FULMINATION. 
descended from the top to the bottom of the 
vessel in which the air was contained. In the 
next produce of air, from the same process, 
the flame descended blue, and very rapidly 
from the top to the bottom of the vessel.’ 
“ These greenish and blue-coloured llames, 
descending from the top to the bottom of 
the vessel, are precisely descriptive of the 
inflammable gas separated from the powder. 
If it can be produced with certainty by the 
repetition of Dr. Priestley’s experiments, or 
should it by any means be got pure from 
the nitrous etherized gas, my curiosity will 
excite me to make it the object of future 
research ; otherwise, I must confess, 1 shall 
feel more disposed to prosecute other che- 
mical subjects: for having reason to think 
that the density of the acid made a varia- 
tion in the product of this gas, and having 
never found that any acid, however dense, 
produced an immediate explosion, I once 
poured 6 drachms of concentrate acid upon 
50 grains of the powder. An explosion, 
nearly at the instant of contact, was effected : 
1 was wounded severely, and most of my 
apparatus destroyed. A quantity moreover 
of the gas I had previously prepared, was 
lost by the inadvertency of a person who 
went into my laboratory, whilst I was con- 
fined by the consequences of this discourag- 
ing accident. But should any one be de- 
sirous of giving the gas a further examina- 
tion, I again repeat, that as far as I am en- 
abled to judge, it may with safety be pre- 
pared by pouring 3 drachms of sulphuric 
acid, diluted with the same quantity of wa- 
ter, upon 50 grains of the powder, and then 
applying the name of a candle until gas be- 
gins to be extricated. The only attempt I 
have made to decompose it, was by exposing 
it to copper and ammonia ; which during 
several weeks did not effect the least altera- 
tion. 
“ I will now conclude (says Mr. Howard), 
by observing, that the fulminating mercury 
seems to be characterised by the following 
properties : 
“ It takes fire at the temperature of 368 
Fahrenheit; explodes by friction, by flint and 
steel, and by being thrown into concentrate 
sulphuric acid. It is equally inflammable 
under the exhausted receiver of an air-pump, 
as surrounded by atmospheric air ; and it de- 
tonates loudly, both by the blow of a hammer, 
and by a strong electrical shock. 
“ Notwithstanding the compositions of ful- 
minating silver and of fulminating gold differ 
essentially from that of fulminating mercury, 
all three have similar qualities. In tremen- 
dous effects, silver undoubtedly stands first, 
and gold perhaps the last. The effects of 
the mercurial powder and of gunpowder ad- 
mit of little comparison. The one exerts, 
within certain limits, an almost inconceivable 
force : its agents seem to be gas and caloric, 
very suddenly set at liberty, and both mer- 
cury and water thrown into vapour. The 
other displays a more extended but inferior- 
power : gas and caloric are, comparatively 
speaking, liberated by degrees; and water, 
according to count Rumford, is thrown into 
vapour. 
“ Hence it seems that the fulminating 
mercury, from the limitation of its sphere of 
action, can seldom, if ever, be applied to 
mining ; and, from the immensity of its initial 
force, cannot be used in fire-arms, unless in 
cases where it becomes an object to destroy 
them ; and where it is the practice to spike can- 
non, it may be of service, because I apprehend 
it may be used in such a manner as to burst 
cannon without dispersing any splinters. 
“ The inflammation of fulminating mer- 
cury by concussion offers nothing more novel 
or remarkable than the inflammation, by 
concussion, of many other substances. The 
theory of such inflammations has been long 
since exposed by the celebrated Mr. Ber- 
thollet, and confirmed by Messieurs Fourcroy, 
and Vauquelin : yet, 1 must confess, 1 am at 
a loss to understand why a small quantity of 
mercurial powder made to detonate by the 
hammer, or the electric shock, should pro- 
duce a report so much louder than when it is 
inflamed by a match, or by flint and steel. 
It might at first he imagined, that the loud- 
ness of the report could be accounted for, by 
supposing the instant of the inflammation, and 
that of the powder’s confinement between the 
hammer and anvil, to be precisely the same; 
but, when the electrical shock is sent through 
or over a few grains of the powder, merely 
laid on ivory, and a loud report in conse- 
quence, 1 can form no idea of what causes 
such a report. 
“The op ration by which the powder is pre- 
pared, is perhaps one of the most beautiful and 
surprising in chemistry ; and it is not a little 
interesting to consider the affinities which are 
brought into play. The superabundant ni- 
trous acid of the mercurial solution must first 
act on the alcohol, and generate ether, nitrous 
| etherized gas, and oxalic acid. T he mer- 
l cury unites to the two last in their nascent 
1 state, and relinquishes fresh nitrous acid, to 
! act upon any unaltered alcohol. The oxalic 
! acid, a predisposing affinity seems exerted in 
favour of its quantify, is evidently not formed 
fast enough to retain all the mercury ; other- 
wise, no white fumes during a considerable 
| period of the operation, but fulminating mer- 
cury alone will be produced. 
“ Should any doubt still be entertained 
of the existence of the affinities which have 
been called predisposing or conspiring, a 
proof that such affinities really exist, will, I 
think, be afforded, by comparing the quantity 
of oxalic acid which can be generated from 
given measures of nitrous acid and alcohol, 
with the intervention of mercury, and the in- 
tervention of other metals. For instance, when 
two measured ounces of alcohol are treated 
with a solution of 100 grains of nickel in a 
measured ounce and a half of nitrous acid, 
little or no precipitate is produced; yet, by 
the addition of oxalic acid to the residuary 
liquor, a quantity of oxalate of nickel, after 
some repose, is deposited. Copper affords 
another illustration; 100 grains of cop- 
per dissolved in a measured ounce and a half 
of nitrous acid, and treated with alcohol, 
yielded me aboutl 8 grains of oxalate, although 
cupreous oxalate was plentifully generated 
by dropping oxalic acid into the residuary li- 
quor. About 21 grains of pure oxalic acid 
seem to be produced from the same materials, 
when 100 grains of mercury are interposed. 
Besides, according to the Dutch paper, more 
than once referred to, acetous acid is the 
principal residue after the preparation of ni- 
trous ether. How can we explain the for- 
mation of a great er quantity of oxalic acid 
from the same materials, with the interven- 
tion- of 100 grains of mercury, than with the 
intervention of 100 grains of copper, other- 
wise than by the notion of conspiring affini- 
ties, so analogous to what we see in other 
phenomena of nature? 
“ 1 have attempted, without success, to 
communicate fulminating properties, by 
means of alcohol, to gold, platina, antimony , 
tin, copper, iron, lead, zinc, nickel, bismuth, 
cobalt, arsenic, and manganese; but I iurve 
not yet sufficiently varied my experiments 
to enable me to speak with absolute certaintv. 
Silver, when 20 grains of it were treated with 
nearly the same proportions of nitrous acid 
and alcohol as 100 grains of mercury, yielded, 
at the end of the operation, about three 
grains of a grey precipitate, which fulminated 
with extreme violence. Mr. Cruickshank 
had the goodness to repeat the experiment : 
he dissolved 40 grains of silver in two ounces 
of the strongest nitrons acid diluted with an 
equal quantity of wafer, and obtained (by 
means of two ounces of alcohol) 60 grains of 
J a very white powder, which fulminated like 
! the grey precipitate above described. It 
| probably combines with the same principles 
1 as the mercury, and of course differs from 
j Mr. Berthollet’s fulminating silver, before al- 
! luded to. I observe, that a white precipitate 
i is always produced in the first instance ; and 
that it may be preserved by adding water as 
soon as it" is formed ; otherwise, when the 
mother liquor is abundant, it often becomes 
grey, and is re-dissolved.” 
Several trials of the mercurial powder were 
afterwards made at Woolwich, in conjunction 
with colonel Bloomfield and Air. Cruick- 
shank, upon heavy guns, carronades, &c. 
from which Mr. Howard generally infers, 
that any piece of ordnance might be de- 
stroyed, by employing a quantity of the mer- 
curial powder equal in weight to one half of 
the service-charge of gunpowder; and, from 
the seventh and last experiment, we may also' 
conclude, that it would be possible so to pro- 
portion the charge of mercurial powder to 
the size of different cannons, as to burst 
! them without dispersing any splinters. But 
I the great danger attending the use of fulmi- 
nating mercury, on account of the facility 
with which it explodes, will probably prevent 
its being employed for that purpose. 
“ In addition to the other singular proper- 
I ties of the fulminating mercury (says Mr. 
! Howard), it may ire observed, that two ounces 
inflamed in the open air seem to produce a 
report much louder than when the same quan- 
tity is exploded in a gun capable of resisting 
its action. Mr. Cruickshank, who made 
some of the powder by my process, remarked 
that it would not inflame gunpowder. In 
consequence of which, we spread a mixture of 
coarse and fine-grained gunpowder upon a 
parcel of the mercurial powder ; and after 
the inflammation of the latter, we collected 
j most, if not all, of the grains of gunpowder. 
| Can this extraordinary fact be explained by 
the rapidity of the combustion of fulminat- 
ing mercury ? or is it to be supposed (as gun- 
powder will not explode at the temperature at 
which mercury is thrown into vapour) that 
sufficient caloric is not extricated during this 
combustion? From the late opportunity I have 
had of conversing with Mr. Cruickshank, I 
find that he has made many accurate expert- 
