Page images
PDF
EPUB

I. Serpentine from Porthalla Cove, mostly associated with hornblende schist; a. greyish-green and granular, sp. gr. 2·65; b. dark green, sp. gr. 2-56; c. reddish-brown and granular, sp. gr. 2·545; d. dark red, sp. gr. 2.644. II. Hornblende from the Porthalla hornblende-schist. III. Plagioclase (anorthite) from the same rock, slightly weathered. B. H. B.

Microscopic Crystals of Albite in Calcareous Rocks of the Western Alps. By C. LORY (Compt. rend., 105, 99-101).-The author has shown many years ago that the dolomites and limestones of the triassic formation of the Western Alps contain microscopic crystals of albite, often accompanied by bipyramidal quartz and lamellæ of mica. The albite crystals are better developed the more crystalline the limestone in which they occur, but the occurrence of the crystals is not necessarily connected with the general crystalline character of the triassic beds.

The limestones of the lias are not crystalline with the exception of the liassic marble at Villete, which contains crystals of albite, but this is an exceptional deposit and rests directly on the trias. Albite crystals are also found in a very compact, white, nummulitic limestone in the bed of Montricher, near St. Jean de Maurienne.

The genesis of these albite crystals, which has taken place chiefly in the triassic limestones of the Western Alps, has also occurred exceptionally in middle lias and eocene beds. The formation of the crystals is connected with the special nature of the deposits in which they are found and the conditions which have favoured the crystallisation of the latter. C. H. B.

Composition of Volcanic Rocks. By L. RICCIARDI (Gazzetta, 17, 141-154).-The results of analyses of the volcanic rocks of Italy show that their composition is modified by successive eruptions. Thus the eruptive matter emitted from submarine volcanoes in past times was of an acidic nature, and contained about 73 per cent. of silica, but this has gradually changed to a basic character, and now contains only about 48 per cent. of silica. Several examples of this gradual modification are adduced. On the other hand, Etna and Vesuvius, which are always more or less active, have emitted within the last three centuries a product of constant composition, of the basic type. In order to explain this conversion from the acidic or trachytic form into the basic, which is especially exemplified in the case of the submarine volcanoes of Euganei and Pantelleria, the author suggests that the change is brought about by a reaction between the solid constituents of the Mediterranean Sea and the primordial rock. Thus, within the volcanoes, the chlorine is converted into hydrogen chloride by the dissociation of the water, and the radicles SO, and CO, are emitted as sulphurous and carbonic anhydrides, whilst the remaining constituents react with and modify the original rock. In this paper, it is shown that if a typical substance compounded of the fixed residue of the Mediterranean is compared with an argilliferous pliocenic marl, then this substance, mixed in proportions successively decreasing from 50 to 1 with one

proportion of an original trachytic rock as pantellerite, would give products of percentage composition similar to those of the various typical rocks from more recent to more ancient times. For the present, these considerations are limited to the volcanic rocks of Italy, as better studied than other examples, although geological evidence tends to show that similar phenomena occurred in the granitic plateau of central France and in Hungary. Further analyses of the matter emitted in recent eruptions of volcanoes situated in various parts of the world show that the first substance elaborated is always granite. V. H. V.

Meteorite at Djati Pengilon, Java. By DAUBRÉE (Compt. rend., 105, 203-207).-This meteorite fell on March 19th, 1884, and weighed 166 kilos. It possesses a high tenacity, and does not readily break under the hammer. The fractured surface shows a remarkably large number of small cleavage faces, and resembles certain finegrained felspathic rocks; the crust is not firmly adherent. Mean sp. gr. of the meteorite 3·747.

According to an analysis by Retgers, it consists of nickeliferous iron, 213; triolite, 51; olivine, 334; bronzite, 390; and chromite, 0.1 per cent. The metallic portion consists of iron, 88-68; nickel, 10.78; and cobalt, 0.54 per cent. Thin slices of the meteorite are transparent, but contain opaque and tuberculous granules. olivine and bronzite both contain inclosures.

The

This meteorite belongs to a somewhat rare type, and is identical in lithological character with one which fell at Tjabé, a neighbouring place, on September 19th, 1869. C. H. B.

α

Organic Chemistry.

Solid -Dichlorethyl Cyanide and its Conversion into Triethyl Cyanuride. By R. OTTO and K. VOIGT (J. pr. Chem. [2], 36, 78-98). This compound melting at 73-74° was first obtained together with its liquid isomeride by Otto. It crystallises in the clinorhombic system. The lower the temperature at which the chlorination of the propionitrile is carried out, the larger the quantity formed. It would seem to be a polymeride of the liquid compound, the polymerisation being in all probability produced by the hydrogen chloride formed during the chlorination. It is doubtful whether the hydrogen chloride acts mechanically, or really first forms a compound with the liquid cyanide which then breaks up yielding hydrogen chloride and the solid compound. Sulphuric acid does not cause polymerisation. Both the liquid and solid nitriles are converted into a-dichloropropionic acid when heated with moderately strong sulphuric acid. Alcoholic ammonia at 95° converts the solid cyanide into a-dichloropropionamide. Nitrous anhydride has no action on it. When treated with alcohol, zinc and acetic acid, the solid cyanide yields triethyl cyanuride, CN,Ets. This substance crystallises in long, hexagonal

prisms, melts at 29°, volatilises at ordinary temperatures, and boils at 193-195°. Its vapour-density corresponds with the formula, C9H15N3. It is easily soluble in alcohol, ether, and chloroform, sparingly in water, and has an odour resembling that of opium. The aqueous solution is neutral, has a burning taste, and becomes milky when slightly warmed. It is easily soluble in strong hydrochloric acid, and this solution yields a platinochloride. When heated with hydrochloric acid, the cyanuride is decomposed into ammonia and propionic acid.

E. v. Meyer has lately shown (this vol., p. 364) that the compound which has hitherto been called cyanethine is not really a cyanuric compound, but contains an amido-nitrogen-atom. It is therefore probable that the above compound is the true cyanuric compound, and the original compound would then be tri-dichlorethyl cyanuride, CCl,Me CN C(CCI,Me) N:C(CCI,Me)»N. The yield of the non-chlorinated compound was only about one-third of that theoretically possible. When, in the reduction experiment, the alcohol is mixed with water, a base, C9H16N2, is obtained. This crystallises in silky needles or plates, melts at 111°, boils at 273°, but is not volatile in steam. It has an intensely bitter taste, is readily soluble in alcohol, ether, and chloroform, sparingly in water. Its aqueous solution is strongly alkaline, and it is a monacid base. Its hydrochloride forms colourless needles, its platinochloride doubly refractive orange crystals; and its silverderivative white flocks. L. T. T.

Action of Acids on Thiocyanic Acid. By P. KLASON (J. pr. Chem. [2], 36, 57—64).—It is generally stated that thiocyanic acid is decomposed by acids, yielding either perthiocyanic acid and hydrocyanic acid or carbon oxychloride. The author finds, however, that often, under the action of acids, it yields dithiocarbamic acid, its anhydride or bisulphide. When a strong solution of thiocyanic acid contains little or no mineral acid, it is decomposed into perthiocyanic and hydrocyanic acids. A dilute solution is stable either with or without mineral acid. A strong solution in the presence of a large excess of hydrochloric acid gives off carbon oxysulphide, carbonic anhydride, and a little carbon bisulphide, whilst thiocarbamic bisulphide, S2(CS NH2)2, is formed, The same compound is produced when hydrogen sulphide is passed into a solution of thiocyanic acid. If sulphuric acid is substituted for hydrochloric acid, carbon oxysulphide is evolved, and a mixture of dithiocarbamic anhydride, S(CS.NH2)2, and thiocarbamic bisulphide is produced. When warmed with water, these substances yield sulphur, carbon bisulphide and ammonium thiocyanate. With aniline, monophenylthiocarbamide and its thiocyanate, diphenylthiocarbamide, ammonium thiocyanate, sulphur, and hydrogen sulphide are formed.

Dry hydrogen chloride has scarcely any action on dry potassium thiocyanate, but if the salt be moist, thiocarbamic chloride, Cl-CS-NH2, is formed. This is a white, crystalline substance which volatilises without fusing. It dissolves in water, the solution containing hydrochloric and thiocyanic acids in molecular proportion.

L. T. T.

Crystalline Form of Quercin. By C. FRIEDEL (Compt. rend., 105, 95-96). The crystals were prepared by Vincent and Delachanal (this vol., p. 909), and are very brilliant, anhydrous, monoclinic prisms the dominant faces being m, and the other faces p and b, the latter sometimes truncating the edges mp, sometimes being so largely developed that the base of the prism almost disappears. The following measurements were made: mm, 116° 5'; mg, 31° 57′5′; pba, 44° 11'; pm 75° 47′; mb3, 60° 2′; b1b1, 75° 2′. From these numbers it follows that

[blocks in formation]

The inclination of the edge h to the inclined diagonal is 62° 21′, and the angle of the base is 57° 50'. Extinction takes place along the plane g', which is not parallel with the edges mm but makes with them an angle of about 30°.

C. H. B.

Comparative Sweetness of Cane- and Starch-sugar. By T. SCHMIDT (Bied. Centr., 1887, 504).-Experiments proved that 1-53 parts of pure grape-sugar was as sweet as 1 part of pure beet- or caffe-sugar. E. W. P.

Decomposition of Saccharose by Boiling with Lime. By W. NIEDSCHLAG (Bied. Centr., 1887, 488-489).-As it is a known fact that the yield of crystalline saccharose is less after the crude sugar has been boiled with lime, 250 grams of saccharose were dissolved in 1500 c.c. water, 250 grams slaked lime added, and the whole boiled for 21 days, the result was that most of the sugar was decomposed, and a non-crystalline calcium salt formed containing 20-5 per cent. calcium. Another experiment made for 24 hours with lime, strontia, and baryta, when a water-bath was used, and air excluded, and carbonic anhydride passed in, showed that here again the sugar was decomposed but not to the same extent.

E. W. P.

Substituted Methylenediamines. By A. EHRENBERG (J. pr. Chem. [2], 36, 117-131).-Kolotoff, by the action of trioxymethylene on diethylamine, obtained tetrethylmethylenediamine: this base and its lower homologue could not be prepared by Hofmann's reaction, employing methylene iodide and the corresponding secondary monamine, owing to the fact that the salts of the methylenediamines are extremely unstable, and decompose into trioxymethylene and the hydriodide of the base originally employed. Tetramethylmethylenediamine also could not be obtained by Kolotoff's reaction, but higher homologues were prepared by its means.

Tetrethylmethylenediamine dissolves to the extent of 1 part in 10 parts of water, and on treatment with dilute acids, with perfectly dry hydrogen chloride, and with alcoholic solutions of platinic chloride and of oxalic acid, yields the corresponding salts of diethylamine, whilst prolonged boiling with moist ethyl iodide converts it into tetrethylammonium iodide. When dry carbon bisulphide is added to the dry

base, a molecular compound, CH2N2Et, CS2, is obtained, which boils at 130-140° with decomposition; if, however, the materials are not quite anhydrous, diethylamine diethyldithiocarbamate is formed.

Tetrapropylmethylenediamine, CH2: N2Pr, is formed when trioxymethylene is heated with the calculated quantity of dipropylamine. It boils at 215-225° with slight decomposition, does not solidify in a freezing mixture of ice and salt, is sparingly soluble in water, readily soluble in alcohol, ether, and chloroform, and yields salts with platinic chloride, gold chloride, and trinitrophenol, which, however, could not be obtained in a state suitable for analysis.

Tetrisobutylmethylenediamine, CH2 : N2(C1H,)., prepared in a manner similar to the preceding compound, boils at 245-255° with slight decomposition. The platinochloride, CHN2,H,PtCl, is a fawncoloured, crystalline powder, melts at 196-198° with decomposition, and when heated to boiling in aqueous solution decomposes into the platinochloride of diisobutylamine. The aurochloride is a yellow, crystalline powder, and melts at 185-195° with decomposition. With dry carbon bisulphide, the base forms a molecular compound, CH3N2, CS2, which on standing crystallises in large scales, melts at 54°, and in solution stains the skin yellow.

Dipiperidylmethane, CH2(NC,H10)2, obtained in like manner from piperidine, boils at 230° without decomposition, has a sharp peppermint-like odour, and on treatment with aqueous acids decomposes into trioxymethylene and piperidine. Perfectly dry hydrogen chloride converts the dry base, dissolved in light petroleum, into the hydrochloride if the action is continued only for a short time: this is a white powder which, when separated and dried in an atmosphere free from moisture, contains an amount of hydrogen chloride intermediate between 1 and 2 mols. HCl; the continued action of the gas, however, results in the formation of piperidine hydrochloride. A molecular compound, C1HN2, CS2, is obtained on the addition of dry carbon bisulphide to the dry base; this melts at 58°, is soluble in alcohol and ether, insoluble in water, and on treatment with iodine in alcoholic solution is converted into piperidylthiuram bisulphide, (CS-NC5H10) 2S2, which melts at 130°, and is soluble in alcohol and ether, insoluble in water. Moist carbon bisulphide converts the base into piperidine piperidyldithiocarbamate melting at 174°.

Dipiperidylphenylmethane, CHPh(NCH)2, has been prepared by Klotz by the action of benzaldehyde on piperidine. It crystallises from alcohol in large, flat needles, melts at 78-79°, and is extremely soluble in benzene, carbon bisulphide, ether, chloroform, toluene, and light petroleum. On distillation in a vacuum, or on exposure to a moist atmosphere, it decomposes with the formation of benzaldehyde. W. P. W.

Derivatives of Chlorinated Methyl Formate. By W. HENTSCHEL (J. pr. Chem. [2], 36, 99-113).-In the dark, chlorine acts only very slightly on methyl formate even at the boiling point, but in sunlight action is rapid at ordinary temperatures. If the current of chlorine is continued as long as the gas is absorbed, trichloromethyl chloroformate, Cl.COO CCl3, is the main product. This boils at 127.5—128°, and has a sp. gr. 1-6525 at 14°. Its vapour-density is 6·636 (air = 1).

« PreviousContinue »