or Tungsten.

natural history and chemistry, the name of a peculiar mineral, lately ranged among the semi-metals. See Mineralogy, p. 134, col. 2.

This mineral, which the Germans have called wolfram or wolfrath, a name translated into Latin from lupi, or rather Marsupium lupus ferox, has been met with hitherto only in mines of tin, but for, though many authors would make it more common, it Wolfram is an error owing to their confounding some glossy iron ores with the true wolfram, as appears by the specimens which are frequently found in cabinets under this name. It has been, on account of the bad effects produced by this mineral in the melting of tin-ores, from which it is very difficult to separate it by washing, because of its great specific weight, that the names of *spuma lupi*, *lupus jovis*, and *wolfram*, have been given to it by the miners and smelters.

This is really a metallic ore, and contains the very semi-metal lately discovered in the tungsten; both being mineralized, or rather formed by the same tungstic acid.

1. It is of a black or brown shining colour, of a radiated or foliated texture, of moderate hardness, and sometimes so brittle as to be easily broken between the fingers; but it is very weighty, its specific gravity being = 7,119.

2. When scratched it shows a red trace, and this distinguishes it from the tungsten, *Mineralogy*, part ii., p. 73, col. x., which is a variety of the ore of the same semi-metal.

3. It is found in scattered masses, crystallized into hexagonal flat prisms, coming to a point, with four sides, and these points terminated obliquely.

4. Internally it is shining, with the lustre almost of a metal.

5. When it is broken, its texture appears leafy; and the leaves are flat, but somewhat confused.

6. On some sides they are unequal, and very seldom striated.

7. It is always opaque; and when scraped, it yields a powder of a dark reddish grey.

8. The wolfram will not melt by itself with the blowpipe, the angles being only rounded; but,

9. Internally it preserves its structure and colour without change.

10. With microcofmic salt (phosphate of ammoniac) it fuses with effervescence; and forms a glaas of a pale red in the exterior flame, and much darker in the interior.

11. With borax it likewise effervesces, and forms by the interior flame a glaas of a greenish yellow, which by the exterior turns reddish.

12. Being exposed in a crucible to a strong fire for one hour, it swelled, became spongy, and of a brownish colour; entered into a semi-vitrification; and was attracted by the magnet.

13. Equal parts of nitre and wolfram being put in a red-hot crucible, they detonated, or rather boiled up with a blue flame round the edges, and a nitrous vapour arose; the matter, when cold, on being put into water, partly dissolved; and a few drops of acid produced a white precipitation.

14. Pounded wolfram, digested in a sand-heat with a sufficient quantity of marine acid, to the depth of the thickness of a finger above the matter, after one hour's boiling, the powder turned yellow; which is the same phenomenon as happens with the tungstic acid. See Chemistry Index.

15. It appears by the chemical analysis of wolfram made by Messrs. John and Faust de Luyart, that its contents consist of 22 parts of manganese in the state of black oxyd; 13.5 of iron, 65 of a yellow wolfranic oxyd, and of quartz and tin.

16. A good quantity of this yellow oxyd being collected, it was observed that it was entirely insipid, and that its specific gravity was = 6,120. It effervesces with microcofmic salt; produces a transparent blue colour without any shade of red; and effervesces also with borax and with mineral alkali. This same matter does not dissolve in water; but when triturated with it, forms a kind of emulsion; to which the acetous acid gives a blue colour, but does not dissolve it.

This matter, however, dissolves completely in caustic vegetable alkali, both by the dry and moist way; and the liquor acquires a great bitterness. By pouring on it some nitrous acid a precipitate ensues, which leaves on the filter a white salt; and this being well edulcorated, has a taste at first sweet, afterwards sharp and bitter, producing a very disagreeable sensation on the throat. It is in fact a true acid combined with a portion of the alkali and precipitating acid.

17. This acid melts, if alone, by the flame urged with the blow-pipe.

18. This white salt is a true metallic triple salt, as appears by putting 100 grains in a crucible with powdered charcoal; for after one hour and a half of a strong fire, when cooled a button was found, which fell to powder between the fingers. Its colour was brown; and, on examining it with a magnifier, there was a congeries of metallic globules, of the bigness of pins heads; which, when broken, exhibit the metallic appearance of a steel colour in the fracture; and their specific gravity was = 17,600.

19. These metallic globules, melted with other metals, gold and platinum excepted, afford ductile alloys with silver or copper; and hard ones with cast iron, tin, antimony, bismuth, and manganese.

It has been supposed that this is a new metal before unknown: That this was evinced, 1. by its specific gravity, equal to 17,600; 2. by the tinges it gives to different glasses; 3. by its great difficulty to fuse, which is greater than that of manganese; 4. by the yellow colour of its calx; 5. its alloys with other metals; 6. its infusibility, at least by a direct method, with mineral acids; 7. its easy solution in alkalis; 8. the emulsion it gives with water; 9. and by the blue colour it gives to acetous acid. We are not certain, however, how far this opinion has been corroborated by later experiments.