tive, and that for chabasie positive, and from certain crystals of chabasie including an excess of silica, which is a substance plesiomorphous with chabasie. (Dr. Thomson stated that there are two distinct species of chabasie, one of which includes soda and the other lime, and from the admixture of which the phænomena might perhaps arise.)

Professor JOHNSTON stated verbally the results of his analysis of the single and double iodides of gold, results which he found to correspond generally with those already obtained for the chloride.

Professor GRAHAM gave an account of some recent researches which he has published in reference to the constitution of certain compounds as far as respects their constituent water. He illustrated his views by sulphuric acid, with 1 and 2 atoms of water, by oxalic acid with 1 and 3 atoms of water, and by nitric acid containing 1 and 4 atoms of water. Other compounds were also adduced, such as oxalate of magnesia, which contains two atoms of water, or that which may be considered as the water of crystallization of oxalic acid. The oxalate, binoxalate, and quadroxalate of potash, and several other saline compounds were also brought forward in explanation of his views.

Anhyd. oxal. a. .(C+ċ)

Oxal. water........(Ĉ+ċ) Á

Oxal. acid..... .Ĥ(C+C) 2 H
Oxal. potash...K (C+Ċ) Ĥ

Binox. pot... K(C+Ċ)Ĥ+(Ċ+Ċ)2 H2

Quadrox.

pot...K.(C+Ċ)H+(Ĉ+Ċ)2H+H(Ö+Ċ)H2

He then drew attention to ammonia, which he considered as frequently performing the function of water in saline compounds; a view which he impressed upon the Section by drawing attention to the composition of the sulphate and of two distinct ammoniurets of copper.

On a new Method of testing the presence of Muriatic Acid in Hydrocyanic Acid. By Professor GEOghegan.

This proceeding is essentially preliminary to the adoption of the usual modes of determining the strength of any given specimen of this agent. The insoluble compounds into which the chlorine of muriatic acid enters, and by the formation of which chemists usually recognise its presence, are known to resemble, in many respects,

those to which cyanogen gives rise when combining with the same bases. The method proposed by Dr. Geoghegan is founded on the property which the double salt of the iodide of potassium and bicyanide of mercury possesses of being decomposed by acids, and then producing biniodide of mercury. This compound, which has been analysed by Liebig, and subsequently by Dr. Apjohn, is easily prepared by mixing, in the proportion of atom and atom, the iodide of potassium and bicyanide of mercury, each dissolved in a small quantity of hot water. After a short time silvery scales (resembling acetate of mercury) are formed, which constitute the salt in question. The circumstance of this salt being decomposed by all the ordinary acids, would appear to show that it is not capable of demonstrating the presence of muriatic acid in particular; but as the only other impurities likely to be present in the hydrocyanic acid are sulphuric and tartaric acids, if the appropriate tests of these latter do not indicate their existence, then the formation of biniodide of mercury on the addition of a crystalline scale, or solution of the double-salt above mentioned, may be considered as furnishing conclusive evidence of the presence of muriatic acid. It may be also stated, that the only hydrocyanic acid likely to contain sulphuric that prepared from the ferrocyanide of potassiumcan be generally recognised, as to the source from whence derived, by its possessing a slight bluish or bluish-green tinge, which is quite distinctive. The mode of detecting the presence of muriatic acid above detailed has the advantage over those usually employed, of being very readily applied, and the formation of the reagent is perfectly simple; it is capable of detecting 1-4500th part of the acid: if no change of colour ensue on the addition of the salt, we may conclude that the specimen of hydrocyanic acid contains no impurity which can interfere with the subsequent estimation of its strength. This method, however, is inapplicable to the alcoholized acid of Germany, as the biniodide is soluble in spirit, yielding a colourless solution. If the presence of muriatic acid have been ascertained, its neutralization can be readily effected by the addition of successive small portions of precipitated carbonate of lime, as long as any is dissolved; when free, muriatic acid has been got rid of, and not till then can the estimate of the strength of the specimen under examination be proceeded in with any hope of a correct result. The method of Dr. Ure for effecting this latter end is sufficiently correct for ordinary purposes, if we substitute for the red precipitate which he employs, pure peroxide of mercury; as, independent of the presence of minium and other impurities, red precipitate is seldom, if ever, free from pernitrate of mercury: if perfect accuracy be desirable, the best method, and probably as simple a one as that just alluded to, is the formation of cyanide of silver by the addition of the nitrate of that metal.

On Bleaching certain Varieties of Turf for the Purpose of producing a White Fibre for the manufacture of Paper. By R. MALLET.

The kind of peat used for this purpose is that which exists immediately beneath the vegetable surface of almost every lowland or flat bog in Ireland, and is found existing in a stratum frequently of about three feet thick. It consists of the leaves and stems of various mosses, the roots and fibres of many small aquatic and marsh plants, &c. in the first stage of that very slow decomposition which is the character of every peat moss.

The fibres are tough, and retain perfectly, in most instances, their original form, and are arranged more or less in parallel strata; its colour is a reddish brown, and its specific gravity, as obtained from various bogs, varies from 360 to 650. It is proposed either to use the fibre bleached from this for paper-making alone, or in place of the various adulterations now used in paper from rags, such as chalk, gypsum, clay, cotton-flyings, hair, leather-cuttings, hop-bines,

&c.

The same material is capable without bleaching of being converted into an excellent species of board paper or mill-board, by simple pressure under an hydraulic or other press, and subsequent saturation in an exhausted vessel, with glue and molasses, drying oil, rosin, and oil, or any other suitable material. When so treated, it will withstand well the action of high-pressure steam.

This species of turf contains from 3 to 11 per cent. of ashes when humid, and when dried, merely atmospherically, from 4 to 6 per cent. of water. The ashes are of a white or yellowish white colour, and contain,

The author cannot account for the loss on this analysis, and has been unable to repeat it. He states that ashes from the bottom of the same bog where this red turf was obtained give a totally different result, viz.

The fibrous matter of this red turf is intimately combined with various complicated, vegetable results of slow decomposition, but containing in greatest proportion the extractive matter to which Berzelius has given the name Geine, from yn, terra. The extract obtained from turf in the way about to be described seems to be

nearly the same as that which he describes, in fact to be ulmin in an impure state.

The specimen of turf to be bleached for paper is softened in cold water until its parts by agitation will separate; the finer particles are washed off; the fibre which remains is digested in the cold with a very dilute solution of caustic potass or soda, containing only 50 grains of alkali to a quart of water. The solution, containing the geine in solution, is pressed from the fibres; the latter are then soaked for some time in very dilute sulphuric acid, consisting of 150 grains of the sulphuric acid of commerce, in a quart of water. The iron is obtained in solution, and the ammonia if any exist in the turf. The fibre is now again separated by pressure from the dilute acid, and digested in the cold, with dilute solution of chloride of lime, of the strength commonly used by paper-makers to bleach fine rags. After the bleaching has taken place the fibre is strained from the liquor, well washed, and applied to the manufacturer's purposes.

The extremely dark-coloured solution obtained by the caustic alkali is now treated with an excess of dilute sulphuric acid, and the acid of the previous washings may be in part used by the manufacturer for this purpose. The alkali is neutralized, and the geine precipitates. It is collected on a filter or by other suitable means, and well washed with cold water, and finally dried by a steam bath, after which, if perfectly dried, it ceases to be soluble in water. It may now be used either in oils or distemper as a colour, being a rich brown bistre.

The solution from which it has been separated contains sulphate of potass, and occasionally, in very minute quantity, sulphate of am

monia.

The quantity of soluble matter in the turf operated on was found from 14 to 30 per cent.; and from one hundred weight of turf of proper quality may be obtained about 18 pounds of fine white fibre fit for paper-making, and a much larger proportion of a coarser and less white description.

When the turf is digested in the chloride of lime, a thin film of an unctuous-looking matter floats after some time on the solution, and by careful management may be obtained in small quantity; it appears to be a mixture of a gum resin with something analogous to wax, and of artificial camphor.

This substance smells like common camphor. Its specific gravity is 0.990, which is a little more than that of camphor. It is at ordinary temperatures always partly solid and partly fluid. When deprived of adhering water it shows a tendency to crystallize; the more fluid part gradually evaporates when it is exposed to air, and a varnish is left on the vessel which contained it. Its point of homogeneous fusion is somewhere between 290 and 300; it evaporates rapidly between that and its boiling-point, which seems to be about 360. As it boils away, its boiling-point rises; it is insoluble in water; a great part dissolves in alcohol, and the remainder is soluble in caustic potass and in fixed oils.

Proof spirit dissolves from it a very minute quantity of a substance which seems to be a gum resin. It is entirely decomposed by a red heat, in close vessels, and also by concentrated and boiling sulphuric acid, which reduces it to charcoal, and a substance apparently analogous to artificial tannin.

The bistre, or colouring-matter, obtained from the turf is not affected by carbonic acid, nor by sulphuretted hydrogen, nor by protochloride of tin: strong nitric acid will not change its colour, although by long standing it is decomposed by it. Chlorine bleaches it slowly; caustic alkalies redissolve it. It is scarcely bleached at all by the sun's rays, nor does it when properly washed and dried show any tendency to deliquesce; it is therefore an excellent colour for paper-staining and other such purposes, as few common agents will injure it, and it can be readily removed from surfaces by an alkali.

The proportions of useful products above given can only be considered as approximations, having been deduced from experiments on a small scale; they would probably be much increased, and the relative expense of preparing the material reduced, if the process were carried on with greater quantities.

On some singular Phænomena of Flame from Coal-Gas.
By R. MALLET.

If an Argand gas-burner be lighted, and a conical tube of a certain diameter be inserted concentrically within it, with its extremity entering a certain distance, within the burner, and, while the gas is inflamed, a current of air be propelled through the conical tube in the same direction with the streams of gas, under certain conditions, the whole of the gas-flame will retract or be drawn back between the internal surface of the burner and the external surface of the conical tube, and nothing whatever will pass forward but a stream of strongly heated carbonic acid and aqueous vapour. This very singular phænomenon of the passage in opposite directions of two currents in such close contact does not appear to be affected by the size of the burner, provided a certain proportion be preserved between it and the conical air-tube. The experiments were made with two burners chiefly, one of which was three quarters of an inch internal diameter and one inch and a half deep, measured along its axis, and the other seven sixteenths of an inch internal diameter, and one inch and three eighths deep.

With these it was found that the retraction of the flame was produced most perfectly in the case of the large burner by a tube of five sixteenths of an inch diameter, but yet took place to a certain extent until the diameter of the tube was reduced to one eighth of an inch, and in the case of the smaller burner it was most perfectly produced by an air-tube of three sixteenths of an inch diameter;

E