112 



CHEMISTRY. 



derivative was prepared which in many respects 

 resembled pentacetyl tannin. 



Some very interesting properties and reactions 

 of the chlorides of selenium are described by M. 

 Chabrie. Treating the tetrachloride as prepared 

 by Berzelius for determination of vapor density, 

 two molecules of the substance were dissociated 

 at 860 C. into one molecule of SejCl 2 and three 

 molecules of chlorine. The subchloride, Se s Clj, 

 is a much more stable body, and may be distilled 

 unchanged at 360 0. Determinations of the 

 density of its vapor yield values closely approxi- 

 mating to 7'95, the theoretical density of a mole- 

 cule of the formula Se 2 Cl a . Other interesting 

 reactions were observed between selenium tetra- 

 chloride and benzine. When the two substances 

 are brought together for reaction, the selenium 

 tetrachloride is decomposed as when it is heated 

 to 360 0., the liberated chlorine reacting with 

 the benzine to form several chlorbenzines, and 

 all the selenium remaining in the form of Sen- 

 da. When the benzine and SeCl 4 are brought 

 together in the presence of aluminum chloride, 

 on treating the mixture with water, separating 

 and distilling the oil obtained, three distinct frac- 

 tions may be collected. The first is monochlor- 

 benzine : the second, at 227-228 C. under a re- 

 duced pressure, consists of phenyl selenide, a yel- 

 low oil of specific gravity 1-45 at 19'6 C. The 

 third fraction, boiling between 245 and 250 C., 

 consists of another new compound, Se 9 (CeH 6 )s- 

 C 6 H 4 C1. It is a red oil, of specific gravity 1-55 

 at 19 - 6 C. On allowing it to stand, it deposits 

 yellow crystals of a compound of powerful odor, 

 which may be obtained recrystallized from alco- 

 hol in long rhombic prisms. This substance is se- 

 leno-phenol, C 8 H 6 SeH, analogous to thiophenol 

 and mercaptan, and in alcoholic solution readily 

 reacts with salts of mercury and silver. 



A new gaseous compound of nitrogen and hy- 

 drogen has been discovered by Dr Theodore Curt- 

 ius, having the composition HN S , and has been 

 called by him, after its derivation, azoimide. The 

 gas dissolves in water with great avidity, forming 

 a solution which possesses strong acid properties, 

 and dissolves many metals, such as zinc, copper, 

 and iron, with evolution of hydrogen gas and 

 formation of nitrides, the metal taking the place 

 of the liberated hydrogen. In view of this prop- 

 erty, the name azoimide is regarded as not 

 sufficiently descriptive, hence Prof. Curtius 

 proposes instead Stickstoffwasserstoffsaure, for 

 which the nearest English equivalent would be 

 hyrazoic acid. HN 3 possesses a fearfully pene- 

 trating odor, produces violent catarrh, and re- 

 sembles hydrochloric acid in its affinity for water. 

 Having isolated the new substance, Prof. Cur- 

 tius and Herr Radenhausen have found it to be 

 a clear, colorless, and very mobile liquid of phe- 

 nomenally explosive nature. The liquid pos- 

 sesses the intolerable odor of the gas and the 

 aqueous solution. It mixes readily with water 

 and alcohol. It boils when the operator is so 

 fortunate as to carry out a distillation in safety 

 without decomposition at 37 C. But it ex- 

 plodes with extraordinary violence when sud- 

 denly heated or when touched with a hot body, 

 and also sometimes without apparent provoca- 

 tion at the ordinary temperature, with produc- 

 tion of a vivid blue flame. 



The new peroxide of sulphur, S04, discovered 



by Traube, of Berlin, is obtained when solutions 

 of sulphuric acid containing at least 40 per cent, 

 of acid are subjected to electrolysis as a crystal- 

 line deposit upon the anode. It is not the anhy- 

 dride of an acid, but a neutral oxide of a simi- 

 lar character to hydrogen peroxide. In water it 

 parts with its oxygen readily and is reduced to 

 ordinary sulphuric acid. It is stable in a mod- 

 erately concentrated solution of sulphuric acid. 

 It is but a weak oxidizing agent, but imder cer- 

 tain circumstances acts as a powerful reducing 

 agent. 



Two gaseous fluorides of carbon, the tetrafluor- 

 ide, 0*4, and the difluoride, C a P 4 , have been 

 isolated by M. Moisson and M. Chabrie. Fluor- 

 ine directly attacks carbon with varying degrees 

 of energy, according to the form in which the 

 carbon is presented. Pure lampblack instantly 

 becomes incandescent throughout. The action 

 on the other forms of carbon is slower in propor- 

 tion to their density, and in the harder varieties 

 has to be assisted at first by the application of 

 heat. The products of combination are gener- 

 ally gaseous mixtures of the two fluorides. The 

 tetrafluoride is a colorless gas that liquefies un- 

 der a pressure of five atmospheres at 10 C, is ab- 

 sorbed and decomposed by an alcoholic solution 

 of potash into potassium fluoride and carbonate, 

 and is slightly soluble in water and more readily 

 so in carbon tetrachloride, alcohol, and benzine. 

 The most convenient way of preparing it depends 

 on the reaction of silver fluoride and the vapor 

 of carbon tetrachloride. A gas obtained by al- 

 lowing fluorine to stream through red-hot car- 

 bon appears to be the C a F 4 described by M. 

 Chabrie. 



Fluoride of methyl, CH S F, obtained by MM. 

 Moisson and Merlaus by the action of methyl 

 iodide on fluoride of silver, is a gas that liquefies 

 at ordinary temperatures under a pressure of 

 32 atmospheres, is slightly soluble in water, and 

 more readily so in methyl iodide or methyl alco- 

 hol, is very stable, and saponifies with great dif- 

 ficulty, lit is also obtained, but of inferior puri- 

 ty, by the action of pentafluoride of phosphorus 

 on methyl alcohol. 



Another fluoride of methyl, isobutyl fluoride, 

 C 4 H 8 F, prepared by the action of isobutyl iodide 

 upon silver fluoride, is colorless, and in the liquid 

 condition mobile, and boils at 16 C. The gas 

 burns on ignition with deposition of carbon and 

 the formation of clouds of hydrofluoric acid. 

 It does not attack glass. M. Moisson has pre- 

 pared by means of the reaction of silver fluoride 

 with the iodides of the corresponding organic 

 radicles the fluorides of methyl, ethyl, propyl, 

 and butyl, and finds them in each case mo're 

 stable than the analogous chlorine compounds. 



Methylene fluoride, CH a F a , prepared by M. 

 Chabrie, is a gas obtained by heating methylene 

 chloride with silver fluoride, has a deri3ity as 

 compared with air of 1'82, and is absorbed by 

 alcoholic potash. It completes a series of which 

 the chlorine, bromine, and iodine members have 

 long been known. M. Chabrie has found that 

 hard Bohemian glass tubes may be used in these 

 reactions with silver fluorides, for with them the 

 corrosion is so insignificant that for practical 

 purposes it need not be regarded. 



Boron iodide, BI 3 , is prepared by M. Moisson 

 by three methods, the most convenient of which 



