and even pernicious substances to valuable purposes, may also find a cheap and easy method of obtaining molybdenum from its ore; and if it be a peculiar metal, possessing distinct properties, will undoubtedly know how to apply it to some useful purpose.

The metal called tungsten, like chromium and molybdenum, can hardly be described as known, or even as positively existing. There is found in Sweden a heavy mineral, called, from its great weight, tungsten, or ponderous stone; it is white and opaque; there is also found in tin mines a brownish black mineral, called wolfram. Both these minerals, on being subjected to analysis at different periods, and by different celebrated chemists, were found to contain a peculiar acid, to which Scheele, who first discovered it, gave the name of tungstic acid. On being exposed to a strong heat, with charcoal, this acid is decomposed, and a metal is obtained, which has been called tungsten, tungstenum, and wolframium. It is said to have a greyish-white colour, like that of steel. It is very hard, being scarcely scratched by a file, and nearly as heavy as gold. As a metal, nothing more is known of it; but it is said that it is employed in France to precipitate the colouring matter of certain woods, so that this can be collected and formed into cakes, which are used by painters.

His

In the mine of Mariahilf, near Zalethna, in Transylvania, an ore is found of a bluish-white colour, and of a metallic lustre. In 1782, a Mr. Muller, of Reichenstein, concluded, from his experiments on this ore, that it contained a metal different from every other. opinion has been subsequently confirmed by the experiments of several chemists, and to this metal the name of sylvanite was given. It is now called tellurium. Its colour is bluish-white, intermediate between zinc and lead; it is laminated like antimony, and is very brilliant. It is comparatively light, and so brittle that it may be reduced to pow der. It requires a little greater

heat than lead to melt it. It may be boiled and evaporated, and is next to mercury and arsenic in the scale of volatility. Its combination with oxygen possesses acid properties. This metal has been the subject of considerable research; it has been united with chlorine, hydrogen, and other substances, but only small quantities of it have ever been obtained for experiment, and neither it nor its compounds have ever been put to any use.

There is something a little curious connected with the discovery of columbium. In 1801, while Mr. Hatchett was arranging some minerals at the British Museum, one of them, a dark coloured, heavy substance, attracted his attention, on account of its resemblance to chromate of iron. It was stated to have come from Massachusetts, in North America, and was described as a heavy black stone, with golden streaks. Mr. Hatchett analyzed this mineral, and found it composed of oxide of iron and a white substance, possessing the properties of an acid. The acid had a metallic base, and, exhibiting peculiar properties, he gave it the name columbium. Soon after this period, a Swedish chemist, Mr. Ekeberg, detecting a metal different from every other with which he was acquainted, gave it the name of tantalum; but in 1809, Dr. Wollaston, having procured specimens of the mineral from which Mr. Ekeberg had obtained his metal, proved that the tantalum of this chemist and the columbium of Mr. Hatchett were the same substance. It has since been more than once examined, and the metal found to be of a dark grey colour, having somewhat the appearance of iron. It is so hard as to scratch glass, and is affected by none of the acids.

In the valley of Menachan, in Cornwall, there is found a black sand, resembling gunpowder in its appearance. In 1791, Mr. Gregor analyzed this, and found it to contain a new metal, to which he gave the name of menachine. Mr. Klaproth, a Prussian chemist, of much

CHEMICAL SOCIETY.
To the Editor of the Chemist.

55, Great Prescot-street,
Goodman's-fields.

SIR,-I beg leave to inform you, that at a former Meeting of the friends of the Chemical Society, a Committee was appointed, for the purpose of framing the laws and regulations, which being now completed, they avail themselves of your polite offer to make their proceed ings public, through the medium of your useful and valuable Periódical; and to inform those gentlemen who may wish to become the founders, that a Meeting will take place here on August 12th, his majesty's birthday, for the purpose of electing and installing the officers, and establishing the Society.

Gentlemen who may be inclined to attend, are requested (if convenient) to send their names and addresses to me, on or before the 11th instant.

I am, Sir,
Your most obedient servant,
W. JONES,
Sec. Pro. Tem.

NATURAL HISTORY. M. CUVIER lately presented a Report to the Academy of Sciences on the state of natural history, and the increase of our knowledge in that department since the return of maritime peace, the details of which are very curious. In 1778, Linnæus indicated about 8000 species of plants; M. Decandolle now describes 40,000; and in a short time they may probably exceed 50,000. Buffon estimated the number of quadrupeds at about 300; M. Desmarets has just enumerated above 700, and he is far from considering the list complete. M. de Lacepede wrote, twenty years ago, the history of all the known species of fish the whole did not amount to 1500; the cabinet of the king alone has now above 2500, which is only a small proportion, says M. Cuvier, of what the seas and rivers can furnish. We no longer venture to fix the number of birds and reptiles; the museums are crowded

with new species, which require to be classed. Above all, we are confounded at the continually increasing number of insects; it is by thousands that travellers bring them from hot climates: the Royal Museum at Paris contains above 25,000 species, and there are at least as many more in the various cabinets of Europe. The work of M. Strauss, on the Maybug, shows, that this insect, an inch in length, consists of 306 hard pieces, serving as shells or envelopes, 494 muscles, 24 pair of nerves, and 48 pair of

tracheæ.

TO PURIFY CORN SPIRIT.

M. ZEIZE has announced to the world, that a small quantity of chloride of calcium (oxymuriate of lime) moistened with water, added to the wash made from potatoes or grain, the liquid being allowed to subside before it is distilled, makes the spirit which results more like brandy. It is freed from the peculiar taste all corn brandies have, and is quite as good as that made from wine. The chloride must be

good; and the only way to ascertain the quantity which ought to be employed, is to try with a small portion of the wash.

H

1

[Price 3d.

t

To decompose Water

Chemistry as a Science. Art. XXII.
Chromium. Molybdenum. Tung-
sten. Tellurium. Columbium.
Titanium. Selenium. Osmium 354

Dictionary of Chemistry

Distillation. Art. I...

Animal Heat

353

To make Names grow in Fruit

TO DECOMPOSE WATER.

(From a Correspondent.) MR. EDITOR, Having observed that, in No. XIV. of the Chemist, a Correspondent inquires after a means for the decomposition of water, I take the liberty of transmitting you two methods: one is, to decompose it by means of carbon, and the other by galvanism. First, to decompose it by carbon. Let your Correspondent provide f himself with a glass retort, A,

Sulphuretted Hydrogen Gas .....

to contain water, which he may heat by the lamp, B, or by any other means he pleases; also with a porcelain tube, C C, an open furnace, D, a little pneumatic trough, F, and a receiver, E, to collect the gas. He must put some charcoal in small pieces into the tube, so as nearly to fill it, then place this in the furnace, where it must be subjected to a good heat. The retort must be adapted to one end of the tube, and a bent tube at

the other end to convey the gas into the receiver. On making the water boil, the steam or vapour passes over and through the charcoal, which when red hot will separate the oxygen of the vapour from the hydrogen. The gas, however, which will pass into the receiver, is not pure hydrogen, but contains a quantity of carbonic acid gas, resulting from the union of the carbon with the oxygen, and is called carbonated hydrogen gas. The other method of decomposing water, by galvanism, is the most convenient for obtaining the two gases separate and pure.

As our Correspondent has sent us another little drawing with his second method, we must postpone it till another Number. It may be useful, however, if we point the attention of the reader to one inference to be drawn from this experiment: this is, that in consequence of carbon at a red heat decomposing water, a small quantity of this fluid, particularly when scattered in drops from an engine, may promote combustion rather than retard it. If it be decomposed, it will give oxygen to the flame, which only makes the conflagration more rapid. To extinguish fire, therefore, either a large quantity of water should be thrown, or some other means taken to exclude the

air, and reduce the temperature below the burning point.-ED.

CHEMISTRY AS A SCIENCE, Art. XXII.

CHROMIUM. MOLYBDENUM. TUNGSTEN. TELLURIUM. COLUMBIUM. TITANIUM. SELENIUM. OSMIUM. THERE is found, though in small quantities, at the mine of Beresof, in Siberia, a mineral of a beautiful red colour, with a shade of yellow. It is called the red lead of Siberia, and was used as a paint. In 1797, this mineral was examined by M. Vauquelin, the French Chemist, and found to contain a peculiar acid, till then unknown, with a metallic base. His experiments have since been frequently repeated,

and the base of this acid reduced to a metallic state, by heating it with charcoal. This metal was called chromium. It is very brittle, of a greyish-white colour, intermediate between steel and tin. It is very slightly maguetic, and, for a metal, is very light. It requires a powerful heat to melt it, and is only slowly acted on by aqua regia. It has only been obtained in small quantities by a few eminent chemists, and for the purposes of examination. Nothing more is known of it, and it has been put to no use. Chromium, however, is the colouring material of a number of beautiful minerals. The one we have already mentioned is an ore of lour to the oxide of chromium, lead, and the emerald owes its cowhile the spinelle ruby derives its tint from chromic acid.

In Sweden, and in other parts of Europe, there is found a mineral somewhat resembling plumbago, though of a lighter colour, and which was long confounded with it. it was a different substance, posScheele, however, observed that thus taught chemists to distinguish sessed of different properties, and them. Plumbago has been already described, and to the other he gave the name of molybdena. This mineral, on being analyzed, was found to consist of sulphur and a peculiar acid, having a metal for its base. The acid is now called the molybdic, and the metal obtained from it molybdenum. In consequence, however, of the difficulty of obtaining it, hitherto it has been procured only in small quantities, and has been put_to no use. In fact, by no art has it been found possible to obtain it in any other form than small grains, so that its properties are very imperfectly known. With some other metals it unites readily, and forms brittle alloys. Its colour, even, has not been settled, though this has been the object of numerous and laborious experiments. As the ore, however, may be easily obtained, that industry and skill which have already converted so many apparently useless

and even pernicious substances to valuable purposes, may also find a cheap and easy method of obtaining molybdenum from its ore; and if it be a peculiar metal, possessing distinct properties, will undoubtedly know how to apply it to some useful purpose.

The metal called tungsten, like chromium and molybdenum, can hardly be described as known, or even as positively existing. There is found in Sweden a heavy mineral, called, from its great weight, tungsten, or ponderous stone; it is white and opaque; there is also found in tin mines a brownish black mineral, called wolfram. Both these minerals, on being subjected to analysis at different periods, and by different celebrated chemists, were found to contain a peculiar acid, to which Scheele, who first discovered it, gave the name of tungstic acid. On being exposed to a strong heat, with charcoal, this acid is decomposed, and a metal is obtained, which has been called tungsten, tungstenum, and wolframium. It is said to have a greyish-white colour, like that of steel. It is very hard, being scarcely scratched by a file, and nearly as heavy as gold. As a metal, nothing more is known of it; but it is said that it is employed in France to precipitate the colouring matter of certain woods, so that this can be collected and formed into cakes, which are used by painters.

In the mine of Mariahilf, near Zalethna, in Transylvania, an ore is found of a bluish-white colour, and of a metallic lustre. In 1782, a Mr. Muller, of Reichenstein, concluded, from his experiments on this ore, that it contained a metal different from every other. His opinion has been subsequently confirmed by the experiments of several chemists, and to this metal the name of sylvanite was given. It is now called tellurium. Its colour is bluish-white, intermediate between zinc and lead; it is laminated like antimony, and is very brilliant. It is comparatively light, and so brittle that it may be reduced to pow der. It requires a little greater

heat than lead to melt it. It may be boiled and evaporated, and is next to mercury and arsenic in the scale of volatility. Its combination with oxygen possesses acid properties. This metal has been the subject of considerable research; it has been united with chlorine, hydrogen, and other substances, but only small quantities of it have ever been obtained for experiment, and neither it nor its compounds have ever been put to any use.

There is something a little curious connected with the discovery of columbium. In 1801, while Mr. Hatchett was arranging some minerals at the British Museum, one of them, a dark coloured, heavy substance, attracted his attention, on account of its resemblance to chromate of iron. It was stated to have come from Massachusetts, in North America, and was described as a heavy black stone, with golden streaks. Mr. Hatchett analyzed this mineral, and found it composed of oxide of iron and a white substance, possessing the properties of an acid. The acid had a metallic base, and, exhibiting peculiar properties, he gave it the name columbium. Soon after this period, a Swedish chemist, Mr. Ekeberg, detecting a metal different from every other with which he was acquainted, gave it the name of tantalum; but in 1809, Dr. Wollaston, having procured specimens of the mineral from which Mr. Ekeberg had obtained his metal, proved that the tantalum of this chemist and the columbium of Mr. Hatchett were the same substance. It has since been more than once examined, and the metal found to be of a dark grey colour, having somewhat the appearance of iron. It is so hard as to scratch glass, and is affected by none of the acids.

In the valley of Menachan, in Cornwall, there is found a black sand, resembling gunpowder in its appearance. In 1791, Mr. Gregor analyzed this, and found it to contain a new metal, to which he gave the name of menachine. Mr. Klaproth, a Prussian chemist, of much