212 ANNUAL OF SCIENTIFIC DISCOVERY. 



melts in a crucible of carbon before the oxyhydrogen blowpipe at a temper- 

 ature at which rhodium fuses ; but the fused mass contains 4*5 per cent, of 

 carbon. It has a silvery lustre, and scratches glass and topa/ with ease. 

 Tungsten appears to be even less fusible. Comptes Rendus, xlvi, 1098 



ON THE PREPARATION OF CALCIUM. 



Lies Bodart and Gobin have communicated to the Academy of Sciences a 

 note on the preparation of calcium, which is of much interest. The author 

 found it impossible to obtain the metal by the action of sodium upon chlorid 

 of calcium at a high temperature, but the reduction succeeds extremely well 

 when the iodid is employed instead of the chlorid. The iodid of calcium 

 was obtained by the action of iodhydric acid upon white marble, evaporating 

 the solution and fusing the salt out of contact of air. As thus prepared it 

 resembles chlorid of magnesium. Equal equivalents of sodium and iodid of 

 calcium are to be mixed and gradually heated in a covered iron crucible to 

 a strong red but not to a white-red heat. After an hour the crucible is to be 

 removed from the fire and allowed to cool. In this manner the author 

 obtained a button of calcium weighing about three grammes, by employing 

 four grammes of sodium. The metal was pale yellow with a reddish reflec- 

 tion, and proved, on analysis, to be pure. The authors promise more ample 

 details with respect to the properties of calcium, as well as a notice of their 

 results in reducing barium and strontium by a similar process. Comptes 

 Rtndus, xlvii, 23. 



NEW FACTS RESPECTING ALUMINUM. 



It has generally been stated that aluminum could resist the highest tem- 

 perature without absorbing oxygen ; but we now learn, that if the temperature 

 be raised from a white to a welding heat, aluminum will burn with great in- 

 tensity until a stratum of alumina is formed upon its surface sufficiently 

 thick to exclude the atmosphere. As regards alloys, that made with iron is 

 not malleable, but will crystallize. An alloy of 100 parts of aluminum and 

 3 of nickel is more fusible and harder than the pure metal. Bismuth forms 

 with aluminum in the proportion of one to three, an alloy which is very fusi- 

 ble, but also very subject to oxidation when in a state of fusion. If two 

 equivalents of aluminum and one of oxide of lead be exposed to a white 

 heat, a violent detonation ensues, the crucible breaks into pieces, and even 

 the doors of the furnace are driven to a distance. Similar effects occur with 

 oxide of copper, or the sulphates of potash or soda. Aluminum is now much 

 used for jewelry, especially bracelets, pins ; and combs ; in cabinet-making, 

 it is excellent for inlaid work ; its lightness renders it extremely convenient 

 for pencil-holders, thimbles, seals, small statues, medallions, vases, and the 

 like; for spectacles, as it does not blacken the skin like silver. But one of its 

 most useful applications consists in using it for reflectors of gas-lamps, since 

 it resists the effects of sulphurous emanations, which silver and brass do not. 



Mr. Gerhard, of London, has recently patented a simple and economic pro- 

 cess for obtaining the metal, whereby it is produced at a considerably less 

 expense than by the means heretofore practised. In this process hydrogen 

 gas combines in an oven with the fluoride of aluminum, and forms hydro- 

 fluoric acid, which acid is taken up by iron, and is thereby converted into 

 fluoride of iron, whilst the resulting aluminum thus obtained remains in the 

 metallic state in the bottom of trays containing the fluoride. 



