of liberty? The Whigs indeed complain bitterly of the injury done them by the existing race of "Utopians," who are naturally more impatient under the repulse which they have received from an Opposition bound to them by many ties of kindred, than under the discountenance of a Ministry to whom they are, and ever must, remain entire strangers. Of this infatuated party, we pity the wild enthusiasm of some, and detest the malignant turbulence of others; but in the excess of their insanity, every one sees the promise of an approaching and speedy dissolution. We engaged to shew, that the unwary zeal of the Reviewer had prompted him to state his case in such a manner, as to lead irresistibly to the inference, that the public interests demand the continuance of his friends in Opposition; and we proceed to fulfil our promise by quoting his own words: "As long as men are ambitious, corrupt, and servile," says he, every sovereign will attempt to extend his power; he will easily find instruments wherewithal to carry on this bad work; if unresisted, his encroachments upon public liberty will go on with an accelerated swiftness, each step affording new facilities for making another stride, and furnishing additional confidence to attempt it." Splendid as are the pretensions of his friends, the Reviewer does not, we presume, assert their entire exemption from the frailties and corruptions of human nature; it might be necessary, therefore, if they were in power, to watch even their operations. He admits as much, indeed, and eludes one of the difficulties of the discussion, by assuming the fact. "Of the imputations cast upon party men," says he, "for deserting their followers or their principles when they take office, it is the less necessary to speak at large; because, as soon as they have the government in their hands, they ought to be closely watched, and are pretty sure to be so by those whom they have dis Edinburgh Review, No 59, p. 184. placed."* But the present Ministers, who are, in the opinion of the Reviewer, "beyond all comparison the most contemptible, in pretensions, of any that have ever governed a great nation," would, in the supposed event, become the Opposition; and if the character thus given of them be just, it is impossible that men can be worse qualified for the undertaking. Nay, they have in fact discovered their utter incapacity, on a former occasion, for this great constitutional trust. "The risk," says the Reviewer, "would be considerable, of the new Opposition rather encouraging than checking such a dereliction of duty: they followed this course during the year 1806, when the country had not the benefit of a constitutional Opposition."+ But how splendid are the qualifications of the Whigs for this great undertaking!—" It is certain," we are told," that at no period of the English history was there ever embodied so formidable an association in behalf of the principles of civil and religious liberty, and, in general, of liberal, enlightened, and patriotic policy, as the great body of the Whigs now are." The country, it would seem, has but a choice of evils; but as there can be no comparison betwixt the danger of having even a weak and corrupt Ministry, when overawed by the constitutional terrors of a formidable Opposition, and that of having an administration resistless in talent, and overwhelming in influence, which, instead of being retarded in a career of guilty ambition, would be more rapidly impelled by an under-current of sympathising corruption; as there can be no comparison betwixt the occasional perversion of power and the utter extinction of liberty, the inference is irresistible, that things ought to remain as they are, and that the Whigs perform their best and noblest service to their country in the ranks of Opposition. Edinburgh Review, No 59, p. 195. +Ibid. p. 195. Ibid. p. 197. 1818.3 Literary and Scientific Intelligence. LITERARY AND SCIENTIFIC INTELLIGENCE. Platina. A very singular mass of pla. tinum has lately been found in South America, and is now deposited in the Royal Museum at Madrid. Dn. Ignacio Hurtado is the proprietor of certain lands in the Quebrada de Apotó, in the province of Notiva, in the government of Chocó. In this Quebrada is situated his gold mine, called Condoto. One of his negro slaves, named Justo, found this mass of platina in the year Dn. Ignacio, 1814, near the gold mine. most generously, and full of ardour for the sciences, presented this unequalled specimen to His Most Catholic Majesty, through his Excellency Sor. Dn. Pablo Morillo, commander-in-chief of the Royal Spanish armies in the province of Venezuela, who transmitted the same, together with other objects of natural history, belonging to the botanical department, under the Spanish naturalist, Dn. José Mutis, to Europe, through General Pascual Enrile, who brought it safely to Spain, and forwarded it to the hands of the king himself by Captain Antonio Van Halen. Being an unique specimen, his majesty gave it to the museum. Its figure is oval, and inclining to convex. The Spaniards term it" Pepita," which signifies water worn, and not in situ. the horizon, allowing for the necessary cor- was perceptible at the time. At half-past seven, a beautifully coloured parhelia appeared on an attenuated Cirrostratus, namely, one on each side of, and both horizontal with, and equidistant from, the real sun, which was then 22° in altitude. These two mock-suns sometimes appeared at the same time for two or three minutes, and at other times alternately, when their colours were brightest: they disappeared twice from the intervention of clouds; and, at the place of their re-appearance, a bright light was first perceived in the cloud, gra dually forming into the shape of a cone lying horizontally, with its apex turned from the sun; and at the base of this cone, nearest the sun, there was a light red, a delicate yellow, and lastly, a pale blue, which altogether formed the mock-sun: when the parhelia appeared most perfect, they were circular, of an orange colour, and nearly as large again as the apparent size of the sun's disc: only two parts of the solar halo, in which they were situated, could be traced; and these were perpendicular through the phenomena, which did not disappear till after eight o'clock. Its large diameter is two inches, four lines and a half, and its small diameter two inches. Its height is four inches and four The State of the Clouds and Instruments. lines. Its weight is one pound, nine ounces, and one drachm. Its colour is that of na--During this rare and pleasing sight, there tive silver. Its surface is rough, and here were, in the vicinity of the sun, Cirrocu and there spotted with yellow iron ochre. muli and plumose Cirri descending to CirThe negro who found it suspected that it rostrati, and Cumulus clouds rising in the contained gold: he tried to fracture it, but W. from whence a fresh breeze and vapour he was only able to make a dent in the me- sprang up. The barometer at 30 inches, tal, which is, however, sufficient to show its but sinking slowly; the thermometer rose from 56° to 62°; and De Luc's whalebone character. hygrometer receded from 65° to 60°. Before ten o'clock, the azure sky was completely veiled with compound modifications of clouds, followed by large passing Nimbi and a few drops of rain. To avoid every possible doubt about the mass of platina, it should perhaps have been mentioned, that the Spanish Secretary of State, his Excellency Dn. José García de Leon and Pizarro, had taken all the measures to ascertain the fact of its being genuine native platina. Precious Opal. Two mines of precious opal have lately been discovered in the kingdom of Mexico, in the district of Gracias de Dios, sixty Spanish miles in the interior of Honduras. The opals are imbedded in Perulam earth, and are accompanied by all the other varieties of opal, but particularly with the sky blue Girasol, and the sun opal of Sonnenschmidt. Parhelia at Gosport.-At half-past six, A.M. a fine parhelion appeared on a thin vapour passing to a Cirrostratus cloud; it as situated E. by N., and its altitude from The Rhinoceros.-It has been questioned if a musket-ball would penetrate the hide of a rhinoceros. An opportunity lately occurred of making the experiment on the carcass of an old animal of uncommon size, which had been killed near Givalpara, on the border of the wild country of Asam, a spot where rhinceroses abound. After repeated trials the bullet was found always to By off, for the skin being very thick and extremely loose, it was constantly by that means put out of its course. In that part of the country there are many rhinoceroses, and elephants in vast numbers. So numerous a flock was seen crossing the A Barhamputa River, at a breadth of two miles, that the channel seemed full; nor was the end of the line perceptible, although they had been some time passing. boat, going down the river, was obliged to put about, as it was impossible to get by them; and it was a considerable time before the line had left the jungles of the eastern side, whilst the jungles on the western side prevented their course being traced by the eye. The people of the country say, that the rhinoceros is much an overmatch for the elephant; as the former being very nimble, gets round the elephant, makes his attack in the same manner as the wild boar, and rips up the belly of his antagonist. Gas Lights. By the list of the Local Acts, it appears, that legal powers were obtained, in the last session of Parliament, to light with gasBath, Leeds, Nottingham, Oxford, Liverpool, Edinburgh, Worcester, Kidderminster, Sheffield, Brighthelmstone, -ten of the most considerable and most intelligent cities and towns in the empire. Gas Light Apparatus.-Mr Mair, of Kelso, has, by a simple process, constructed an apparatus which produces gas sufficient to supply ten different burners, the flame of each far surpassing that of the largest candle, and which completely illuminate his shop, work-shop, and dwelling-house, with the most pure pellucid brightness, the cost of which is only about three pence per night. Wax cloth bags have been invented, which, when inflated with gas, are removed at pleasure from place to place, and when ignited, they answer all the purposes of candles. By this process, it would seem that any person, with bags as above prepared, may be furnished with gas from the coal-pits, and apply the gas so procured to whatever number of tubes for lights he has occasion for. Cow Tree.-M. Humboldt and his companions, in the course of their travels, heard an account of a tree which grows in the valleys of Aragua, the juice of which is a nourishing milk, and which, from that circumstance, has received the name of the cow-tree. The tree in its general aspect resembles the chrysophyllum cainito; its leaves are oblong, pointed, leathery, and alternate, marked with lateral veins, projecting downwards; they are parallel, and are ten inches long. When incisions are made into the trunk, it discharges abundantly a glutinous milk, moderately thick, without any acridness, and exhaling an agreeable balsamic odour. The travellers drank considerable quantities of it without experiencing any injurious effects; its viscidity only rendering it rather unpleasant. The superintendent of the plantation assured them that the negroes acquire flesh during the season in which the cow-tree yields the greatest quantity of milk. When this fluid is exposed to the air, perhaps, in consequence of the absorption of the oxygen of the atmos phere, its surface becomes covered with membranes of a substance that appears to be of a decided animal nature, yellowish, thready, and of a cheesy consistence. These membranes, when separated from the more aqueous part of the fluid, are almost as elastic as caoutchouc; but at the same time they are as much disposed to become putrid as gelatine. The natives give the name of cheese to the coagulum, which is separated by the contact of the air; in the course of five or six days it becomes sour. The milk, kept for some time in a corked phial, had deposited a little coagulum, and still exhaled its balsamic odour. If the recent juice be mixed with cold water, the coagulum is formed in small quantity only; but the separation of the viscid membranes occurs when it is placed in contact with nitric acid. This remarkable tree seems to be peculiar to the Cordilliere du Littoral, especially from Barbula to the lake of Maracaybo There are likewise some traces of it near the village of San Mateo; and, according to the account of M. Bredmeyer, in the valley of Caucagua, three days journey to the east of the Caraccas. This naturalist has likewise described the vegetable milk of the cow. tree as possessing an agreeable flavour and an aromatic odour; the natives of Caucagua call it the milk-tree. New Researches on Heat.-MM. Dulong and Petit have lately given to the world a Memoir on Heat, which gained the prize medal for 1818, of the Academy of Sciences. The title of the paper is, "On the Measure of Temperatures, and on the Laws of the Communication of Heat." Law 1. If the cooling of a body placed in a vacuum terminated by a medium absolutely deprived of heat, or of the power of radiating, could be observed, the velocity of cooling would decrease in a geometrical progression, whilst the temperature diminished in an arithmetical progression. 2. For the same temperature of the boundary of the vacuum in which a body is placed, the velocity of cooling for the excess of temperature, in arithmetical progression, will decrease, as the terms of geometrical progression diminished by a constant number. The ratio of this geometrical progression is the same for all bodies, and equal to 1.0077. 3. The velocity of cooling in a vacuum for the same excess of temperature increases in a geometrical progression, the temperature of the surrounding body increasing in an arithmetical progression. The ratio of the progression is also 1.0077 for all bodies. 4. The velocity of cooling due to the contact of a gas is entirely independent of the nature of the surface of bodies. 5. The velocity of cooling due to the con 1818.] Literary and Scientific Intelligence. tact of a fluid (gas), varies in a geometrical progression, the excess of temperature varying also in a geometrical progression. If the ratio of the last progression be 2, that of the first is 2.35; whatever the nature of the gas, or whatever its force of elasticity. This law may also be expressed by saying, that the quantity of heat abstracted by a gas in all cases proportional to the excess of the temperature of the body raised to the power of 1.233. 6. The cooling power of a fluid (gas) diminishes in a geometrical progression, when its tension or elasticity diminishes also in a If the ratio of geometrical progression. this second progression be 2, the ratio of the first will be for air 1.366; for hydrogen 1.301; for carbonic acid 1.431; for olefiant gas 1.415. This law may be expressed in the following manner : The cooling power of gas is, other things being equal, proportionate to a certain power of the pressure. The exponent of this power, which depends on the nature of the gas, is for air 0.45; for hydrogen 0.315; for carbonic acid 0.517; for olefiant gas 0.501. 7. The cooling power of a gas varies with its temperature; so that, if the gas can dilate so as to preserve the same degree of elasticity, the cooling power will be found diminished by the rarefaction of the gas, just as much as it is increased by its being heated; so that ultimately it depends upon its tension alone. It may be perceived, from the above propositions, that the law of cooling, composed of all the preceding laws, must be very complicated; it is not therefore given in common language, but may be found in a mathematical form in the body of the memoir. stances. Lithography-The French Academy of Fine Arts, having appointed a Committee to examine the lithographical drawings of M. Engelmann of Mulhause, in the Upper Rhine, have reported, that the stone must be rendered capable of imbibing water, and also of receiving all greasy or resinous subThe first object can be effected by an acid, which will corrode the stone, take off its fine polish, and thus make it susceptible of water. Any greasy substance is capable of giving an impression upon stone, whether the lines be made with a pencil or with ink; or otherwise, the ground of a drawing may be covered with a black greasy mixture, leaving the lines in white. Hence result two distinct processes: first, the engraving, by tracing, produced by the line of the pencil, or brush dipped in the greasy ink: secondly, the engraving by dots or lines, as is done on wood or copper. Impressions of prints may be easily obtained without any reversing, by transposing on the stone a drawing traced on paper with the prepared ink. All kinds of close calcareous stone, of an even and fine grain, which are capable of Composition of the Ink.-Heat a glazed Drawing. This ink is used for drawing water. Printing. While the stone is moist, it should be passed over with the printer's ball those parts not wetted. A sheet of paper, charged with ink, which will adhere only to be spread on the stone, and the whole comproperly prepared for printing, is then to mitted to the press, or passed through a roller. Instead To preserve the drawing on the stone from dust, when not in use, a solution of gum-arabic is passed over it, which can be of ink, chalk crayons are sometimes used easily removed by a little water. for drawing upon the stone or upon paper, the stone. The crayons are thus madefrom which a counter-proof is taken upon three parts of soap, two parts of tallow, and one part of wax, are all dissolved together When the whole is in an earthen vessel. well mixed, a sufficient quantity of lampintense colour, is added; the mixture is black, called Frankfort black, to give it an then poured into moulds, where it must reproper to be used as chalk pencils. main till it is quite cold, when it will be French Kaleidoscopes. Our readers will no doubt have seen the various paragraphs in the French papers respecting the improvements on the kaleidoscope, and will tensions of that class of inferior opticians have formed their own opinion of the preWe have had occasion to see several of their instruments, and it is a remarkable fact, that not one of the makers of those which we have seen have the slightest knowledge of the principles or construction of the kaleidoscope. The very reflectors are placed at the wrong angle, the eye wrong placed, and the pictures destitute of symmetry. They are indeed inferior to the common kaleidoscopes made by the Jews in London, or the beggar boys in Edinburgh. Improvement and Extension of Iron Railways. The Highland Society of Scotland have recently announced the following premium, viz. A piece of plate, of fifty guineas value, will be given for the best and approved essay on the construction of rail-roads, for the conveyance of ordinary commodities. In this essay it will be essential to keep in view, how far rail-roads can be adapted for common use in a country; the means of laden carriages surmounting the elevations occurring in their course; and whether rail-roads, or the wheels of carriages, may be so constructed as to be applicable to ordinary roads as well as to rail-roads, so that no inconvenience shall be experienced on leaving either to travel on the other: the essay to be accompanied with such models or drawings as shall be sufficient to illustrate the statements it contains. It is desirable that some account should be given of the principal rail-roads in Britain, together with a brief history of their introduction. The premium not to be decided until the 10th November 1819. And with the same view, the following circular letter has been addressed to the various iron-masters in Scotland and England, viz. "SIR,-Although the railway that is now in contemplation in the vicinity of Edinburgh be entirely a matter of local concern, the peculiar plan of it is certainly to be viewed in a different light, as an object that well deserves the attention of the various classes of the community throughout the kingdom. Instead of insulated patches of railway here and there, for particular purposes, and for the conveniency of private individuals, as is now the case, it is here proposed, through the medium of railways, to open extensive communications to branch them out from the metropolis of Scotland in various directions, and to distant points-and thus to facilitate conveyance in general by an improved system of roads for heavy carriages. "The Highland Society of Scotland have, in a very patriotic manner, offered a premium of fifty guineas for the best essay on the means of attaining so desirable an object as the introduction of railways for the purposes of general carriage. With a view to the establishment of the railway in question, for the conveyance of commodities to and from Edinburgh, and thereby to give a commencement to the system generally, a subscription for a survey has been opened, and plans by Mr Stevenison, engineer, are in considerable forwardness. "It seems to be desirable, that railways, for alternate carriage and general use, should proceed on a continued level, or upon successive levels; and a simple system of lockage (if it may be so called), by which loaded waggons may easily be elevated or depressed, from one level to another, would appear to be a desirable attainment. The edge railway is generally used and preferred in Scotland, as causing less friction and less expense of horse power; and it would tend to facilitate the general use of railways, if, by some simple change, the wheel usually employed for the road or street could be made also to suit the rail-way, or the railway wheel be made to suit the road or street, so that the cart or waggon which brings the commodity from the colliery or stone-quarry, the farm-yard, or the manufactory, to the railway, might travel along it to the termination of the railway, and proceed from thence through the streets of the town to the dwelling of the consumer, without unloading or change of carriage. "The general use of railways by ironmanufacturers, for their own peculiar objects, qualifies them in an eminent degree to afford valuable suggestions on the best means of perfecting the railway system; and from a desire to collect the general sense of enlightened and scientific men, we take the liberty of submitting the annexed queries to your consideration, and to request, if agrecable to you, that you will be pleased to favour us with any suggestions which may occur to you upon the subject. 1. What is the best breadth of railway, and the best form of a waggon or carriage, for the conveyance of commodities in general? 2. Supposing the trade alternate, it will be desirable that the railway should proceed on a continued level, or upon successive levels. What are deemed the best means, with reference to economy and despatch, for elevating or depressing the laden carriages from one level to another? 3. Supposing the edge railway, which is generally preferred in Scotland, to be adopted, can a wheel be so constructed as to be applicable to streets or ordinary roads, as well as to rail-roads, so that no inconve nience shall be experienced on leaving either to travel on the other? |