OF METALLIC VEINS.

From the beauty and splendour of some metallic substances, and the universal utility of others, they have in all ages been highly esteemed, and sought after with the most eager research. Metals are distinguished from other substances chiefly by these properties: their brilliancy, colour, opacity, density, hardness, elasticity, ductility, malleability, tenacity, fusibility, power of conducting heat and electricity. The metals are reckoned the following, arranged according to their density and weight.

1. Platina. This name is given by the Spaniards of South America, from its resemblance to silver (plata signifying silver in the Spanish language) to a substance met with in the province of New Grenada: it has hitherto been found only in a metallic or native state in the sand of torrents, drawn down probably from the primitive mountains.

2. Gold is found chiefly in primitive mountains, sometimes in veins and sometimes distributed through the stony matter. The substances most commonly accompanying gold are quartz, feldspar, calcareous spar, pyrites, red and vitreous silver ore, and lead; but it is found more frequently in the sand of rivers. The countries where gold is discovered in the greatest abundance are Transylvania Hungary and Sweden in Europe, Siberia in Asia, Peru and Mexico in America what is drawn from Africa is the produce of the sands of torrents and rivers.

Gold has been found in different parts of the British slands, as at Silsoe in Bedfordshire, in the Lead hills in Lanarkshire in Scotland, and on the Wicklow hills not far from Dublin in Ireland. This last mine is now in the hands of Government; but does not answer the expectation at first formed of its value.

In the reign of James the Vth of Scotland, who died in 1542, many persons were employed in washing the sand of

the

the brooks near Lead-hills, to separate the gold particles, which, in the course of some seasons, amounted to a very considerable value: pieces exceeding an ounce in weight have been found in that neighbourhood.

3. Mercury, or Quicksilver, is found in various states; native mercury is met with in cavities or clefts of rocks, int strata of clay or chalk, in the form of fluid globules: it is also found combined or amalgamated with silver: mercury is likewise discovered mineralised with sulphur; when this combination is of a bright scarlet colour it is called cinnabar, or vermilion.

Mercury is found in parts of Germany and Hungary, but the richest mines are those of Almaden in the south of Spain.

4. Silver, in its native state, is found in considerable quantities in Mexico and Peru: it is also met with in Siberia, Saxony, Sweden, Norway, Bohemia, France, chiefly in primitive mountains, amidst masses of spar, quartz, lead ore. Silver is likewise met with combined with antimony and with arsenic, of which last combination is the silver drawn from the lead mines in the south of Scotland.

5. Copper appears in many various states, of which the most common is the yellow pyrites, and is met with in both primitive and secondary mountains, sometimes in beds, at others in veins: in Britain this is the principal variety of copper ore, particularly in the noted Pary's mine in Anglesea.

6. Iron. This metal, in a native state, is extremely rare; one of the most common ores of iron is the martial pyrites. One of the richest ores is the hæmatites, or bloodstone, found in many parts of Britain, especially at Ulverstone in Lancashire, whence large quantities are carried to the great works at Carron in Scotland, to be smelted with the common ironstone of that country. The magnet is an iron ore generally found in primitive mountains, especially those

composed

composed of gneiss and micaceous schistus: the magnet is also found in the form of sand on the banks of certain rivers, as the Elbe in Germany, and in Sweden and Italy.

7. Lead. This metal is most commonly found in both primitive and secondary strata, in beds and veins, with quartz, fluor spar, sparry iron ore, pyrites, and various sorts of silver ore. This ore is procured from the Mendip hills in Somersetshire, from Derbyshire, and in great abundance from the Lead-hills in Dumfriesshire, Scotland.

Lead ores are of various colours, blue, brown, black, white, green, red, yellow: the black ore, also called plumbago, employed to make pencils, is found in Cumberland and Scotland.

8. Tin. The common tinstone is found chiefly in primitive rocks, as in granite, gneiss, micaceous schistus, and porphyry, both in masses and veins: this is the ordinary tin-ore of Cornwall, and is also procured from the rivers of Saxony, Bohemia, and the East Indies. A species called tin pyrites is very rare, being hitherto found only in Corp wall among copper pyrites.

9. Bismuth is a very rare metal, and is usually found in a pure native state in quartz and spar: it is met with in Flanders, Saxony, Sweden, and in the mines of Brittany in France.

10. Zinc, One of the most common ores of zinc is a combination with sulphur of various colours: it is the production of Saxony, Bohemia, Norway, Hungary; it is also met with in France and in Derbyshire.

Calamine is a variety of zinc, found in stratified rocks, often forming entire beds, with indurated clay and calcareous spar: this species occurs in the German lead mines, also in Derbyshire, and the lead mines of the south of Scotland.

11. Antimony has been discovered, but very rarely, in a native state, but the most common ore is combined with

sulphur,

sulphur, and is the produce of most European coun

tries.

12. Cobalt. The common ore of this metal is of a bright shining white colour, and is generally found with the ores of silver and nickel it is met with in beds in primitive rocks, and in veins in those of a secondary composition: it is found in most parts of Europe.

13. Nickel. This metal, combined with sulphur, is found in veins generally accompanying ores of cobalt, to which it seems to have a near relation; it is produced in Britain as well as on the continent.

14. Manganese is discovered in veins and masses, commonly in primitive mountains; the ore is generally of a gray colour, and sometimes red. Manganese is met with in the Mendip hills and at the lead mines in Scotland.

15. Molybdena is found in primitive rocks, in particular in tin mines, in Saxony, Sweden, France, and at the foot of Mont Blanc.

16. Arsenic is found in a native state in many parts of the continent, in veins of primitive mountains, accompa nied by ores of lead, cobalt and silver.

The Marcasite is a compound of arsenic and pyrites, met with accompanying tinstone and some other minerals.

Realgar and Orpiment are also varieties of arsenic, found in many parts of the continent, and in the neighbourhood of the volcanoes Etna and Vesuvius.

17. Tungsten and Wolfram; 18. Uranium; 19. Titanium; 20. Tellurium: these are metals lately discovered, of whose nature and uses little is hitherto known.

OF EARTHQUAKES.

VARIOUS Opinions have been formed, and various hypotheses proposed, to account for earthquakes, by both the

antients

antients and the moderns; but the most satisfactory mode of explaining these dreadful phenomena of nature has hi therto been to do it on the principles of électricity; and various experiments have been instituted, in which the elec tric fluid has been made to produce effects of the same kind with those occasioned by earthquakes. It is, however, cer tain that in earthquakes appearances present themselves; and facts are observed, which cannot be explained according to any one theory of those adopted for their solution ; it is therefore not unphilosophical to suppose that many causes may be combined in their production.

Earthquakes have been felt in most countries of the globe; there are, however, particular places seemingly more subject than others to their ravages. It may be observed, in general, that earthquakes are more frequent within the tropics; but there are spots even in that region more rarely visited by this dreadful calamity than others in the temperate or even the colder tracts of the earth. In the islands in the West Indies, and in some parts of the continent of America, within the torrid zone, earthquakes are more frequent than in most other quarters of the globe: but Italy, Sicily, Portugal, and some other spots without the tropics have been oftener exposed to the devastations of those concussions than many islands and tracts lying within the tropics. Of all the West India islands Jamaica has suffered the most frequently and the most severely; while Mexico and Peru are more subject to earthquakes than any other regions of the American continent. Portugal has in a manner been shaken to its foundation, while Spain, of which Portugal is naturally a portion, is comparatively free from such disasters.

Observations on phoenomena so awful and so déstructive, can scarcely be very numerous or correct; the operation of their causés is too rapid, the effects are too sudden and unexpected, to be the subjects of cool and attentive investiga