Imatges de pÓgina
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spects from glass, and in texture com. ordinary fact, which afterwards led
pletely resembling whinitone. Its to the discovery of fome curious pro-
fracture was rough, ftony, and cry- perties of whinstone, will be fully.ac-
ftalline; and a number of shining fa- counted for in a subfequent part of
cettes were interspersed through the the paper.
whole mass. The crystallization was Another portion of the same glass
ftill more apparent in cavities produ- being perfectly melted by a very strong
ced by air bubbles, the internal sur- heat, the temperature was reduced to
face of which was lined with distinct about 28 of Wedgwood, and was
cryftals*.

maintained at that pitch during fix
Having shown this result to several hours. The result was a perfeAly solid
of my friends, Dr Hope regretted mass crystallized to a certain depth
that the substance, previously to its from the outside, though ftill virteous
artificial cryitallization, had not been in the heart.
reduced to the state of solid glass ; In another experiment, perform-
fince the adversaries of the systemed like the last in all respects, ex-
might alledge, that, during the action cept that the heat was maintained
of heat, the original cryftallized tex. at 28 during twelve hours, I obtain- .
ture of the stone had never been com

afs entirely crystalline and pletely destroyed. Being convinced ftony throughout, with facettes ap

, of the propriety of this observation, pearing in the solid parts, and fmall I determined, in future, to reduce crystals shooting into some of the cathe ftone firft to glass, and to perform vities. the cryftallization after a second fu- Soon after I had communicat. fon.

ed these results to Dr Hope, he For this purpose, with the allito performed, with complete success, an ance of Dr Kennedy, to whose co- experiment fimilar to the first, in operation I am greatly indebted for which I had obtained a cryftallized the success of all the following ex. subftance, by the gradual cooling of', periments, I reduced a quantity of the melted flone. The same was the fame whinstone to most perfect likewise, soon afterwards, performed black glass. A crucible, filled with by Mr Boswell of Auchinleck. fragments of this glass, being then My experiments, already describes exposed to a heat, which, from pre- ed, were confined to one species of *, vious trials, was judged to be more whinstone, but have fince been exosni than sufficieot to reduce its contents tended to fix other varietiest. Theyli to fusion, the fire was very gradually were all first reduced to glass by the lowered till all was cold. I thus ex. application of a ftrong heat, and subpected to obtain a result fimilar to fequent rapid cooling. After a fethat last mentioned, but found, to cond fufion they were crystallized, by ny great surprise, that the fragments being kept long in a stationary teme had never beenin complete fusion, lince perature, between 28 and 39. This they still, in a great measure, retain- last operation was best performed in ed their original shape. This extra- a long and narrow muffle, wholly

surround."
* I howed this refult at a meeting of the Society on sth of February.,
11. Whin of the Rock of Edi. buigh Castle.
2. Whin of the Bafalric Columns on Arthur's Seat, near Edinburgh.

Whin from the neighbourhood of Dudding tone Loch.
Whin of Salisbury Craig near Edinburgh.

Whin from the Water of Leith.
6. Whin of the Bafältic Columns of Staffa.

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surrounded with burning coals, ac- could be maintained with so great cording to a practice long followed steadiness as to render the result alby Dr Kennedy, by which the heat most certain.

HINTS OF INSTRUCTION TO ANY WHO MAY ADOPT THE ROUTE OVER LAND

1 FROM INDIA, THKO' COUNTRIES IN ASIA, AND THRO' BULGARIA, &c.

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(From Yackson's Journey from India towards England, in 1797.) AT

T Bussora, the traveller should that, should an individual of any coun

equip himself like the Arabs. try act meanly, the people would It will be necessary for him, as soon condemn all his nation; and the bad as he embarks, or even before, to suf. conduct of one person might thus enfer his beard to grow ; but, as it may danger the lives of hundreds of his be uncomfortable to wear his beard countrymen, who might adopt the at full length, it will be sufficient if fame route. he do but preserve his muftachoes. From Bagdad there is but one This, however, must be particularly mode of travelling, which is under the attended to, and can by no means be guidance and protection of the Tardispensed with ; for, though a man tars, or messengers of government. without a beard might be safe in a These men are under the immediate large city, or in any civilized place, order of the Basha and his minifters ; yet in a journey of this nature, where but are at all times ready to enter inin he will often meet with barbarous to any contract with an individual, wandering tribes, who would not he- which they usually make very profifitate a moment about putting him table to themselves, particularly when to death if they should discover that they have to conduct thofe who are he was a Fringui*, he will perceive enabled to obtain firma uns f; for, hy the necessity of imitating the Arabs virtue of these, the Tatars are enain dress as nearly as poflible.

bled to take several horses and at. As few Europeans have any know-' tendants, and a large quantity of ledge of the Arabic language, parţi- merchandise on their return, which cularly as it is spoken in Arabia, he pays them very well. In the Author's will be much at a loss, especially when firmaun it was intimated that he was he has none but Arabs about him. an English Conful, which enabled his He will, therefore, find it useful to Tatar to obtain guards (free of exhave with him a kind of vocabulary, pence) whenever there was danger to to enable him to ask useful or neces- be apprehended from the wandering fary questions.

tribes. This is by far the fafest way When the traveller arrives at Bag- of travelling, as the person of a cordad, he will find that the English are ful is seldom insulted. more respected than any other nation; Great care should be taken when he will therefore feel the neceffity of an agreement is about to be made ading in the most honourable mana with a Tatar, It is advisable to pay ner in every transaction, that he may him only half of the money agreed support the dignity of the national for at Bagdad, that he may have an character ; for such is the illiberal interest in delivering the traveller way of thinking among these people, safe at Conftantinople. Care should

be *A term given to Christians in General. The Arabs call Europe Fringuifan.

7. These give the Tatar and traveller a great deal of authority over the people, particularly over those who are appointed by government to accommodate the Ta

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tars.

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be taken also, that the Tatar does drawn by the merchants, which will not engage to carry merchandize for usually meet due honour, while they any one, which he will do if possible. offer no temptation to robbers.

The necessaries which the traveller From Coottantinople, if the travel. takes should be compressed into as nar. ler be unacquainted with the language, row a compass as possible. A little it will be neceffary to engage a Janitea, coffee, and sugar, will be service. Zıry to conduct him to the frontiers, able in the winter seafon ; and fome who will be paid in about the same Spirits, either brandy or hollands, may proportion as the Tatars. be useful ; but he should by no means It has often been a subject of inbe encumbered with either of these in, quiry, which is the speedieft method summer.

of forwarding dispatches to and from The traveller flould be equipped' India? The Author is of opinion, in the same manner as the Tatar, that the route by which he came must which will always enfure him respect. be the most expeditious for forward. Some have attempted to travel under ing dispatches to India. When the the character of the Tatar's servants messenger arrives at Bagdad, he can (the Armeniao merchants in particu- fet out immediately in a kiraffe down lar do this,) but the Author confi. the Tigris till he reaches the Hie, ders it as too degrading for the cha. down which he will proceed till he racter of an Englishman. The Ta enters the Euphrates. By this chantars, who are accustomed to travel. nel he may be able to reach Buffora very fast, usually ride the hindmolt in three days, which muft be much horse of the company, and whip the quicker than going by land to Hilla, the other beasts to keep them going, and from thence down the EuphraThis should never be permitted ; but tes. whoever attempts a journey of this The usual mode of forwarding difkind should be a good horseman. patches from India is by the way of

The traveller ought not to encum- Buffora, over the Great Desert to ber himself with specie, except about Aleppo; from thence to Conftanti. half a dozen piastres, to give as pre. nople, and afterwards by the German fents to those who may render some poit to Vienna and Hamburgh. This little services. He will, it is true, he is certainly done at an easy expence, often solicited for gifts, but should and much less than by way of Bagalways refer the applicants to his dad; but the latter would, no doubt, Tatar; and when they find that, be a quicker route in case of necefli. they will not apply a second time. tý, as the Arabs are obliged to cross It is much more prudent to take bills the Great Desert on camels.

DESCRIPTION OF THE VIEW,
M
ELVILLE-Callie, the Seat of either fide a small extent of low-lying.

the Right Honourable Henry level mead, between the descent and Dundas, stands in a low fituation, on the bank of the river. The tract of the northern bank of the North Esk, level mead on the northern bank is near to the village and parills church the broadelt, and here stands Meie, of Lalfwade, at the distance of about ville Castle. From the higher grounds five miles South Weit from Edin. immediately above, the prospect is, hurgh and about three miles Wet suficiently rich, extensive, and.yafrom Dalkeith. It is not seen from ried. Some fine wood is scattered any considerable ditance. The ad. near the House, and round the Park. jacent grounds, on both fides of the In the present view, Melville. siver, advance boldly almost to the Castle is supposed to be seen from, very edge of the stream; then termi- the southern bank of the river, .on rating somewhat abruptly, icare on which it ftands. .

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ON

ON THE STUDY OF NATURAL PHILOSOPHY, NATURAL HISTORY, AND MATHE

MATICS.

From Dr Aikin's Letters from a Father to his Son, Vol. II.

ment.

ONE
NE of the most material circum- research, and the powers of intelleet

stances on which the relative va- in comparing and abitracting. The lue of an object of study depends, is, ftudies, then, which range under the that it be something real, Hable, of heads of natural philosophy and nageneral import, and not indebted for tural history, and are comprehended iis consequence to temporary and under the general term of physics, conventional modes of thinking. In appear to me to take the lead of all this respect, nature has greatly the mental pursuits with respect to exadvantage over art. Whatever is tent, variety, and dignity. Lit it learned concerning her is an eternal be understood, however, that I intruth, which will preserve its relation clude among them the study of one -20 other things as long as the world of the noblest objects nature presents, endures. The motions of the hea, and certainly the most interesting to

. senly bodies, the influence of the ele- a human creature that of man himments, the properties of minerals, felf. To ascertain what he essentially megetables, and animals, are grand is, what are the faculties of body and faats, which speak a common language mind which characterize him as the to all mankind in all ages, and afford head of the animal creacion, and what a perpetual fund of use and entertain. are the variations induced in him by

The more wide and compre- education, habit, climate, and mode henfive a survey is taken of these ob- of life, is ftri&tly a branch of physics, jects, the better they answer the pur. and has by the best writers been treatpose of enlarging the mind, and eso ed as such. tablishing a basis for truths of uni- It is, doubtless, impoffible for a versal application. Hence the ad- þingle mind to embrace all the objects vantage of studying them in a con- here pointed out, so as to fathom the pected and systematic mode, and depths of human knowledge in each ; framing general propositions concern. to be at the same time the mind of ing them. But the foundation for Newton, Loeke, Boyle, and Haller; these must be a very accurate investi. but according to the degree in which gation of particular facts, since the a man hath imbibed the leading ideas inftant their guidance is quitted, and which constituted the intellectual tur. reliance is placed upon analogical de- niture of such minds, I should estiductions, error commences. Obser- mate the value of his attainments; vation and experiment must there. and I should prefer, though not in fore go hand in hand with reasoning ; point of genius, yet with respect to nor was there ever a true philosopher acquisitions, one who combined' a. who did not unite these processes. I tolerably accurate acquaintance with can conceive of no employwent of all the branches of knowledge poffcfthe human faculties nobler than those sed by these, to a complete adept in, taking the scale of creation, detec. any one of them. The last mentionting all its mutual connexions and ed of the above persons, Haller, was dependencies, investigating the laws, scarcely, I believe, surpassed by any by which it is governed as a whole, man in the variety, and at the lo and the economy of its constituent time the solidity, of his parts, and alternately making use of knowledge. Buffo may

be the fagacity of the senses in minute as one whose general views

Ed. Meg. Feb. 1800.: M

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grand, and whose pursuits were plan- the formation of those general theoned upon as enlarged a scale, as those rems in which systematical knowledge of any person whom studies of this consists. It is certain, for instance, clafs have rendered famous, though that while the Linnän class of cryptohe wanted accuracy and solidity in gamia fubfifts, the vegetable economany of the particulars of his fpecu- my must be very incompletely known. lations. As a criterion of this capa. It cannot, however, be abolished ciousness and elevation of understand. without the minutest examination of ing, I would suppose a delegate sent the generative organs of mosses, ferns, from this earth to explore some other algæ, lichens, &c. which may thereworld, and bring back the most com- fore reasonably employ the ableft and plete and important information con moft philosophical naturalift. Boncerning it :- the pe fun duly selected net, a philosopher in every sense of for such a mission would, in my idea, the word, occupied himself for years poffefs a title to the superiority in in microscopical observations and exquestion.

periments on the smallest parts of naAlthough nature, thus studied, ture, but it was with the purpose of appears to me the noblest of all sub- establishing important conclusions jects that can occupy the mind, I am concerning the essential characters of far from affixing the same propor. the animal and vegetable kingdoms, tionate value to inveftigations of de. and the limits between each. Modern tached

parts of the works of nature. chemistry is one of the most impariIn these, all the grandeur of large and ant branches of physics, and compreconnected views is frequently loft, hends many truly sublime speculations and the whole attention is employed relative to the globe we inhabit; but on petty details, which lead to no. its theory is entirely built upon exthing further. A very little mind periments, in which the niceft mech. may successfully apply itself to the anical attentions are necessary to avoid arrangement of shells and butterflies fundamental errors. by their forms and colours, and gain · Mathematical ftudies must already nothing by the process but the simple be supposed to ftand high in my eftiideas of form and colour, as serving mate, fince I have placed in the first for marks of distinction. To such class those large and fublime views of minds, ao arrangement of ribbands nature, some of which could not ori. by their shades and patterns would ginally have been formed, nor can be a perfectly similar employment. now be comprehended, without the I do not deny that even these humble principles of mathematics. But be labourers in science are necessary to fides iheir undoubted value as means, complete the great fabric of the sys- they have by many been pursued ultitem of nature, and give accuracy and mately as affording the highest and uniformity to its nomenclature. Their purest exercise to the intelectual industry and exactuels deserve praise ; powers. but it is better for a student, capable Fully sensible of my own inadeof more extensive views, to make use quacy to judge of their worth in of their labours, than to'imitate them. this respect, and fearful of giving way What I have faid, however, must be to partiality, 1 small only speak of understood with limitation ; for, as I them from obierving their effects uphave already observed, it is incumbent on others. As far as I have remarkon the inquirer into nature to spare ed, few of those who, during the early no pains in the accurate search after part of their lives, bave gone deep facts; but these should be facts not into mathematics, acquire such a retrilling or insulated, but effential to lish for them, as to be induced spon

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