overthrow: I grant that compound, chrystallized, inclined rocks, void of organic remains,-compound inclined rocks of mechanical mixture by deposition, imperfectly or minutely chrystallized with very few organic remains, and horizontal rocks containing animal remains in abundance, would be freer perhaps, from objection; but, until Werner's theory be actually overthrown, I see no good reason for quitting either it, or its language. marks of La Metherie on the augite, cocolite, sahlite, allalite, massite, and erzolite, and on the sulphurets of silver, lead, and iron; Journ. de Phys. Jan. 1816. 27. To a Geologist, a specimen of a country continuing the same for fifty miles together, is a good and valuable specimen: to a modern mineralogist, a specimen is valuable, if it be so beautiful and so rare, as to be a curiosity in these respects; it is esteemed in proportion as it is useless; and it is considered as still more valuable, if it require the skill of a lapidary to cut it, a microscope to discern its external figure, a goniometer to take its angles, and a complex mathematical formula to express in how many possible ways its external form might have arisen by additions to, or defalcations from, its primitive chrystal. I am aware, that, in many cases the chrystal aids in determining the mineral, but so seldom chrystals are perfect, that the man who wishes to be a mineralogist, must principally rely on geognostic situation, on the Wernerian characters, and on chemical analysis. Chrystallo The whole of Hauy's theory of chrystallization, which threatened to confine mineralogy to mathematical formulæ, and microscopic investigation, and convert a cabinet of minerals into a plaything for young gentlemen and ladies, has received a shock from the dissonance between similarity of primitive form, and similarity of chemical composition in many cases, particularly in the arragonite, which the late analysis of Bucholz and Meissner, in Schweigger's Journal, Ann. de Ch. June, 1816. p. 176, show to be very frequently void of any trace of strontian, and in many cases, containing this earth in quantities so small, that it can only be considered as acci-graphy is best fitted for amateurs, dental; contrary to the statements of Stromeyer and Gehlen, whose discovery of strontian in the arragonite was supposed fully to account for all its anomalous chrystallization. The late analysis of the Rev. Mr. J. Holme, affords little assistance. The angles of many chrystals determined by Hauy, have been corrected by the more accurate goniometer of Wollaston, as in the chrystals of quartz, and of sulphat of barytes, by W. Philips, Esq. in his paper before the Geological Society, noticed in Thomson's Annals, Feb. 1816. To these may be added the re and to be employed on a lady's cabinet. But the most serious obstacle to Hauy's system, is, a late paper of M. Methuon, abridged by Mr. Grenville, in the first number of Brande's Journal. The author insists, that chrystals are not the result of undisturbed solution or fusion, but the produce of a peculiar decomposition of amorphous chrystallizable matter, in contact with air, and the ordinary atmospheric moisture; the particles of this matter during decomposition arrange themselves according to certain laws of attraction, not yet to the phenomena, and the growth of drusy chrystals of quartz, on the surface of quartzose stones lying loose on shistose and secondary mountains, and of the veins of calc spar in limestone, will readily agree to the probability of M. Methuon's statement. One of our best and most accurate mineralogists in Philadelphia, has assured ed similar facts, and possesses similar specimens in his own collection. M. Hauy has published (Ann. de Ch. April, 1816. 447.) some observations on pyro electric minerals, the oxyd of zinc, some Spanish tourmalins, and Siberian topazes. accurately determined; the process is carried on in the dry way, in the air. M. Methuon gives a history of his discovery of such chrystals gradually formed from chrystallizable matter during his residence at Elba: of his pursuing the same investigations with full success, by the gradual formation of chrystals from shapeless chrystallizable matter, on the chimney-me, that he has repeatedly observpiece in his own apartments, on his return; such as alalite, garnet, green idocrase, pyroxene, peridot and pyrites. He describes how any one else, by a few months patience, may obtain the same results. He deduces from these facts the following corollaries; 1. Chrystals begin to form at their summit edges and solid angles. 2. Nature produces, by direct process, all simple and compound chrystals, without first forming any nucleus. 3. The matter serving to form chrystals, is in the state of a solid mass before, and continues in that state during the whole process. It is the chrystallizable matter. 4. This matter is that, which, by infiltration, has filled the chasms and clefts of mountains, and the cavities of rocks; which composes veins, stalactites, and stalagmites, am, in general, all that is found in the form of blocks and nodules, in the midst of large masses. To hasten artificially the production of chrystals out of his chrystallizable matter, he makes it into balls, incloses a number of them in a space surrounded by a slight wall of loose bricks, waters them once in two or three days, so as to keep up merely a state of constant but moderate humidity, and examines them every fortnight, and changes their places, putting those above that were before below. Every person who has attended Thomson's Annals for April, 1816, has given the analysis of a flexible small grained sandstone from China; flexible when wet, silex 95.40; lime, with a trace of iron 3.10; alumina 0.50 100. Dr. Meade, of Philadelphia, has a specimen of course grained flexible sandstone, which he found last summer in the neighbourhood of Lebanon, New York state. Quere, are not all the granular dolomite limestones elastic when wet, as well as as the Pittsfield marble? (Pittsfield, Massachusets.) Dr. Thomson is a strenuous supporter of the atomic theory of Dalton: I know not where two men more able are to be found; and what they urge is truly entitled to respectful consideration. But, the proposition that the particle A has a strong affinity for, a violent inclination to combine with 4 particles of B, but not the slightest for 3 particles, is, at first blush, so revolting to common notions, that it requires strong proof to make it out. This proof has not been given; we have a few coincidences and more approxi mations; nor is it settled, whether we are to calculate by weights or volumes. When Sir H. Davy assumes all his numbers as settled and proven, even in his Elements of Agriculture, where the reader is left to find out the use of them, he certainly somewhat outsteps the line of demonstration. Chemistry seems fast verging into a science of arithmetical and mathematical calculation instead of experiment; and questions are now decided by the Rule of Three, that ought to have no test but the weight and measure of actual analysis. Mr. Brande has, in his second number, reviewed with some sharpness the "Attempt to esta"blish a pure scientific system of "MINERALOGY, by the electro che"mical theory, and the chemical "proportions, by J. Jacob Berze"lius, of Stockholm." Perhaps Mr. Brande's able review of this work may be too vituperative, but I confess, I read the work of Berzelius carefully, without deriving from it any clear ideas, so confused did it seem in its facts and applications, and so needlessly abstruse throughout. It contains no mark of the clear head, the distinct and manifest application of facts to the theory, which distinguish the writings of Dalton and Thomson. Dalton, Thomson, and Davy, seem to insist on the atomic theory as regulated by the weights of the atoms; Berzelius in solids, and Gay Lusac in gases, insist on the bulk or volume as a regulator of the multiple combination. The whole of the atomic theory is extremely ingenious, and perhaps its defenders have rendered it probable; but we have not yet a sufficient induction of accurate facts to establish it fully. VOL. I. Mr. Hume of Long Acre was, I believe, the first chemist that assigned oxygen as the basis of silex; and numerous facts look that way. Berzelius in his new system of mineralogy treats silica as an acid, and speaks with perfect decision of the siliciates, bisiliciates, trisiliciates, &c. The facts have not yet duly prepared us for this language. In geology, A. H. de Bonnard has given a geognostic description of the Erzgebirge. The rocks observed are, 1st. Granites, six varieties: one like that of Cornwall alternating with mica-schist, and containing tin. Another passing into eurite (weisstein, white stone). Another alternating with psammite and phullade (grauwacke, and primitive and transition schist). Another also containing tin, forming a transverse mass in gneiss. Another alternating with mica-schist, and gneiss. Another forming veins (filons) and shooting into the mica-schist and gneiss. He is inclined to consider these as so many distinct formations. 2. Eurite, weisstein, white stone, usually confounded with gneiss. It consists of a. Very fine granular feldspar, sometimes almost compact, colour grayish-white or yellowish. b. Brown mica in various proportions: when this is abundant the rock is stratified, fissile, the feldspar friable like dolomite; it is otherwise when the feldspar is compact, and the mica in small proportions. c. It incloses garnets generally, sometimes disthene, and other mixed or disseminated minerals. d. Sometimes this rock incloses a granitoid, passing into gra3 K nular eurite, and which alternates with the eurite. The eurite is accompanied in the Erzgebirge by subordinate blocks of ophiolite or serpentine. It does not shoot out in filons. The gneiss lays on it conformably. It is is surrounded by mica-schist and phyllade, which rest on it also conformably. Eurite loses part of its feldspar, and then contains quartz; it passes into mica-schist. Eurite is of age next to granite. 3. Gneiss. It rests either on granite or eurite. It passes into micaschist or phyllade, and its youngest portion sometimes alternates with these, appearing in them in thin beds (bancs), It contains as subordinate rocks, beds (bancs) of porphyry, amphibolite, quartz, primitive limestone, and pyrites. It contains many thin metallic strings, of the ores of silver, copper, lead, cobalt, bismuth, antimony, arsenic, &c. It encloses a transverse mass (stehenderstock) of granite, con taining tin. Two warm springs were observed in the gneiss near amethyst. 4. Mica-schist (glimmersheiffer) rest conformably on the gneiss; sometimes on the eurite or on the granite, wherewith its lower strata sometimes alternate. Encloses as subordinate rocks, beds (bancs) of serpentine, schistose diabase (grunstein scheiffer hornblende schist?) and limestone, talc steatite, oxydulated iron, pyrites and blende. 5. Hyalomicte (graisen or greiss) forms mountains at Zinnwald: encloses blocks of granite, and stanniferous quartz. 6. Ophiolite: serpentine. Two formations; one in beds stratified on eurite, alternately therewith and with the mica-schist: the other forming a powerful and extensive mass, not distinctly stratified, reposing unconformably on gneiss. Both contain asbest and oxydu. lated iron. 7. Phyllades and schists. Several formations a Primitive schist, follows gneiss and micaschist, conformably. They enclose ampelite, jasper-slate, amphibolite leptinite. Sometimes pass into psammite (grauwacke, killas). They also enclose as subordinate rocks, blocks of porphyry, quartz, granite, syenite, gneiss, granular diabase, schistose diabase, calcair; also ores of copper, lead, and iron. These ores are more abundant in the passage of primitive phyllade into micaschist, schistose amphibolite (hornblende slate) or slaty jasper In this case, the rock contains wacke. b. Transition phyllade: lies on the primitive conformably. It is diffi cult to determine the limits. It is distinguished principally by its alternating with psammite, (grau wacke,) of which, and of calcair, (primitive limestone,) it contains beds (bancs). In the Hartz, organic remains are found in the slates generally called primitive by the German mineralogists. It is also to be observed, that conformity of stratification is one of the principal characters of rocks of the same class. This character belongs to the primitive and what are called the transition phyllades: hence it is doubtful whether there be suffi cient foundation to divide them into primitive and transition. The last species of phyllades, contain blocks of diabase, schistose jasper, and schistose granular quartz. If we follow the schists into the newer formations, we shall find the slate clay, often called clayslate, (scheifferthon,) alternating * Primitive slate or schist has been found, as is said, to contain vegetable impressions, hence it is a phyllade. T.C. with micaceous psammite or sand- | bably belonging to the old red stone of the coal formation in Zwickau and other places. 8. Syenite. This is found in blocks subordinate to the primitive phyllades, in unstratified masses, much like the third-described granite of which it is a suite, and seems with it to constitute one formation. Syenite is various in the proportion of its constituents, and sometimes puts on the character of granite. It is accompanied by beds (bancs) of porphyry, gneiss, amphibolite, calcair, strings or veins of diabase, basaltic hornstone, and metallic veins. 9. Pyrites. This mineral occurs in such abundance in the Erzgebirge, as to merit separate consideration. It forms beds in the gneiss and mica-schist. These pyrites are of iron, copper, arsenic, zinc: sometimes oxydulated iron, with ores of copper and lead, unite in the limestone which forms a gangere for all these minerals. 10. Amphibolite, micaceous and schistoid. (Hornblendgestein, hornblendscheiffer). In subordinate beds in gneiss, mica-schist, and primitive phyllade, which often pass into this rock. sandstone formation (gres rouge, fodte liegende). When the paste becomes coarse they pass into clay porphyry, and argillolite (thonstein). Sometimes they contain rolled fragments of agate, jasper, gneiss, &c. In Germany the miners generally suppose porphyry accompanies coal. In Saxony and Silesia it reposes on the coal strata. 14 Calcair. Primitive limestone. In beds in gneiss, in mica-schist, in primitive phyllade, in syenite. It is sometimes compact, sometimes granular, sometimes saccharoid, often accompanied by mica, talc, amphibole, pyrites, quartz, diabase, &c. When these are in blocks they contain iron and other ores worth working. It is also found in transition formations. Here it often contains sparry veins, which seem to have been organic matter destroyed and supplied by chrystalline infiltration. (?) 15. Trapp. a. Schistose diabase (grunstein scheiffer). In power. ful beds in mica-schist, and primitive phyllades. b. Granular diabase (grunstein) in the preceding rocks and in calcair. c. Granular diabase 11. Schistose Jasper (keisel scheif- in the transition rocks. d. Diabase fer, leidischerstein) lapis lydius? and hornstone (corneenne) apThis is met with in primitive phyl-proaching basalt, in strings or lades, in psammites and transition veins in syenite. e. Variolite (man. phyllades. delstein, toadstone) between the 12. Quartz. In beds, in gneiss transition schists and the coal. mica-schist, and primitive and tran-f Wacke and Wackite, in transisition schist. In strings or veins in almost all the older rocks. Generally found in beds on the surface of mountains. 13. Porphyries. a. In beds in gneiss. b. In primitive phyllade, c. covering gneiss unconformably (abweichende übergreiffende lagenung.) d. Sienitic porphyry. e. Reposing on gneiss and containing anthracite. f. Newer porphyry, pro tion formations, and in the red sandstone. Sometimes it is found in basalt, and sometimes resting directly on granite. Sometimes wacke is found in phyllade with many vegetable impressions. g. Basalt, forming the summit of many mountains in the Erzgebirge; sometimes reposing on granite, on wacke, on calcair, on white sandstone. |