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Author: Subject: Silver Fulminate Synthesis
Sobrero
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I doubt you have to purify your silver; as nitro-genes already stated the SF synthesis is quite tolerant towards impurities. I also prepared SF today , proving this synth doesn't need high grade chemicals at all.
I used 1.10g silver from a silver spoon (let's say 90% silver with copper, nickel, ... impurities), 10ml denaturated ethanol and 10ml 60% technical grade nitric acid and following Axt's procedure on the first page of this thread.
Yield seems to be almost quantitative, as indicated by Fedoroff. I know that nitro-genes, who used approximatively the same synthesis, checked if Ag(+)-ions were present in the filtrate by adding tap water, and the solution just turned very slightly white, indicating an almost 100% yield.

"There exists a world. In terms of probability, this borders on the impossible." (Jostein Gaarder)
Rosco Bodine
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analogues of fulminates

The famous explosives researcher Munroe ,
made an interesting note concerning which I know of nothing further , regarding the formation of similar
compounds to fuminates , derived from higher alcohols .

See attachment , " Notes and Correspondence" towards the bottom of the page .

It is possible that a propanol or butanol derived "quasi" fulminate of silver might be an interesting compound .

[Edited on 21-4-2007 by Rosco Bodine]

Attachment: Munroe's note concerning fulminates.pdf (273kB)

The_Davster
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Fascinating, if he had someone researching these in 1911 there should be some data on them somewhere.

Rosco Bodine
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Yeah one of the things I wondered about is if a double salt might form from the normal fulminate and a quasi-fulminate , if both were dissolved in ammonia and the
solution neutralized , as this might be a strategy for
taming silver fulminate .

A double salt might form in situ from a use of mixed alcohols .

Also other metals which do not form the normal fulminates , might possibly form a quasi-fulminate .
Copper for example , or other metals might do this .

[Edited on 21-4-2007 by Rosco Bodine]
ssdd
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Ok so after looking up what metals may be alloyed with my silver supply I found the following.

When copper is added to a strong nitric acid the liquid turns a vivid green color. This happened when I added my silver to the nitric in my first attempt a few weeks ago. When copper is added to a weak acid solution it turns a pale blue color. This seems to be what happened when I used the 3 molar nitric.

So my guess would be that I have a fairly high copper content. Would this have much effect? If so, by what methods can I purify the silver?
The_Davster
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Dissolve your impure silver in your dilute nitric acid, then add lots(to compensate for any excess acid) of copper metal to this. Silver powder/crystals will collect on the copper and can be removed from the copper without any force really. Then use that silver to make the SF, but using concentrated nitric acid.

ssdd
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Ill have to give that a try sometime this week, thanks.
Hennig Brand
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I have been messing around with Silver Fulminate quite a bit lately, very interesting material. I first made it about 3 years ago, but never got great yeilds(less than 0.5g from 1g silver). In the last few days I have been consistantly getting better yeilds, always over 0.75g and the last batch was 0.91g SF/1g Ag. At least with my materials there is a very small difference in temperature between forming SF and destroying SF. With my ethanol (homemade 90%) added acetone is a must, but how much is added is very important. I have found for a 1g silver batch, with 8mL 85% HNO3 and 8mL H2O, that 8mL ethanol 90%, and 2.5 mL acetone to be about optimal. Much less than this seems to sacrifice yeild, much more and the reaction is more violent and very difficult to keep from loosing your yeild to decomposition. For my materials and set-up, the reaction starts around 65C, with care(swirling and cold water bath the temperature is allowed to rise to 75C at most if possible, where a good bunch of white precipitate appears. Once you see that precipitate get that temperature below 70C with the cold water bath and swirling(I keep it around 65C for the rest of the reaction, although I feel the important part of the reaction is in those first 10 seconds anyway, the rest of the exothermic reaction taking place doesn' t seem to add anything to the yeild at all). In truth I feel the only thing gained from keeping the temp over 70C after the precipitate forms is decomposition of your hard won product.

This is what I have found to be workable for my material. I am aware that this synthesis is very sensitive to any changes, even small ones, even small differences in the amount and type of impurities in your alcohol-acetone, or small differences in how much water or nitric acid evaporated while heating. Every time I do this reaction it goes a little differently, and I think that I am doing it exactly the same(more or less).

Anyway 0.91g from a gram of silver is good as far as I am concerned. Liebig claimed to get about 1g from a gram of silver.

I have been turning most of my SF into bangsnaps using the old fashed method like in COPAE. Just put a little powder on the budgie gravel and wrap in tissue. Mine are about 100 times stronger though if there really is only 80 micrograms in the commercial ones.

I have tried to read everything I can get my hands on about silver fulminate, and most of it seems to either be blatantly wrong or very inadequate when describing a synthesis. In there defence it is a little like trying to learn how to throw a baseball by reading.
otonel
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I have a 100ml solution of 10% silver nitrate and I want to make silver fulminate.
Can someone help me to calculate how much nitric acid and alcohol is necessaries to use for complete reaction.
Is my first try to make fulminates and I need your help and advice.
quicksilver
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1st of all are you aware of that particular material's sensitivity? Have you done some background in researching it's appropriate handling, mfg, &, buffering?
2nd; using a silver nitrate solution is not not appropriate especially since the solution may be a water based solution....is it?

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Turning 100ml of solution into fulminate is madness, far too much for a first attempt.
otonel
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Sorry I dont explain correct, I have 100 ml silver nitrate but I dont want to use all at on time.
For my first attempt I think 5 ml of solution is enough an relatives safe in case of accidental explosion
quicksilver
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I don't want to repeat myself; however did you do your homework? Sensitivities, research, solvent, buffers?
ANY primary is much too serious to get into if there is a need to start at the bottom and silver fulminate is sensitive enough to make this a very brief conversation if there is little common knowledge.

otonel
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Quicksilver I do my homework I know how sensitive is that fulminates and tomorrow I will try to make using my 10% solution 10 ml mixed with 10 ml 70%HNO3 heated and I will add 12 ml ethanol.
I think is good proportion of chemicals and I use 10% solution because if I boiled to make concentrated solution is hard for me to appreciate how concentrate is.
I ask for your help not for warnings, I have experience with another primaries and if I accomplish to make fulminate what is best option to keep that, is good to use kerosene or a nitrocellulose dissolved in acetone
quicksilver
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If you answer my questions, I'll answer yours. My purpose is to maintain an element of safety.

Where did you hear about combining a fulminate in nitrocellulose lacquer?

Do you understand that silver fulminate is still extremely sensitive within a fluid?

Where have you been getting your source material from?

otonel
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 Quote: Originally posted by quicksilver 1st of all are you aware of that particular material's sensitivity? Have you done some background in researching it's appropriate handling, mfg, &, buffering? 2nd; using a silver nitrate solution is not not appropriate especially since the solution may be a water based solution....is it?

1. I m aware of silver fulminate sensitivity, I read a lot of chemistry articles and homemade explosives about that explosive
2. I want to use my 10% solution because if I boiled to make concentrated solution is hard for me to appreciate how concentrate is.

Where did you hear about combining a fulminate in nitrocellulose lacquer?
That was just my idea

Do you understand that silver fulminate is still extremely sensitive within a fluid?
I understand and I search a way to decrease friction and impact sensitivity I read somewhere about military uses of silver fulminate in special detonators and I think is a method to reduce that sensitive

Where have you been getting your source material from?
I bought silver nitrate solution from a pharmacy

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There are very few EFFECTIVE & reliable methods to deal with the sensitivity issue. It will continue to be notoriously vicious even with a buffering concept (use of dextrin) that was an early 1920's technique the pyrotechnics industry toyed with when making "snap caps" (throw down toys for sidewalk impact). I have never heard of a commercial usage for silver fulminate as it presents all the problems inherent in a material with it's level of sensitivity (static, friction, impact, etc) and no remarkable benefits. Mostly it has been left alone after the attempts to buffer and use a feather to manipulate was deemed impracticable even for the toy fireworks industry. (see AFN article on fulminate from "Collections").

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I used to cut the tip of a soft plastic straw into a small scoop and use that to measure out ~8mg for individual bang snaps, which worked well. I loaded several hundred by this method in a short period of time a while back without incident.

I have tried Silver Fulminate mixed with Nitrocellulose lacquer to make explosive heads for electric igniters (squibs?), which worked very well. I only stored them for a couple of weeks or so, so I'm not really sure about long term storage stability of these explosive igniters.

I have always found that the reports of extreme sensitivity were overblown, however I have not done a thorough study, and there could exist special conditions that could lead to extreme sensitivity (I don't know for sure). I also imagine the high cost of Silver was a huge deterent to its use as it was with other primaries using Silver.

I tend to avoid it as an initiator mostly because there are other, more well known primaries that have been tested and proven to be effective and safe (relatively). I always keep it in the back of my mind though, as it has excellent initiating abilities in small quantities, is very storage stable, and uses very common chemicals for its synthesis.

[Edited on 23-5-2011 by Hennig Brand]
quicksilver
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 Quote: Originally posted by Hennig Brand I have always found that the reports of extreme sensitivity were overblown, however I have not done a thorough study, and there could exist special conditions that could lead to extreme sensitivity (I don't know for sure). I also imagine the high cost of Silver was a huge deterent to its use as it was with other primaries using Silver.

Frankly, I found it to be really uniquely sensitive. Perhaps within NC lacquer (and thinned enough) it could be contained for a period of time but remember fulminates' big problem was their shelf-life if exposed to temperature at and above 40C.
Simply from an empirical standpoint, I found it potentially nightmarish if weights above a gram were employed. I believe at that weight it becomes a fairly dependable "finger-eraser".
No exaggeration: I have some serious respect for it. I also agree that it also was the base metal that had additional impact on it's usage.

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 Quote: Originally posted by quicksilver Frankly, I found it to be really uniquely sensitive. Perhaps within NC lacquer (and thinned enough) it could be contained for a period of time but remember fulminates' big problem was their shelf-life if exposed to temperature at and above 40C. Simply from an empirical standpoint, I found it potentially nightmarish if weights above a gram were employed. I believe at that weight it becomes a fairly dependable "finger-eraser". No exaggeration: I have some serious respect for it. I also agree that it also was the base metal that had additional impact on it's usage.

I found it to be really uniquely sensitive. Et tu!?

The Philadelphia medical museum, Volume 1. 1805
Edited by John Redman Coxe

Professor Veau-de-Launay, in a letter to J. C. Delametherie, gives the following
account of an accident with fulminating silver, in his laboratory.

" I had employed one of my pupils, a very good operator, to prepare a small
quantity of fulminating silver, which he executed with skill.

The quantity obtained was about five grains, or a quarter of a gramme: it was
deposited in a crystal capsule, about two lines in thickness. He had taken a small
quantity, about half a grain, which was separated with a card, and then dried, and
afterwards detonated by slight friction. Next day, that is td fay 24 hours after the
preparation, this young person was desirous of taking an equal quantity from the
capsule to repeat the experiment, but he had scarcely touched the preparation with
the corner of a card, when a violent detonation and explosion took place in the
capsule, which was shattered into a thousand pieces. His face was covered with the
vaporised preparation, which was almost black, and adhered strongly to the skin ; his
eyes experienced a strong shock, which produced extreme pain; the opaque cornea
became red and inflamed. Happily his fear was the greatest evil : by washing and
bathing his eyes and face frequently with cold water, the effects of the detonation
were soon dissipated.

Fortunately, none of the fragments of the glass had touched his eyes or his face; they
were thrown nearly in a horizontal direction, to a considerable distance : some were
thrown upwards of 12 feet.

Nickelson’s Journal

---
Minutes of Proceedings of The Institution of Civil Engineers: with
other Selected and Abstracted Papers Vol. LXI London 1880

ABEL ON EXPLOSIVE AGENTS.

[Minutes of 23 March, 1880].
WILLIAM HENRY BARLOW, F.R.S., President, in the Chair.
(Paper No. 1712.)

" Explosive Agents applied to Industrial Purposes."

By FREDERIC AUGUSTUS ABEL, C.B., F.R.S., Assoc. Inst. C.E., Past
President C. S. and Soc. Tel. Engrs., President of the Institute of
Chemistry, &c.

[Attached]

Silver fulminate was employed for the purpose of instituting more
precise experiments than could be made, in operating on a larger
scale with gun cotton, on the influence of the material com¬posing
the tubes, on the condition of their inner surfaces, and of other
variable circumstances, on the transmission of detoriation. Half a
grain of fulminate, freely exposed and ignited by a heated body,
will transmit detonation to some of the compound placed 3 inches
from it, but does not do so with certainty at a distance of 4 inches.
But when that quantity of the fulminate is inserted into one end of
a stout glass tube 0.5 inch in diameter, and 3 feet long, its
detonation is invariably induced by that of a similar quantity of the
fulminate placed inside the other extremity of the tube. This result
is uncertain when the length of tubes, of the same thickness and
diameter, exceeds 3 feet 3 inches. Glass tubes transmitted the
detonation more rapidly than tubes of several other materials of
the same diameter and thickness of substance. Thus, with the
employment of double the quantity of fulminate required to
transmit the detona¬tion with certainty through a glass tube of the
kind described, 3 feet in length, it was only possible to obtain a
similar result through a pewter tube 31.5 inches long, a brass tube
23.7 inches long, an India rubber tube 15 8 inches long, and a
paper tube 11.8 inches long. The difference, in the results was not
ascribable to a difference in the escape of force on the instant of
detonation, in consequence of the fracture of the tube, nor to the
expenditure of force in work done upon the tube at the seat of
detonation; since the glass tubes were always destroyed by the
first explosion to a greater distance along their length than any
other, and the brass tubes, which were in no way injured at the
seat of the explosion, did not transmit detonation to so great a
distance as the pewter tubes, which were always deeply indented.
The transmission of detonation appeared also not to be favoured
by the sonorosity or the pitch of the tube employed, as the
sono¬rous brass tube did not favour the transmission to the same
extent as the pewter tube. Moreover the transmission of
detonation [90] by the glass tubes was not affected by coating
them with several layers of paper, or by encasing them in tightly
fitting India rubber tubes. These differences appeared, on further
investigation, to be ascribable not to any important extent to the
difference in the nature of the material composing the tubes, but
simply, or at any rate chiefly, to differences in the condition of the
inner surfaces of the tubes. Thus, brass tubes, the inner surfaces
of which were highly polished, and paper tubes when coated inside
with highly glazed paper, transmitted the detonation of the silver
fulminate to about the same distance as the glass tubes. On the
other hand, when the inner surfaces of the latter were slightly.
roughened by coating them with a film of fine powder, such as
French chalk, they no longer transmitted detonation to the distance
which they did before. Other slight obstacles to the unimpeded
passage of the gas wave through the tubes greatly reduced the
facility with which detonation could be transmitted by means of
tubes. Thus, when a diaphragm of thin paper was inserted about
halfway into the glass tube, detonation was not transmitted, even
with the employment of about six times the quantity of fulminate
that gave the result with certainty under ordinary conditions.
Similarly the transmission of detonation by increased charges of
mercuric fulminate and of gun cotton was prevented by the
introduction into the tubes of light tufts of carded cotton wool, just
sufficient in quantity to shut out the light when looking through the
tubes.

Attachment: Explosives Able on Explosive Agents II.doc (192kB)

-------------
The First Chemical Achievements and Publications by Justus von Liebig
(1803-1873) on Metal Fulminates and Some Further Developments in Metal
Fulminates and Related Areas of Chemistry
Wolfgang Beck

PDF
Attachment: silver fulminate.pdf (349kB)

djh
----
The paradox of the fall of the Shah,” Mr.
Milani says, “lies in the strange reality
that nearly all advocates of modernity
formed an alliance against the Shah and
chose as their leader the biggest foe of
paid dearly for this folly. What price the
rest of the world will pay remains an
open question.

John Muravchik
Wall Street Journal 19I11
Review of : Abbas Milani - A Monarch Dethroned
Palgrave Mcmillian
quicksilver
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For many years you've always gotten some of the better written material on energetic chemistry & pyrotechnics. I only wish that folks would "cut & paste" more of the contributions. The material from Britain & "ABEL ON EXPLOSIVE AGENTS." are particularly unique.
Just my opinion of course, but since the UK's 7/7 tragedy, there has been less and less public domain reading on those subjects (within & from the UK).

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 Quote: Originally posted by quicksilver Simply from an empirical standpoint, I found it potentially nightmarish if weights above a gram were employed. I believe at that weight it becomes a fairly dependable "finger-eraser". No exaggeration: I have some serious respect for it. I also agree that it also was the base metal that had additional impact on it's usage.

Attachment: Explosive Contact dermatitis from silver fulminate II.doc (19kB)

djh
----
Yes! there are books that
I own you cannot DL from
Hennig Brand
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I am not sure we are all talking about the same chemical here. For instance this story posted by The Wizard (very interesting though by the way), has the opening,

" I had employed one of my pupils, a very good operator, to prepare a small
quantity of fulminating silver, which he executed with skill.

Now Fulminating Silver is normally another name for Silver Nitride (Ag3N), which is a very different animal than Fulminate of Silver (AgCNO) or Silver Fulminate, which is what it is normally called. I don't have any experience with Silver Nitride but from watching videos and reading it seems like it is many times more sensitive than Silver Fulminate, and with very little utility.

The two names are so often mixed up that it leads to a lot of confusion.

I usually make less than a gram at a time of Silver Fulminate. A gram will make a hundred or so fairly strong bang snaps, (each one being able to make your ears ring if used indoors). I wouldn't handle it in large quantities.

The price of silver is sort of depressing, if only I had invested.

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 Quote: Originally posted by quicksilver There are very few EFFECTIVE & reliable methods to deal with the sensitivity issue. It will continue to be notoriously vicious even with a buffering concept (use of dextrin) that was an early 1920's technique the pyrotechnics industry toyed with when making "snap caps" (throw down toys for sidewalk impact). I have never heard of a commercial usage for silver fulminate as it presents all the problems inherent in a material with it's level of sensitivity (static, friction, impact, etc) and no remarkable benefits. Mostly it has been left alone after the attempts to buffer and use a feather to manipulate was deemed impracticable even for the toy fireworks industry. (see AFN article on fulminate from "Collections").

Chemical experiments
By George William Francis
London 1842
Book has been republished.
I beleive there was an American edition.

1535. Put a minute quantity of one of the fulminates along with a little glass dust on
a stone, and rub it with the face of a hammer, immediate explosion will ensue. This
fact occasions the fulminate of silver obtained by the above process to be used for
Waterloo crackers and other similar objects of amusement.

1536. To make Waterloo crackers.—Take 2 slips of stiff paper or card-board about |
of an inch wide, and 4 or 5 inches long each ; lay a mixture of powdered glass and
gum water over one end of each paper for about an inch in length, let this dry, and
then put 1/4 or an 8th part of a grain of fulminating silver upon the glass on one piece
of the paper ; place the other piece of paper upon this, so that the glass upon the
one shall rest upon the glass of the other, and the free ends of both papers be
outwards. Paste a piece of thin paper over the whole covered parts, to attach them
to each other. Upon pulling the outward ends of the papers, the two surfaces of glass
will grind upon each other, and occasion the explosion of the fulminating silver.
When these crackers are made of a larger size, with a grain or more of fulminate, they
are used as attachments to a door and doorpost, so that if any one should enter at
night, the explosion of the composition may indicate the opening of the door.

1537. Put the amount of about as much as a mustard seed of fulminating silver
into a pair of snuffers when quite cold ; upon snuffing the candle, it will explode.

1538. Put the same quantity on to a piece of paper pasted over, and while the
paste is wet, fasten it with paper all round the head of a pin ; stick the pin thus
charged in the wick of a candle. When the tallow shall have burnt away down to the
pin, the fulminating silver will explode and put out the candle. Let it be remembered,
that with this and similar experiments the grease is always scattered.

1539. Put 1/4 of a grain in a piece of tinfoil, put it then at the bottom side of a
drawer, and on opening or shutting the drawer, the powder will explode.

1540. Mix the same quantity with glass powder or sand, to which a little weak gum
water has been added. Wrap a little of this mixture in a small piece of thin paper.
When dry, throw the ball thus formed with some force against the floor or other hard
substance, and detonation will be the result.

1541. If one of these balls be put under the leg of a chair, it will go off when any
one sits down in the chair.

1542. As a cheaper material for the above purpose, the ammoniuret of mercury
may be used ; it is prepared by dissolving the protoxyde of mercury in ammonia, and
is nearly as explosive as the ammoniurets of the noble metals, gold, silver, &c. These
fulminates should always be kept under water, for when dry, even the falling of them
into a phial, or the taking them up with a piece of paper, or the point of a knife may
occasion a most terrific explosion.

djh
---
It is essential that persons having explosive
substances under their charge should never
lose sight of the conviction that, preventive
measures should always be prescribed
on the hypothesis of an explosion.

Marcellin Berthelot - 1892
Explosives and their power - Page 47

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The Boston journal of philosophy and the arts, Volume 3
1826
ART. XV.—On some Kinds of Fulminating Powder inflammable by Percussion, and their
Use in Fire-arms. By P. W. Schmidt, Lieutenant in the Prussian service.* (Philos. Mig.)

A POWDER inflammable by percussion, has been used for some years past, especially in
fowling-pieces. The following formula: have been given for the preparation of this
powder, the principal ingredient of which is chlorate of potash.
1. 100 parts of chlorate of potash (fulminating salt,) 12 parts of sulphur, and 10 parts
of charcoal are closely mixed. The grains are produced by forcing the soft paste
through a sieve.
2. 100 parts of chlorate of potash, 42 parts of saltpetre, 36 parts of sulphur, and 14
parts of lycopodium.

These are the usual ingredients that have hitherto been mixed with the chlorate of
potash for the purpose of making priming powder. The guns, however, with which
this powder is used, are very various in their construction. In some it explodes of
itself by means of the mechanism of the lock, on being cocked, into a small conical
recess, which communicates with the touch-hole, in others, it is put in previous to
every shot. In the former kind of guns a quantity of powder sufficient for a certain
number of shots is kept in a recess attached to the lock, called a magazine; and the
locks (which were invented in England by Mr Forsyth) are called maginine locks.

In some guns the stroke of the cock, which is in the shape of a hammer, falls
immediately on the fulminating powder strewed in the above recess. In order to
protect the powder from wet, small balls of it were covered over with wax, and
placed sometimes in the conical recess, and at others fixed lo the cock itself. In both
instances the ball was kindled in the recess just mentioned, by means of the
percussion.

Besides these, other contrivances have been used for the purpose of igniting this kind
of powder; yet they have all their defects, and offer so many difficulties in practice as
to have prevented their general introduction.

Latterly, they have contrived in Germany to fix the powder in a small case of very thin
copper foil, for the purpose of keeping it dry ; and for that purpose a cylinder is
screwed into the body of the gun instead of the touch-hole, and

From Schweigger's Journal, Band xi. p. 66.

rests for the sake of greater support on the plate of the lock, instead of resting on the
pan. The inner space of the cylinder is filled in loading with the same powder as that
of the shot. The igniting box, at the bottom of which is the detonating powder, is,
previous to firing, upturned on the cylinder. In this cylinder is a small round aperture
leading to the inner space of the cylinder. On the trigger being pulled, the cock strikes
the igniting box, and the fulminating powder is kindled by the blow, flows through
the aperture, inflames the shot, and breaks the igniting-box.

Mr Wright seems to have taken great pains with the subject.* He recommends, for
the firing cases, to use fulminating mercury, saying that sportsmen had justly
complained of the powder made of chlorate of potash, since it soon produces the
oxidation of the barrel and touch-hole, and the charcoal which remains after the
firing, rendering them unfit for use. The advantages of his new powder he
enumerates as follows: It does not make the gun rusty so soon as the other; it
produces neither dirt nor moisture; it is not liable to explode as the other powder,
and if it does explode its effects arc less destructive, inasmuch as its power does not
extend so far.

The following is his mode of preparation:
" I place two drachms of quicksilver in a Florence flask, and pour six drachms
(measure) of pure nitric acid on the mercury; this I place in a stand over a spirit-lamp,
and make it boil till the quicksilver is taken up by the acid ; when nearly cool, I pour it
on an ounce (measure) of alcohol in another flask: sometimes immediate
effervescence ensues, with the extrication of nitrous aether; and often I have been
obliged to place the mixture over the lamp, till a white fume begins to rise, when the
effervescence follows. I suffer the process to continue (removing the lamp) till the
fumes assume a reddish hue; when I pour water into the flask, and the powder is
found precipitated to the bottom, 1 pour off and add fresh water, permitting the
powder to subside each time before the water is pourea off, so as to free the
substance as much as possible from the acid, and then I pour it on a piece of filtering
paper, and place the powder in an airy room to dry. It should be kept in a corked (not
stoppered) bottle."

For the filling of the cups, he makes use of an ivory pin, which has a scoop at one end
for the purpose of receiving

* Mr Wright's paper will be found in Phil. Mag. vol. Ixii, p. 203. Bos. Jour. JVOT. £ Dec.
1825. 18

the powder, and at the other is cut flat. With it he puts in as much fulminating
mercury as will cover the bottom; he then dips the flat end into a strong tincture of
benzoin, and rubs this substance gently about the case; by which means the powder
is set fast and covered as with a varnish.

Professor Schweigger, speaking of these kinds of experiments in his chemical lectures,
observed on the practicability of kindling gunpowder by the admixture of other
substances, as has been shown in a criminal investigation that took place at Munich a
few years ago. A box filled with gunpowder was sent to an individual provided with
fulminating papers, which were to inflame on the box being opened. Fortunately,
however, the murderous design was frustrated ; for although the papers exploded,
they did not kindle the powder. The assassin was discovered and punished. M.
Gehlen, who had been examined at the trial, was led by the circumstance to make
several experiments for the purpose of kindling gunpowder by means of Brugnatclli's
fulminating silver, but they all failed.

It seems that in England, too, difficulties had been found in igniting gunpowder with
fulminating mercury; for Mr Wright observes, " if any one doubts the practicability of
firing gunpowder by means of fulminating mercury, by procuring a percussion-gun, he
may try the experiment and be fully satisfied."

Professor Schweigger having, therefore, requested me to try some experiments on
this subject, especially with fulminating silver, I made them in the chemical laboratory
of our university, and the following were the results.

I. Fulminating silver was prepared in the usual way ; five drachms of fuming nitric
acid, and five of alcohol were poured over one drachm of fused nitrate of silver.
When the effervescence and solution were complete, water was added. The
precipitate of fulminating silver was filtered off, and all the remaining acidity washed
from it with water. The liquid which had passed through the filter gave with muriatic
acid a copious precipitate of chloride of silver. The fulminating silver, which was of a
whitish tint, was now subjected to the following experiments :

1. When damp it ignited very rarely, and only by a strong blow. When dry, it explodes
easily, and with a much slighter blow.
2. When touched with sulphuric acid, it exploded equally strongly, whether damp or
dry.
3. Damp or dry, it exploded in the fire.
4. The substance which remained after the ignition, was of a bluish brilliant hue and
a disagreeable metallic taste. I could gather but little, which, dissolved in water,
produced a faint red tint on litmus paper.
5. I failed in several attempts to ignite gun-powder with the fulminating silver. I
therefore put quantities of the size of a small pin's head, into some copper boxes,
fastening it in some with tincture of benzoin, in others with a solution of gum arabic
in water; and others I tried to press on the bottom without any other aid. I applied
them to guns prepared for the use of igniting-boxes, and thus kindled the gunpowder
with incredible swiftness. The series of experiments thus made in the presence of
Professor Schweigger, leave no doubt that fulminating silver will easily ignite gun-
powder in a mannner that will secure it against a rapid dispersion on exploding.

II. The fulminating mercury was prepared in the manner prescribed by Mr Wright. But
I must observe that the experiment only succeeded by the application of fuming nitric
acid. The fulminating mercury, when obtained, was washed till every particle of
acidity had disappeared from it. It was then submitted to the following experiments :
1. When dry, it exploded like fulminating silver, and with a much slighter blow than
required for the powder made of chlorate of potash. Thus it would appear as if the
fulminating quicksilver had not in this respect the advantage over the igniting powder
made with the salt just named.
2. When perfectly dry only, it could be ignited with sulphuric acid.
3. In the fire it exploded, both wet and dry.
4. The substance remaining after the explosion, had a bluish brilliant tint and a bitter
acid metallic taste. With a small quantity dissolved in water, litmus paper was slightly
reddened. I made no further investigation, inasmuch as the examination of the acids
of fulminating metals, before and after the explosion, was not my object; especially
since Dr Liebig has lately published a series of very interesting experiments, the
repetition of which would require very extensive labour.* Liebig calls those acids
fulminic acids, which

* Vide Ann. it Chim. et it Phys. part xxiv. p. 294, or the translation in Gilbert's Annalen
ier Phys. part Ixxv. p. 393—422.

Mr Liebig found that Brngnatclli's detonating silver was dissolved in lime-water or
solutions of the caustic alkalies, whereby being the property of all metals, he
distinguishes into silver and mercury fulminic acids, &.c.

The great advantages, however, of the fulminating quicksilver as igniting powder,
extolled by Mr Wright, I did not find confirmed; although l proceeded to fill copper
boxes, as I had done with the detonating silver, which all ignited the charge.
III. I also submitted to experiment the first-named mixture, principally consisting of
chlorate of potash ; and found

1. That it exploded only by a hard blow. Its efiicts were much less than those of the
detonating silver or quicksilver. Mr Wright, indeed, says the contrary of the latter; it
seems, therefore, that I used a better kind of fulminating mercury ; but for that very
reason I must give the chlorate of potash the preference for practical use.

2. In the fire it pufled away like gunpowder.

3. The substance remaining after the explosion is blackish and dusty, and contains
less of acidity than that left by the quicksilver. Thus, and indeed from all my
experiments, it is evident that it oxidizes the iron less than the fulminating mercury.
Moisture is also left by the latter; and the charcoal left by the mixture of chlorate of
potash, after kindling a copper box filled with it, is very unimportant:—therefore this
mixture is preferable as an igniting powder. This is also the reason why the
manufacturers no longer use the fulminating quicksilver. I know one who makes and
fills weekly several thousands of copper caps, for which he uses the chlorate 31,25
per cent of oxide of silver was deposited. They produce peculiar salts, called
fulmiiuttts, which explode with great violence. These salts are dissolved l.iy nitric acid,
sulphuric acid, and acetic acid ; the silver fulminic acid contained in them, and so
difficult to be dissolved, is deposited; and by heating a solution of fulminate of lime
to the boiling point, and adding a moderate quantity of nitric, acid is deposited, on
cooling, at the bottom of the vessel, in the shape of long white crystals. This acid may
be easily dissolved in boiling w ater ; from which it crystallizes again in cooling, has a
disgusting metallic taste, and reddens litmus paper. But it cannot subsist of itself
without combination with a metal; and m the same manneras there are prussic acids
of iron, copper, silver, and gold, so the fulminic acid combines with silver, quicksilver,
copper, iron, zinc, ice, into proper fulminic acid, which again form different
combinations with the bases, e. ir. potash, soda, barytes, strontian, lime, &c. Thus,
for instance, silver-fulminate of potash consists of 35,03 parts of silver-fulminic acid
and 14,ir2 of potash ; silver-fulminate of soda, of 88,6ti parts of silver-fulminic acid
ar.d 11,34 of alkali. When cooling, Berthollet's detonating silver forms granular
shining white crystals. One part of this salt makes as violent a report as three parts of
Howard's (Bru^natelli's) fulminating silver With magnesia the silver-fulminic acid
combines in two ways. One combination is a simple decrepitating, not detonating,
insoluble powder, of a rosy tint; the other forms white capillary crystals, and
explodes very loudly. The first combination was used for the analysis of fulmic acid in
the dry way ; in which the fulminating silver was evinced to consist of 32,22 of
oxygen, 3,22 of hydrogen, 11,28 of azote, 9,68 of carbon, and 41 of silver. mixture, the
preparation of which is both less expensive and less dangerous than that of the
fulminating quicksilver. There is another circumstance attending this mixture. In filling
the caps, it will sometimes happen that the quantity put in is doubled, which I find is
of no injurious consequence with this mixture; but might endanger the person firing
with the fulminating mercury, as the box will burst too violently.

With respect to the power of igniting the charge, the different kinds of powder whLh I
have compared are equally effectual.

IV. I submitted the mixture of chlorate of potash mentioned above to the following
experiments.
1. That part only ignited which was struck, without igniting that lying around it.
2. In the fire it burns away with noise.
3. I placed it in the usual way in copper caps, but could not ignite a charge with them.
The cause of this may be explained by the construction of the locks, with reference to
the properties of this detonating powder. That part of the cap situated just above the
opening of the cylinder remains, as the blow cannot fall on it unignited, as shown by
the experiment No. 1. But the communication of the ignited part with the charge, is
prevented by the manner in which the cock strikes the cap. In guns in which such
powder is used for igniting, it lies as above stated, in small balls in a conical aperture.
Here it is nearly all ignited by the striking of the cock, and must of necessity flow
inwards, every other way of escape being shut up.

In conclusion:—I have to add that the method of filling the caps recommended by Mr
Wright is not only laborious, but even dangerous. How are manufacturers to employ
that method when they have to fill several thousands a week ? I have made various
trials, and the following process seems to me to be the best.
Pour some adhesive solution or tincture over the powder, and mix it into a stiff kind
of liquid. Take with a brush or a stick a large drop of it, and apply it against the
bottom of the cap.

This method is both quick and free from danger; whilst on filling with the dry
detonating powder, the least careless touch may produce an explosion.

In order to prevent the corrosion of the cylinder, and its becoming useless by the
formation of sulphuret of iron (an evil very common with iron touch-holes, and
caused more by the action of the gun-powder than by that of the igniting substance),
the inside of the cylinder should be lined with a metal which will neither oxidate nor
easily combine with the ingredients of the powder.
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