176 On Fulminating Gold. 
pretends to argue, I feel myself completely justified in. relin- 
quishing the present controversy: it would indeed be litigious 
in the extreme for me to continue to oppose one who writes 
not against me, but against the new system (that metallic salts 
are super-salts with excess of oxide) of which your correspon- 
dent G. 5. is the author. 
Yours obediently, 
London, March 6, 1216. H. 
XELI. On Fulminating Gold. By J.B. Vax Mons, of 
Brussels*. 
Tare is a preparation of gold which presents much interest, 
and on which the nephew of the illustrious Driessen has published 
a very good essay:—I mean fulminating gold. This compound 
may be procured by all the methods of putting ammonia in re- 
action on dissolved gold; by aqua regia, with which we precipi- 
tate gold by the help of a soluble oxide, and by the muriate of 
gold which we decompose by means of ammonia; by the oxide, 
of gold which we treat with ammonia, either gaseous or liquid 
or with any ammoniacal salt; and finally, by this same oxide, 
which we must keep some time in a dark and damp place 
where the air is stagnant. 1 prepare it with most advantage by 
precipitating by potash a diluted solution of muriate of gold 
and muriate of ammonia. The precipitate is at first muriate of 
ammonia and gold; but the instant the ammonia becomes free, 
it is aurate of ammonia, called ammonium of gold, or fulminating 
gold, which is produced. 
Fulminating gold is not decomposed by any acid, and it is not 
by the alkalies: nevertheless the first of these bodies disunite 
it by the adjunction of a hyperoxygenated muriate and liquid 
chlorine; without this adjunction, but with the assistance of 
heat, double muriate being produced. This happens from the 
combustibles having more energy than its metal. This com- 
pound is a salt in which the oxide of gold performs the functions 
of acid, and the ammonia the function of an oxide: it is there- 
fore, as I have already said, an aurate of ammonia, which exists 
by an engagement the more intimate as the oxygen of the gold, 
with which the oxygen of the ammonia is proportioned, presents 
more caloric to displace. The acids, inorder to decompose this 
salt, ought either to take the ammonia from it or dissolve at 
once its two elements; but for the first effect it is necessary 
that the oxide of gold should be insulated from the oxygen 
wanting caloric, and for the second effect it would be necessary 
* Communicated by the Antior, 
that 
