of detection by the usual agents. Its residuum contained traces of sulphate of lime. If it be mixed with potash, and heated until partially decomposed, no sulphurous acid is given off, but the residuum being dissolved in water and nitric acid added, a brown flocculent matter precipitates, which is artificial ulmine. Nitrate of barytes tests sulphuric acid in this filtered liquor. Red sulphate of iron does not at all affect the gum, though it coagulates abundantly with gum-arabic. Nitric acid, by acting on it, forms a large quantity of oxalic acid in fine crystals, but no mucous acid.

The gum, treated with diluted sulphuric acid, produces two remarkable substances,-sugar, and an acid.

24 grammes (370.6 gr.) of old cloth, well dried, were reduced into gum by 34 grammes (525. gr.) of sulphuric acid, as before described; the acid mixture diluted with water deposited 3.6 grammes (55.5 gr.) of ligneous matter but little altered. The clear fluid, thus diluted, was boiled 10 hours, and then saturated with carbonate of lime. This fluid did not precipitate sub acetate of lead, and contained no gum. It was evaporated, and dried as far as possible, and gave an odour of caromel. It then weighed 23.3 grammes (359.8 gr.) furnished by 20.4 grammes. (315 gr.) of cloth, though there were some losses. This sugary matter was made into a syrup, and, in 24 hours had began to crystallize; in a few days, the whole was a solid mass of crystallized sugar. This was strongly pressed in cloths, and crystallized a second time: it was then moderately pure, but, treated with animal charcoal, it became of extreme whiteness. The crystals were in spherical groups, formed by the union of small diverging plates. They are fusible at 212° Fahrenheit. The sugar has an agreeable taste, and produces a sensation of coolness in the mouth. It dissolves in hot alcohol, and crystallizes by cooling. Dissolved in water, and fermented by a little yeast, it gave a vinous liquor which furnished alcohol by distillation. Burnt with potash, and its charcoal washed with diluted nitric acid, it gave a fluid not troubled by nitrate of barytes. It is evidently identical with the sugar of grapes and of starch.

When the diluted acid mucilage was boiled with oxide of lead

for a long time, to separate all the sulphuric acid, a peculiar acid was formed at the same time with the sugar above described. This was dissolved out from the evaporated sugar, by rectified alcohol, but as a portion of sugar was also taken up, it was evaporated to a syrup, and agitated with ether. The ether upon evaporation gave an acid nearly colourless, very sharp, almost caustic, and setting the teeth on edge. It was deliquescent and uncrystallizable. It became brown in the air by degrees, if warmed; and, when heated in a capsule, it turned black and began to decompose below the heat of boiling water. If diluted in this state with water, flocculi of carbonized vegetable matter separated, and sulphuric acid was detected in the fluid. If heated above the boiling point of water, its decomposition is very rapid, and much sulphurous acid is disengaged.

This acid does not affect metallic solutions. Nitrate of barytes and sub-acetate of lead are not troubled by it. It acts on carbonates with effervescence. It appears to dissolve all metallic oxides, forming soluble salts, uncrystallizable, deliquescent, and insoluble in rectified alcohol. It dissolves iron and zinc, liberating hydrogen. It forms with barytes and oxide of lead, salts, very soluble, and of a gummy appearance. It will even dissolve a certain quantity of sulphate of lead. It is composed of sulphur, carbon, hydrogen, and oxygen; or, of a vegetable matter and the elements of sulphuric acid, but the state of combination is unknown.

If sulphuric acid be allowed to act on silk for a short time and then the mixture be diluted with water, a mucilage is obtained resembling gum tragacanth. More water being added it precipitates entirely, but a large quantity of hot water dissolves it. If the silk be treated in a mortar with sulphuric acid for 24 hours, a different result is obtained. It is then entirely soluble in water, and when the acid is separated by chalk, and the solution evaporated, a reddish transparent substance is obtained resembling glue, the solution of which is abundantly precipitated by infusion of galls, and sub-acetate of lead.

Gum, treated with sulphuric acid, gave results very nearly the same as cloth. Sugar became darkened by the acid, but de

posited no charcoal; the substance obtained from the neutralized solution was of a deep brown colour, and of a sweet bitter taste. It gave, when heated, vapours of sulphurous acid.

M. Braconnot then proceeds to shew that by abstracting the elements of water from wood, it is converted into a substance resembling ulmin. Ligneous fibre is not at all soluble in cold potash, but if equal weights of caustic potash and saw-dust, moistened with a little water, be heated in a platinum or iron crucible, and, continually agitated at a certain point, the wood will soften, and instantly dissolve in the alkali, with much swelling. If the crucible be then withdrawn, and put into water, all the mixture will dissolve, except a small earthy residue; and a deep brown fluid will be obtained, containing potash combined with ulmin; an acid will separate the latter, which only requires washing to be pure. If the acid liquor be saturated with lime, and evaporated to dryness, alcohol, when digested on it, will separate acetate of potash. Wood, thus treated, gives a fourth of its weight of ulmin.

Artificial ulmin, when dry, is black as jet; it is very brittle, breaking into angular fragments; its fracture is vitreous, it is nearly insipid and inodorous. When dried, it is insoluble in water, but if just precipitated, it dissolves in small quantities, making a brown solution. It does not contain more than 2500 of ulmin, but it froths on agitation like solution of natural ulmin.

When compared with natural ulmin, from the beech tree, by the action of re-agents, it was very similar to it. It combines with potash readily, and neutralizes it. The combination is very soluble, and is precipitated by acids, earthy and metallic salts, and lime water this combination may, perhaps, be useful as a colour. It combines with ammonia; it is soluble in concentrated sulphuric acid, but is precipitated by water; it dissolves readily in alcohol, and appears, when slowly evaporated, to crystallize from it. The solution is precipitated by water. When heated, it swells and burns with a little flame.

Such is a brief account of M. Braconnot's paper, but the matter is so excellent, and so free from any thing extraneous, that

its value should not be estimated until the paper itself has been read, for which, see Annales de Chimie, xii. p. 172.

IV. GENERAL LITERATURE.

1. Grecian University.-An University has been established at Corfu, by Lord Guildford, under the auspices of the British. Government. His Lordship has appointed to the different schools Greeks of the first abilities, and his attentions have been seconded with much effect by Count Capo d'Istria, a native of Corfu, who, being apprised that M. Polito, a young Leucadian, possessed of knowledge and talents, desired to profess chemistry in the Ionian islands, remitted to him funds sufficient to procure the apparatus necessary for the laboratory, &c.

The

2. Homer's Iliad.-There has been discovered in the Ambrosian library, at Milan, a manuscript copy of the Iliad of Homer, which has attracted the attention of the learned for its antiquity, appearing to border on the fourth century; and, by 60 pictures in it equally ancient. It is more ancient by about six ages than the one on which the editions of Homer are founded. characters are square capitals, according to the usage of the best ages, without distinction of words, without accents, or the aspirates; that is to say, without any sign of the modern Greek orthography. The pictures are upon vellum, and represent the principal circumstances mentioned in the Iliad. These pictures being antique and rare, copies of them have been engraved with the greatest exactness. They are not perfect in the execution, but they possess a certain degree of merit, for they give exact representations of the vestments, the furniture, the usages, the edifices, the arms, the vessels, the sacrifices, the games, the banquets, and the trades of the time, with the precise characters of the gods and heroes, and other numerous marks of their antiquity. M. Angelo Maio, a professor at the Ambrosian College, has caused the manuscript to be printed in one volume, with the engravings from the pictures, and the numerous scholia attached to the manuscript. These new scholia fill more than 36 pages in large folio; they are all of a very antient period, and the

greater part of them are by authors anterior to the Christian Era, and to the school of Alexandria. The authors quoted are 140 in number, whose writings have been lost, or are entirely unknown. There are among them titles of works which have not come down to us, and unedited fragments of poets and historians; they quote the most celebrated manuscripts of Homer, such as the two of Aristarchus, those of Antimachus, of Argolichus, the common one, in short, all the best of them; but no authorities are so often quoted as those of Aristarchus, Aristophanes, and Zenodatus, that is to say, the learned men to whom the poems of Homer are indebted for the most ingenious corrections. The manuscript, however, does not contain the Iliad entire, but only the fragments which relate to the pictures.

Gent. Mag. lxxxix. 445.

3. Premium of the Highland Society of London.-At a late general court of the Society, the following premiums were resolved :

Twenty guineas, and the medal of the Society, to the author of the best "Essay on the Present State, Character, and Manners, of the Highlanders." The Essay to be delivered to one of the secretaries on or before the 1st of March next.

Twenty guineas, and the medal of the Society to the author of the best "Essay on the Remains of Buildings, and such. Monuments as may evince the Degree of Civilization which the ancient Gaelic Scots had attained." The Essay to be given to one of the Secretaries, before March, 1821.

Twenty guineas, and the medal, to the author of the best

Essay on the Etymology of the Gaelic language; its Connexion with other Languages, where it originally existed, and whence derived." The Essay to be given in before the 1st of March, 1822.

Twenty guineas, and the medal, to the author of the best Essay on the ancient History of the Kingdom of the Gaelic Scots, the Extent of the Country, its Laws, Population, Poetry, and Learning." The Essay to be given in by the 1st of March, 1822.

Twenty guineas, and the medal, to the author of the best