* 
of acting as an assistant, I have taken up my pen to give you a brief 
statement of their results. 
~ A considerable quantity of paracyanogen was obtained by exposing 
‘the bicyanide of mercury to a low red heat, according to the direction 
given by Brown, in an iron tube closed air tight by a plug of the same 
metal, traversed by a perforation filled with stucco.. During the ope- 
ration the vapor of mercury with a part of the cyanogen, escaped 
through the orifice by passing through the pores of the stucco, while 
the remainder of that gas was converted into paracyanogen and re- 
mained in the tube in the shape of a black porous mass. So far, as 
might easily have been anticipated, the results obtained agreed with 
those indicated by Brown, as his coincided with those of previous ex- 
perimenters. On exposing however the paracyanogen resulting from 
this process to heat in glass tubes, instead of the evolution of nitrogen 
and the conversion of the carbon into silicon, carburets of nitrogen, 
‘ inwhich more or less cyanogen was present, were given off, and the 
residue appeared to consist of carbon and not of silicon. This result 
entirely, agreed with the habitudes of paracyanogen, as described in 
works on chemistry, and was equally inconsistent with the —_ 
of Mr. Brown. 
With the view of making an experiment ona larger scale, which 
should prove decisive of the facts in question, the iron tube above de- 
scribed was again charged with five or six ounces of the bicyanide of 
mercury, and kept for several days at a heat just below redness. The 
vapor of mercury was given off through the stucco during the whole 
period, but as far as could be determined by the absence of odor and 
the application of a lighted taper of flame, unaccompanied by 
cyanogen. This treatment should, according to the experiments of 
Mr. Cedi: when continued during such a length of time, have been 
alone sufficient fo determine the formation of silicon. The tube was 
then heated to redness in a wind furnace for four hours, and subse 
quently kept at a white heat for as many more. On opening it, the 
whole of the materials were found to have been volatilized, while the 
iron of the tube remained unchanged, except that in one or two places 
a few scales had been formed. These, when detached and dissolved 
_ in muriatic acid, left a small quantity of the carbonaceous residue 
which remains after the solution of iron in that solvent. 
As the heat applied to the bicyanide before it was placed in the furs 
nace, must. power hve converted the greater portion of the cya 
vhich it con ch blag and according to the eX 
shoul d have gh moe 
