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fibre is deprived, not only of its ex. which it reacts by its contraction, se cess of irritability, but allo of a part follows, that during the whole period of the irritable principle necessary to of life, the irritable fibre is in conciits tone, or rather, the fibre lures rual action, that life confifts in ac. more irritability than it receives, and tion, and is not a partive state as some is consequently in a state of exhauftion, authors have maintained. Belides, either temporary or irreparable.

external objects having no immediate In the state of temporary exhaustion action on the nerves, but acting og the fibre loses its tone, and suffers a them and producing different fenfadefe&t of irritabiliiy. A stimulus ap- tions, only by the intervention of the plied at this time, will not make it irritable fibre, it is clear, that the contra&i, except it be very strong. ideas which we have of external obAfter some time the irritable principle jects are not agreeable to those ob. will be again accumulated in the fibre, jedis, but are changed and modified and it will then contraét. It is only by the irritable fibre which transmits by degrees, however, that it recovers them to us. Hence objects appear its irritability. This, I venture to different to us, according to the dif. affirm, is a fact, as new as important, fcrent Itates of that fibre. and it explains a great number of The irritable fibres in any indi. phenomena hitherto inexplicable. vidual, whether animals or plants, The motion of the heart, the men compose a system of fibres, the integ. ftrual flux, the periodical notions of rant parts of which act continually animals and plants, as well as their on the whole, while the whole reacts periodical diseases, are explained by on the particular parts, so that any it; that is, they are explicable only stimulus which acts on one tibre of on this principle, that a itimulus, tho' the fyítem will deprive it of a part of always present, and continuing to act its irritability ; but that loss will soon on the fibre, produces no fenlible ef- be repaired by the tyttem, and each fect till the irritability of the ex- fibre will firnih in proportion a part hausted libre is again accun ulated. of its irritability to lappiy the luss

The total or irreparable exhaustion suitained by any liagle tibie. Thus of the fibre, consists in the loss of all a weak stimulus, continually a&iog its irritability, in what is called gan- on a part of the fytem, such as flow grene. The fibre changes colour,' poisons, the abuse of fpirituous libecomes livid or black, becomes sub. quors, a hidden ulcer, &c. io tima ject to the laws of unorganised mat- exhaust the whole fyftem and cause ter, begins to decompose and to be- dcath. For the same reason a very come putrid. A very strong stimulus Brong stimulus partially applied, will, by its action, reduce a libie to such as the distilled waier of the this state in a short time. Such, for jauro-cerasus, opiuin, the poison of instance, is the state of the fibre in the raule-snake, &c. will instantaneanimals killed by trong poisons, by ously exhaust the irritability of the the bite of the rattlesnake, &c. The whoie syitem and kill the animal. By irritability of many insecis, and of nany experiments, I am certain, that most planis, is irreparably spent by the muscles of animals, killed by such the stimulus of the venereal act, lo stimul', are perfectly deftirute of irrithat they die immediately after the ability. : work of generation is performed.

The irritable fibres of a system are The irritable fibre, from the first not all poffeffid of the same degree moment of its existence, to its disio- of irritability. They have diffcient lution, being conftantly furrounded capacities for the irritable prieciple ac. by, bodies which act on it, and on cording to their distance from the

en :. . hearts

heart. Fibres equally diftant from the system, and as the sum of their the heart, have the same capacity, action is nearly equal to the fun of Qaid a dimalas which affects one af.. the irritable principle, absorbed by the fe&s all at the same time, and in the lungs, and distributed by the circulafame manner. Hence the sympathy tion, the whole fyftem will be in of different parts equally remotes health, and the fibres which confti

When the irritable fibre has lost tinte it, will be in tone. When one its cohe, either from an excess or de of these stimuli, or severai of them, fect of the irritable principle, it is di- act with greater force than ordinary feafed, and the fyftem it belongs to or when the fibre becomes more irti. suffers aod becomes diseased by fym table, while the degree of their doo pathy. All the diseases, whether of tion is the same, the exhauftion of animals or plants, may be referred to the system, and one of the difcases, two classes. 11, Diseases of accumu- which are the consequence of it, will lation, proceeding from the accumu. follow. The abstraction of one, of bution of the irritable principle by the of feveral of these ftimuli, will prodiminished action of babitual Atimuli. duce an accumulation of irritability 2d, Diseases of exhaustion, proceeding in the fyftem, and one or the discafrom the defect of the irritable prin- ses, which are the consequence of ciple, by the increased action of ha- this, will follow. bitual, or the addition of new ftimu [We shall conclude this extract,

with the following obseryations of the Medicines cure diseases, by' acting author.] on the irritable fibre, and by exhaust. If my principles are true, says he, ing its irritability in cases of accu. medicine, which has nitherto been mulation, or by diminishing the ac- an art of mere conjecture, will be tion of habitual stimuli, and of course brought in time to the certaioty of a total exhaustion in cases of exhaus. calculation, and after tables Ahall be rion. The effect of poisons is explio constructed to express the force or incable in the same way.

tensity of the stimulus, the degree of Poisons, medicines, and in general irritability in the fibre, and the corall the surrounding bodies act only tain figos by which thefe may be on the irritable fibre, and therefore known, the calculation will be fo affect the system exa&tly in the same simple and easy, that it will make a manner. Fontana concludes, after part of education. Besides, the irri. having made fix thousand experiments, table fibre being the same through. that the poison of the viper kills ani- out all organised nature, diseases, and mals by acting on the blood. But their remcdies will consequently be frogs, that live a long time after their the same for all organised beings; heart has been cut out, and which there will then be po distinction bea are coosequently entirely deprived of tween medicine, the velerinary art blood, are killed as quickly by the and agriculture, but these sciences poison of the viper, as if their blood will be confounded, and form only had not been let out,

0.1e, under the name of universal Those stimuli which I call habitu- Physiology. The art of pharmacy and al, because they are more or lefs in of writing prescriptions, will become perpetual action on the irritable fibre, useless ; a bottle filled with alcoliol, are heat, light, 'food, air, the circus or liquid laudanum, will be substitu. Jation of the blood, the generative, ted to the enormous quantity of drugs and the nervous stimulus. So long which are contained in the shops of as the action of these stimuli is in pro. apothecaries. The traffic in mediportion to the degree of irritability io cines.but hold. By continuing my Vos. XII, No. 68,

predictions

predictions, I înall expose myself to " value any ideas but fuch as are ridicule ; for, as Helvetius says, “ confopant to our own, because self« Every idea too remote from our or- “ love prompts us to admire our“ dinary views and manner of think- « felves in others.” 6 ing, appears ridiculous. We never

Account of such Stones found in Scotland as are fit for ornamental Architecturet. TT is a singular loss to the arts, e. the places where I have seen finguI specially to ornamental architec- larly excellent stones, most of which ture, that men of fortune are not ge- are fit for any thing that ever was nerally naturalists, at least, so far as done in stone in any part of the to be acquainted with the peculiar world. distinguishable characters, qualities, . The first that I will take notice of and excellencies of the. finer stones, are some excellent marbles. and to be able to judge which is 1. A few miles from Blairgowrie best for, their particular purposes; in Perth hire, not far from the high and, not to be obliged, as they gene- road side, towards the north, there is rally are, to leave it to the caprice or an excellent, granulated, broad-bedded interest of the stone-cutter, to chuse limestone, of a sugar loaf texture, and for them, who is naturally supposed as white as the finest staiuary marble; to study his present ease and advan- I look upon this to be a good species tage, more than the duration and fu- of the true Parian marble of the an. ture beauty of the piece.

cients; and as it inay be easily raised When men of rank and fortune ate in blocks and slabs perfectly free of tend to the progress and encourage- blemishes, is uniformly of a pure, ment of the arts, they are sure to ar-, white, and free and easy to be work- . rive at copliderable degrees of perfec- ed in itatuary and other ornamental tion in any country. Ancient Egypt, architecture, I think it only requires Babylon, Greece, and Italy, are so to be well known and brought into famous for their. great works in orna. use, to become of great value. mental architecture, for the rare qua- . . 2. There is some of this fpecies cf lities of their materials, and ihe ex- stone in the Duke of Gordon's lands, cellent workmanship of some remains in the forest of Glenavon, compofed of antiquity, that they have been the of fine 'glittering broad grains like wonder of many ages, and they, ftill spangles, as large as the scalez "of fishcontinue to be admired. It bas, manyes, but the situation is Femiote, and times vexed me to reflect, that our difficult of access. wealthy people and eminent artists 3. The fine white ftatuary marble should send to foreign countries, for of Asline in Sutherland. The marble ftones for ornamental architecture, of Alint has a just title to an enti. when, perhaps, no country can pro- nent rank among peculiar and excel. duce so great a variety of the most ex- , lent stones; and although I pointed cellent fones for that purpose as are out that marble in my general view to be found in Great Britain ; and, of the limestones of Scotland, I will therefore, in case posterity rould take the freedom to repeat here, that grow wiser, I will point out a few of it is the whitest, the pureft, and best

that * From Williams's Natural Ilistory of the Mineral Kingdom.'

that ever I saw: That there is none 5. In the farm of Blairmachyldach, better, if so good, in all Europe: about three miles south of FortwilThat blocks and slabs of any size may. liam, in the bed of a river, there is be cut out perfectly solid and pure, a very singular marble, consisting of a free from any flaws or blemishes black ground, and flowered with whatsoever : That there is enough of white. This stone is of a fine close it to serve all Britain, and much more, grain or uniform texture, but not very bat there is bad access to it; nor hard, and the flowering in it is light, would it be easily quarried, being fi- elegant, and beautiful,like fine needletuated in and under the bed of a small work, or rather resembling the frosty civer, with some cover above it of a fret work upon glass windows in a loose, soft, white limestone.

winter morning; and this flowering This excellent stone is of the.pu- is not only upon the outside, but rest white, and of a fine smooth uni. quite through all parts of the body forin texture in the inside, of a bright of the stone. . appearance when broken, and of so

10 . Secondly, Jasper, of which there is

. Seram fine and pure a quality, that the ed- an extensive rock, near Portfoy in ges of a . fragment are semi-transpa

Banff-Shire ; some parts of that rock kert. Jo Thort, this is a very luperi. contain a beautiful mixture of green or marble; but I am afraid, that the

and red, &c. which appear finely real best quarry is only known to my- fhaded and clouded through the self. It is only to be seen in one body of the stone when polished. place in the river, the rest of it co. I ca

I saw chimney - pieces of this stone vered with the white shattery lime

men

in

in the old ruinous house of the fone mentioned above. It is now Boyne in that neighbourhood, in twenty years since I vilted that coun- which a considerable portion of red, try, so that I have forgotten the par

the par.

or ti

or fine rose or blush colour, is shaded ticular name of the place. But a with the green, and fpread out in gentleman (I think Mr MóKenzie heur

F.Mkenzie beautiful clouds through all parts of of Ardloch) lived then in a large the stone. These jambs and lintels house near this marble, fine masses of

were exceeding beautiful, and retainwhich were to be seen in his office

ed the lustre of their polish undecayhouses. The marble is in the bed of ed

ed. This would be a valuable jasper the river, not far to the northward of that house.

quarry, if properly opened; but as

the body of the rock is hard and ill 4. Near the farm-houses upon the

to work, I have seen no good samples north lide of the ferry of Ballachy

of it, excepiing the above-mentioned lich in Lochaber, there is a limestone

one old jambs. Īll-chosen imperfect blocks of marble rock, of a beautiful afen- are iorn off from the ouifide of the grey colour, and of a fine regular uni

Mi- rock, which hurts its reputation, I form grain or texture, capable of be

have seen fine rock there of a great ing raised in blocks or llabs of any beauty, but I never saw any of it fize, and capable of receiving a fioe quarried, nor can it be quarried withpoiiih. This fingular rock is finely sprink

out ikill and expence. led throughout with grains and specks Thirdly, Agate. There is a large of fine bright mundick, or pyrites, patch of fine agate upon the side of a and likewise with grains and specks hill near the church of Rothes in Moof beautiful lead ore of a fine tex- ' ray, chiefly of a fine mixture of the ture, which to the eye appears to be red and white colours. rich in silver. This would make a This is a very beautiful patch of bright and beautiful metallic marble. rock. It is very hard and heavy, of

a fire

P

2

a fine smooth uniform texture, and of neves, near Fortwilliam, is perhapes considerable brightness, in which the the best and most beautiful in the red and white, &c. are remarkably world ; and there is enough of it to clear, and finely mixt and faded serve all the kingdoms of the world, through the ftone.

though they were all as fond of gra. This is the largest and most beau. Dite as ancient Egypt. tiful agate rock I ever saw, and so There are extensive rocks of red fine and hard as to be capable of the granite, upon the sea-shore, to the west high ft lustre in polishing.

of the Ferry of Ballachylifh, in Ape Fourthly, Porphyry, of which a great pin; and likewise at Strontian, as well part of the hill of Bineves in Lochaber as many other parts of Argyle-lhire. is compolęd, The porphyry of Bineves I have seen beautiful red granice by is a serrarkably fine, beautiful, and e. the road fide, north of Dingwall, and legant stone of a reddish cast, in which in several other parts of the north of the pale-rose, the bluth, and the yel. Scotland, which had been blown to lo with white colours, are finely blend. pieces with gun powder, and turned ed and shaded through the body of off the fields. There are extenfic the stone, which is of a gelly-like tex. rocks of reddish granite about Peture, and is, undoubtedly, one of the terhead and Slains; and both of red finest and most elegant stones in the and grey granite in the neighbour. world.

hood of Aberdeen. The hill of CrufAbout three-fourths of the way up fel in Galloway, and several lower this hill, upon the north-west lide, hills and extensive rocks in that neigh. there is found a porphyry of a green, bourhood, are of red and'grey granite, ish colour, with a cinge of a brownish where there are great varieties of that red. This stone is smooth, compact, Atone, and many of them excelleot. hard, and heavy, of a close uniform Upon the sea-shore, near Kinedore, texture, but of no brightness when weft of Losliemouth in Moray, there broken. It is sported with angular is a bed of stone about eight feet fpecks, of a white quartzy substance. thick, which I think fhould be called Fiftbly, Granite, wbich, with the a composite gradite. This fingular granite-like porphyry above-mention, Atratum is composed of large grains, ed, I reckon the glory of all stones, or rather small pieces of various bright as all the beauties and excellencies and beautiful stones of many different of all other stones of mixed colours, colours; and all the pony parts are are most emipenily contained in these. exceeding hard, and fit to receive the The figer and most elegant red gra. highest polish; but what is most finpite, and the fineft grabite-like por, gular, about a sixth or eighth part of phyries, are so pear a-kią to one ano- this remarkable ftratum is good clean ther in quality and appearance, that blue lead ore, of the species called I will not attempt a distinguishable potter's ore. defcription of them, Scotland is rea . I know that the separate ftony parts markable for a great oumber and yze composing this ftratum are all hard, riety of granites, of which I have gi. fine, and solid, and capable of the ven some account in my general view moft brilliant polish ; but I do not of the prevailing rocks of North Bri- now remember whether or not solid tain ; and I believe, I may venture to blocks of it can be raised perfe&tly fay in favour of many $cots granites, free from all cracks and flaws. If that the world cannot produce any they can, I imagine, from the beauty more excellent in quality and beauty. and variety of the colours of the The elegant reddith granite of Bi. Rony parts, and the great quantity of

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