16. Psammites and Sandstones. a. Fine grained Psammite (feincornige grauwacke) and psammitic phyllade (grauwacken scheiffer) in the primitive phyllades which are sometimes found under our third granite. b. Quartz psammite (grauwacke) of all sized grains passing into grauwacke schist (scheiffrige grauwacke), sometimes into argillaceous pudding stones in extensive strata covering conformably primitive country. It includes transition schists, jasper schists and calcair. In the Erzgebirge this is not traversed by any metallic vein, while in the Hartz, and other countries, metallic veins abound in it. c. Micaceous Psammite or sandstone of the coal formation, alternating with slate clay and coal, covering either concavely, common porphy ry, or the transition country conformably, so that the formations extend from the mica-schist to the coal. (Terrain houiller.) d. The red psammites, the psephites, the psammitic pudding stones, I consider as belonging to what is called the (old) red sandstone formation, whose relation to the coal forma tion is not accurately determined. e. White sandstone (quadersandstein) containing fossil shells. f. The sandstone in the neighbourhood of Carlsbad. This covers (not the coal like the quadersandstein) but the lignite of Carlsbad.

17. Coal Formations. Combustible carbons, steinkohle. a. Anthracite. Scheiffrige Glanzkohle, in beds in the porphyry over the gneiss. b. Coal of the principal formation, scheifferkohle, pechkohle: sometimes covering porphyry concavely, and sometimes covering transition strata conformably. Sometimes in contact with the red sandstone, and sometimes with variolite or mandelstein. c.

The coal of the white sandstone. d. The brown coal, lignite is not found in the Erzebirge.

The preceding memoir I consider so interesting as to induce me to give this long account of it.

M. Menard de la Groye, in a memoir on the geognostic appearances at Beaulieu in the department of the mouths of the Rhone, has entered into a comparison between the second ry trapps, basalts and volcanic products, and concludes that the secondary trapps are of two kinds, the soft and the hard, (doux et aigres). That the former may be of neptunian, the latter of submarine volcanic origin, in this manner. When the lava was first formed, the basalt with peridot, forming the summit of this district was formed exposed to the air only, while the rest of the lava spreading over a soil covered with water formed what the Germans call the fleetz trap; and that a complete passage can be observed between the grunstein and the basalt. The supposed flatz trap of Beaulieu, like the undoubted volcanic strata contains, peridot, titanium, idocrase, pyroxene, obsidian, and the balls in concentric layers, frequently found in volcanic soil. Primitive trap contains none of these.being composed of amphibole and feldspar in confused mixture.

This memoir, published in the Journ de Phys for February and March, 1816, has been contested by J. Andrè de Luc, in Journ. de Phys. for May. M. de Luc contends that the pyroxenes, the leucites, the oxydule of iron containing titanium in the ferrugineous sand of volcanoes, have been ejected in the state in which we see them and not formed in the lava which surrounds these substances. I hat this has been frequently the case

with Etna and Vesuvius, and that the leucates that almost cover the road between Rome and Frescati, have been ejected from the extinct volcano of Monte Cavo or Monte Albano.

But the most important essay on this subject is that of M. P. Louis Cordier, of which La Metherie has given Brogniart's analysis, in the Journ. de Phys. for April, 1816.

Cordier, took volcanic stones (laves lithoides) and by strong pressure (not trituration) he broke them down into pieces of from Toto of a millemetre in size. He washed away the dust, dried the subsiding particles, and examined them with a microscope. The general result was, that vol canic rocks presented particles of various appearances, white, bottle green, brown and reddish brown. The white grains, were either referable to feldspar, peridot, or amphigene. The yellowish, greenish, or blackish green grains, he refers to amphibole. The opake black grains are titaniferous iron, magnetic.

2. The volcanic stones that melt into a black glass, contain chiefly pyroxene, sometimes as much as 45 per cent.

3. The principal component parts of these rocks, are pyroxene and feldspar. The latter melts into a white glass or enamel. Hence he divides volcanic stones into leucosthenes that afford a white glass or enamel, and basalts that afford a black glass.

4. Basaltic rocks treated like volcanic rocks offer the same appearances exactly to the microscope, and by the usual tests and analyses.

5. This mode of examining rocks, presents marked difference between primitive and basaltic or

secondary traps, which the Wernerians refer to neptunian, the French and Italian mineralogists for the most part to volcanic origin.

Primitive traps, petrosilex and hornstone, frequently enclose and are mixed with diallage, serpentine, talc, chlorite oxydulated, and sulfuretted iron: volcanic rocks, never. These last enclose and are mixed with, peridot, amphigene, pyroxene, titaniferous iron; substances which the first named rocks never present.

6. Whether the volcanic rock be antient or modern, vitreous in appearance or stony, bruised and viewed with a microscope, it always presents similar substances, consisting chiefly of pyroxene, feldspar, peridot and titaniferous iron: (frequently also leucite or amphigene.) Hence there is no analogy between primitive and basaltic traps.

(On this it may be observed that pyroxene, amphibole, and diallage scarcely diffe: in chemical analysis except as to a little more or less of magnesia; diallage seems to be hornblende with chrome: its geologic situation, being in the immediate neighbourhood of chromated iron.)

Dr. Thomson's account of the basalt over the coal at Dudley, containing augit or hornblende, seems to confirm Cordier's account, Ann. of Ph. Sept. 186.

M. Cordier in the Journ. de Phys. for May, 18:6, has also given an account of the salt mountain at Cordonna in Catalonia, 16 leagues from Barcelona. It is about 100 metres high, but a third larger at the base than Montmartre. It is washed at its base by the Cordonnero. There is no vegetation upon it. The minerals it contains, are coarse grained white and coloured

common salt, grey clay, common and anhydrous gypsum. The common salt consists of of the whole mass. Impure salt mixt with argillaceous matter, gypsum and pure common salt about 7.There is no regularity in the form of the masses, in their position, or stratification. The mountain rests upon grey and red micaceous sandstone, argillaceous shist, and grey limestone, not bituminous, and containing few or no organic remains. In the opinion of the inhabitants of the neighbourhood the mountain has suffered no diminution, but that can hardly be the case, as the salt is soluble. Upon the whole, appearances indicate that the rock is based on transition strata, (intermediaires) covered by secondary layers, and that we must allow of a transition gyps and rock salt formation.

Mr. Mornley has found a block of meteoric iron, near the bank of a river, about 50 leagues from Bahia in the Brazils, in a barren granitic country. It measures six feet by four feet, contains about 28 cubic feet, weight about 14.000 lbs. A specimen sent to Dr. Wollaston was found to contain nichel.

M. Beudant has found that the moluscæ of salt and of river water may be gradually accustomed to live within the one or the other. This will account in some degree for the mixture of marine and fresh water shells in the same rock.

CHEMISTRY.

M. Buchholz, in the German Pharmaceutical Almanack, has noticed the property of honey to pro mote the solution of borax; equal parts of honey and borax form a substance like gum arabic soluble in three waters. It greens the syrup

M. J. F. John has found a peculiar acid in stick lac.

Gay Lusac has found that sulphuric ether, kept for two years in a bottle with a glass stopper, half filled and occasionally opened, is converted into acetic acid, alcohol, and a peculiar oil which is not the oil of wine. M. Planche had made nearly the same observations.

The memoir on a new classifi cation of simple bodies, by M. Ampere, seems to add to Our knowledge nothing but names, wherewith we are overwhelmed already.

R. Dulong has distinguished four distinct acids formed by phos phorus and oxygen.

M. Theodore de Saussure from experiments on the atmosphere, calculates the proportion of carbonic acid in winter at 4.79 parts, in volume in 10,000 parts; or 7,28 parts in weight.

In summer the proportions were 7,13 parts in 10,000 by volume, and 10,83 by weight. The experi ments were made in the open air, near the lake, a league from Ge

neva.

Journal de Pharmacie. M. Kir choff who published the method of converting starch into sugar by means of dilute sulphuric acid, has made experiments on the conversion of starch into sugar by means of gluten. He concludes that sugar is formed in grains during germination by means of

1 Quadrasteo phosphat, 2 Binosteo phosphat, 3 Bige phosphat,

Royal Institute of France. Gay Lusac by decomposing the prussiat of mercury by muriatic acid, has found it to be a hydracid, con taining carbon 44.39; azot 51.71; hydrogen 3.90; or vapour of carbon one volume, hydrogen and azot half a volume each. He calls the radical of this acid, cyanogen, and the acid itself hydrocyanic acid. Cyanogen may be procured by exposing prussiat of mercury to a lamp heat; it comes over in the form of a gas of spec. gr. 1.8 absorbable in water which takes up four volumes, a sharp taste, the gas burns with a (blue and) purple flame.

Heat from pressure and friction. Thomson's Annals, vol 7, p. 241. Dr. Thomson observed the drag wheels of some loaded waggons on Blackfriars bridge, excite so much heat on the wet pavement, that the moisture was raised by it in manifest steam.

Composition of alcohol. Ib 243. Alcohol, olefiant gas and vapour of water, of each one volume. Other, olefiant gas 2 volumes, vapour of water 1 volume, according to Gay Lusac.

H. Chevreul has found the sugar of diabetic urine to possess all the characters of sugar of grapes. Ann. de Ch. xcv. 319.

Dr. Thomson in the same volume has given an analysis of his

4 Osteo phosphat, or bone earth, 5 Phosphat

6 Gephosphat or apatit,

infusible before the blowpipe.

Acid. Lime.

5

1

5

2

6

3

5

5

6

In an experiment on the strength of iron used for cables at Blackwall, near London, an iron wire of 1.25 inch diameter was broken by a weight of 40 tons. That is an iron wire of English iron of 078 inch diameter, requires 348.88 lbs. to break it, whereas in count Sickengen's experiments a wire .078 of an inch of Swedish iron, required 549.25 lbs. to break it.

M. H. F. Link, (Thomson's Ann. June, 1816,) has ascertained that the chemical properties of gluten and albumen are extremely alike, not differing more than different varieties of resin or gum.

In the Annals of Phil. for Aug. 1816, Dr Thomson gives a memoir by himself on phosphuretted hydrogen gas discovered in 1783, by M. Gingembre.

The usual methods of obtaining this gas, are 1st, dissolving phosphorus in a boiling alkaline solution: or 2dly, mixing together 2 ounces of fresh slacked lime, a quarter of an ounce of phosphorus in grains, and half an ounce of water in a retort, which produces much gas for a long time: or 3dly, putting phosphorus into a mixture of sulphuric acid, water, and zinc, in the common proportions for procuring hydrogen: or 4thly, decomposing phosphuret of lime previ ously made by heat in a glass tube, with water, to which Dr. Thomson adds a new process: 5thly, fill a tubulated retort, hold