Chemical Science. 389 
with the other elements, but only from a minute trace of water in- 
troduced with the materials operated upon. 
From further experiments of this kind it was concluded, that 
when fulminate of silver mixed with sulphate of potash was decom- 
posed by heat, only half its carbon became carbonic acid, and only 
that proportion of nitrogen was set free which with the carbon would 
form cyanogen, so that the silver was left in a state of asubcyanuret. 
If the elements thus analytically obtained are correct, the follow- 
ing will be the equivalent number of fulminic acid: 
1 atom oxide of silver . » 145.161 
2 — cyanogen ‘ ‘ 65.584 
2 — oxygen. : . . 20.000 
230.745 
and on experiment it was found that 3.833 of fulminate of baryta 
decomposed by muriatic acid gave 1.585 of chloride of barium, 
which by calculation would give 228.873 as the number of fulminic 
acid, a result sufficiently in accordance with the former to justify the 
calculated number. 
The authors then consider the probable nature of fulminic acid. 
That the metal should be an essential principle can hardly be ima- 
gined, inasmuch as one metal may be replaced by another; thus a 
fulminate may be obtained with zinc only, analogous to that of silver : 
are not therefore the various fulminic acids formed by the different 
metals super salts, of which the acid really contains no metal but 
only cyanogen and oxygen ? 
As fulminates may be obtained with oxides which lose their 
oxygen with difficulty, oxide of zinc for instance, as well as with 
silver or mercury, it is evident they must all include one common 
principle of fulmination independent of the bases, and which can 
only be acompound of oxygen and cyanogen, or of oxygen, car- 
bon, and nitrogen. Again, if the fulminates be compared to neu- 
tral tartrates, and the various fulminic acids to bitartrate, a perfect 
avalogy will be found; thus neutral tartrates of zinc, copper, silver, 
or mercury, are only half decomposed by potash, just like the 
fulminates of the same bases: all the fuliminic acids form double 
salts with bases like the bitartrates: fulminic acid with a base of 
silver is, in consequence of its insolubility, precipitated by acids 
like cream of tartar : and there are many fulminates, as well as neu- 
tral tartrates, in which acids produce no precipitates, because the 
corresponding acid fulminates, or tartrates, are soluble; such are 
the fulminates and tartrates of zinc and copper. Hence it appears 
to the authors extremely probable, if not certain, that the various 
fulminates form a particular class of salts, all containing the same 
acid composed of an atom of cyanogen and an atom of oxygen only, 
and which is without doubt the cyani¢ acid, The neutral fulminates 
