1816.) Experiments on Prussic Acid. 361 
the same part as chlorine in the chlorides, will be denoted by the 
term cyanuret.* It will be difficult to give the prussic radical a 
more convenient name ; for it will be seen that it acts at once the 
part of a compound and simple body; and _ if we wished to denote 
it by the name carluret of axote, which would suit it as a compound 
body, circumloeutions would be necessary to denote its numerous 
compounds. I return now to the properties of the combination of 
cyanogen and potassium, or of the cyanuret of potassium. 
Its solution in water is very alkaline, even when a quantity of 
hydro-cyanic vapour is employed much greater than the potassium 
is able to absorb. . Yet the chloride and iodide of that metal are 
perfectly neutral. This very remarkable difference, depending 
doubtless on the peculiar disposition of the molecules, does not exist 
with regard to sulphur. 1 heated in sulphureted hydrogen a quantity 
of potassium which would have disengaged 50 parts of hydrogen 
from water; and I withdrew the sulphuret from the action of the 
gas as soon as the combustion was completed. The diminution of 
volume was 50 parts, and the residue, treated by potash, left 50 parts 
of hydrogen; so that the potassium had combined with 50 parts of 
sulphureted hydrogen, and it had decomposed 50, of which it had 
seized the sulphur, and left the hydrogen. 
This combination of sulphureted hydrogen and sulphuret of pot- 
assium, in which this last substance seems to act the part of the 
oxides in the salts, dissolves in water without effervescence, and 
renders it alkaline. The sulphureted hydrogen had not rendered the 
water muddy by its decomposition. Thus, sulphur and cyanogen 
present this analogy, that both of them form alkaline combinations 
with potassium. t 
Knowing the composition of hydro-cyanic acid, and that potas- 
sium separates from it as much hydrogen as from water, it is easy to 
find the proportional number which represents the capacity of this. 
acid, as well as that which represents that of cyanogen, the capa- 
city of oxygen being 10; for we must take such a quantity of 
hydro-cyanic acid that its hydrogen is capable of saturating 10 of 
oxygen. In this manner we shall find the proportional number for 
this acid 83°846 ; and subtracting from this number the weight of 
the hydrogen, there remains 32°520, which is the proportional 
number for cyanogen. 
A high temperature produces a very remarkable alteration in 
hydro-cyanic acid. On passing its vapour through a porcelain tube, 
we obtain hydrogen, a little azote, and cyanogen, mixed with a 
considerable portion of the acid not decomposed ; and the inside of 
® The term cyanide would be better.—T. 
# LIconsidered the part similar to the oxides which the sulphurets play in certain 
combinations analogous to the salts in the memoir which I read last year to the 
Philomatic Society, but which is not, yet published. In it I gave the analysis of 
sulphureted sulphite of strontian, in which the sulphur converted into sulphuric 
acid is capable of saturating a quantity of base double that in the sulphite; from 
which I conclude that, setting out from the sulphite, we may increase the quantity 
of oxygen or of sulphur without altering its neutrality, 
Vou. VII. N° V. 
