The fovereign has four wives, and an unlimited number of concubines: the prefent fultan, a plain unoftentatious man, is fuppofed to have 500, and to be the father of 350 children, of which 300 are males. The army confifts chiefly in horsemen, and is faid to be very numerous: in his own stables are 500 horfes. The people are fingularly courteous and humane, paffionately attached to drafts or chefs, and the exports are flaves, gold-duft, horfes, oftrich-feathers, falt, and civet. The flaves are furnished, it is reported, from a country of favages to the east of Begarmee, which is itself the foutheast of Bornou, and must border on, or be very near to, Abysfinia. These favages are faid to feed on human flesh; but it is no uncommon circumftance to flander thofe whom we injure, to excuse the injury. The falt is procured from Domboo, a town to the north-caft of Bornou, where it is collected on the borders of the lakes, and carried by the merchants of Agadez, a town on the weft, to the negro nations: the trade, if confined to the fubjects of the king of Bornou, would undoubtedly be very lucrative. They obtain the civet in a rude way, by tormenting the cat, whose perspiration, &c. collected, affords the perfume fought after. The quantity obtained from one cat is generally about half an ounce. They manufacture, from their iron ore, a few flight tools for the purpose of husbandry, and their other manufactures are cotton cloths, or Turkey carpets. The route, from Mourzouk to Cafhna, in about 16° 20′ north latitude, is next defcribed. Here again the barren Hyatts, and the fandy defart, are interfected by fertile and inhabited spots; and, in this route, is Agadez, whose inhabitants carry on, as we have faid, the trade in falt with the kingdom of Bornou. Cashna is about 13° of latitude from the Gold Coast, and it comprehends what has been usually called the kingdom of Nigritia, or Soudán. These terms are fometimes limited to the kingdom of Cafhna, but with more propriety comprehend the different diftricts to the fouth, and probably to the east, which again, in the exaggerated strain of eastern titles, are transferred to the king of Cashna, and he is ftyled fultan of all Soudán. Soudán, like Nigritia, means only the Land of the Blacks. The rains in Cashna are lefs violent than in those of Bornou, but it is said to be the western boundary of camels and grapes: neither are found between Cashna and the Atlantic. The people are lefs courteous and less intelligent than in Bornou: their coin is cowries, the fhell employed for this purpose in India, from whence its ufe may have been derived. They are, we have faid, the carriers of falt to the western provinces; and a thousand ca mels, mels, bred and maintained for this purpose, annually traverse the dreary wilderness interpofed, on this account. They export alfo fena, gold-duft, flaves, civet, cotton-cloths, goatfkins, and buffaloes hides. They receive in return various articles of drefs, horfes and mares, trinkets, hardware, &c. Of the country between Cafhna and the Gold Coaft little is known. Mountains intervene, inhabited by the husbandman and fhepherd, who live chiefly in huts, though there are towns for the more stationary inhabitants, defended by walls; and a dawning ingenuity is faid to promife future valuable manufactures. Pagans and Mahometans mix without any religious enmity, and their commerce and returns are not very different from thofe of Cafhna, though the articles generally change their places, and what is there received is here returned. The jealoufy of the inhabitants of the coaft prevents them from being acquainted with fire-arms; they use only the fabre, the bow and arrow. The next chapter furnishes a general view of the trade to and from Fezzan, but, in our progrefs, we have given a fufficiently accurate outline on that fubject. The want of camels, and the unfitness of the country for this mode of conveyance, renders the merchants of Fezzan little acquainted with the country weft of Cafhna. The following chapter contains a fhort defcription of the route from Mourzouk to Cairo, but, this journey presents the fame images: the verdant fpots, and the dreary defert; the dark black mountains, and the hills covered with a scanty brushwood, have but different names. The account ends with conclufions drawn from the foregoing narrative; and the most important of thefe is the probability of opening a valuable and lucrative trade from the higheft navigable reaches of the river Gambia, or the new established fettlement (a fettlement however, we fear, already in the decline) of Sierra Leone. This is a subject which requires the moft mature confideration, and an examination more attentive than it is poffible to beflow in an article of this kind. Major Rennel's Geographical Memoir, and the map annexed to this volume, we have already noticed they are in every refpect excellent. While we return our thanks to this truly patriotic fociety for their attempts, and for the favour of their volume, which is not to be purchased, we might enlarge a little on the most probable method of purfuing difcoveries in this unknown continent. The various fuggeftions, however, which arise have undoubtedly occurred to the different members, and it may appear impertinent to add, what may have been maturely confidered and properly difcarded: but perhaps we may may be allowed to add a few reflections. Of the two ways in which difcoveries of this kind are to be profecuted, by fingle perfons, or by companies, we fhould undoubtedly prefer the latter. Different people fupport each other; bred in different Jines, their attention is varioufly directed, and their united obfervations will throw an additional luftre on the undiscovered parts of the peninfula. On the western coast, an unhealthy climate, as well as the jealoufy of the kings, whofe traffic in flaves would be impeded, if fire-arms were introduced to the interior regions, would be impediments too formidable to an attempt on that fide. The great defert, which stretches from fouth-west to north-eaft, is a powerful objection to any trial on the fide of Suez and Morocco. The jealoufy of the Mabometans, and the wandering Arabs would at least delay, and probably hinder any travellers from Cairo. From the Mediterranean then this fcheme must be undertaken; and to leffen the extent of the journey by land, it fhould certainly begin where this fea makes its deepest indentation, from the Great Syrtis, the deepest part of the Gulf of Sidra. At this place camels may be fent from Tripoli, and a small caravan depart for Mourzouk, the capital of Fezzan. From Fezzan they may proceed with the caravans to Bornou, where the hofpitable courteous difpofition of the inhabitants feems to fecure them a favourable reception: the other stations should be Cushna, Gonjah, and Tombuctoo, and a few months refdence in each place would be fufficient: the whole abfence would perhaps not exceed eighteen months, if, as is probable, they could penetrate from Gonjah to the Gold Coast. In the caravan thould be a botanist, a phyfician, an interpreter, and a draughtsman: to which, perhaps, might be added a natural philofopher, who fhould have the care of the aftronomical inftruments, to be carried in a litter on camels or on mules. In the prefent age of enterprize and perilous adventure, proper perfons would not be wanting to pursue this or a fimilar plan; and the prefent funds of the fociety appear to be fully fufficient for the purpose. A Philofophical Inquiry into the Nature and Properties of Common Water: with annexed Obfervations on its Medicinal Qualities, &c. By P. Lewis, M. D. 8vo. 35. 6d. Jerved. Sold at No. 62, Wardour-ftreet. THIS is a correct and ingenious compilation of what has been advanced on the subject of water, in its various ftates, by philofophers and chemifts. This fluid, while of the most general and indifpenfible ufe, has perplexed each class; the one not not knowing where it should be arranged, the other whether it may not be farther compounded, or what its ingredients may be. We are now approaching more nearly to fome certain conclu. fion than in former times: we know that the itate of bodies, whether folid, fluid, or gazeous, is tranfitory or accidental, and that it depends in a great meafure on the degree of attraction between its more minute particles; perhaps on its degree of specific heat. Dr. Lewis first confiders the conversion of water into earth, by diftillation, or agitation, a fübject which was formerly examined in the phyfical fyftems at length, and by the most laborious experiments. It was at laft concluded that the shining particles, depofited after repeated diftillations, were abraded from the glass; but it was never ascertained that the lofs of weight in the glass was in the exact ratio of the earth obtained, or that the latter was in proportion to the lofs of water. It is by no means improbable, that water, in its fluid ftate, may retain for a time a portion of earth, which will not be depofited till it is in a great degree deprived of its specific heat, or till it has undergone fome degree of decompofition from repeatedly changing its ftate of fluidity to that of vapour, and the contrary. That this circumstance has fome fhare in the event will be obvious, from reflecting that, in the experiment, water disappears: if therefore the whole of the earth came from the glass, where is the water that was first put in ? It must have escaped with the heat; in other words it must have been decomposed. This is a dilemma, which should be examined and explained. On this fubject our author gives no opinion. He hints at the eafy deftructibility of glafs, which we can readily admit, fince it is broken into minute scales, merely by the heat and light of the fun, fo that in windows expofed to it, the prifmatic colours are frequently obfervable. This, however, is not the hinge on which the question turns. The conglaciation of water' is the next fubject of remark, and our author has collected much information relative to high degrees of cold, either observed in high latitudes, or procured by art. Water, in a ftate of liquidity, gives Dr. Lewis a foundation for explaining and fupporting the doctrine of latent or fpecific heat. Though our author follows good authorities in fuppofing that any body fufficiently comminuted may be styled an imperfect fluid, yet we ought to remark, that this fuppofition leads to confufion. Animals, it is faid, may be drowned in fand: in fact, they are killed for want of air, the fame as would happen if they were fuffocated between two feather-beds. Sand too, in its more minute ftate, falls like water to a level, and is raised in ftorms like the fea. Thefe are circumftances connected with the smallness of the particles; and, when Mofes pounded pounded the golden calf, or by a chemical procefs, as Stah! fuppofes, reduced it to a powder, fufpended in water, are we to admit that it formed a fluid? Again, gypfum and -fand boil over the fire: this reprefentation is fallacious. The air entangled in the interstices is rarefied and efcapes, which gives a flight motion to the particles. A fluid, however, muft be more strictly defined: it is capable of diffolving peculiar folids, without lofing its tranfparency: it affumes the form of an air by means of heat, and returns to it again by cold: it is a fubftance containing specific heat, by the lofs of which it becomes folid, and by its increased proportion a gas. In this view, the minutest sand cannot be styled a liquid: diminish its parts fo far as the imagination can proceed, we fhall ftill find a congeries of folids. The Examination of water, in a state of vapour, and the section on the compofition of water, conclude the first part. In the latter, the author does not decide, though he seems to lear towards the new doctrine. We have followed the fubject fuffici ently in other parts of our Journal. The medicinal qualities of water are well known. Stagnant waters are confeffedly injurious; but the waters, hardened by felenite, are hurtful only to weak bowels, and particular conftitutions. In general, they are certainly not unwhole fome. Snow-water, if it contains any impregnation, has a very fmall proportion of muriatic acid: in towns we generally find, perhaps from the fmoke, a fmall proportion of vitriolic acid, which does not appear in fnow-water, because it is usual ly congealed in a region above where the smoke reaches. Thefe circumstances makes copper coverings for houfes fufpicious; but we have never seen any impregnation from lead, unless where the leaves of trees have produced a flight fermentation by fall ing into the water in fummer: We fufpect that felenite, without fome affiftance, will not diffolve lead: fixed air, as it is ufually combined in water, is equally incapable of uniting with this metal. The correction of water' is a fubject fufficiently understood; but we shall extract a fact from this part of the work, which we were not before acquainted with: it relates to a new method of depriving fea-water of its falt. A Mr. Allen, of Newhaven, in America, has of late, by a very fimple procefs, fucceeded beyond all expectation. He procured a common hogshead, with a falfe bottom, about three or four inches above the level head. This falfe bottom is perforated with a number of holes, and over them is laid a filter of Hannel. The barrel is then nearly filled with the finest fand, beat down exceedingly hard; and a tube, communicating with the |