Imatges de pàgina
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vulgar error; for, if it were not for the mines, Spain (so much degraded by other radical causes) would long since have vanished from the list of European kingdoms. Mr. Townsend, in his Travels, and even the Spanish writers themselves, have pointed out the real causes of the degradation of that kingdom, which have not the smallest connexion with the mines or with precious metals. The establishment of the Inquisition, which has annihilated all mental energy, the prejudices of the numerous nobles against industry, the traveling flocks of sheep which depopulate, the country, the want of farms and farm-houses, while the peasants live in distant villages, &c. &c. are all native radical causes of decay; and if the Spaniards had well-regulated laws and customs, and a temperate share of English freedom, the mines of Peru would, like our commerce, only supply additional stimulants and rewards to industry. Besides, the example is not applicable; for, even if distant colonial mines were prejudicial to a state, the argument cannot apply to native mines, which we know, from so many practical instances, to be of superlative advantage.

In a more private point of view, it is to be regretted that studious men, and connoisseurs in general, do not pay more attention to mineralogy, the principles of which are of easy acquisition. The specimens also not only are unperishable, but may be inspected at all times in their native state, and are within the purchase of a moderate income. Shells only please the eye, and are adapted to female amusement. Insects soon decay, and larger animals require great space and expense. A dry herbal is little pleasing, and plants cannot be studied at all seasons. Yet zoology and botany may be studied from prints, while it is impossible to delineate or colour a mineral with any near approach to nature; and the texture and weight, which are most essential considerations, cannot be represented. Hence the study of mineralogy must be attended by specimens, and a small collection supply the want of prints. It is impossible to understand numerous passages of history and of the classics, not to mention treatises on the arts of architecture and sculpture, and books of travels, without some skill in mineralogy. The mistakes arising from ignorance of this science are inhnite; and we have seen the obelisks of Egypt pronounced to be formed of an artificial compound by travelers otherwise respectable, who did not know that there are vast chains. of mountains of red granite! To travelers in general we must recommend this science as indispensable; for their mistakes are sometimes as gross as if they called a tiger an elephant, or a willow an oak. If they-possess a small tincture or rather tinge of the science, it is derived from the writings of sir John Hill, whose works are now as much antiquated as those of Paracelsus in chemistry. Mr. Kirwan's Elements should be studied by every traveler,

who means to describe ancient edifices, or even the common features of a country

The work now before us has the advantage of being founded on modern principles, and is in other respects deserving of considerable approbation. But the author's self-importance, which is too apparent in the rapid sufficiency of many of his decisions, has led him to publish in two thin quarto volumes what might have appeared in an octavo ; and a great part of the work is a mere re-publication of his own treatise on the Shetland Isles, printed some years ago. This is unfair, as the purchaser not only must pay a great price for a little information, but must again buy what he probably before possessed. If the author had sedulously endeavoured to stop the sale of his work, and injure his own reputation, he could not have acted in a more effectual manner.

The preface is in the following terms. . . I undertook the journeys, of which I now presume to lay the notes before the public, in order to acquire, from actual observation, a knowledge of the mineralogy of the Scottish Isles.

· I have chosen the form of a journal, because I wished to convey the information I had gleaned in the style of detailed observation, and in that order which the appearance of the country naturally suggested. But, in adopting this form, I am anxious to caution the reader against expecting that entertainment, and kind of information, which form the ground-work of the many journals through the more interesting parts of our island. If any one shall find this Out. line of the mineralogy of these countries deficient in incident, in episodes and stories, and in descriptions of picturesque and romantic scenery; let bim recollect, that to indulge in such descriptions was incompatible with the design of this work. I do not despise those ornaments; and I hope that I have not been insensible to the emotions which naturally arise from the retired and striking scenes which often burst upon me in the unfrequented tracts which my pursuits led me to explore : but I have thought it foreign to my purpose to obtrude these things upon the public.

• Another resolution I had formed to myself, and which partly indeed led me to choose the form of a journal, was, to shun the fasa cinating evil of speculation and hypothesis, which mars all faithful observation. It would ill suit my talents to venture upon deep speculation, were I inclined ; and perhaps the state of mineralogical knowledge forbids it. It is a fitter task for me to record faithfully what I have myself examined, and to give a fair report of the materials which were collected, than to expose myself, by the form or arrangement of the work, to the danger of having the facts twisted and perverted by hypothesis, the rage for which is as remarkable in this as in the other sciences.

o While, in mineralogical pursuits, there is much to interest a philosophical mind, the object of true value is its application to economical purposes. I fear that the theories of the formation of the earth, interesting as they are, often mislead the mind, and pervert the understanding ; and those who yield to them become so in.. volved in delusive speculations, so blind to fact and experience, that, like Archimedes, they find but one thing wanting to raise worlds.

« Of the utility of this science there can be no question; more particularly when it is freed from the vague suppositions of the theorist. It is a ground-work, without which the observations of the geologist, and the labours of the miner, will ever be uncertain, and of little utility. It is a science, the cultivation of which will raise a country to importance, by exciting new sources of industry, even in situations where the labours of the husbandman will be employed in vain. But, though I am well convinced that the importance of every thing in mineralogy is in proportion to its accuracy, I would not be understood to represent these notes as a complete account of the mineralogy of the countries of which they treat - I give them to the public as an imperfect outline. The mineralogical history of a country is to be accomplished only by studying at leisure all the varieties and disposition of the strata and veins, and the appearances of the mountains and valleys : an investigation which the utmost care, in a rapid survey, must leave in many particulars im-' perfect, especially when the mineralogist is perplexed with the dif

ficulties of traveling among unfrequented islands. · "I have in this, as in a former work, separated the particular account of the strata and veins from that of the particular fossils ; as the common method of conjoining them appears often to lead to confusion, and can never be sufficiently correct. In describing the fossils, the method and nomenclature of the best mineralogists has been followed. The chemical characters, which form even the foundation of many mineralogical systems, I have seldom employed; from a conviction that the chemical part of mineralogy, notwithstanding the late improvements in the art of analysis, is still to be considered as imperfect. We have only to observe the contradictory results obtained by the best chemists in decomposing the same fossil, to be convinced that the analysis of the present day, although much improved since the time of Bergman, is still of no very great utility in mineralogy.

• The drawings of scenery, and the mineralogical plans, which accompany this work, were executed by the elegant pencil of my friend Mr. Charles Bell. In the views of scenery, he has happily expressed the different characters which the rocks assume from the effects of the weather-a circumstance which renders them the more valuable. The mineralogical plans are of much consequence in elucidating several curious facts, which otherwise would with difficulty have been understood. These engravings are not to be judged of as picturesque representations; they were not intended as ornaments, nor were they selected as being the most beautiful--the design being to mark the characteristic features of the scene, not as a landscape, but as a mineralogical delineation.' Vol. i. P. v.

This expression of the weather is a whimsical effort of Mr. Jaméson's imagination. If he mean that the plates look weatherbeaten, we have no objection.

In an introduction, our author gives some account of Werner's system of rocks, the most difficult branch of mineralogy, particularly so far as concerns keralite or petrosilex, grunstein, amygdaloïd, trap, and basalt. But Mr. Jaméson shows a woeful penury of language when he divides rocks into 'primary, transition, and stratified. This poor substantive transition is, throughout the book, pressed into the service of an adjective, as if Mr. Jameson did not know that transitive is an English word !

Lehman first divided rocks into primary and secondary; Werner added the transitive, volcanic, and alluvial. Of all the provinces of the three natural kingdoms, the study of rocks is the most difficult; and we should rejoice to see an ample compilation on the subject. Metals, salts, inflammables, gems, &c. &c. are sufficiently known; but the study of the grandest features of nature is still in its infancy, though the Alps have been ably described by de Saussure.

- The primitive strata are the following: granite, gneiss, micaceous shistus (schistus ], ardesia, sienite, porphyry, primitive limestone, primitive greenstone, greenstone shistus, serpentine, quartz, pitchstone, and topaz rock. Granite is considered by Werner as the fundamental rock, or that upon which all others are laid, and it is but very rarely that it alternates with other rocks. It is disposed in layers or strata, which are often enormously thick, and frequently horizontal, and extend thus for many miles through a whole chain of mountains. All the other primary strata alternate with each other, but never with the transition or stratified rocks. The greenstone, wacken, and pitchstone, are the only exceptions, the two first being common to the three first-mentioned formations, but the pitchstone only to the pri. mary, and stratified, or flotzgeburge. · · The transition, or uebergangsgeburge, comprehend all those rocks, the lowermost strata of which contain few or no petrifactions : in the higher they are more abundant; but only petrifactions, the originals of which no longer exist. These mountains also abound in metallic veins and in grottoes. Those of Antiparos, Crete, &c. are in this kind of rock, as are the Hartz metalliferous mountains, and those of Derbyshire. They seem to have been formed after the primitive, and earlier than the stratified (flotzgeburge) rock. The strata of this formation are the following : grawacken, grawacken slate, sandstone, some species of ardesia, greenstone, mandelstone, limestone, and Dr. Reuss conjectures that some species of sienite and porphyry may belong to this class of rocks.

• The stratified (flotzgeburge) appear to have been formed after the transition rocks. They consist of sandstone, limestone, argillite, with numerous petrifactions ; also basalt, shistose porphyry, pitchstone, greenstone, wacken, and the various coal strata.

• From the view of these three formations, we observe that the greenstone and wacken occur in every one of them; but the basalt is peculiar to the stratified rocks. * The volcanic comprehend the various stony substances altered.

by action of fire : these are, lava, pumice, volcanic ashes, and volcanic tuff.

• The alluvial consist of gravel, sand, clay, &c. and are the debris of the other strata.' Vol. i. P. xv.

This greenstone for grunstein is again an error of ridiculous and constant recurrence. The German is better ; and Mr. Jameson might as well put red-stone for ruby.

The remainder of the introduction we shall transcribe, as it is an abstract of the whole book, and may give our readers such å general view as we should ourselves have compiled.

PRIMARY Rocks.

. Granile.—This rock forms but a small portion of the Scottish isles, it being found only in the isle of Arran, and in the lower part of Mull called Ross, and in the Shetland islands. Upon the main land, however, I observed it forming mountains in Sutherlandshire ; a considerable part of the county of Aberdeenshire seems to be formed of it ; and also the lofty mountain of Cruachan, upon the west coast. Granite veins are pretty frequent in several of the islands, as in Arran, where they traverse the common granite, and in Coll, Tiree, Rona, the Orkney and Shetland islands, &c. where they traverse micaceous shistus, gneiss, or hornblende slate. Upon the mainland, in the route from Bernera to Perth, the granite veins are extremely common.

Gneiss.--Thiş rock I observed in Coll, Tiree, Rasay, Rona, in the Shetland islands, and in several places upon the mainland of Scotland; in particular, it forms the summit of the high mountain called Ben Lomond. It sometimes alternates with micaceous shistus and hornblende rock, and it is traversed by granite veins, as is the case in Coll, Rona, &c.

Micaceous Shistus.—This rock forms a portion of the isles of Arran, Bute, and Mull; it is just to be observed in Coll, but a very considerable extent of the Shetland islands are [is] composed of it. In the mainland it appears. to extend through the whole district of Cowal, and to the extremity of the isthmus of Cantyre, and in all the country from Bernera to Dunkeld ; and from Dunkeld to Loch Lomond by Inveraray, the micaceous shistus is the prevalent rock, Upon the east coast it is frequent among the other primary strata. It alternates with shistose quartz in the island of Mull, and with hornblende and gneiss in the island of Coll; and it is to be observed in several places passing to ardesia, and it is traversed by granite veins, and has pieces of granite inclosed in it.

Ardesia.-Primitive argillaceous shistus. This rock occurs in Arran, Bute, Isla, Jura, Easdale, and Seil. In Isla there is a species of it which contains pieces of granite, which, however, seem to have been formed at the same time with the ardesia. In Easdale, Seil, Bute, and Arran, it is quarried for economical purposes; but the slate of Easdale is by far the best. . .

Sienite. A rock nearly allied to sienite seems to form the craig

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