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Chemical Notices from Foreign Sources.

The author gives a fresh account of his experiments on magnetic condensation, which, from M. Lallemand's paper of October 19, 1874, he concludes are still not thoroughly known.

Decomposition and Preservation of Wood.-M. Max Paulet. The author purposes to give an account of the destructive action which takes place in wooden railway sleepers injected with sulphate of copper. It is generally admitted that the protective action of the metallic salt is due to its combination with the ligneous tissue, and especially with the nitrogenous matter, which becomes insoluble and poisonous to living beings. This explanation is insufficient. The author has studied the action of metallic salts, and especially of sulphate of copper, upon the nitrogenous matter of wood, and finds that the albumino-cupric precipitate is not absolutely insoluble in water, and that it is especially soluble in water charged with carbonic acid. The nitrogenised matter in wood is partly soluble and partly insoluble. The soluble albuminous portion is fixed by the metallic salt, which combines also with the insoluble nitrogenous matter. The water, especially if charged with carbonic acid, dissolves and removes the metallic compound. Recent observations, however, have satisfied the author that the reactions are not always so simple. A sleeper of beech-wood, for example, saturated with cupric sulphate after having been buried in the ballast of a railway for eight or ten years, is found to be decayed in several parts. The portions affected are very brown in the vicinity of the rail. The wood is not worm-eaten, but it is chemically altered. If it no longer contains copper it contains quantities, often enormous, of iron furnished by the rail. This abundance of iron does not prevent the alteration of the timber. It has penetrated into the wood in a state of solution, since it has travelled far from the point of contact. Portions of wood which were in immediate contact with the iron, or which contained chinks into which scales of oxide of iron might have fallen, were of course set aside as not decisive. This precaution having been taken, it was established that in the layers of wood near the rail the woody fibre was brown, soft, brittle, and readily pulverised. The density of the wood was singularly diminished. Parts of the wood not attacked had the specific gravity o'755, whilst the affected parts had fallen to 0.380. The affected wood still contains nitrogenous matter. It was entirely soluble in caustic potash, like ulmic acid. If treated with water acidulated with nitric acid it gives up to the solvent the lime which it contains, and a large amount of iron. This iron, although it must have been in a soluble state when it entered the wood, has become insoluble. Hence, ferrocyanide of potassium, applied to a ferruginous portion of this ferruginous wood does not produce a blue colouration. At the same time that nitric acid removes the iron contained in the modified wood it produces an evolution of carbonic acid, as if from an impure carbonate. This quantity of carbonic acid far exceeds what is found in wood decayed in the air. One-fourth of a gramme of the modified wood has yielded 105 c.c. of carbonic acid. This modified wood contains 3 per cent of ash, whilst normal beech-wood contains less than the half of this amount. Whilst boiling in the acidulated water a part of the wood dissolves. When the solution is concentrated in a platinum capsule, the residue blackens and carbonises. The parts of the sleeper more remote from the rail are less ferruginous, except in cases where the ballast is surcharged with oxides of iron; but carbonate of lime is very abundant in the affected parts. The copper gradually passes out of combination, and disappears altogether, giving place to the carbonate of lime. The process is as follows:-The carbonate of lime contained in the ballast becomes soluble in an excess of carbonic acid, penetrates gradually into the wood, and substitutes the copper. Hence, to determine the degree of the change undergone by the wood, it is sufficient to determine the quantity of carbonic acid or of carbonates present. The tenacity of the woody fibre is inversely as the carbonic acid present.

As long as the copper remains in its original combination its preservative action continues. The carbonate of lime is not a septic agent, but it eliminates the preservative body from its compounds, and restores the matter to be preserved, if not to its natural state, at least to one which facilitates the access and the action of destructive agents. This confirms and explains the fact, already established by observation, that sleepers are decomposed most rapidly in calcareous soils.

Germination of Chevallier Barley.-M. A. Leclerc.The object of this memoir is to show that when grains germinate in a limited space there does not take place, as MM. Dehérain and Landrin announced (Comptes Rendus, lxxviii., p. 1488), an occlusion of nitrogen gas at the outset of germination; and that the final augmentation of the nitrogen gas in experiments of long duration is due to a partial decomposition of the grain.

Letter on the Phylloxera.-M. L. Roesler. Expression of Work Relative to an Elementary Transformation.-M. J. Moutier.-A mathematical paper; not suitable for abstraction.

Analogies between the Escape of Gases from Supersaturated Solutions, and the Decomposition of Certain Explosives.-M. D. Gernez.-The author concludes from his experiments that there is the strongest analogy between the escape of a dissolved gas, taking place on the surface of the solution into a gaseous medium, into which the gas passes as into a rarefied atmosphere, and that decomposition of explosives which cannot, as in the case of oxygenated water, be ascribed to a particular catalytic force.

Atomic Structure of the Molecules of Benzine and Terebene.-G. Hinrichs.-This paper requires the accompanying diagrams. The author refers to his work, "Principles of Chemistry and Molecular Mechanics." Davenport: Iowa, U.S.

Titanic Ethers.-M. E. Demarçay.-Of all the titanic ethers, the only one hitherto known is the trichlorhydrin, TiCl3OC2H5. The author has produced the hydrochlorate of monochlorhydrin, Ti(OC2H5)3C1,HCI.

Pyruvic Ureides; Condensed Ureides.-M. E. Grimaux.-This paper treats of dipyruvic-triureide, tetrapyruvic-triureide, and dipyruvic-tetraureide.

Aerial Corpuscles and Saline Matter in Snow.M. G. Tissandier.-In the snow which fell between the 16th and 25th of December last, the author distinguished the presence of an abundance of foreign substances, including certain salts. The dry residue from the evaporation of a litre of snow-water was determined. Snow collected in a court yielded 0.212 grm.; from the towers of Notre Dame, o 118 grm.; and from the country, o'104 grm. The residue obtained on the evaporation of snow is an impalpable greyish powder, of which the organic matter, rich in carbon, burns brightly. The residual ash amounted to 57 per cent in Paris, and 6: in the country. It consisted of silica, carbonate of lime, alumina, chlorides, sulphates, nitrate of ammonia, and very appreciable amounts of iron. He suggests that a portion of the matter suspended in the air may have a cosmic origin.

Researches on the Gastric Juice.-M. Rabuteau.— The author confirms the results of Braconnot, Prout, Lassaigne, and Schmidt, showing that the acidity of the gastric juice is due, not to the lactic, but the hydrochloric acid.

Moniteur Scientifique, du Dr. Quesneville,

December, 1874.

Chemical Products at the Vienna Exhibition.-M. E. Kopp.-(Continued.) An account of the pharmaceutical products, essential oils, perfumery, drugs, and raw materials for pharmacy and chemical manufactures.

According to M. Ch. Kopp, of Neufchatel, the specific gravity of different kinds of diamonds is

NEWS

5

Then follow receipts for the manufacture of artificial

1. Ordinary crystalline diamond, for ornamental 3.550 purpurin; for dyeing woollen knitting-yarn; for a black

purposes

2. White diamond in natural grains 3. Black diamond in natural grains

2.636

2.653

on woollen cloth; for a blue-green on cotton-yarn; a marine blue on silk; a black (printed) on woollen pieces 4. Grey diamond of commerce in fragments 3'596 and yarns; and a green and black (printing) on calico. 5. Black artificial diamond 3.412

Certain Properties of Weighted Black Silks.--M. J. Persoz.-The author shows that weighting-which began with the modest aim of making up the loss sustained in ungumming-is now carried to the extent of 100, 200, and 300 per cent. This increase of weight is produced by treatment with salts of iron and astringents, salts of tin and cyanides. The bulk is augmented proportionably to the weight. As a matter of course, the chemical and physical properties of the silk thus treated are materially modified. What is sold as silk is, in fact, a mere agglomeration of heterogeneous matters, devoid of cohesion, held temporarily together by a small portion of silk. The elasticity and tenacity of the fibre are sensibly reduced. From being in its natural state one of the most permanent of organic bodies, and sparingly combustible, burns like tinder if touched with flame. It is, moreover, liable to undergo spontaneous decomposition, and to absorb gases with the evolution of heat, which sometimes leads to actual combustion. The adulterated silk when burning scarcely gives off the characteristic odour of animal matter. It leaves an ash of oxide of iron, exceeding 8 per cent.

Industrial Preparation of Sulpho-Carbonate of Potash.-M. A. Gelis.-Already noticed in the CHEMICAL NEWS.

Applications of Indigo.-M. A. Schultz.—Reserved for insertion in full.

Titration and Assay of Manganese.-M. A. G. Pouchet. Reserved for insertion in full.

Liebig's Annalen der Chemie und Pharmacie.
November 9, 1874.

Contributions to the Knowledge of the Ammonia Derivatives of Benzol.-Dr. H. Salkowski.-(Second part; compounds of the benzol series.) In this paper the author treats of the trinitro compounds, including picric ether (trinitro-aniline); picric methylic ether (trinitroanisol); the reduction of trinitro-aniline, resulting in dioxydiamido-benzol. Passing to the dinitro compounds, he treats of experiments with the a series, the reduction of a-dinitranilin, the sulphate of tri-amido-benzol, the conversion of a-dinitranilin into dinitro-benzol; experiments in the B series, B-dinitro-anisol, the solubility of a- and ßdinitro-anisol in alcohol; B-dinitro-phenetol; B-dinitroaniline; solubility of a- and ẞ-dinitro-aniline in alcohol; the transformation of B-dinitro-aniline into dinitro-benzol; the mono-nitro compounds; experiments in the ortho- and para series; and decomposition of para-nitro-anisol by ammonia.

Synthesis of Methyl-Aldehyd.-B. C. Brodie.-After the gas-which the author had obtained by the action of electricity upon about equal volumes of hydrogen and carbonic acid-had been freed from carbonic oxide, carbonic acid, and traces of oxygen, there remained 1912 volumes, which, on analysis, were found to contain 2.6 volumes of nitrogen. Deducting this, there remained 188.6 volumes, which was found to consist of

Hydrogen
Marsh-gas
Methyl-aldehyd

5.2

188.6

Volumetric Determination of Copper Applicable to the Analysis of Ores, Alloys, Bronzes, and to Toxicological Cases.-M. Prosper Lagrange.-Reserved Its percentage composition is therefore—

for insertion in full.

Les Mondes, Revue Hebdomadaire des Sciences.
No. 16, December 17, 1874.

M. F. Guicheteau finds that vines and trees infested by the phylloxera may be cured by driving common iron nails into the trunk.

Chalk as a Source of Heat.-M. Maridort thinks that in a common household fire lumps of chalk mixed with the coal may increase the proportion of heat utilised, though not the amount actually produced. In the furnace of a steam-boiler the addition can be only pernicious.

No. 17, December 24, 1874.

The only chemical paper in this number is an account of the manufacture of chlorine, by Mr. W. Weldon.

Reimann's Farber Zeitung, No. 47, 1874.

The editor announce that one of "our leading practical dyers" has succeeded in constructing a machine which performs all the manipulations of mordanting, dyeing, washing, &c., automatically, in the shortest possible time, and in a more trustworthy manner than the best workman. Another discovery is a method of fixing all the aniline colours upon wool, much faster, and with increased lustre. The dye-kettles can be exhausted in one operation till clear as water, and heavy shades can be dyed in very dilute solutions. Colour is thus economised, and the inconvenience of smearing in dark shades is avoided. All blue tones can also be produced in full brightness from the redder kinds of methyl-violet.

It is further announced that an eminent chemist is in the very act of discovering the long-sought-for constitution of ultramarine-a matter which will be of the highest importance for a manufacture which has hitherto groped about in the dark.

Communications from the Laboratory of Professor Wislicenus, in Würzburg.-These consist of a paper on para-di-pimalic acid, diacrylic acid, and para-di-pinic acid, by J. Wislicenus, in which we have an account of the preparation of para-di-pimalic acid from the decomposition of glycerin-iodo-propionic acid with oxide of silver; the behaviour of the para-di-pimalates at elevated temperatures; and a notice of the salts of diacrylic acid, and the reduction of para-di-pimalic acid by hydriodic acid. Next follows a memoir on the constitution of dinitro-ethylic acid, by Sylvester Zuckschwerdt; a paper on the products of the oxidation of ethyl-sulphinic acid by nitric acid, by the same author; an essay on the constitution of crotonic acid, by W. Hemilian; and a memoir by Dr. Hermann Goldenburg on the action of nascent hydrogen upon benzoin.

Remarks on the Javanese Calisaya, and on Conchinin.-O. Hesse.-The author holds that the species cultivated in Java is not the true calisaya of Weddell, but a distinct, though closely approximating species.

Communications from the Chemical Laboratory at Griefswald.-These include a memoir by Dr. M. Hayduck on ortho-amido-para-sulpho-toluolic acid, giving an account of its behaviour with concentrated sulphuric acid; the behaviour of the diazo compound of the amido acid with acetic acid, hydrated and anhydrous, and phenol, behaviour of ethyl-cresol-sulphuric acid when heated and melted with hydrate of potash; behaviour of the diazo compound with fuming sulphuric acid; nitro-ortho-brompara-sulpho-toluolic acid; amido-ortho-brom-para-sulphotoluolic acid; amido-para-sulpho-toluolic acid; the met

Patents.

ganese with charcoal of wood, or of peat, coke, or anthracite coal.
An improved method for the recovery of sulphuric acid when com-
bined with certain chemical products. Thomas Jackson, manufacturing
chemist, Clayton, near Manchester, Lancaster. May 5, 1874.-No.
1583. My invention consists in recovering sulphuric acid when com-
bined with nitric acid, muriatic acid, benzol, naphtha, or any other
coal-tar oils by means of chlorine or any other oxidising agent.

morphoses of di-brom-ortho-amido-para-sulpho-toluolic | bonic acid gas evolved; and, secondly, in mixing black oxide of manacid; di-brom-ortho-cresol-para-sulphuric acid; the dibrom-ortho-cresol-sulphates of baryta and lime; tri-brompara-sulpho-toluolic acid, and its baryta and lime salts; the nitro-diazo compound of di-brom-ortho-amido-parasulpho-toluolic acid; and a paper by M. Schäfer on certain brom-amido-sulpho-toluolic acids.

In a previous communication (CHEMICAL NEWS, vol. xxx., p. 221), we spoke of the application of stannous chloride as a reducing agent for assay of iron ores, and the observations we then made led to a little adverse criticism by another author, who recommended the use of ammonium sulphide. Partly on this account, but more from the fact that no analytical text-book within our reach gave what we considered reliable information as to the method of working with tin salt, we have made some careful experiments in this direction, not only in order to establish the accuracy of results yielded by it, but to show that, for rapidity of action and simplicity of detail, it stands first for its purpose in the technical determination of iron.

(1). 03120 grm. annealed iron wire, known from analysis to contain a mere trace of foreign matter, was dissolved in HCl, treated with Cl water, boiled to expel free Cl, diluted to 500 c.c., reduced with SnCl2 solution, and titrated with standard bichromate, of which each c.c. was worth o'00997 grm. iron. 313 c.c. were used=0'3120 grm. iron in wire.

(2). 0.3470 grm. wire treated as above gave o‘3369 grm. 0'36589 grm.

iron.

(3). 0.3650

iron.

From these results, it is evident that the process loses nothing in exactness, from the fact of the whole of the iron existing as ferric salt.

Laboratory and Assay Office, Darlington,
February 1, 1875.

LECTURES ON THE MORPHOLOGY OF
CRYSTALS

AT THE

CHEMICAL SOCIETY.

By NEVIL STORY MASKELYNE, M.A., F.R.S., &c. (Continued from page 26).

LECTURE VI.

Referring to published information upon the use of stannous chloride as a reducer for ferric salts, we find the following objections presenting themselves, viz., the fear of adding excess of stannous salt, and the want of suitable means to prevent such excessive addition; but we have proved that, by the method of use given below, these objections no longer hold good. In this process I grm. of ore is dissolved in 30 c.c. of strong HCl, or, if not decomposed by HCl, it is first fused with alkaline carbonate, and brought into HCl solution; in either case, the solution is made up to 500 c.c. with distilled water and caused to boil. The stannous chloride may now be added in small portions at a time, but it must be in dilute clear acid solution, a convenient strength containing 10 grms. of tin per litre. The colour of the ferric solution is a fair guide to the addition of the tin-salt within certain limits; but when the colour becomes faint some other indicator must be used, and this we find in a dilute, recently-prepared solution of potassium sulphocyanate, which is disposed in drops over the surface of a white tile. Special care must be taken to add the trial drops of iron solution quickly to those on the tile, and to have the beaker containing the solution in pretty close proximity to the tile, so as to guard against oxidation of solution on the glass rod with which the test drops are added. The reduction is carried so far, that only a faint tinge of pink is produced when the last addition of tin-salt has been made and allowed to boil for a few moments. The next step is the titration with potassium bichromate ; and, as a vital part of the process, we make the preliminary addition of Through when it is an axis of diametral symmetry. three drops of bichromate (standard solution I c.c.=0'01 grm. iron), then test with potassium sulphocyanate. A distinct access of colour in this test, as compared with the last test made in reducing, is accepted as proof of the absence of stannous salt, and it only remains to complete the assay in the usual manner.

In his sixth lecture, Mr. Maskelyne discussed the general subject of geometrical symmetry, first in relation to a plane, and then in relation to a solid figure, and afterwards considered in what way the principles of geometrical symmetry could be applied to the symmetry of the faces, or again of the forms of crystals. A plane figure, for instance, is symmetrical to a point, that is, is centro-symmetrical when straight lines passing through the point meet at equal distances from it corresponding points of the figure. Similarly, in the case of symmetry to a line, perpendiculars on the line meet corresponding points on the figure at equal distances from the line, and the figure may be symmetrical to two or more intersecting lines. The portions of a figure symmetrical to a line will not necessarily be congruent without retroversion over the line. A solid figure, again, may be symmetrical to a centre or to a plane, or to several intersecting planes, or it may be symmetrical to a line or axis of symmetry; and such an axis may be an axis of diametral, trigonal, tetragonal, &c., symmetry. In such cases, a radius vector perpendicular to the axis of symmetry at any point upon it will meet corresponding points of the solid at equal distances from the axis as it moves in a plane perpendicular to that axis

We have made a large number of assays by this method, and have tested its capabilities, thoroughly comparing it with pure zinc, ammonium sulphide, sulphurous anhydride, and sodium bisulphite, and it has given us every satisfaction. It requires no filtration, no prolonged boiling to eliminate dissolved gases, and there is no fear of loss from effervescence, &c.; and we are sure that when we state that by other processes the time occupied by a reduction alone is not less than from thirty to forty-five minutes, and that by tin-salt ten minutes are sufficient for the purpose, one, and not the least, of its advantages must be evident.

2

π

and in the cases of trigonal or hexagonal symmetry.

It is evident that crystals can only in a conventional sense be said to be symmetrical figures in the meaning here given to the word; but, either by considering a crystal form as an ideal figure constructed in equipoise, that is to say, with its faces parallel to the faces of the form, and with corresponding faces at equal distances from the centre, or, again, by considering the relative positions of the poles of the faces as distributed on the sphere of projection, we are in a position to deal with the symmetrical relations of crystals very much as if those natural bodies were really constructed in true geometrical symmetry.