240 DR BROWN ON THE PRODUCTION OF SILICON FROM PARACYANOGEN. 



a column of alcohol was poured upon it ; and after it had passed through, in the 

 course of eight hours the same quantity of pure water was sent through, and was 

 followed in its turn by alcohol. The magma was shaken up a little way in the 

 tube, and the aperture sealed ; and the open extremity, hitherto corked, was then 

 drawn out to a capillary bore. The adhering spirit was distilled away towards 

 the capillary, and the product obtained dry in the form of a light mouse-brown 

 powder. A careful analysis, and the observation of its chemical properties, appear 

 to warrant the conclusion that this body is composed of paracyanogen and iron, 

 and that it is the true compound radical of the ferrocyanides ; but it would only 

 interrupt the continuity of the present investigation to discuss this subject in the 

 present place, and it must consequently be reserved for a separate memoir. It is 

 sufficient to mention at present, that the substance in question contains nitrogen, 

 carbon, and iron, in the ratios of 1, 2, and 1, and that it is called the paracyanide 

 of iron in this section and the next. It needs scarcely be added, that, whether or 

 not it be the radical of the ferrocyanide of potassium, that salt certainly contains 

 its coefficients, and may accordingly be substituted for it in transformative experi- 

 ments, the supernumerary cyanide of potassium being calculated for as an inci- 

 dental and inactive ingredient. The compound, which has given rise to these re- 

 marks may be readily procured in larger quantities, by putting the mixture of sul- 

 phur and ferrocyanide of potassium into one of the porous clay-bulbs of LESLIE'S 

 hygrometer, luting up the little stem, and heating it a few hours to the lowest 

 visible heat of iron in the dark, immersed in a sand-bath or, better still, in stucco 

 powder. Sulphocyanide and cyanide of potassium are, as it were, filtered through 

 the sphere, and the paracyanide of iron is left within in such a state of aggrega- 

 tion, that it may be washed in water with impunity if it be not exposed to the 

 air. The processes of the section may now be introduced. 



1. Take the paracyanide of iron, and having introduced it into a crucible of 

 Berlin porcelain, lute on the lid with a strong fire-clay. Put it within two Hes- 

 sian crucibles, filling the empty space with stucco powder, and placing some 

 heavy body above the enclosed crucible. Apply the fiercest heat of a powerful 

 wind-furnace for two hours. 



There are two products in this experiment. The crucible is lined with a crust 

 of an intensely hard, greenish- black substance, resembling obsidian, and contains 

 a coaly powder, aggregated into little masses. These are of the same chemical 

 composition, the latter being unfused and amorphous, the former fused and semi- 

 crystalline ; but the description of the semicrystalline product is reserved till the 

 next paragraph. The amorphous substance, treated according to rule, yields 

 silicic acid and peroxide of iron. This and all the following experiments may be 

 performed, either in porcelain crucibles, or vessels of hammered iron. With the 

 latter there can scarcely be any fallacy ; and, if there be, it is entirely removed 



