é 
150 Dr. Cutbush on the Formation of 
azote, and more lately Dr. Ure has denominated it prussine. 
We know that cyanogene is usually obtained from the cya- 
nuret of mercury, by heating it in a glass tube, and that it 
is susceptible of combining with several substances, formin 
peculiar acids; of these, the hydrocyanic (prussic) and fer- 
rocyanic, are the most prominent and important. The com- 
bination of cyanogene with hydrogen affords a triple prepa- 
ration, distinct from that which has been called the ferrocy- 
anic acid; for it is known, that prussic acid, as such does 
not unite with oxyd of iron, as heretofore supposed, to form 
Prussian blue, but only a compound of cyanogene and iron, 
and consequently the cyanogene is changed into a new acid, 
the ferro-cyanic. It is admitted, nevertheless, that the fer- 
ro-prussic acid stil] retains a portion of hydrogen. ‘Vhe hy- 
drocyanic acid may be obtained, however, from the ferro- 
eyanite of iron, and by distilling the cyanuret of mercury 
with muriatic acid; but then we separate al] the iron from 
the cyanogene, or decompose the ferro-cyanic acid in the 
first instance, and in both cases the cyanogene combines 
with hydrogen, forming hydro-cyanie acid. The cyanuret, 
cyanides, and cyanidides are synonimous terms. We must 
suppose, when we admit the formation of an acid, that cy- 
anogene unites with the particular substance that changes its 
iron a third and with sulpbur a fourth, possessing respee- 
th 
miasmata, and in all probability the separation of hydrogen 
from its combination, the chlorine changing to the state of 
