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time, let me discharge a melancholy duty to the memory of a deceased friend, who fhowed his early attention to my attempt of giving an English Orlando, and whofe difpofition, as a friend, a fcholar, and a patron of genius, led him in the most cordial manner to continue that countenance in India, which he had given to the work in England: with the name of Major Pearfon, whofe lofs I have every reafon to regret, let me join the name of Mr. Clement Francis, now of Calcutta, who with the ardour of unfeigned friendship, has done every thing to promote my fubfcription in that part of the world.

"To Mrs. Angelica Kauffman, whofe pencil needs no praife from me, I am beholden for the elegant defign to the firft volume, which he was pleafed, in the most polite manner, to contribute towards the embellishment of my book. "To other friends I am indebted for acts of kindness. To Dr. Warton, of Winchefter, for his warm encouragement in the progrefs of my labour; to his brother Mr. Thomas Warton; to my friend Dr. Burney; all zealous admirers of our Poet; and to the worthy

and elegant author of Leonidas, the great lover and judge of the works of the imagination, by whom I was very early ftimulated to fo arduous an undertaking.

Among thofe whofe good wishes have always gone along with the tranflator, it is with peculiar fatisfaction that I can infert the name of Dr. Samuel Johnfon; and I am happy in this opportunity of giving a public teftimony of my fincere and refpectful affection for him, whofe friendship I'confider as one of the moft grateful circumftances of my life, fince the value of his cha racter can only be known by thofe who live with him in the habit of intimacy; but, alas! fuch knowledge leads us continually to lament the condition of mankind, in which, at a certain period, every warning of mortality makes us dread a diffolution of the deareft connections, while we are tempted to re gret, that fome of the apparently fuperfluous years, allotted to the profligate or the ufelefs, cannot be added to thofe whofe lives are an honour to human nature."

15th May, 1783.

ART. XII. Conclufion of the Experiments and Obfervations concerning the attrac tive Powers of the Mineral Acids. By Richard Kirwan, Efq. F. R. S. Read as the Royal Society December 12, 1782. 4to.

MR. Kirwan purfues the ftudy of chemistry for his amufement, and yields to few, if any, in the accuracy of his accounts, and the neatnefs of his experiments. This pamphlet, which confifts of feventy pages, contains a relation of his folutions of metal, in various acids.

These observations are to be confidered as a fupplement to the paper which was formerly laid before the Royal Society, and, if we are not miftaken, gained the medal which is annually prefented, according to the will of Sir George Copley, by the Prefident, to the author of the most ingenious and useful difcoveries.

In the former paper, Mr. Kirwan ftated the quantity of each mineral acid taken up at the point of faturation by alkalies and earth, and also that taken up by phlogifton, when thefe acids are converted by it into an aerial form.

On the prefent occafion, he relates how much of thefe acids was taken up, at the point of faturation, by each of the metallic fubftances.

Thefe folutions, however, conftantly retained an excess of acid, fo that they did not immediately answer Mr. Kirwan's purpofe. They ferved, indeed, for the foundation of his obfer vations, and as feveral of the experiments may be of utility, he relates their refult, as concifely as poffible; and confines himself to those circumstances which have a relation to his future in veftigations, or that have not hitherto been fatisfactorily explained.

The acids, which our ingenious chy mift employed, were fo far dephlogifticated, as to be colourlefs, and his metals were either very fine filings, or reduced to powder, in a mortar. He added them, by little and little, to their refpective menftruums, as a much great

er quantity was thus diffolved than if he had at once injected the whole. Thefe folutions he performed in glafs phials, with bent tubes.

In the vitriolic, nitrous, and marine acids, he diffolved iron, copper, tin, lead, filver, mercury, zinc, bifmuth, nickel, cobalt, regulus of antimony, and regulus of arfenic. In aqua regia alfo, in which the marine and nitrous acids were mixed in different proportion, he made feveral experiments on gold.

The advantages refulting from these inquiries are very confiderable, not only in promoting chemical fcience, which as it is a phyfical analysis of bodies effentially requires an exact determination, as well of the quantity and proportion, as of the quality of the conftituent parts of bodies, but alfo in the practical way.

Several important proceffes have been very inaccurately defcribed by ancient chemical writers, and by fome of a modern date. For they frequently defcribe the acid which they have employed, by a reference to the quantity of fixed alkali, earth, or metal, which could be naturalized or diffolved by a given quantity of fuch acid.

Mr. Kirwan, however, informs us of the quantity of real acid capable of producing that effect; the remainder, therefore, muft have been water; and the quantity of real acid and water being known, the fpecific gravity is easily found by the help of annexed tables, and an acid of the fame ftrength may very easily be found.

The importance of this knowledge, likewife, in the art of pharmacy is very obvious, efpecially with regard to medicines formed of metallic fubftances, the powers of which depend on the proportion of their ingredients, and their action on each other.

The degree of precifion, moreover, which Mr. K. exhibits, will tend confiderably to the improvement of the arts of dying and enamelling. Many of their ingredients at prefent are obtained by vague proceffes; and that afed for preparing the precipitate of CASSIUS frequently fails, becaufe the ftrength of the acid is not fufficiently known.

Again, this accuracy may be of infinite fervice in the examination of mineral waters, and in affaying ores. may likewife furnish a new criterion for diftinguishing metals from each other, and the purer from their alloys. It may even fometimes inform us of the quality and quantity of the alloys.

Mr. Kirwan, however, informs us, that the principal end which he had in view, was to afcertain and measure the degrees of affinity or attraction that fubfilt betwixt the mineral acids and the various bafes with which they may be combined-a fubject of the greatest importance, as it is upon this foundation that chemistry, confidered as a fcience, muft finally reft.

Much has been done, and many general obfervations laid down on this head.

Objections, however, have arifen to those which have feemed to be firmly established; and fo many tables of affinity have been formed, that feveral chemifts of eminence have doubted whether any general law could be traced.

Thefe exceptions Mr. Kirwan has examined, and found them to arife from the introduction of new powers. He has alfo laid down rules, qualified with fuch reftrictions as are obferved in the action of thefe antagonift powers.

The following is Mr. Kirwan's as count of chemical attraction: "Chemical affinity or attraction is that power by which the invifible particles of dif ferent bodies intermix and unite with each other fo intimately, as to be infeparable by mere mechanical means. In this refpect, it differs from magnetic and electrical attraction. It alfo differs from attraction of cohefion in this, that the latter takes place betwixt particles of almoft all forts of bodies, whofe furfaces are brought into immediate contact with each other, for chemical attraction does not act with that degree of indifference, but caufes a body already united to another to quit that other and unite with a third, and hence it is called elective attraction. Hence attraction of cohesion often takes place betwixt bodies that have no chemical attraction to each other; thus regulus of cobalt and bifmuth

kave

have no chemical attraction to each other; for they will not unite in fufion, yet they cohere with each other To ftrongly that they can be feparated, only by a ftroke of a hammer.

Hence bodies, which refufe to unite to each other chemically, when they are most minutely divided, as when both are in a vaporous or aerial ftate, or when both are in a liquid ftate, may be judged in the firft cafe to have none; or in the fecond cafe to have at best but a very fmall affinity to each other. But thofe that unite, when one of them only is in a liquid ftate, may be faid to have a ftrong af finity to each other, and it is thus that acids unite to alkalies, earths, and metals for the most part."

Mr. Kirwan then relates the rules laid down for determining the degrees of affinity, and points out their deficiencies. From this account he deduces,

First, That the quantity of real acid neceffary to faturate a given weight of each bafis is inverfely as the affinity of each bafis to fuch acid.

Secondly, That the quantity of each bafis requifite to faturate a given quantity of each acid, is directly as the affinity of fuch acid to each bafis.

For the tables of the quiefcent and divellent affinities, and the reafonings from them, we must refer our readers to the work itself.

Mr. Kirwan then treats of the affinity of the mineral acids to metallic fubftances, and gives a further proof of his acuteness, knowledge, and ingenuity, in the course of his experi

ments.

The laft fubject, on which he difcourfes, is of the precipitation of me

tals, by each other, from the mineral acids. Under this head, he treats of the abfolute quantity of phlogiston in metals; of the affinity of metallic calces to phlogifton; of the affinity of the vitriolic acid to phlogifton in fulphur; of folutions in the vitriolic acid; of folutions in the nitrous acid; of folutions in the marine acid; of precipitations of and by iron; of precipitations of and by copper, tin, lead, mercury, bifmuth, nickell, cobalt, regulus of antimony, and regulus of arfenic.

In his experiments he difplays great patience and accuracy, and in his remarks great acumen and intelligence; fo that we are happy to inform our chemical readers, that he feems, in a note, to promife a continuation of thefe experiments.

There are fome flight inaccuracies in the language, which do not furprise us, though we with them corrected. Mr. Kirwan fays affaying of ore, now it fhould have been, the affaying of ore, or elfe affaying ore. If aaying be a fubftantive, it requires an article before, and the prepofition of after it. If it be a participle, the article and prepofition fhould both be omitted. We find alfo a nominative abfolute very frequently, in the remarks, which though, perhaps, it may in fome cafes be admitted into our poetical language, yet it fhould not be employed in profe, or, at least, as feldom as poffible. There are a few other trifling inaccuracies, which Mr. Kirwan will eafily difcover. We only mention them, in order to recommend thefe neceflary, though minute ornaments of a good style, to authors of every clafs and denomination.

ART. XIII. Travels to the Coaft of Arabia Felix: And from thence by the RedSea and Egypt, to Europe. Containing a fhort Account of an Expedition undertaken against the Cape of Good-Hope. In a Series of Letters. By Henry Rooke, Efq. late Major of the 100th Regiment of Foot. 8vo. Blamire.

THESE travels are related in a feries of thirteen letters. In the three firft is comprised, among other matters, a narrative of the expedition undertaken against the Cape of Good Hope, in 1781; from which we learn no facts, that are not already in the pofLOND. MAG. Aug. 1783.

feffion of the public. The fourth prefents us with a very entertaining ac count of Joanna, one of the little Comora iflands, which are five in number, and are fituated in the Indian

ocean.

The fifth confits of remarks on the mortaley

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mortality that raged in the fleet after leaving Joanna, which is very juftly afcribed to the malignity of the night dews that defcend very copiously in all hot countries, where there is much wood. These are always pernicious to men, who by duty or imprudence are exposed to their baleful effect. In the prefent inftance, the fickness affected thofe principally who flept on fhore. The advice of phyficians, who recommend fleeping on board fhip to people who touch at places for refreshment, in low latitudes, ought therefore to be followed as ftrictly as poffible. Some animadverfions are added on the expediency of providing better and more roomy tranfports for the conveyance of troops that are fent on diftant expeditions. Large fhips are pointed out as the fitteft for this purpofe, and chiefly because in them the men can be beft inftructed in military difcipline, which, by amufing the mind and exercifing the body, preferves both in health and vigour.

Round Morebat bay, into which the fleet put for water, the country prefents nothing to the view, but naked hills and fandy plains. Fruits or vegetables it yields none; of cattle only a few half ftarved goats and diminutive bullocks, and of water, only a few of its falt particles, which oozes through the fand. Yet, to defend thefe miferable supports of existence, the natives are kept in perpetual warfare: for the Budoos or wild Arabs, who inhabit the interior parts, the jackalls and wild dogs, all defcend to prey on the fandy plains of Morebat.

In the fixth we have a description of Mocha, its inhabitants, and their manners, and the author's voyage thither from Morebat, as he relinquifhed his Indian expedition, in order to feck cooler climes for the recovery of his health. The feventh contains a tragical incident, characteristic of the Mahometans of that coaft, which occurred in the paffage to Judeah, where the natural advantages are faid to be few, and the moral defects great.

The eighth exhibits a journal of the voyage to Suez; the Turkish mode of navigation on the Red Sea, which is

tedious and unfkilful beyond belief; and the conftruction and management of the veffels employed in it.

In the ninth we are made acquainted with the manner of travelling in caravans, particularly in thofe annual pilgrimages, which, from motives of vanity, religion, fuperftition, and commerce, are undertaken from Aleppo and Cairo to Mecca. He alfo relates the toils and fufferings of his own journey across the ifthmus, from Suez to Cairo. The cruelty and weakness of the Turkish government, and the barbarous manner in which it executes its laws and inflicts punishment, are here exemplified in a melancholy account of fome English people, who had for fome years carried on an illicit trade from India to Cairo, by the connivance of the Pacha and chief Bey.

When a new Pacha, however, was fent from Conftantinople, with ftrict orders to enforce the Grand Signor's prohibition of these proceedings, the interlopers not aware of this change of men and measures, were furrounded between Suez and Cairo, by a large troop, by whom they were plundered, wounded, ftripped, and then left naked in the defert, expofed to the rays of an African fun, without water or provifions. From this defperate extremi-. ty only three efcaped.

Such was the mode adopted by the new Pacha and Bey, to put in force the dormant Firman. The caravan was plundered by their order, and the fpoil appropriated to their ufe. By an artifice of the fame dark nature, they got poffeffion of the English fhips, and imprifoned the crews; and fearful it might draw on them the refentment of the British government, who with a fingle frigate could annihilate their whole trade on the Red Sea, they compelled all the English who were then at Cairo, to bind themfelves under the penalty of a large fum, that no fteps fhould be taken to revenge what had happened, obliging them to find proper perfons to be furety for them.

A vifit to thofe ftupendous monuments of human vanity and ancient grandeur, the pyramids, with fome ftrictures on the oppreffions of nume

rous

rous jarring defpots, and the ravages of the plague, which more than counterbalance the lavish bounties of nature to Egypt, compofes the tenth. The eleventh relates an inftance of the rapine and extortion practifed by the lords of this unhappy country, both on natives and ftrangers, which, as a fpecimen of the work, we shall lay before our readers:

"In one of my rides about this city, I was met by a party of Turkish foldiers, who accofting me, and fome European friends who were of my party, faid, that by order of their maiter, Muftapha Bey, they were come in fearch of us, and that they muft immediately conduct us to him. We did not at all relish this falutation, and would gladly have been excufed the honour of paying a vifit to a Bey, but, having no alternative, we proceeded quietly under their efcort. We were not, you may be fure, extremely comfortable in this fituation; and in our way endeavoured to divine the cause of it, but in vain: we found we had nothing else to do but fubmit patiently, and wait the event. Being arrived at the Bey's palace, my companions were fet at liberty, and I only was detained; one of my friends however stayed with me to act as interpreter, and plead my caufe. We were now ushered into the prefence-chamber, and found this potentate fitting crofs-legged on a carpet, fmoking a pipe feven or eight feet long; he was a middle-aged man, rather corpulent, had a black and bufhy beard that reached below his breaft, and his countenance was handfome, although ftern and fevere; his myrmidons, who were bearded like himself, ftood in a circle round him, into the midft of which we were introduced.

"The Bey, being informed that I was the perfon whom he had fummoned, furveyed me attentively, and with an imperious tone of voice, pronounced my crime and my fentence in the fame breath, telling me, an Armenian merchant having reprefented to him, that an Englishman, who had paffed through Cairo two years before, owed him a fum of money, his orders were that I

thould immediately discharge the debt incurred by my countryman. I heard with aftonishment this extraordinary charge and verdict, and in reply endea voured to explain the hardship and injuftice of fuch a proceeding, telling him, that, in the firft place, I doubted much whether the debt claimed by the Armenian was juft, and in the second, fuppofing that it was, did not confider myfelf by any means bound to difcharge it; but all endeavours to exculpate myself on the principles of reafon or juftice were totally ufelefs, fince he foon removed all my arguments by a fhort decifion, which was, that without further ceremony, I must either confent to pay the money or remain prifoner in his caftle. I began then to enquire what the fum was, which the Armenian pretended to be due to him, and found it to be near five hundred pounds, at which price, high as it was, I believe I fhould have been induced to have purchased my liberty, had not my friend advised me to the contrary, and given me hopes that it might be obtained without it, recommending to me rather to fuffer a temporary confinement than fubmit to fo flagrant an extortion. Accordingly I protested againft paying the money, and was conducted under a guard into a room, where I remained in arreft,

"It was about noon, the ufual time of dining in this country, and a very good pilau with mutton was ferved up to me; in fhort, I was very civilly treated in my confinement, but fill it was a confinement, and, as fuch, could not fail of being extremely unpleasant : my only hopes were founded in the good offices of Mr. R, an Italian merchant, whofe fervices to me and many of my countrymen, who have been embroiled in affairs of the like nature here, deferve our warmest gratitude.

My apartment was plenfantly fituated, with a fine view of the Nile and a rich country; but I fhould have enjoyed the profpect much more upon another occafion. On a kind of lawn, fhaded with trees, in front of the castle, two or three hundred horfes ftood at. picquet, richly caparifoned, belonging

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