One-half of each portion was treated with nitrate of silver. The first had no effect on litmus paper, and scarcely gave the slightest cloud with the test. The second became slightly cloudy by the test, but was equally without any action on the blue paper. The third portion reddened the paper strongly, and produced an abundant dense cloud, when I dropped into it the nitrate of silver, and a pretty copious precipitate collected at the bottom of the tube. The remaining half of the third portion was evaporated by a gentle heat to about half a fluid drachm. The precipitate which a drop of it, placed on a slip of glass, occasioned with a drop of nitrate of silver, was insoluble in nitric acid, and perfectly soluble in ammonia. Another drop, similarly treated with muriate of barytes, gave no precipitate, nor cloud. The remainder was neutralized with pure ammonia, further evaporated, and poured on a slip of glass; when it afforded a multitude of well-defined crystals of muriate of ammonia.

The precipitate from the first half of the same portion by nitrate of silver, being collected, washed, and dried, fused on a slip of platina foil before the blowpipe into horn silver.

The presence of free muriatic acid in the ejected fluid, and consequently the accuracy of Dr. Prout's conclusions, seem to be fully confirmed by the preceding experiments. J. G. C.

2. Pyroxylic and Pyroacetic Spirits.

In a paper read before the Society of Physics and Natural History of Geneva, on the 16th Oct. 1823, MM. Macaire and Marcet have given a description and analysis of two fluids, analogous in many of their properties to alcohol, particularly in being capable, like it, of forming ethers when acted upon by acids. Pyroxylic spirit, the first of these, is obtained during the rectification of pyrolignous acid; the second was described long ago by M. Chenevix under the name of pyroacetic spirit, and may be prepared by subjecting the greater number of the acetates to distillation.

Pyroxylic spirit is colourless and transparent. Its smell is strong, pungent, and ethereal, and has a strong resemblance to that of ants. Its taste is strong, hot, and slightly pungent, leaving a distinct impression of the flavour of oil of peppermint. Its specific gravity, after having been distilled off dry muriate of lime, is 0.828. It boils at 150°. It reddens litmus paper very slightly; but this effect is probably produced by a minute residue of acetic acid; for when the spirit is distilled off litharge, a small portion of the oxide is rendered soluble in water. The dissolved salt is not precipitated by barytes, nor by nitrate of silver, and it contains no nitric acid: it appears, therefore, to be an acetate. When heated, the spirit burns with a fine blue flame, without leaving any residue. Alcohol dissolves it in

every proportion, and the addition of water renders the solution opalescent, and the spirit gradually ascends to the surface. Water alone converts the spirit into a semi-opaque fluid, resembling an emulsion, which persists for an indefinite length of time in this state, without a separation of the two fluids taking place, and without becoming transparent. It is equally insoluble in oil of turpentine. Camphor dissolves in it with great facility. Olive oil does not dissolve in it, either when cold or hot. Potash dissolves in it without producing any sensible alteration, except causing it to assume a yellowish tinge, and producing a slight elevation of temperature.

Pyroxylic spirit, when mixed with its volume of sulphuric acid, may be distilled over unaltered; but if thrice that quantity of acid be employed, it blackens, and is decomposed, and a small quantity of a gas is evolved, which is a mixture of hydruret of carbon and hydrogen. The gas contains no olefiant gas; for it burns with a feeble blue-coloured flame, and sustains no speedy diminution of volume when mixed with chlorine.

When distilled with its volume of nitric acid, there passes over an ethereal fluid, together with a considerable quantity of nitrous vapours. This new fluid has an agreeable odour, reddens litmus paper even after having been distilled off litharge, burns with a dull heavy flame, and dissolves in all proportions in water and alcohol, communicating to them a sweet taste, like that of sugar. It differs, therefore, in all its properties from nitric ether.

The spirit is not altered by being exposed to a current of nitrous gas; neither does it yield an ether when repeatedly distilled with its volume of muriatic acid.

A current of chlorine sent through a quantity of the spirit, at first imparts to it a deep-yellow colour; but after the process has gone on for a few minutes, the liquid suddenly becomes again colourless. By this treatment, its volume augments onetwelfth. The new fluid thus obtained is colourless and transparent, and smokes with ammonia. It has a peculiar and very pungent smell, and excites tears. Its taste is hot, leaving an impression exactly similar to that of horse-radish. After distillation off litharge, its specific gravity is 0.889. It burns with a blue flame and a white smoke, which gives thick vapours with ammonia. Water and alcohol dissolve it. It is precipitated by nitrate of silver; and it becomes more acid, and acquires a slight yellowish tinge by exposure for some time to the air and light; but by distillation off a little litharge, it may be restored to its original purity.

These two liquids, formed by the action of nitric acid and chlorine, appear, therefore, to be ethers, endowed with peculiar properties; and the mode in which the pyroxylic spirit is de

composed by acids appears also to be completely analogous with the decomposition of alcohol, in the formation of those compounds to which the name of ether has been already appropriated.

Pyroacetic spirit is strikingly distinguished from the pyroxylic in many of its most important characters. Its specific gravity is inferior, being only 0.786. Its taste and smell are also different; and it burns with an intense white flame, very different from the blue flame of pyroxylic spirit. It is also completely soluble in oil of turpentine.

Sulphuric acid neither blackens it, nor renders it turbid, but communicates to it a fine orange-yellow colour; and the mixture continues transparent, even after the application of heat.

When distilled along with muriatic acid, a volatile fluid passes over having the odour of that acid; but this is completely removed by re-distilling it off potash.

A current of chlorine, sent through the pyroacetic spirit, communicates to it a slightly-yellowish shade, but without presenting the subsequent phenomenon of a sudden discoloration. The resulting fluid has a suffocating odour, somewhat similar to that of the chloro-pyroxylic ether, but stronger. After a few instants, it separates into two distinct fluids; the one, thick, heavy, oily, and transparent; the other, lighter, and slightly opalescent. The latter burns with a light flame, of a bluish colour, and leaves an abundant acid residue. It dissolves in water, and imparts to it a hot taste, followed by a sensation of sweetness; but it does yield a trace of the horse-radish flavour, which characterises the ether formed by chlorine and the pyroxylic spirit.

The oily fluid, after a few days, acquires a slight yellowish colour, and burns with a thick flame of a deep-green colour, emitting suffocating fumes, which contain abundance of muriatic acid. It is soluble in alcohol, but insoluble in water. When poured into the latter, it subsides to the bottom in separate drops.

Both of these spirits were analyzed, by volatilizing a known weight of them through red-hot oxide of copper. The pyroxylic spirit, decomposed in this way, was found to consist of

Carbon...

Oxygen.

Hydrogen.

$44.53

46.31

9.16

100.00

Or very nearly, of 6 atoms of carbon, 4 of oxygen, and 7 of

hydrogen.

The pyroacetic spirit was found to consist of

Or very nearly, of 4 atoms of carbon, 2 of oxygen, and 3 of hydrogen.-(Bibliotheque Universelle, Oct. 1823.)

3. Argillaceous Iron Ore.

The analysis of this ore, given in the last number of the Annals, was incorrectly stated. The reader will perceive that the quantities of lime and carbonaceous matter, having been obtained from 200 grains of the ore, should have been divided by 2; and a small quantity of alumina separated from the precipitated oxide of iron being added, the composition will be nearly as follows, and as it will be found stated in Phillips's Mineralogy, p. 237, viz.

Protoxide of iron, with a trace of man

This limestone, which is highly esteemed for the goodness of the lime which it yields, I have found to consist of

MINERALOGY.

5. Composition of Tourmaline.

86.17

7.10

3.40

1.67

1.00

0.66

100.00 R. P.

M. Gmelin, who has devoted a good deal of attention to the analysis of this mineral, deduces the following conclusions from his researches. All the tourmalines hitherto examined by him contain from two to six per cent. of boracic acid, which appears to be quite an essential ingredient. All of them contain also

two alkaline bases, which are a mixture in some cases of potash and soda, in others of potash and lithia. Magnesia also exists in most specimens, but does not appear to be so essential an ingredient as the preceding. Oxide of iron is sometimes present in a very large proportion; sometimes it is altogether wanting.

The rubellite, from Rozena, in Mahren, consists, according to his analysis, of

The substance

This mineral does not contain a trace of soda. which Klaproth and Bucholz mistook for that alkali was in fact a mixture of boracic acid, potash, and lithia.

The schorl from Eibenstock, in Saxony, which was more recently analyzed by Klaproth, consists, according to Gmelin, of

The tourmalines examined by him were six in number, and were all from different localities.-(Schweigger's Journal, vol. xxxviii. p. 514.)

6. Petalite.

Dr. Bigsby has discovered Petalite on the north shore of lake Ontario, on the beach in front of York, the capital of Upper Canada. It is a rolled mass weighing about a ton. The mineral has been examined by Dr. Troost; it occurs in crystaline masses, of a greyish white colour, with a tinge of green, and resembles some varieties of Tremolite, for which indeed it was first taken.-(See Jour. Acad. Nat. Sciences, No. 8, vol. 3.) 7. New Localities of American Minerals. By John W. Webster, MD. MGS. Lond.

Zircon and Green Felspar of Beverly (Mass). In a former