150 Chemical Notices from Foreign Sources. methods of reasoning peculiar to the chemist," and tried to elevate into its place that power "peculiar" to the brute creation" instinct or intuition." Is there not as much philosophic reasoning in the true working of the theory and laws of heat? Is there not as much science about hydraulics and steam? Is there no philosophic reasoning relating to mechanism, or in the principles of mechanics? To sum up-what in this world works alone, and has one groove to run in without interference from anything else? In a chemical manufacture, where chemical conditions and physical conditions run side by side, in, out, through, and commingling with, one another, what is the use of chemistry alone? It stands unsupported; but when propped up with the sciences, collateral and cognate, is like the house built upon the rock,-the winds of strikes and the storms of bad prices beat upon it, but it falls not, for it is founded on rock. Before concluding, another "Lancashire lad" wishes me to ask how Mr. Morrison came to know that "good white caustic soda from red liquors alone, is-almost an impossibility," seeing that a firm have made "good white caustic soda" from red liquors alone for some years past; but I am afraid that this manufacture will not improve while we have superintendents of processes describing chemical compounds as "salts," "sublime," "scummy sort of crust," instead of describing what they really are. I am, &c., A LANCASHIRE LAD. CHEMICAL NEWS, Simultaneous Formation, in the Hot Springs of Bourbonne-les-Bains, of various Crystalline Mineral Species, especially of Antimonial Grey Copper (Tetrahedrite), Copper Pyrites (Chalcopyrite), Phillipsite, and Chalcosine.-M. Daubrée. Action of Borax in Fermentation and Putrefaction. M. J. B. Schnetzler.-The author finds that borax in small quantity arrests fermentation and putrefaction, and prevents the development of low forms of organic life. Ebullition of Sulphuric Acid.-A. Bobierre.-Noticed elsewhere. Comparative Study of Gums and Mucilages.-M. Giraud.-The author's investigations have been principally directed to gum tragacanth. Mucilaginous bodies which swell up in water may be divided into three distinct groups. In the first of these is placed gum tragacanth, characterised by the presence of a body capable of giving rise to pectic compounds. To the second belong the mucilages not containing pectic principles, and characterised by the fact that even the weakest acids render them insoluble in water, such as the mucilage of quinces. The third class is free from pectic principles, and is not precipitated by dilute acids, but transformed rapidly, on the application of heat, into a matter comparable with dextrin, and into a saccharoid body. These different bodies present the following properties in common:-Under the influence of dilute acids they are transformed by heat into a sugar different from ordinary glucose, which crystallises readily, does not ferment, and has a greater reducing power than glucose. It belongs to the galactoses of Berthelot. The CHEMICAL NOTICES FROM FOREIGN gummy principles comprised in the last two groups differ Ruthenium, and its Oxygenated Compounds. MM. Sainte-Claire Deville and H. Debray.-Pure ruthenium is as sparingly fusible as iridium; and if heated in an oxidising atmosphere it burns with brilliant sparks, a smoky flame, and a decided odour of ozone. The authors submitted ruthenium to the action of oxygen in a porcelain tube, heated to a temperature a little higher than the melting-point of copper. Fremy's crystals were thus reproduced in very fine specimens, into which the whole mass of oxide was transformed, only a very small portion having been transported by sublimation outside the "boat" which it had filled. This observation connects the phenomena with the " apparent volatilisations" of which Troost, Hautefeuille, Ditte, and the authors have given numerous examples. These facts have been explained by the momentary production of an unstable compound, which is dissociated almost at the time of its formation. Hyper-ruthenic acid (RuO4), the analogue of osmic acid discovered by Claus, is yellow, crystalline, but so unstable that its form has not been determined. It melts at 40° C., and at 108° it is destroyed with explosion. When decomposed it yields strongly ozonised oxygen. Osmic acid, on the contrary, produced by the direct action of oxygen upon metallic osmium, may be maintained in the state of vapour without decomposition. Ruthenic oxide is not reduced by heat like the oxide of iridium. It is found along with iridium, iron, and even platinum in most precipitates and solutions which contain at the same time the two former metals. Iridium, especially, retains ruthenium with great tenacity. Mr. Matthey informs the authors that four or five repetitions of Claus's process do not always suffice to free iridium from the last traces of ruthenium. from gum arabic in all their characters. Gum tragacanth is sparingly soluble in cold water, and is far from giving, as is asserted, 30 to 50 per cent of soluble gum. The filtrate is a mixture of different bodies, and not a definite principle like arabine. If gum tragacanth is digested in the waterbath with 50 parts of water, after twenty-four hours all the gummy matter is transformed into soluble gum, having lost the property of swelling up after drying. This new matter is not arabine, but pectine. Submitted to the action of acidulated water (1 per cent), it is modified in the water-bath in about three hours, becoming totally soluble. The new body produced is pectine, precipitable by alcohol. The amount of glucose formed during this reaction scarcely corresponds to a tenth part of the material employed. Hence it appears that gum tragacanth contains more than half its weight of a pectic principle insoluble in water, and probably identical with Fremy's pectose. Examination of the Whey of Luchon.-M. F. Garrigon. Determination of Boracic Acid.-M. A. Ditte.-If it be required to determine boracic acid contained in a solution in which it is contained alone, or in combination with alkaline oxides, a little ammonia is added to the liquid in order to neutralise any free acid, and then an excess of a saturated solution of pure chloride of calcium. All the boracic acid is then found as borate of lime, as a gelatinous precipitate, soluble in heat in chloride of calcium in excess. The matter introduced into a platinum capsule may be then evaporated to dryness without the least trace of boracic acid being volatilised. When dry, the crucible is filled with a mixture in equal equivalents of pure, crystalline chlorides of sodium and potassium, and heated moderately at first, and then to fusion. The borate of lime, much less fusible, collects at the bottom of the crucible in a spongy matter more or less agglomerated, and dissolves partially in the melting saline mass. If at the bottom of the crucible a temperature is maintained higher than in the upper part, the dissolved borate of lime crystallises on the surface of the liquid, and forms a ring, which rises along the side of the crucible, just above the surface. Soon all the borax is conveyed into this ring, and nothing remains at the bottom of the crucible. The composition of the crystals is BO3,CaO. They are insoluble NEWS both in hot and cold water. A cold concentrated solution of alkaline chlorides does not affect them; if hot, it dissolves a very small quantity. The matter, when cold, is separated from the crucible, and treated with cold water, when the chlorides dissolve. The crystals are washed on the filter, dried, detached from the filter, and weighed. Care must be taken not to fuse the amorphous borate or lime which occupies the bottom of the crucible in an early stage of the operation. The temperature of the bottom of the crucible should be kept as high as possible short of such fusion. The crucible cannot be heated with a Bunsen burner, but with a gas blast-lamp. On approaching the point at which the borate of lime is fused, the volatilisation of the alkaline chlorides becomes visible. There should be part of pure dried chloride of calcium for 3 parts of the mixture of alkaline chlorides. Microzymas and Bacteria, in reference to a Remark of M. Balard.-M. A. Bechamp.-A reply to the paper in Comptes Rendus, lxxix., p. 1272, November 30, 1874. Butyric Fermentation Produced by Aquatic Vegetation Immersed in Solution of Sugar.-M. Schützenberger. Phenomena of Diffraction Produced by Circular Net-Work.-J. L. Soret.-Not adapted for abstraction. Berichte der Deutschen Chemischen Gesellschaft zu Berlin No. 17, 1874. Isomeric Dibrombenzols.-V. Meyer. The author establishes the difference between the nitro-dibrombenzol of Meyer and Stüber, and that of Riese. Constitution of Certain Substituted Benzols.--C. Wurster and E. Nölting.-The authors describe the preparation of tetra-brom-benzol from tri-brom-aniline, and discuss its supposed constitution. New Property of Glycerin.-R. Godeffroy.-Already noticed. Correction. Eugen Demole.-In the author's method for preparing glycol (Berichte, No. 8, p. 641, 1874) the alcohol should be used, not at 80, but at 91 per cent. Formation of Paralactic Acid by Fermentation. R. Maly. In the author's experiments on the formation of lactic acid by the action of the mucous membrane of the stomach upon various sugars in dilute solution, a small quantity of paralactic acid was simultaneously formed in many, though not all, cases. Its presence was proved by the analysis of the zinc salt. Derivatives of Guanidin.- M. Nencki.-The author descrites formoguanin, its nitrate, hydrochlorate, and double platinum salt; choracetate of guanidin and guanolin. Colouring Matters of Urine of the Indigo Group, and on Pancreatic Digestion.-M. Nencki.-Reserved for insertion in full. Action of Alcoholic Potash-Lye upon DichlorNitro-Benzol.-A. Laubenheimer. The result of the reaction is chiefly tetra-chlor-oxazo-benzol, (C6H3Cl2)2N2O. 1,3 Dichlor-Benzol and its Derivatives.-Otto N. Witt.-The author examines 1,2,4 dichlor-aniline, dichloraniline-chlor-hydrate; 1,3 dichlor-benzol, dichlor-nitranilin, dichlor-nitro-benzol, and dichlor-phenylen-diamin. Dinaphthyl-Methan and some of its Derivatives.Julijan Grabowski.-An account of dinaphthyl-methan; its behaviour with picric acid; tetra-nitro-dinaphthyl-methan ; and dibrom-dinaphthyl-methan. Reduction Products of the Nitro-Benzoic Acids.— P. Griess.-The author gives the name meta-oxy-benzoic acid to the compound C14H10N2O5, which he formerly designated as azo-oxy-benzoic acid. He examines its behaviour with tin and hydrochloric acid, and describes orthazo-benzoic acid, C14H10N2O5. Constitution of the Pseudo-Nitroles.-V. Meyer and J. Locher.-An account of the action of nascent hydrogen upon propyl-pseudo-nitrol; of chromic acid upon the same body; and of dinitro-propan. Allylic Alcohol in Crude Wood-Spirit.-B. Aronheim.-The author announces that he does not intend to continue the investigation of this subject. Notice on Diazo-Amido Compounds.-P. Griess.The two compounds diazo-benzol-amido-brom-benzol and diazo-brom-benzol-amido-benzol are identical. On Nitro-Ethan.-A. Geuther. Boiling-Point of Glycerin.-A. Oppenheim and M. Acid and Phosphorus.-C. Graebe.-Not suitable for abstraction. Difference between the Boiling-Points of Diphenyl and Diphenylen Compounds.-C. Graebe.-The differences, as shown in a table, are about 40° or 41°. On Cyanamid.-E. Mulder.-The author examines the behaviour of cyanamid with oxalic ether, and the action of the former upon alloxantin, the result of which is iso-uric acid. This body is more readily oxidised than uric acid. Urea does not react upon alloxantin, neither does dicyandiamid. Melamin reacts, but without forming iso-uric acid. Hydurilic acid does not decompose alloxantin. Cyanamid: Methods for Desulphurisation.-E. Mulder and J. A. Roorda Smit.-Not suitable for abstraction. Contributions to the History of Cyan-Acetic and Malonic Acids.-J. van't Hoff.-This paper relates to the action of bromine upon cyan-acetic acid, to ethylmalonate of potash, and chloro-malonic ethyl-ether. Dissociation of Sulphate of Copper.-Alex. Naumann.-If a crystal of blue vitriol is exposed, in the vacuum of Hofmann's apparatus for determining the density of vapours, to the temperature of the vapour of boiling alcohol, if the crystal is sufficiently large in comparison with the size of the vacuum, a few spots become white, especially those which receive which the heat first by contact with the mercury or the side of the glass tube. Nitroso-Benzol and Nitroso-Naphthalin.-A. Bayer. As the increase of the tension becomes gradually slower-The author has not yet succeeded in isolating the former and slower, the white spots extend, and arise on parts of body, nor in obtaining the latter in a state of perfect purity. the crystalline surface previously unattacked. But even To prepare the former, he introduces a solution of NOBr after an hour's observation the tension still increases, in benzol into a solution of hydrargyro-phenyl in benzol whilst the white of the parts first attacked becomes a in equivalent proportions. The liquid turns green, dedirty or greenish white, and the crystal is affected to a positing colourless crystals-probably hydrargyro-bromide greater depth. If the crystal is small the whole surface of phenyl-and gives off an odour of oil of mustard. The is at once attacked, but becomes gradually darker again filtered liquid, on distillation in steam, yields a fine green as the tension of the vapour rises. liquid of penetrating odour. The green matter, however, could not be isolated. With tin and hydrochloric acid there was a formation of aniline. On gently heating for a short time with acetate of aniline a deep orange colour appeared, and proportionately large quantities of azobenzol were obtained. Dilute alkalies destroy the green colour, but not the odour. Concentrated hydrochloric acid decomposes the substance with an orange, Preliminary Communication.-W. Spring.-If oxychloride of phosphorus is cautiously added to well cooled chlorite of potash a yellowish green gas escapes, which is readily absorbed by water or potash-lye, but no chlorous acid or chlorite of potash is regenerated, but hypochlorous acid or hypochlorite of potash. The gas was proved not to be chlorine. and concentrated sulphuric acid with an intense violet-red colouration. From the formation of aniline and azobenzol it is highly probable that the green body contains nitroso-benzol. The benzol employed as solvent plays no part in the reaction, since it may be replaced by chloroform or bisulphide of carbon without affecting the result. To produce nitroso-naphthalin hydrargyro-naphthyl was dissolved, with the aid of heat, in 50 parts bisulphide of carbon, and when cold treated with a mixture of bromine and bisulphide of carbon, previously saturated with NO at -20°. Nitroso-naphthalin combines with aniline at once, forming a red substance; in concentrated sulphuric acid it dissolves with a cherry colour; if heated with alkalies and acids it is decomposed; and if dissolved in phenol it yields a blue colour on the addition of sulphuric acid-all phenomena which point to a nitroso derivative. PATENTS. ABRIDGMENTS OF PROVISIONAL AND COMPLETE Improvements in the treatment of sewage, night-soil, and towns'refuse, and like matters to utilise them as manure, and in the production of an artificial fuel to be employed in the said treatment, and for other purposes. William Henry Hughan, Southport, Lancaster. June 5, 1874.-No. 1959. The petitioner throws into closets, sewers, or sewagetanks a preserving powder to prevent decomposition, which he calls the sanitary powder; then he adds a second powder, which causes the manurial products to be precipitated, which he calls the precipitating powder; he then drains off the water by downward filtration, and the residuum is mixed with hot superphosphate manufactured in the usual manner, and in about twenty-four hours becomes a dry sewage phosphate manure or night-soil phosphates. The petitioner forms the above-named sanitary powder of portland cement or like materials, sulphates of soda, magnesia, and potash, mixed in oil (mineral oil preferred) until of a consistency of mortar, and decomposed by sulphuric acid, well boiled, and when dry is ready for use. He also manufactures a powder for the same purpose from material such as kainit and seaweed boiled with clay (china preferred) and soda waste, all reduced to pulp until saponified, the mass being then treated with sulphuric acid. The precipitating powder is formed of portland cement or like material with a little fluor spar mixed, soaked, or set in oil, mineral, or the distilled oil from the carbonisation of coal-ashes hereinafter mentioned, until indurated, and then powdered. For use in dry closets the petitioner forms a powder from the carbonisation of coal-ashes in gas revolving-retorts, the gas and oil being collected. The cinders are separated, and the black ash portion is the powder for closets. The contents of the closets and powder are mixed with animal cement powder, viz., farm-yard manure (or rich street-sweepings or sea-weed) triturated in a mill with diluted sulphuric acid (or plaster of Paris), and further incorporated with clay and quartz or sea-weed until capable of being moulded into bricks, which are dried, calcined, closed from, and then burnt in the open air as cement until all the charring has disappeared: the resuit of the mixture is a rich nitrate manure. The fuel is formed by mixing peat, pulp, sand, and clay with hot Yorkshire or other similar lime, and slaking in closed vessels. The ashes from this fuel form a good portland cement. Improvements in the manufacture of sulphate of potash, and in apparatus employed therefor. Gharles Stuart Gorman, chemist, Irvine, Ayr, N.B. June 6, 1874.-No. 1971. The features of novelty which constitute this invention are:-First. Mixing with chloride of potassium, alkali or chrome waste, lime, and magnesia, as and for the purposes described. Second. Introducing the gases and vapours into the decomposing chamber through a pipe extending throughout the chamber before the gases and vapours are allowed to mix with the chlorides, and terminating the gas inlet-pipe in or about the centre of the top or bottom of the decomposing chamber. Third. The employment of metallic oxides unmixed with the chlorides to promote the oxidation of sulphurous acid before it is introduced into the chlorides under conversion. Fourth. The employment of chlorine to promote the oxidation of the sulphurous acid as and for the purposes described. Fifth. The employment of nitric acid to promote the oxidation of the sulphurous acid as and for the purposes described. Improvements in the treatment of sugar and cane juice. James Duncan, sugar refiner, Mincing Lane, London. June 8, 1874.-No. 1989. The reduction of the glucose in sugar by means of lime and the precipitation of the lime by means of sulphuric acid as herein before described; also the neutralisation of the free acids arising in the course of the foregoing process by means of carbonate of lime. CHEMICAL NEWS, several other agents may be substituted for the bichromate of potash ; aniline black is also obtained by heating this product, or emeraldine, or other insoluble aniline black along with an excess of aniline, and with or without chlorhydrate of aniline or other aniline salt. The product is soluble in alcohol, and may be rendered soluble in alkali or water by heating with sulphuric acid. Improvements in the manufacture of sulphate of soda and sulphate of potash. William Hunt, manufacturing chemist, of Castleford, near Normanton, York. June 10, 1874.- No. 2016. According to this invention the chloride of sodium (common salt) or chloride of potassium, before it is decomposed in the chambers by a mixture of sulphurous acid gas, steam, and air, is made or moulded into layers or blocks, and perforated with a series of holes at short distances apart. By means of these perforations the direct entrance of the gaseous mixture into the interior of the layer or block is secured, greater surface for the gaseous mixture to act upon is produced. and the draught of the gaseous mixture through the chambers is less impeded than when the lumps operated upon are solid. The decomposition of the salt is effected in less than one-half the time required in the ordinary process, and finely ground rock-salt may be advantageoasly employed. Improvements in the manufacture of sulphates, and in apparatus employed therin. James Hargreaves, chemist, and Thomas Kobinson, ironfounder, both of Widnes, Lancaster. June 10, 1874.-No. 2018. This relates to further improvements in and in connection with the patentees' direct action process of producing sulphates of soda and potassa, or either of them. First. For preventing loss of heat by radiation from the sulphurous acid flues, the arch or covering connection between the chambers is lowered, and the connecting pipe between the sulphurous acid flues is laid in the solid brickwork, and the heated gases conveyed through the said connecting pipe. By preference the said cor necting pipe is laid below the circulating pipe at one end of the sulphate chambers. Second. For keeping cool the bearings of rotary exhausting apparatus employed in the manufacture of sulphates we form the bearing brackets hollow at a distance from the sides, and cause a current of water to flow through the said hollow bearings. We also use oil or other lubricant over and over by pumping or raising it, and allowing it flow over the bearings. Third. Instead of using a syphon to take the products of combustion into the chambers when heating chloride with the products of combustion, we employ a cover for the feed-hole of such form that an annular passage is left around the feed-hole, and we cause the products of combustion to flow through the said annular space and through the feed-hole. By reversing the current of gas we cause the remaining sulphurous acid and steam to pass through the said feed-hole and annular opening previous to discharging a chamber. Fourth. For preventing gases from passing through the walls of brick chambers we build into the said walls plates of iron or other metal. Improvements in the treatment of animal charcoal used in the decolorisation of sugar solutions. Charles James Crossfield, and James Barrow, sugar refiners, and Edmund Alleyne Cook, analytical chemist, all of Liverpool, Lancaster. June 10, 1874.-No. 2024. This consists essentially in so treating spent or used charcoal as to produce pyrophosphate therein. Improvements in the manufacture of soft white soap. Gerard Joan Jacobson, Opollo Stearine Works, Schiedam, Holland. June 10, 1874. -No. 2030. A very useful household soap is made of oleine (oleique acid) mixed with soda or kalie lye and hot water in the quantities specified as follows:-2 gallons of distilled oleine, 1 gallon of lye, 5 gallons of hot water. While pouring the hot water into the oleine the mass should be constantly stirred, and at the same time the lye must be slowly dropped in; stirring must be continued until the whole mass has assumed the appearance of a thick yellowish soap without curdles. After twenty-four hours' rest the soap is perfectly white and ready for use. Improvements in preserving fresh uncooked meat and other animal food, and antiseptic m xtures for that purpose. Alexander Herzen, doctor of medicine, Florence, Italy. June 11, 1874.-No. 2032. This invention relates to the preservation of fresh uncooked meat and other animal food in its natural condition, without change of colour or flavour, by immersing it for a time in a solution of a mixture of boracic acid, borax, salt, and saltpetre, and then packing it, preferably in fat of the same kind. THURSDAY, 8th.-Royal Institution, 3. Prof. Seeley, "On the Fossil Quekett Club, 8. Anthropological, 7.30. Royal Institution, 8. Improvement in the preparation of products of aniline, and matters from which aniline is or may be derived, suitable to be used in dyeing and printing, and in the preparation of colouring matters. John FRIDAY, 9th.-Royal Astronomical, 8. Casthelaz, manufacturing chemist, Crumpsall Vale Chemical Works, near Manchester, Lancaster. June 10, 1874.-No. 2009.-According to this invention aniline or nitrobenzine is treated with sulphuric acid in excess, and with bichromate of potash or other oxidising agent with or without heat. From the product a soluble colouring-matter can be extracted, which imparts a brown tint to woollen or other matters, the said brown tint changing to black when the dyed matters are treated with a bath of bichromate of potash, followed by an alkaline bath. Chromic acid, or ammoniacal solution of copper, or salt of copper, and Weekly Evening Meeting. 9. Sir William Thomson, "On Tides." SATURDAY 10th.-Royal Institution, 3- Mr. G. Smith," On the History of Assyria." Physical, 3. Prof. H. M'Leod, "On an Experiment April 9, 1874. 1. Steatite.-A year or more ago I obtained from Mr. The iron found might, in part at least, be due to a trace of iron pyrites, which also occurred in the matrix of the specimen. Neither gold nor copper were present. [C3H5(NO2)303]. By SERGIUS KERN, St. Petersburg. Richard Talling, of Lostwithiel, some small specimens of ON SOME PROPERTIES OF NITRO-GLYCERIN a very pretty pink variety of soapstone. It presented a considerable resemblance to certain pink figure stones from China, but exhibited a rather more saliny lustre in places, while in other spots it was more sub-translucent. Its hardness was above 1 on the surfaces of the plates and fibres of which the mineral consisted, while in a direction at right angles to these fibres the hardness exceeded 2. The specific gravity was 2.70. The mineral, on analysis, proved to be a hydrated magnesium silicate, with mere traces of alumina, iron, and manganese. It contained less than 1 per cent of hygroscopic water; removed either over sulphuric acid in vacuo, or at 100° C. The dry mineral gave the following percentage: Magnesia 32.89 63.18 4'47 100'54 378 100'00 It is a silicate of magnesia, in which one-fourth of the magnesia is replaced by water. Analyses 10, and 12 to 22 in Dana's "Mineralogy," p. 453, referring to similar minerals from different localites, also agree well with the above formula. In other analyses, likewise referred to talc by Dana, the divergences can often be explained on the supposition of the presence of about 1 per cent of hygroscopic moisture, and the replacement of some of the magnesia by ferrous oxide. Some experiments now in progress on saponite, pagodite, and agalmatolite will, I hope, clear up some remaining difficulties connected with the so-called soapstones. 2. Not many months ago I received from Mr. Talling a nearly white crystalline mineral, which I have been unable to identify with any known species. It occurs in short, silky crystals, implanted on a translucent pale green vitreous substance, not unlike allophane. The crystals there have a slight greenish hue resembling that of ferrous sulphate. The quantity received as yet has been sufficient merely for a qualitative examination. The mineral contains much water, some fluorine, and a good deal of silica, and of ferrous oxide. It loses 15.14 per cent of its weight at 100° C., and 20:24 per cent at a red-heat; the total loss thus amounting to no less than 35:38 per cent. 3. Native Gold from Cornwall. Some grains of gold from Ladock gave, on analysis, 92 34 per cent. ICO OO 4. Native Silver.-A beautiful old specimen of native silver from Huel Herland recently came into my posses STUDYING now the properties of some explosive substances, At the following temperatures nitro-glycerin underwent 262°-the most strong explosion. 294°-very feeble explosion, accompanied with a yellowish flame. It is seen from this small table that the explosive properties of nitro-glycerin nearly disappeared at a high temperature. LECTURES ON THE MORPHOLOGY OF AT THE CHEMICAL SOCIETY. By NEVIL STORY MASKELYNE, M.A., F.R.S., &c. (Continued from page 121). LECTURE XII. THE symmetrical system next passing under review was that in which two original planes of symmetry intersect at an angle of 60°. Two such planes will result in a third plane of symmetry inclined on each of them at 60°; and if we first consider the repetitions that, for instance, a pole lying independently on the sphere (that is to say, not engaged with a circle of symmetry) would undergo as the result of the form to which the pole belongs, being symmetrical to these three planes and to a centre, we shall see that it will result in twelve poles, the faces of which would be parallel in pairs and grouped as in Fig. 11, with the form {k} where the spots represent the poles as distributed on one hemisphere, and the eyelets those opposite to them on the opposite hemisphere of projection. It is, however, to be observed that the zone plane perpendicular to the three plane of symmetry itself fulfils the conditions necessary for a potential plane of symmetry. If, now, we call the first three planes of symmetry, S1, S2, S3, and their zone plane the plane C, and if we suppose the plane C to be actually symmetral, the poles of either hemisphere in the last figure will be repeated on the oppo. site hemisphere, as in Fig. 12; and one sees at once that we have a series of systematic triangles, e.g., S3, S2, C, containing each two poles, so disposed that the whole figure will be symmetrical to a new triad of planes 2, viz., 23, 22, 21, which will evidently be inclined each at 30° to two, and at right angles to the third, of the planes S. Thus a symmetrical system, in the former case trigonal in symmetry, becomes a system hexagonal in symmetry without the introduction of any new condition that was not involved in The sphere will be divided, in the latter into twenty-four systematic triangles, with the first case. case, CHEMICAL NEWS,, C. These axes are parallel to the edges of a rhombic in which the only variable element is that single angle at The assignment of symbols to the seven kinds of forms of the system will not be difficult. If we commence by treating the form with faces parallel to the plane C as the parametral plane {111} the poles of the axial planes, X Y, YZ, Z X, will evidently lie on the great circles, S and will have the symbols (001), (100), and (010). FIG. II. their sides, S and E, quadrants, and their angles, so, right angles, while their side C, and their angle =c 30. Hence, the general scalenohedron of this form will have twenty-four faces. The selection of an axial system for hexagonal crystals presents some difficulties. The system adopted by Professor Miller has, however, this advantage, in point of geometrical simplicity, over that of the crystallographers who take four axes, viz., the normals of the planes 2 and C, that the latter have a redundant axial element to deal with; and it further presents the symbols of the forms in the system in a more symmetrical manner than that of an "ortho-hexagonal" axial system proposed by Schrauf, in which the normal to the plane C, and two of the perpendicular axes of symmetry lying in that plane, serve for the axes, the parameters on the two latter being in the relation The pole in which a great circle passing through the poles (111) and (100) would intersect with the zone circle [S] of the planes S and Σ, i.e., the zone circle [1 1 1], is obviously, by the zone rule, (211). While, further, any pole lying on the great circle, S, must fulfil the condition =1, and its symbol will be (hkk}. Since the pole (211) is that of the zone circle E, the symbol of Σ, is seen to be [211], and a pole on this great circle must fulfil the condition h=k=l, 2h-k-l-o, or h=. 2 and by the zone rule the great circles [C] and [E], will intersect in a pole (o 11); and, further, a pole lying on the great circle, [C], i.e., on [II 1], must satisfy the condition p+q+r=0. We have then determined the symbols for each of the different kinds of forms of this system. Thus, recapitulating these results, the general form, the poles of which lie within the systematic triangle, is a twenty-four faced scalenohedron, which we shall term the di-scalenohedron. Its symbol will be {h kl, efg}, where the second member |