more inflammable when fresh from the pit than after long exposure to the air. 2d. The pyritous shales that form the floors of the coal-seams decompose the water that lodges in them, and this process is constantly operating on a great scale in the extensive wastes of old mines. In whatever mode we suppose the gas to be generated, it is disengaged abundantly from the High Main, but more particularly from the Low Main coal-seam, and that in a quantity and with a rapidity that are surprising. It is well known that the gas frequently fires in a shaft long before the coal-seam is reached by the sinkers; and that the pit-men occasionally open with their picks crevices in the coal or shale, which emit 700 hogsheads of fire-damp in a minute. These blowers (as they are termed) continue in a state of activity for many months together, and seem to derive their energy from communicating with immense reservoirs of air. All these causes unfortunately unite in the deep and valuable collieries situated between the great north road and the sea. Their air-courses are 30 or 40 miles in length, and here, as might be expected, the most tremendous explosions ensue.

The after-damp, or stythe, which follows these blasts, is a mixture of the carbonic acid and azotic gases, resulting from the combustion of the carburetted hydrogene in atmospheric air, and more lives are destroyed by this than by the violence of the fire-damp.

To guard against these accidents, every precaution is taken that prudence can devise, in conducting and in ventilating the mines. Before the pit-men descend, waste-men, whose business is to examine those places where danger is suspected to lurk, traverse with flint-mills the most distant and neglected parts of the workings, in order to ascertain whether atmospheric air circulates through them. Large furnaces are kept burning at the upcast shafts, in aid of which at Wall's End colliery a powerful air-pump, worked by a steam-engine, is employed to quicken the draft: this alone draws out of the mine 1000 hogsheads of air in a minute. A kind of trap-door, invented by Mr. Buddle, has also been introduced into the workings of this colliery. This is suspended from the roof by hinges, wherever a door is found necessary to prevent the escape of air. It is propped up close to the roof in a horizontal position; but in case of an explosion the blast removes the prop, when the door falls down and closes the aperture.'

The metalliferous or lead-mine measures compose the northern and western boundaries of the coal-field. Some of the members of the metalliferous formation coincide with those of the coal-districts; such as coal, shale, and sand-stone: but other rocky masses, as the mill-stone grit, sand-stone with impressions of marine-shells, shale and lime-stone, with the encrinal fossil, chert, and basalt, serve to discriminate the lead-mine measures. Tables of the substances traversed at the different workings are subjoined; and the nature of the several sandstones, lime-stones, basalts, &c. of the formation, is detailed.

The variety of carbonate of lime called satin-spar forms a thin stratum in a bed of black slate-clay, which crops out at Aldstone

close

close to the brewery. The specimens are generally intersected by veins of iron-pyrites and slate-clay. Some buildings stand upon the bank out of which this mineral was quarried, and the proprietor, to save them from being undermined, has built a wall close to the face of the rock; so that satin-spar is no longer to be procured, and is become a scarce mineral.'

--

In the lime-stone, shale, and sand-stone of this formation, are found madrepores, millepores, vertebral columns of the cap encrinite, pectinites, large oysters, impressions of arcæ, anomia, &c. The lime-stones are the most productive in lead-ore, and next to them the stratum of sand-stone called hazles. In prosecuting his examination of this mining field, Mr. Winch specifies some of the most remarkable veins of lead, with their bearings, qualities, &c., the varieties of leadore and of other mineral substances obtained from the veins, and six mineral springs, which have been discovered in this range of his observations. A separate section is allotted to the consideration of the beds on the banks of the Tweed, from Dryburgh towards the east, which differ materially from the usual lead-mine measures. The porphyritic formations of the Cheviot Hills are likewise shortly discussed.

On the surface of all the formations, and imbedded in the soil, are found blocks, or detached masses of various rocks, as of blue corralloid lime-stone, closely grained sand-stone, hard black basalt, porphyry, and porphyry-slate.

• Considerable quantities of marl have been discovered on the west side of the river Till, in situations which seem to have been the bottoms of lakes; and in this alluvial matter horns of some species of bos and cervus are found imbedded. The marl is of a light grey colour, and contains bivalve and univalve shells which retain their pearly lustre. This substance has been noticed at Wark, Sunnylaws, Learmouth, Mindrum, the Hagg, the Hopper, and at several other places in that neighbourhood. It probably rests in some places on the beds that I have described as prevailing on the banks of the Tweed, and at others on porphyry or grey-wacké.'

This communication, in its entire form, and with its accompanying plates and appendices, will form a valuable article in the library of every coal-owner.

On a Whin Dyke traversing Lime-stone in the County of Northumberland. By the Hon. Henry Grey Bennet, M.P. F.R.S. Vice-President of the Geol. Soc. The most remarkable circumstance contained in this very brief notice is the deterioration of the lime-stone in the vicinity of the trap-vein.

Description of an insulated Group of Rocks of Slate and Green-stone in Cumberland and Westmoreland, on the East Side

of

of Appleby, between Melmerby and Murton. By the Rev. W. Buckland, Professor of Mineralogy in the University of Oxford, and M.G.S.Of the local anomalies and disturbances which are here recorded, we could convey no intelligible idea without transcribing a large portion of Mr. Buckland's paper, and referring to the plates. It seems to result, however, from this gentleman's ingenious investigation, that the red sandstone of the plain of Carlisle is identical with that which traverses the vales of Cheshire, Salop, Lancashire, and Yorkshire, — the repository of the gypsum and rock-salt quarries, and is a more recent deposition than the magnesian limestone, which is incumbent on the upper strata of the principal English coal-fields.

ART. XIII. The Florist's Manual, or Hints for the Construction of a gay Flower-Garden. With Observations on the best Methods of preventing the Depredations of Insects. By the Authoress of Botanical Dialogues, and Sketches of the Physiology of Vegetable Life. Illustrated by Two engraved Plans. 12mo. pp. 74. 4s. 6d. Boards. Colburn. 1816.

WE E cannot refrain from expressing the satisfaction that we feel, in marking the growing attention which the study of botany now receives from the female sex: from those who are so peculiarly fitted to become the admirers of plants and flowers. The terms and modes of expression, which the Linnéan system introduced into botanical works, for a long time rendered the cultivation of this science rather objectionable to delicate feelings: but the writings of Professor Martyn, and more recently those of the distinguished president of the Linnéan Society, have happily restored to botany that purity and loveliness which it ought never to have lost.

The small work before us is composed with the laudable view of giving instructions for the formation of a a gay and mingled flower-garden, without any great extent of ground, or the intermixture of fountains, statues, or temples; in short, without any considerable sacrifice of property. It is meant to guide the exertions of ladies, who, with limited means, have a taste for what is beautiful and ornamental; and the views of the fair author are rather happily expressed in a few lines: 'It is not only the amusement of the present moment that I seek to afford. To use and not to fatigue the understanding, to interest and not to absorb the mind, is the true art by which happiness is to be attained; and while from the wonderful structure of the creature, we are led to the contemplation of the Creator, we shall find this a more certain panacea to the

daily chagrins of human life, than all that the dissipation of the gilded hours of indiscriminate society has ever been able to afford.' (P. 41.)

We are here presented with short but comprehensive directions for laying out flower-beds, which are illustrated by two plans. The breadth of those beds that are represented is such, that the plants are every where readily within the reach of the hand, without the necessity of treading on the garden mould; and the shape which the fair author prefers is lunated, waving, or irregular. To enable her readers, to attempt successfully the formation of a varied and brilliant flower-garden, she has also given a catalogue of common herbaceous plants, with their colours, as they appear in each season from February to August; and short notices are added, stating the varieties of colour, with any peculiarity in the form or habit of the species. Both Latin and English names are given, and the former are carefully accented. The writer also discusses, in rather a cursory manner, the best modes of securing plants from the ravages of insects; and we agree with her in thinking that the most certain way of accomplishing this object, without risking the health of the plant, is to gather the insects carefully, and then destroy them. The humanity of the fair directress recommends that snails should be instantly immersed in water, as the surest and most gentle mode of extinguishing life. The appetites of other animals are also mentioned, as affording the means of destroying insects; and here she takes occasion to relate a little anecdote of a hen, with her brood of chickens, obtaining admission into a garden, and completely clearing several rose-trees from the aphides which infested them. In addition to these remarks, we beg to state the great advantage that we have known to arise from burying slices of potatoe near the roots of plants, where the wireworm abounded: thus attracting the insects as by a bait, and enabling us to destroy them. Slices of turnip have in a similar manner been used with singular success, to save whole fields of wheat from the ravages of the slug.

The necessity of preserving the leaves and stems of bulbous plants from injury, and suffering them to decay of themselves, is well urged by the author; and we hope that she may induce her fair readers to inquire more deeply into the interesting subject of Vegetable Physiology.

very

This little volume is written in an easy and agreeable style; occasionally, however, indulging in expressions rather singular than accurate, and somewhat bordering on the phraseology of the sentimental novel. Thus we have 'paucity of colour,' the visual, the olfactory, and the saporific senses,' &c. The term recrements.

recrements is used for secretions, or elaborated juices; though its true import is that of something superfluous, and rather injurious than useful to the plant. Our duty, moreover, will not permit us to dismiss this publication without adverting to the numerous and inexcusable typographical errors, which abound particularly in the list of plants to which we have already alluded.

ART. XIV. Flora Tonbridgensis; or a Catalogue of Plants growing wild in the Neighbourhood of Tonbridge Wells, arranged according to the Linnæan System, from Sir J. E. Smith's Flora Britannica. With Three Plates of rare Plants. By T. F. Forster, F.L.S., &c. Small 8vo. pp. 216. 9s. Boards. Arch. 1816.

ΤΗ

HE study of indigenous plants is now prosecuted in this country with such ardour and accuracy of research, that scarcely a district in England is unable to boast of a tolerably accurate catalogue of all the plants which it presents, with the particular situations in which they are found. By a correct knowlege of the habitats of plants, we have it often in our power to ascertain mistakes, to reconcile synonyms, and to make nearly the same use of wild-growing plants as of a well arranged and carefully named Herbarium. Some districts, indeed, are little adapted to become the subjects of such local publications: those, for example, which lie in the neighbourhood of large manufacturing cities; where the advanced state of agriculture, and the factitious fertility and slightly varying surface of the soil, offer but a scanty reward to the laborious peregrinations of the botanist. It is rather a melancholy confession, which as lovers of the science we are constrained to make, that the draining of morasses, the inclosing of heaths and commons, in a word, the improvement of the productive powers of the soil, are in this view regarded by us with regret: but, happily for the solace of such feelings, when we look to the mountainous districts of England, to Scotland with her Hebrides, and to the sister-shores of Ireland, we still see many extensive tracts of country abundantly fitted for the growth of native plants, and apparently incapable of being ever forced into a state of tillage.

The vicinity of Tonbridge, which furnishes the field for Mr. Forster's observations, is yet, considering its limited extent, rich in botanical treasures; though now less abundant than formerly, owing to the progress of improvement. Since the year 1795, Mr. F. has been in the habit of paying a summer-visit to Tonbridge Wells; and on these occasions his attention was naturally attracted by the numerous plants growing