140 Scientific Intelligence. 



SCIENTIFIC INTELLIGENCE. 



I. CHEillSTRY AND PHYSICS. 



1. A new oxyd of Silicon, — Wohler lias comniunicated to tbe Academy 

 of Sciences a brief notice of a new oxyd and cblorid of silicon, AVhile 

 occupied with the study of the conducting power of aluminum for the 

 galvanic current, Wohler and Buff observed that when a plate of this 

 metal is made the positive pole in a solution of chlorid of sodium, a gas 

 is disengaged which takes fire spontaneously in the air. Supposing that 

 the silicon contained in the alumiiuim had something to do with the 

 phenomenon, the authors sought to prepare the gas by purely chemical 

 means. By heating silicon to redness in a current of dry chlorhydric 

 acid gas the acid was easily decomposed, hydrogen being evolved and a 

 new chlorid of silicon produced. This is a fuming, very mobile liquid, 

 more volatile Ihan the ordinary chlorid, SiCls. It is decomposed by 

 water into chlorhydric acid and a new oxyd of silicon. This latter is a 

 white matter, slightly soluble in water, and very soluble in altali, even in 

 ammonia, disengaging hydrogen gas with effervescence, and becoming 

 converted into silicic acid. Heated in the air it tatesfire and burns with 

 a very white light, disengaging hydrogen, which takes fire. The authors 

 are studying the constitution of the "new chlorid and oxyd, — Comptes 

 Mend us, xliv, 834. 



2. On the artificial production of Glycerine. — Wurtz has succeeded in 

 preparing glycerine artificially from the tribromid of allyl, CsHsBra, 

 which is obtained by the action of bromine upon the iodid of allyl, CeHsI, 

 iodine being set free. The bromid is a heavy colorless liquid which at a 

 temperature below 10° C, crystallizes in beautiful colorless prisms. By 

 the action of this bromid dissolved in acetic acid upon acetate of silver 

 an oily liquid was obtained boiling at 268° C, neutral, colorless, and 

 heavier than water. This liquid is triacetine, CisHuOis. By saponifica- 

 tion with baryta- water, acetate of baryta and glycerine were formed. The 

 latter was identified by its properties and by analysis. — Comptes Rendus^ 

 xliv, 780. 



3. Preparation and properties of Manganese, — Bhunnkr has prepared 

 metallic manganese by the action of sodium upon fluorid of manganese. 

 The materials are mixed and pressed together in a Hessian crucible, the 

 mixture covered with a layer oi chlorid of sodium and this with a layer 

 of fluor spar in pieces of tlie size of a pea. The crucible is covered, 

 placed in a forge and heated gently. The reduction takes place before 

 the crucible becomes red hot, and_is indicated by a hissing noise and 

 yellow flame. The heat is then raised nearly to whiteness and the whole 

 is allowed to cool slowly. The metal is found as a fused mass. Manga- 

 nese as thus prepared possesses properties very diflx^rent from those usually 

 attributed to this metal. Its color is that of cast iron; it is very brittle 

 and extremely hard, scratching the best tempered steeh It takes the 

 most perfect polish and does not change in moist air at common temper- 

 atures: polished specimens were kept two months in the laboratory with- 

 out change. The density of this manganese varied from Y'lSS to 7*206. 

 It is not attracted bj the magnet and has no action on the magnetic 



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