520 Prof. Wohler on inflammable Siliciuretted Hydrogen. 



ammonia, for hydrosulphide of sulphide of ammonium, and for 

 cyanide of ammonium ; and Gerhardt had explained the abnor- 

 mal condensation to 8 vols, exhibited by the body C^ CI''' 0^, 

 obtained by the action of chlorine on methylic aether, by assu- 

 ming that that density was not the density of its vapour, but 

 the density of a mixture of phosgene gas, C^CFO^= 4 vols., 

 and the chloride of carbon, C^ Cl'*= 4 vols., which might have 

 been formed. 



Wohler has described a method* by which the preparation of 

 inflammable siliciuretted hydiogisnt, hitherto only formed by 

 the aid of the galvanic current, is effected by a purely chemical 

 process, and as readily as is that of.phosphuretted hydrogen. 



40 grms. of fused chloride of magnesium, 35 grms. of well- 

 dried silicofluoride of sodium, and 10 grms. of fused chloride 

 of sodium are finely pulverized in a hot mortar, well mixed, 

 and then placed in a stoppered bottle. 20 grms. of sodium 

 in small pieces are then added, and mixed with the powder 

 by being well shaken. At the same time a Hessian crucible is 

 raised to a full red heat, and the above mixture projected into it, 

 the crucible rapidly covered, and the heat somewhat raised. 

 When the action is over, and no more sodium flames issue 

 from the lid, the crucible is taken out, allowed to cool, and 

 broken. The result is a fused, blackish-gray slag, contain- 

 ing metallic, lustrous lamellae and beads. This slag serves 

 directly for the preparation of the gas. A slag which yields a 

 spontaneously inflammable gas may also be prepared by taking 

 other than the above proportions; and also when, instead of 

 silicofluoride of sodium, a mixture of cryolite and water-glass is 

 used; or instead of chloride of magnesium, fused chloride of 

 magnesium and sodium. 



To generate the gas, some of this slag coarsely pounded is 

 placed in a small two-necked bottle, into one neck of which tits 

 a i'unnel-tube reaching nearly to the bottom, and into the other a 

 short and somewhat wide gas-delivery tube. The bottle is quite 

 filled with water, and placed under the surface of the water in 

 the pneumatic trough, so that the delivery-tube is also filled with 

 water, and no air remains. A gas-jar filled with water is jilaced 

 over the delivery-tube, and concentrated hydrochloric acid gradu- 

 ally added through the funnel-tube, care being taken that no air- 

 bubbles are passed in at the same time. The gas is generated 

 with great violence, and a thick foam is carried along with it into 

 the jar, which, however, gradually settles down, so that the gas 

 may be ti-ausferred from one jar to another. The whole opera- 



* Liebig's Annalen, July 18.58. 



t Phil. Mag. August 1857, June 1858. .._j 



