and have made ufe of this, already familiar to us, and which feems liable tobino sobjection,ofince it is not confined to many particular fpe cies.* $50 The following experiments were performed with various kinds of win ftone, and have likewife been extended to lava. To investigate the relation between these two claffes of fub tances, feems, in the prefent state of geology, an object of confiderable inportance; for they resemble each other in fo many refpects, that we are naturally led to afcribe the formation of both to the fame caufe, and to believe that whinftone, as well as lava, has been expofed to the action of heat. In the course of the paper, I fhall mention feveral accidental results, which, if confidered feparately, might feem unworthy of notice, but which, by affording the means of comparifon between the two claffes, are of great fervice in the general inveftigation. The whiaftone firft employed was taken from a quarry* near the Dean, on the Water of Leith, in the neighbourhood of Edinburgh. This ftone is an aggregate of black and green ifh-black hornblend, intimately mixed with a pale reddish-brown matter, which has fome refemblance to felf. par, but is far more fufible. Both fubftances are imperfectly and confufedly cryftallized in minute grains. The hornblend is in the greateft proportion; and its fracture appears to be firiated, though in fome parts foliated; that of the reddish-brown matter is foliated. The fracture of the tone emmaffe is uneven, and it abounds in fmall facettes, which have fome degrees of luftre It may be fcratched, though with difficulty, by a knife, and gives an earthy fmeil On the 17th of January 1798, I introduced a black lead crucible, filled with fragments of this ftone, into the great reverberating furnace at Mr Barker's iron foundry. In about a quarter of an hour, I found that the fubftance had entered into fufion, and was agitated by a strong ebullition. I removed the crucible, and allowed it to cool rapidly. The refult was a black glafs, with a tolerably clean fracture, interrupted however by fome fpecks. In fubfequent experiments, I endeavoured, by flow cooling after fufion, to prevent the whinstone from becoming vitreous, and to compel it to refume its original character by cryftallization. In this I fo far fucceeded as to obtain a substance, which was not glafs, though it did not poffefs the properties of whinftone. The production of this intermediate subftance, which much refembled the liver of an animal, is accompanied with fome curious particulars, which I fhall enumerate and explain in another part of this paper. On fome occafions, too, I obtained a vitreous mafs, in which were a multitude of little fpheres, having a dull or earthly fracture. At laut, on the 27th January, I fucceeded completely in the object I had in view. A crucible, containing a quantity of whinftone, melted in the manner above defcribed, being removed from the reverberatory, and conveyed rapidly to a large open fire, was immediately furrounded with burning coals, and the fire, after being maintained feveral hours, was allowed to go out. The crucible, when cold, was broken, and was, found to contain a fubitance, differing in all refpects *In characterising the particular fpecimens, I have adopted, with fearely any variation, defcriptions drawn up by Dr Kennedy, whole name I fhall have occafion frequently to mention in the courfe of this paper. In the employment of terms, we have profited by the advice of Mr Deriabin, a gentleman well verfed in the language of the Wernerian School.shop Called Bell's Mills Quarry. fpects from glafs, and in texture completely refembling whinftone. Its fracture was rough, ftony, and cry ftalline; and a number of fhining facettes were interfperfed through the whole mafs. The cryftallization was ftill more apparent in cavities produced by air bubbles, the internal furface of which was lined with diftinct crystals Having fhewn this refult to feveral of my friends, Dr Hope regretted that the fubftance, previoufly to its artificial cryftallization, had not been reduced to the ftate of folid glass ; fince the adverfaries of the fyttem might alledge, that, during the action of heat, the original cryftallized tex. ture of the ftone had never been com pletely destroyed. Being convinced of the propriety of this obfervation, I determined, in future, to reduce the ftone first to glass, and to perform the cryftallization after a fecond fufion. For this purpose, with the affiftance of Dr Kennedy, to whofe cooperation I am greatly indebted for the fuccefs of all the following experiments, reduced a quantity of the fame whinftone to moft perfect black glass. A crucible, filled with fragments of this glafs, being then xposed to a heat, which, from previous trials, was judged to be more than fufficient to reduce its contents to fufion, the fire was very gradually lowered till all was cold. I thus expected to obtain a refult fimilar to that last mentioned, but found, to my great furprife, that the fragments had neverbeen in complete fufion, fince they still, in a great measure, retained their original fhape. This extra ordinary fact, which afterwards led to the discovery of fame curious properties of whinstone, will be fully ac counted for in a subsequent part of the paper. Another portion of the same glass being perfectly melted by a very strong heat, the temperature was reduced to about 28 of Wedgwood, and was maintained at that pitch during fix hours. The refult was a perfectly folid mafs cryftallized to a certain depth from the outfide, though ftill virteous in the heart. In another experiment, performed like the laft in all refpects, except that the heat was maintained at 28 during twelve hours, I obtain." ed a mafs entirely cryftalline and ftony throughout, with facettes appearing in the folid parts, and small cryftals fhooting into fome of the cavities. Soon after I had communicated thefe refults to Dr Hope, he performed, with complete fuccefs, an experiment fimilar to the firft, in which I had obtained a cryftallized fubftance, by the gradual cooling of the melted ftone. The fame was likewife, foon afterwards, performed by Mr Bofwell of Auchinleck. My experiments, already deferibed, were confined to one fpecies of whinftone, but have fince been extended to fix other varietiest. They were all firft reduced to glafs by the application of a ftrong heat, and subfequent rapid cooling. After a fecond fufion they were crystallized, by being kept long in a ftationary temperature, between 28 and 30. This laft operation was beft performed in a long and narrow muffle, wholly I fhowed this refult at a meeting of the Society on 5th of February. 1. Whin of the Rock of Edinburgh Castle. 2. Vhin of the Bafaltic Columns on Arthur's Seat, near Edinburgh. Whin from the neighbourhood of Duddingftone Loch. 3. 4. Whin of Salisbury Craig near Edinburgh. 5. Whin from the Water of Leith. 6. Whin of the Bafaltic Columns of Staffa. furround HINTS OF INSTRUCTION TO ANY WHO MAY ADOPT THE ROUTE OVER LAND FROM INDIA, THRO' COUNTRIES IN ASIA, AND THRO' BULGARIA, &c. AT (From Jackson's Journey from India towards England, in 1797.)~ T Buffora, the traveller fhould equip himself like the Arabs. It will be neceffary for him, as foon as he embarks, or even before, to fuf. fer his beard to grow; but, as it may be uncomfortable to wear his beard at full length, it will be fufficient if he do but preferve his muftachoes. This, however, must be particularly attended to, and can by no means be difpenfed with; for, though a man without a beard might be fafe in a large city, or in any civilized place, yet in a journey of this nature, wherein he will often meet with barbarous wandering tribes, who would not he fitate a moment about putting him to death if they fhould discover that he was a Fringui*, he will perceive the neceffity of imitating the Arabs in drefs as nearly as poffible.. As few Europeans have any knowledge of the Arabic language, particularly as it is fpoken in Arabia, he will be much at a lofs, especially when he has none but Arabs about him. He will, therefore, find it ufeful to have with him a kind of vocabulary, to enable him to ask useful or neceffary queftions. that, fhould an individual of any coun try act meanly, the people would condemn all his nation; and the bad conduct of one perfon might thus endanger the lives of hundreds of his countrymen, who might adopt the fame route. From Bagdad there is but one mode of travelling, which is under the guidance and protection of the Tartars, or meffengers of government. Thefe men are under the immediate order of the Bafha and his ministers; but are at all times ready to enter into any contract with an individual, which they ufually make very profitable to themselves, particularly when they have to conduct thofe who are enabled to obtain firmaunst; for, by virtue of thefe, the Tatars are enabled to take several h horfes and attendants, and a large quantity of merchandise on their return, which pays them very well. In the Author's firmaun it was intimated that he was an English Conful, which enabled his Tatar to obtain guards (free of expence) whenever there was danger to be apprehended from the wandering tribes. This is by far the fafeft way of travelling, as the perfon of a conful is feldom infulted. When the traveller arrives at Bagdad, he will find that the English are more respected than any other nation; Great care fhould be taken when he will therefore feel the neceffity of an agreement is about to be made acting in the moft honourable man- with a Tatar. It is advisable to pay ner in every tranfaction, that he may him only half of the money agreed fupport the dignity of the national for at Bagdad, that he may have an character; for fuch is the illiberal, intereft in delivering the traveller way of thinking among thefe people, fafe at Conftantinople. Care fhould Aga brod te posit * be *A term given to Chriftians in General. The Arabs call Europe Fringuiftan. †Thefe 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 tars. be taken alfo, that the Tatar does not engage to carry merchandize for any one, which he will do if poffible. The neceffaries which the traveller takes should be compreffed into as narrow a compass as poffible. A little tea, coffee, and fugar, will be fervice. able in the winter feafon; and fome fpirits, either brandy or hollands, may be useful; but he thould by no means be encumbered with either of these in fummer. The traveller fhould be equipped in the fame manner as the Tatar, which will always enfure him refpect. Some have attempted to travel under the character of the Tatar's fervants (the Armenian merchants in particu lar do this,) but the Author confiders it as too degrading for the character of an Englishman. The Ta tars, who are accustomed to travel very fast, ufually ride the hindmoft horfe of the company, and whip the the other beafts to keep them going. This fhould never be permitted; but whoever attempts a journey of this kind fhould be a good horfeman. The traveller ought not to encumber himself with fpecie, except about half a dozen piaftres, to give as prefents to those who may render fome little fervices. He will, it is true, be often folicited for gifts, but fhould always refer the applicants to his Tatar; and when they find that, they will not apply a fecond time. It is much more prudent to take bills MEL drawn by the merchants, which will ufually meet due honour, while they offer no temptation to robbers. From Conftantinople, if the traveller be unacquainted with the language, it will be neceffary to engage a Janizary to conduct him to the frontiers, who will be paid in about the fame propertion as the Tatars. It has often been a fubject of inquiry, which is the speedieft method of forwarding difpatches to and from India? The Author is of opinion, that the route by which he came muft be the most expeditious for forwarding difpatches to India. When the meffenger arrives at Bagdad, he can fet out immediately in a kiraffe down the Tigris till he reaches the Hie, down which he will proceed till he enters the Euphrates. By this channel he may be able to reach Buffora in three days, which must be much quicker than going by land to Hilla, and from thence down the Euphrates. The ufual mode of forwarding difpatches from India is by the way. of Buffora, over the Great Defert to Aleppo; from thence to Conftantinople, and afterwards by the German poft to Vienna and Hamburgh. This is certainly done at an eafy expence, and much lefs than by way of Bagdad; but the latter would, no doubt, be a quicker route in cafe of neceffi ty, as the Arabs are obliged to crafs the Great Defert on camels. DESCRIPTION OF THE VIEW. ELVILLE-Calle, the Seat of the Right Honourable Henry Dundas, ftanes in a low fituation, on the northern bank of the North Efk, near to the village and parish church of Laffwade, at the diftance of about five miles South Weft from Edinburgh and about three miles Weft from Dalkeith. It is not feen from any confiderable diflance. The adjacent grounds, on both fides of the river, advance boldly almoft to the very edge of the ftream; then terminating fomewhat abruptly, leave on either fide a fmall extent of low lying level mead, between the defcent and the bank of the river. The tract of level mead on the northern bank is the broadeft, and here flands Melville Catle. From the higher grounds immediately above, the prospect is fufficiently rich, extenfive, and varied. Some fine wood is fcattered near the Houfe, and round the Park. In the prefent view, MelvilleCaftle is fuppofed to be feen from the fouthern bank of the river, on which it ftands. ON |