452 M. Berthelot on Polymers of Acetylene. 



gas, which is siliciuretted hydrogen. Neglecting the first portions 

 of gas thus disengaged, siliciuretted hydrogen was obtained in a 

 state of purity. Some of this was collected over mercury, and 

 potash passed up to it, by which it was decomposed into hydro- 

 gen and silica. From the increase in volume the formula Si H 4 

 = 2 vols, was deduced. 



The siliciuretted hydrogen thus obtained is not spontaneously 

 inflammable in the air at the ordinary pressure. Yet some of 

 the gas placed in a tube in which was a column of mercury suf- 

 ficiently long to materially diminish the pressure, takes fire in 

 contact with a bubble of air, and gives a deposit of brown amor- 

 phous silicon mixed with silica. ■ In this respect siliciuretted hy- 

 drogen resembles phosphuretted hydrogen. Hence it is that the 

 gas is sometimes spontaneously inflammable and at others not, 

 and even that the impure gas may appear more inflammable 

 than the pure gas. 



The authors have also investigated the product formed by the 

 action of water on the chloride SiCl 3 H. From their analyses 

 and those of Wohler they deduce the composition Si 2 H 2 O 3 . 



Wohler had already thrown out the idea that the series of 

 bodies he had described might have constitutions analogous to 

 organic bodies, silicon playing the part of carbon. This point 

 of view is put in the clearest light by the results of the present 

 investigation : thus the chloride SiCl 3 H corresponds to chloro- 

 form, GCPH; the ether, SiH(€ 2 H 5 0) 3 , to Williamson and 

 Kay's tribasic formic ether, Q H (C 2 H 5 O) 3 ; siliciuretted hydro- 

 gen, Si H 4 , to marsh-gas, G H 4 ; the body Si 2 H 2 O 3 to formic an- 

 hydride, C 2 H 2 O 3 , if it existed. 



These comparisons may furnish a convenient nomenclature for 

 all the series of bodies in question. It would be sufficient to 

 prefix to the names of their analogue in the carbon series the 

 word silici ; thus we should have silicichloroform, siliciformic an- 

 hydride. 



Acetylene, € 2 H 2 , differs from oxalic acid, € 2 H 2 4 , only by 

 four atoms of oxygen. Berthelot* has succeeded in directly- 

 combining oxygen with free acetylene by shaking the gas 

 with a solution of permanganate of potash until the liquid is no 

 longer decolorized. The liquid then contains a large quantity of 

 oxalic acid, which may be separated by the ordinary methods. 

 At the same time some formic and carbonic acids are formed, 

 which may be regarded as arising from a secondary decomposi- 

 tion of the oxalic acid. 



It is interesting to observe that the synthesis of oxalic acid is 

 effected by the successive addition of its constituent elements ; 

 * Comptes Rendus, January 7, 1866. 



