objections seem to be well-founded. But attempting to prove an hypothesis by elimination-by showing that another hypothesis is still more im probable-is not science. Hundreds of enquirers into the phenomena of metalliferous deposits have wished to persuade themselves that they were justified in assuming the metallic contents of veins to be derived from their containing rocks; but, in the absence of any evidence, none have hitherto felt warranted in taking such an hypothesis for granted.

We have spoken candidly of this work, of its many merits and its weak points, for it forms no part of our intention to allow our notices of books to degenerate into mere indiscriminate laudations. It is much to be regretted that before publishing his speculations in the form of a book, Mr. Wallace did not bring them before some of the London scientific societies. In these assemblies-little parliaments of science-new hypotheses are certain to meet with a thorough sifting, and it is only after having gene through such an ordeal that even the most eminent men venture to put hazardous speculations into the more enduring form of a thick octavo. The theoretical weakness of some portions of Mr. Wallace's book militates, however, but very slightly against its general value. Taken altogether, with its magnificent maps and sections, it will long be referred to as a textbook of the Alston Moor district, and as a reliable repertory of facts connected with the conditions of the formation of lead ore in limestone districts.

Bristow's Glossary of Mineralogy.

A Glossary of Mineralogy. By HENRY WILLIAM BRISTOW, F.G.S., of the Geological Survey of Great Britain. London: Longmans.

MINERALOGY has not, in modern years, been very popular in England. This has been attributed by many to the excessive pedantry and technicalities in which writers on the science have loved to indulge—and which some years ago was the subject of a sharp rebuke from Professor Sedgwick. Indeed, of all those branches of natural science which mainly depend upon a classification of species, there can be little doubt that, for a considerable time, mineralogy has been investigated on a comparatively narrow and pedantic system; a system which delighted in multiplying species as much as possible by dwelling upon, and often exaggerating, the minutest differences. That a science pursued in this spirit-particularly when coupled with notions of the unchangeableness of species borrowed from the dogmas of biological science-should have been repulsive to men of larger views, caring little for a pursuit whose whole end and aim seemed to be the measuring of angles, is not surprising. Recently, however, mineralogy, like other branches of natural science, has been pursued in a wider spirit, and abler enquirers have taught us that its main object should be to bring allied species together to trace their similitudes and transitions— rather than to isolate them by barriers, often imaginary. Under this new principle of prosecuting mineralogical researches, the science, hitherto so barren and repulsive, has, to adopt the idea of the greatest mineralogical writer in the English tongue, become a living thing. The mineral kingdom, instead of being put before us as consisting of so many hundred disconnected species, each isolated from the other by impassable barriers, is now presented as a whole-as a regular series of mutable species passing insensibly into each other from one pole of the mineral kingdom to the other. Pursued in this spirit, mineralogy becomes one of the most interesting—indeed we may say fascinating-branches of natural philosophy, and one of the very highest importance in elucidating many of the greatest geological problems yet unsolved.

In making these observations we have, of course, no intention of speaking disparagingly of an accurate knowledge of crystallography, which must be the basis of all sound mineralogical knowledge. We only object to mistaking the means for the end, as seems to have been done by a class of enquirers whom we might best describe as "cabinet” mineralogists, whose object has been to isolate species and regard them without reference to each other; while the object of the geological and chemical mineralogist should be to regard them in their relations and associations-or their paragenesis, to use the word employed by the Germans.

Besides the great work of Dana, there are two other highly popular English mineralogical works-Philips's Mineralogy, edited by Brooke and Miller; and Nicoll's Manual of Mineralogy. The former is a work of great authority, Professor Miller being undoubtedly the most eminent English mineralogist; but neither the systems of classification nor crystallography have met with as much favour as those adopted by Professor Nicoll, whose manual is now out of print, and which must not be confounded with a more recent work of his on the same subject-a reprint, we believe, from the last edition of the Encyclopædia Britannica. But there has been hitherto no work in English at all answering to this "Glossary " of Mr. Bristow. It is a Dictionary of Mineralogy of the most complete kind, and yet in the most portable form, and must become a sine qua non to every practical mineralogist. Unincumbered with any system of classification, it describes every mineral species or variety alphabetically, with cross references to synonymes, English, French and German.

The description of the minerals is at once concise, and yet sufficient for practical purposes. It includes their crystalline and physical characteristics, chemical composition (shown both by formula and analyses), behaviour before the blowpipe, and their principal localities and uses. It need scarcely be said that Mr. Bristow having the resources of the Jermyn Street Museum at his hand, as well as the assistance of so eminent a mineralogist as Mr. Warington Smyth, has had great opportunities of turning out a good book. And he has certainly done so. We can only find one fault, which is the formula he adopts for silicic acid, Si O3. We think that this is a mistake, particularly so in a work on mineralogy, as recent enquiries give us reason to suppose that this acid is isomorphous with other compounds of the form R 02. The benefit of keeping to the old formula is very slight, particularly now that it is renounced by Rammelsberg, who has adopted the formula Si O2 in his new Handbuch der Mineralchemie.

Notwithstanding the great body of information it contains, this little volume has the advantages of extreme clearness of type and great portability. For tourists and practical men interested in mineralogy it will be indispensable; among the former we expect Mr. Bristow's green book will be seen often side by side with Mr. Murray's red volumes.

The Government School of Mines, and the Museum of Practical Geology.

THE Students' Lectures at the School of Mines will be resumed on the 6th of January; when Dr. Hofmann will commence a course of thirty lectures on Organic Chemistry.

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Mr. Warington Smyth will also continue his course of lectures on Mining." In that portion of his course already delivered Mr. Smyth has discussed the conditions connected with the deposition of the useful minerals, and the laws regulating their occurrence, as far as our knowledge goes; examined their accidents, dislocations, and the points to be observed

in searching after them; and described the modes of boring for and excavating them, and the tools employed. In the lectures yet to be delivered, Mr. Smyth will discuss the modes of sinking shafts, driving levels, &c., and the various methods of securing them: describe the usual methods of working away mineral deposits, transporting the produce underground, and drawing it to the surface; as well as the most approved arrangements of draining and ventilating mines.

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Mr. Smyth will also continue his course on Mineralogy," which however is drawing to a close.

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Dr. Percy will likewise resume his course of lectures on Metallurgy." In continuation of those already delivered, he will proceed with a special description of the processes connected with the treatment of argentiferous copper, silver and gold ores, with the alloys of these metals, and the modes of assaying them. Following these, the Doctor will treat of the metallurgy of mercury, antimony and its alloys, bismuth, nickel, cobait-including the manufacture of cobalt colours. Next of arsenic and arsenious acid, and the smelting of the ores of tin. The last section will be on the making and manufacture of iron and steel.

Professor Huxley's course of "Natural History," now about half completed, will also be continued.

Early in February two other courses will be commenced-one of thirty lectures, on Geology," by Professor Ramsay; and another of about thirtysix lectures, by Professor Willis' on " Applied Mechanics."

In addition to these students' lectures, two courses of evening lectures, for working men, will be delivered during the month: one by Dr. Hofmann on the "First Principles of Chemistry;" and another by Mr. Geikie, who temporarily supplies the place of Professor Ramsay, on "Geology." These lectures are of great value as a means of disseminating sound scientific knowledge among the body of the people, by whom the opportunity is fully appreciated. Mr. Geikie's course, which will comprise a condensed description of the geological formations of the British Isles, we strongly recommend to the attention of our readers, residing or sojourning in London, who come within the definition of "working men."

The Geological Survey of the United Kingdom.

Or all the labours of the survey, none are more important than those pursued of late in the Midland, Lancashire and Scotch coal fields, which have resulted in memoirs on the Warwickshire, Lancashire, and Edinburghshire districts, recently issued, the importance of which, in an economic point of view, it is really difficult to estimate too highly, particularly those laid down on the 6-inch scale. In addition to the eight 6-inch maps already published, a new vertical section is now ready, on a scale of 40 feet to an inch, illustrating the position, mineral character, and thickness of each bed of the Permian and Carboniferous strata, as they are met with in South and West Lancashire districts. The system recently adopted of issuing a descriptive memoir with each new map, in which various information of great value is given, and the geologist is pointed out where the best fossil localities, the best exposed sections, &c., may be found, much enhances the value of the maps.

Among the other new publications of the survey are the following:A Memoir on the Geology of the Isle of Wight, by Mr. Bristow, containing a list of fossils, by Mr. Etheridge; and Notes on the Eocene Flora of Alum Bay by P. de la Harpe and Mr. Salter. This memoir describes all the formations in the island, in addition to those already treated on in the late Professor Forbes' memoir, which was confined to the Tertiary Fluvio

marine deposits. The list of fossils is most complete, and numerous illustrations are given of the characteristic forms of such stratum.

A memoir descriptive of map 12 (parts of Berkshire and Hampshire) by Mr. Bristow and Mr. Whitaker, containing a list of fossils by Mr. Etheridge, is also ready. Likewise, a new decade (No. 10) giving a description of the Fishes of the Devonian Epoch, by Sir P. de Malpas Grey Egerton, with a preliminary essay on their systematic arrangement by Professor Huxley, in which the whole question of the classification of the Devonian Fishes is considered, "and results arrived at which seem to necessitate an important modification of the received arrangement of the great order of Ganoidei."

The Iron Ores of Great Britain." part 3, contains a general description of the iron ores of South Wales, classified as follows:

1. Clay iron-stones found in coal measures.

2. Iron ores of the carboniferous limestone.

3. Iron ores of the Permian series.

This we shall refer to more fully on another occasion.

Mining, Quarrying, and Metallurgical Intelligence.

CORNWALL AND DEVON.

ST. JUST DISTRICT.-Notwithstanding the just celebrity and great productiveness of this, probably the most ancient mining district in the world, it is a matter of fact that there are only two mines in it at present paying dividends and those not large ones. This, at first sight, may appear a very unpromising state of things, and might induce many to believe that the district had retrograded from its ancient fame; but a closer examination shows this not to be the case, for we find that the old-established and hitherto well-paying mines have suspended dividends, not from dire necessity caused by exhaustion and poverty, but from the desirability of making large expenditure on new works required by the altered modes of modern mining. Thus, in every direction we see new works going on: new shafts sinking; new pit-work being put in; new stamping and winding engines being erected; all which, although dead work at present, will produce their harvest in good time. The mines paying dividends now are: Wheal Owles, one of the few mines remaining of the thorough old Cornish stamp, divided only into 80 shares, not one of which has changed hands for years. This mine was long under the management of the late Mr.John Boyns, better known in St. Just as "Purser Boyns;" a most worthy and excellent man, and a fine specimen of the legitimate Cornish miner of that "olden time”—now almost a thing of the past-when Cornish men worked their own mines, and consequently worked them fairly and honestly. He has a worthy successor in his nephew, the present purser, Mr. Richard Boyns. Wheal Owles is not a rich mine, but it is well worked and cautiously managed. The produce is principally tin, which is of very fine quality. At the last account the dividend was £400. Boscean divided £240 at the last account. The floors at this mine are now very compact, a new water-wheel, and twelve heads of stamps, having been recently erected, as well as a new tramway laid down.

Among the mines not paying dividends, the most important is Botallack. Few of our readers can be unacquainted with this fine old mine-one of the great sights of Cornwall-worked out under the sea for nearly the third of a mile every one who has "done" West Cornwall, or even read about it, must remember Botallack, with its high precipices, and its engine-houses and machinery perched upon ledges of rock and washed by the storms of

the Atlantic.

This mine is worked under the sea at two points-at Wheal Cock and at Crowns. The accompanying sketch, fig. 1, is a rough section of the latter

mine, showing the position of the workings under the sea on the Crowns lode, and the new diagonal shaft which, after a labour of four years, is now nearly completed.

Those who have visited Botallack may remember standing on the cliff at this part of the mine, and looking down, a distance of 250 feet, upon an engine perched upon a ledge of rock employed in winding from a shaft some little distance below that again. The shaft is called Pearce's whim shaft, and is the one shown in the section: to get to it you had to descend a winding path cut in the cliff, called the "Mules' path," from having been originally made for the use of mules, to carry up the ore from the shaft to the dressing-floors above. This whim shaft has been sunk to a depth of 180 fathoms; but at every succeeding level, longer and longer drivings had to be extended from the shaft seaward, through unproductive ground, in order to reach the orey part of the lode, which dips away from the land, as will be seen by the section, where the orey parts are shown in shading. Thus at the 150fathom level, upwards of 200 fathoms of dead ground had to be gone through; and at the 180-fathom level, 260 fathoms of dead ground. To pursue the shoot of ore further, under such circumstances, became impossible. In a mine working under ordinary circumstances the difficulty could have been met by sinking a new shaft down upon the orey ground; but as it was not possible to sink a shaft in the Atlantic Ocean, this resource was closed to Botallack. The lode was not to be readily abandoned, for it was a very rich one, having in one year, between the 85 and 115, yielded £24,000; and the ground above the 150 having yielded £50,000. At last it was determined to sink a new diagonal shaft from the surface, at such an angle that it should cut the productive part of the lode in the bottom levels. As shown in the section this has now been accomplished, the shaft having been sunk 345 fathoms, cutting the 180-fathom level at a distance of 260 fathoms from Pearce's shaft. As the Crowns lode is enclosed in hard greenstone rock, it was found impracticable-except at an enormous cost