysolites have undergone a species of fusion, which has combined their grains, and rendered their surface convex.

"These drosses are found round the crater, especially from the southern to the eastern side, as well as in the valley of Bue.

"No. III. Light whitish drosses, similar to the cavernous pumice-stone of Lipari; they have the same fibrous texture and prolonged pores; some little light drosses, of a black colour, adhere to this pumice, which separately floats on the water, but which when attached to the black drosses, is carried by their gravity to the bottom: this is the first instance known of Etna having produced a similar substance.

"Found on the W. S. W. torrent of lava, near the crater.

Sand.

"No. IV. Light drosses in separate pieces; the largest are ten inches long, one in width, and two in breadth; from this size they diminish to that of a pigeon's-egg; their pores are rounded, glossy, vitrified, and of a pitch black; some of them seem to be damp as soot; seen through a magnifying-glass, they appear a real vitrifaction, porous, and of a greenish colour.

"These drosses are found at a greater distance from the crater than the former; some even as far from it as six miles.

"No. V. A very fine and shining sand, which, seen through a microscope, is found to be composed of grains of volcanic chrysolites, transparent, and of a golden green, and greenish colour. Among the sand also are fragments of transparent quartz, and laminated felspar.

"Sand of this description fell at Catania, on the 18th of July.

"No. VI. Light sand, formed of small grains and filaments of a glossy vitrifaction, analogous to the drosses No. IV.

"This sand fell in every part of the second region; and on the confines of the first, from the eastward to the south and south-east, on the 18th of July; it is mingled with fragments of the drosses before noticed.

"No. VII. Puzzolana composed half of crys

tals of black schorl, which have received a kind of varnish from fire; of fragments of drosses such as described No. III.; of chrysolites, some yellow and transparent, and others opake and of dull green colour at their edges; of small crystals of white felspar in rhomboidal laminæ, some detached, others united together, and grouped with crystals of schorl, some of them superficially vitrified. The crystals of schorl preserve almost perfectly their natural figure: they are chiefly detached in octagonal prisms, somewhat compressed, and with two broad and one narrow side, terminated by a dyedral summit with hexagonal faces; they present some slight varieties.

"This matter, which fell on the 19th of July, did not extend beyond the middle region, where it spread from the S. E. by S. to the S. W. wherever the watery cloud mixed with the smoke which contained it was carried, and from which it was precipitated by the rain.

lava.

"No. VIII. Pieces of lava tolerably compact, Pebbles of of an oval or wedge-shaped form, from two or three to twelve inches in length, and from one to six inches in thickness; the surface vitrified, and exhibiting small pores; their interior similar to that of No. II. They resemble pebbles rounded by water, and are remarkable among the drosses,

amid which they are found, on account of their singular shape.

They are collected on the cone of Etna, lying among light drosses.

"No. IX. Other pieces of the same form, but more compact: the surface of these is more smooth, and is sprinkled with white spots, which seem produced by the vitrifaction of the felspar; the internal part of these pieces assimilates with obsidian.

"These are found in the same place as the

last.

"No. X. Oval pieces, nearly two inches in length, composed of two parts of white felspar transparent and glazed, some yellow chrysolites, and some prismatic crystals of black schorl; the surface of this specimen was changed by fire, which had chiefly affected the schorl, occasioning it to lose its angles.

"Found near the crater.

"No. XI. A compound stone, divisible in parts, with a vitreous incrustation: one portion exactly resembling lava, which elicits sparks when struck with steel; the laminæ are distinguished one from the other by their different colours, the result of a calcination which has acted differently on the various component matters; in it mica and felspar are found in an un