mercury fulminate


The Allen and Wheelock lipfire revolver,

Invented by Ethan Allen in 1860, the Allen and Wheelock revolver was an attempt to circumvent the Rollin White patient on the bored through cylinder, which allowed for practical metallic cartridge revolvers, and the rimfire cartridge held by Smith and Wesson.  The new revolver used metallic cartridges called “lipfire cartridges” which featured a small lip containing mercury of fulminate which served as the priming component of the cartridge. 

Ethan Allen claimed in his patent application for the lipfire cartridge that it was meant to reduced costs compared to the rimfire, where priming component rimmed the entire cartridge.  The cartridges had to be placed lip up, and recessed were machined into the cylinder so that the lip would fit snugly. The Allen and Wheelock lipfire revolver came in both .36 caliber (Navy) and .44 caliber (Army) models.

While the revolver was intended to evade the Rollin White patent, the fact of the matter was that it still had a bored through cylinder. Only 500 were produced before Rollin White and Smith & Wesson filed court injunctions, forcing Allen and Wheelock to cease production in 1863.


Forsyth lock pistol

Manufactured by Forsyth & Co. In London, United Kingdom c.1807~1810′s - serial numbers are overrated anyway.
.49 caliber twin smoothbore barrels, scent-bottle percussion lock, swivel ramrod and gold inlays.

A very rare type of lock, Forsyth’s design worked a bit like a rotating pez dispenser filled with mercury fulminate priming pellets.


Demonstrating an explosive: mercury(II)-fulminate!

Mercury(II)-fulminate and other fulminates are quite interesting compounds, the fulminate anion’s chemical composition is identical with the cyanate anion (fulminate: -CNO, cyanate: -OCN), only the sequence of the carbon, nitrogen and oxygen is different. With the this small difference something important also changes: cyanates are white powders, doing nothing when heated, while fulminates (especially silver and mercury and other heavy metal fulminartes) explode upon heating

Interesting fact no. 1: when mercury fulminate detonates one of the decomposition products is elemental mercury what is left behind on the surface where it exploded (in the case on the surface of the paper) and it lets us see where did the “reaction happened”. 

Interesting fact no. 2: the famous chemist Justus Liebig when he was a teenager published an experimental writeup (his first publication) about how can we prepare safely silver(I)-fulmite what is also a powerful, light, heat, friction and everything sensitive explosive. 


Webster double scent-bottle percussion shotgun

Manufactured by Webster & Co. at 122 Regent Street, London c.first third of the 19th century.
16 gauge loose powder and shots, Forsyth’s scent-bottle percussion lock, twin side-by side smoothbore barrels with their respective triggers.

A scent-bottle lock, as designed more or less by reverend Alexander Forsyth in Scotland when he started to get annoyed by his game not being immediately shot by his flintlock hunting shotgun - it instead ran away when it heard the detonation in the pan, was a small bottle filled with mercury fulminate that when rotated a full turn would drop enough of it in front of the barrel’s touch hole. A captive firing pin would then be depressed by the hammer into the fulminate, setting off the gun.

This was before the percussion cap was invented by François Prélat in Paris and made thing a little simpler, but it did have the advantage of being very safe to carry around since the scent-bottle’s pin could rotate out of the hammer’s reach.


The Butterfield Priming System,

By the 1850’s the user of percussion caps for an ignition system ended the use of the flintlock mechanism for most military muskets.  However there were many ingenious designs created to compete with the percussion cap.  One such system was invented by Jesse Butterfield in 1855.  Rather than using a copper cap filled with mercury fulminate, the Butterfield system used small cylindrical shaped wafers or pellets of mercury fulminate called “Butterfield’s Wafers”.  This was combined with a feeding mechanism that was installed on the lock of the musket.  The mechanism featured a tube which held a number of wafers, and when the hammer was cocked, a spring loaded mechanism would force a wafer out of the reservoir while a sliding bar would push or feed the wafer onto the nipple for firing.  When struck the mercury fulminate would explode, sending a spark down into the chamber which ignited the main charge.

Butterfield’s system was a good idea in theory.  The idea was that the system reduced the process of loading a musket by one step; placing a percussion cap on the nipple. It was also meant to solve function problems of the caplock system, namely when a spent cap became lodged into the cup of the hammer, it could cause a misfire (happened to me), or in the case of revolvers, jamming up the cylinder.  However since Butterfield’s wafers lacked a metal cap, this was not an issue. In practical terms, however, Butterfields wafers and feeding mechanism failed in real world condition.  The wafers themselves were much more susceptible to the effects of moisture compared to percussion caps.  In addition the feeding mechanism often jammed or malfunctioned.  Misfires were very common.  A few thousand older Springfield and Harpers Ferry muskets were converted to the system, although for the most part regular percussion caps were used instead of the Butterfield wafers.  A small number of Betterfield priming breechloading rifles were produced as well.  Jesse Butterfield also designed a .41 caliber revolver which utilized his system (bottom picture).  In 1861, at the beginning of the American Civil War, the US Government contracted him to produce an order of 2,250 Butterfield revolvers, of which only 650 were delivered.  None were ever officially issued but a few hundred were fielded by soldiers who privately purchased them.