106 



CHEMISTRY. 



The question of how and under what circum- 

 stances sulphur will crystallize from substances 

 containing it, was referred to in a recent mur- 

 der trial at Versailles. The victim had been 

 poisoned, it was said, by lucifer matches. The 

 chemist stated, that after a scrupulous exami- 

 nation of the exhumed matter (interred two 

 years) he had failed to detect phosphorus, prob- 

 ably volatilized or oxidized long ago, but he had 

 separated several pieces of melted sulphur, 

 which he exhibited. From these facts he con- 

 cluded that chemical matches must have been 

 present, for these traces of sulphur, though 

 very small, could not occur in culinary or 

 pharmaceutical preparations. The question 

 was then put did he not know that sulphur 

 similar to that which he had exhibited was 

 found in deposits of fecal matter which had un- 

 dergone a certain fermentation in the air ? and 

 upon this point, the finding of sulphur perfectly 

 crystallized or in concreted masses, in the old 

 deposits in the sewer of Montfaucon, was cited ; 

 the specimens of sulphur here referred to are 

 preserved in one of the public museums. Great 

 doubt was thus thrown upon the source of the 

 sulphur; indeed, judging from the chemist's 

 evidence, he would appear to have argued far- 

 ther than the experimental data justified him 

 in doing. The prisoner was acquitted. 



Industrial Preparation of Oxygen. M. Gon- 

 dolo has made some improvements in M. Bous- 

 singault's process of extracting oxygen from the 

 air by means of baryta. M. Boussingault, in 

 1852, found that in passing a current of air over 

 baryta, heated to dull redness, oxygen was sub- 

 tracted from the air, and binoxide of barium 

 formed, and that, upon then raising the heat to 

 bright redness, the oxygen was set at liberty so 

 easily that the oxygen might be first absorbed 

 and then evolved ad infinitum. M. Gondolo 

 has made, hi carrying out the details of the 

 process, certain changes which admit of oxygen 

 being prepared upon a manufacturing scale. 

 For the porcelain tubes he substitutes iron ones, 

 which may be made either of wrought or cast 

 iron. Internally a coating of magnesia is ap- 

 plied, and externally asbestos, so as to diminish 

 the porosity of the tube and the consumption 

 of fuel. These tubes are arranged in a brick 

 furnace having dampers, by means of which the 

 temperature may be changed at will, and dull 

 redness and bright redness easily obtained. To 

 the baryta a mixture of lime, magnesia, and a 

 small quantity of manganate of potash is added; 

 this prevents fritting of the material. M. Gon- 

 dolo says that he has made one hundred and 

 twenty-two alternate operations, and that the 

 atmospheric oxygen and nitrogen are easily 

 separated upon an industrial scale ; the appa- 

 ratus has been at work during six months, and 

 fulfilled its purpose thoroughly. The process 

 is patented. (Pm Cor. of Chemical News.) 



Oxy chloride of Silicium. KM. Friedel and 

 Ladenburg have reported to the French Acad- 

 emy their discovery of this compound. In 

 passing chloride of silicium through an empty 



porcelain tube, or one filled with fragments of 

 felspar, heated to a temperature approaching the 

 point of fusion for that mineral, and distilling, 

 they observed that the product condensed at 

 the extremity of the apparatus was a liquid 

 less volatile than the chloride. By repeating 

 the operation a great number of times with the 

 more volatile portions, a notable amount of a 

 liquid boiling above 70 is obtained. This 

 product submitted to fractional distillation is 

 easily separated into chloride of silicium and a 

 liquid chiefly boiling between 136 and 139. 

 Limpid and fuming in the air, this liquid bears 

 great resemblance to chloride of silicium ; it is 

 likewise decomposed by water energetically. 

 Analyses were made by introducing weighed 

 bulbs, full of the liquid, into flasks containing a 

 certain quantity of water ; breaking the bulbs 

 afterward, almost the whole of the silica, when 

 sufficient water was present, remained in solu- 

 tion. The acid liquid, saturated with ammonia, 

 was evaporated on the water-bath ; the residue 

 dissolved in water and filtered gave on the one 

 side silica mixed with the glass of the bulb, on 

 the other a solution in which the chlorine was 

 determined. The numbers obtained lead to the 

 formula Si 2 OCl 6 , from which the new body is 

 seen to be an oxychloride of silicium. 



Iodide of Silicium. Mr. M. 0. Friedel has 

 given to the Chemical News the result of his 

 recent studies of iodide of silicium. He makes 

 it by the following process: In a tube he 

 places crystallized silicium. The tube is 

 heated to redness, and through it is passed 

 the vapor of iodine, along with a completely 

 desiccated carbonic' acid. If the distillation of 

 iodine is rapid, or if the silicium does not fill 

 the tube, the product obtained is mixed with 

 much iodine. But with a tube of sufficient 

 length, and the exercise of caution, the crys- 

 tals sublimed in the cool part of the tube will 

 be white, and the liquid proceeding from their 

 fusion yellowish. The product thus obtained, 

 purified when necessary from iodine, by solu- 

 tion in sulphide of carbon and agitation with 

 mercury, may be distilled in a current of car- 

 bonic acid without decomposition. Not so in 

 the air, where its vapor, on being heated, 

 catches fire, and burns with a red flame, emit- 

 ting much iodine vapor. The product, distilled 

 in carbonic acid, is colorless, or slightly yellow- 

 ish. Its boiling-point is 290, and at 120.5 it 

 solidifies and crystallizes into a mass, having a 

 watered appearance (moire) which is nearly 

 always rose-colored, owing to a slight decom- 

 position which takes place at the moment the 

 tube is sealed. In those parts of the vessel 

 which were merely moistened by the liquid, 

 dendrites are formed analogous to those of 

 chlorhydrate of ammonium. The crystalline 

 form of iodide of silicium is cubic, and it may 

 be obtained either by sublimation, evaporation, 

 or refrigeration of its solution, in small regular 

 octahedra or groups of octahedra, which are 

 transparent, colorless, and incapable of action 

 on polarized light. 



