from the earth, and from its weight, much greater than that of air, forms a thick stratum of suffocating gas upon the floor of the cavern. When a man enters, his head and shoulders rise above the stratum of gas, and he breathes pure air; but when a dog is introduced, his head and body plunge completely into the carbonic acid gas, and he soon falls down, suffocated. The animal is then removed by the guide, laid upon the grass outside, and, in a short time, recovers.

Dr. Ozanam has shown that this suffocation by carbonic acid, when produced properly, affects a patient like chloroform, ether, or nitrous oxide, and can be made available in surgical operations. Indeed, he considers that carbonic acid has certain advantages over chloroform, and that it is less dangerous than the latter.

But of all the means hitherto employed to render man perfectly insensible to pain, the most curious, perhaps, is that called Hypnotism or Braidism, discovered many years ago by the late Dr. Braid, of Manchester, and practised successfully by him in England. It consists in placing some object, such as a cork or a piece of polished metal, at a short distance from the forehead of the patient, and requesting him to fix his eyes steadfastly upon it. After some time, which varies from a few minutes to half an hour or so, according to the constitution of the individual, the patient's eyes seem riveted upon the object in question, and for some moments he remains thus, without once closing them; they then suddenly close, and the patient falls into what is termed the hypnotic state, a kind of somnambulism similar to mesmerism. Consciousness has disappeared, and complete insensibility to pain has ensued.

Braid's discovery seems to have been abandoned for some time past by the medical world, but was occasionally put in practice by lecturers on the so-called "electro-biology," &c. Lately, however, it has been taken up again in Paris, by M. Paul Broca, surgeon to one of the hospitals of that city; and Dr. Braid just lived long enough to hear of his method of producing anæsthesia meeting with singular success in the hands of M. Broca. One of the first results obtained by the latter was made known a year or so ago at the Académie de Médecine. It was the case of a woman who had repeatedly refused to be operated upon for a large tumour. At length, M. Broca induced anæsthesia by causing the patient to fix her eyes upon a metallic disc which he held above her forehead. In about a quarter of an hour, a state of complete insensibility supervened, and the operation was performed. On returning to her senses, the poor woman would not believe that the operation had indeed taken place whilst she was under the influence of sleep.

28

BARMOUTH.

BY THE EDITOR.

66

ACATION TOURISTS" make it their business, once a year, to strain every nerve in order to reach the remotest corners of the carth, to visit some unexplored or imperfectly-known region, and accomplish the journey home, during the period called "the vacation." That the last is a somewhat indefinite term is obvious, from the fact that it enables one gentleman to set foot on the Fiji Islands; another, to admire the scenery of the river Amazon; a third, to compass a nine weeks' tour in Canada; and a fourth, to sun himself on the banks of the Niger, and in other portions of tropical Africa! How these feats can be accomplished within a period which we have usually supposed to be limited to five or six weeks, we are at a loss to understand, and it is not our business to institute an inquiry; but, however it may be managed, we fear that, after the revelations of those hardy travellers who brave the perils of the ocean wilds and mountain avalanches, the burning desert and the knife of the savage, in order to serve up a palatable dish of adventures for their readers at home; after a perusal of the narratives of these bold adventurers, we say, there can be little hope that our readers will find much to interest them in the few notes taken during a "vacation tour in Wales," comprising a sojourn of ten or twelve days at a quiet little fishing town, and a series of short excursions in its vicinity.

We shall take courage notwithstanding; conscious that if we are unable to satisfy that craving after the marvellous, which can only be appeased by stories of hair-breadth escapes from such dangers as we have just referred to, yet we have the advantage of being able to direct the attention of our readers to scenes of beauty and interest lying at their own doors, and to speak to them of pleasures, in every way rational and desirable, which they may themselves enjoy, instead of receiving them, with or without modifications, at the hands of others, and participating in them only in imagination. For it matters little to what class or section of society the reader belongs; be he rich or poor, sick, careworn, or ripe for sport

and adventure; be he angler, botanist, conchologist, geologist, paleontologist, pteridologist, ornithologist; indeed, if he be devoted to any or many branches of science, commencing with archæology and ending with zoology-or only a lover of the grand and beautiful in Nature-he may indulge to the full in his favourite pursuit within ten miles of the modest little fishing town which forms the subject of these pages.

The archæologist will find relics of antiquity connected with every period of past history. In the town itself is an old building, rendered interesting by its association with incidents in English history in the fifteenth century.

Llanaber Church, a beautiful little edifice, distant about two miles from Barmouth, and still used for divine worship, is supposed to have been built about the thirteenth century, and abounds in features of archæological interest; so, also, does the old Elizabethan mansion of Cors-y-gedol, about five miles distant. These, along with Harlech Castle, Cymmer Abbey, &c., are associated with the history and habits of the Middle Ages; whilst there is hardly a lake, stream, or mountain slope which does not, either by traditions connected with it or actual remains, carry the tourist back to the Roman occupation, the Druidical age, or to the still more remote eras of mythology.

So much for the archæologist, now for the botanist.

Does he desire to study and collect wild flowers? Then, we may venture to promise him (without at all referring to their glowing colours, which rivet the attention of the traveller so that he can barely find time to admire the grandeur of the surrounding scenery) that he will meet with numbers and variety in the valleys, on the hills, or by the wayside, which will serve to occupy his attention during many a protracted ramble. Forest-trees he will also find in great diversity and splendour; whilst of ferns, mosses, lichens, fungi, &c., the name is legion; and many ferns present themselves of extreme rarity.

Of all these plants a list, prepared by a talented botanist in the neighbourhood,* has been appended to the little handbook before us; and there are few localities, in England or elsewhere, which yield such treasures of plant-life as do these hills and valleys and rugged cliffs.

The marine zoologist will meet but little to interest him on the shores of Cardigan Bay, at least not within a convenient walking distance of Barmouth; but the ornithologist and ento

Mr. J. Pughe, F.R.C.S., Aberdovey.

+ The printed" Guide to Barmouth" is published by Mr. D. Jones, Bookseller, Barmouth. The most experienced guide living at Barmouth is a person called Hugh Richards—a good sportsman and a useful companion to the archæologist.

mologist will find, both on the shores and inland, many interesting birds and insects.

To the shell-collector more especially, is this a locality of deep interest, for, about seven miles from Barmouth, in the direction of Harlech, there is a small tongue of land jutting into the sea, called Mochres, where shells of great rarity, both univalve and bivalve, are to be met with on the beach at low water, more particularly after tempestuous weather.*

And now, what have we for the geologist and mineralogist? Judging from the ecstasies of two learned professors from the metropolis, with whom we journeyed a few miles through this lovely district, as well as from our own observation, we should say that there are few parts of Britain which afford so many opportunities for the study of these subjects as do the hills and rocks of this neighbourhood.

The following extracts concerning the geology of Cader Idris will convey to the reader some idea of the varied character of the strata in this district :

"GEOLOGY.-It consists of silicious porphyry, quartz, and schorl, and is surrounded by slaty hills. Evidences of the volcanic character of the mountain are abundant. Numerous specimens of lava, pumice, and other volcanic products, have been discovered on the sides and base of the mountain. Columnar crystals of basalt are scattered in profusion about the summit and on some of the inferior cliffs, and particularly on one side, there are vast beds of porous stone, bearing evident marks of strong ignition and vitrification-some reduced to the state of slag, and others having the cellular appearance and lightness of pumice."-Black's Guide, p. 121.

"The slope of Cader, on the Talyllyn side, above Llynycae, is an igneous rock, principally composed of amygdaloidal green-stone, and under are masses of felspathic trap and long lines of green-stone, interbedded with altered slate, forming the steep north cliff of the mountain, and overlooking the high valley between the cliff and Llynygader, which itself is formed almost entirely of felspathic ash and conglomerate, with interbedded lines of green-stone-the whole dipping under the igneous rocks of the cliffs. Lingular flags underlie these."-Ramsay.

For the guidance of conchologists visiting this interesting locality, we may add that Mochres may be approached from two points, namely, from Llanduwe, a church and inn, situated rather over four miles on the road from Barmouth to Harlech, or from Llanbedr, a considerable village, three or four miles nearer to Harlech, on the same road. Although a little may be saved in the distance, by approaching it from the first-named place, yet, on account of the tedious walk across a dreary moor which must be traversed, as well as the difficulty sometimes experienced in crossing to Mochres from the mainland by this route, we strongly recommend the tourist to proceed along the beautiful coast-road to the village last-named (Llanbedr), which is close to the peninsula, and from which he may reach the shell-covered beach in a few minutes without any difficulty.

Amongst the numerous mineral products extracted from the soil in various parts of the neighbourhood, the most conspicuous are slate, copper, lead, and gold; and, as reference has already been made to the last-named precious metal in a recent number of this periodical, we shall now add a few details on the subject, which may, perhaps, be interesting to our readers.

In his paper on the Gold Mines of this district, our contributor more than once mentioned the name of Mr. Readwin, to whose enterprise and scientific knowledge this country is indebted for the new mine of wealth which is being laid open in these our home-diggings.*

During our recent visit, we were so fortunate as to meet that gentleman, who is largely interested in several of the most important mines in the neighbourhood; and one of these, the Garthgill mine, we were permitted, through his kindness, to inspect.

Let us narrate the details of our visit.

Having received a note from Mr. Readwin, stating that he would be at the Garthgill mine, which is situated about halfway between Barmouth and Dolgelly, not far from the coachroad, between one and two o'clock in the afternoon, we started from the former place on a magnificent July morning, at about half-past eleven; and, after a smart five-mile walk, arrived at the "Halfway House," a little roadside inn, at a place called Pont Ddu, which is distant about one mile from the workings of the Garthgill mine.

A word en passant concerning this same walk of five miles. The road runs along the northern bank of the river, or, more properly speaking, the estuary of the Mawddach, deviating slightly, here and there, from the upward course of the stream; and, although we have visited many a beautiful scene, in Britain as well as abroad, we must confess that we have never met with anything to surpass this one. We see it before us in imagination as we write. Facing us, through a break in the trees, are the towering heights of Cader, on the opposite side of the river. To the right we have the boundless expanse of ocean peering through the bold headlands at the mouth of the estuary. To the left, the Mawddach, vying in beauty with the choicest portions of the Rhine, and presenting the appearance of a series of beautiful lakes through the windings of the stream amongst the mountains; whilst on all sides are ranges of hills, the slopes of some being fertile meadows, others bare, rugged, and precipitous, and others, again, concealed from the

"The English California," by G. P. Bevan. No. IV. POPULAR SCIENCE REVIEW.