Treparation of a Fulminating Oxalate of Silver, 185 



powder by burning them in cannons of equal diameter, 

 which are cased in cork, so that they may be afterwards 

 placed la water and immersed almost entirely lengthwise* 

 I was desirous of burning in the same manner an arsenical 

 nuxlure along with an equal quantity of the same powder, 

 that I might compare their flames and duration : but 

 scarcely had I time to retire a little, after having set fire t9 

 the two cannons, when the tirst made an explosion and 

 burst, breaking the glass vessel^ and throwing the water in, 

 all directions like radii from a connnon centre. Though 

 the moulh of the tube was not confined, so that the escape 

 of the iiame was free, the cannon split from the top to the 

 bottom and unrolled itself like a card. This powder is so 

 violent in its effects that in mv opinion it would be danger- 

 ous to try to make any application of it. If two long trains, 

 one of gxmpowder and the other of the above mixture, be 

 formed on a table, and if they be made to coincide at one 

 extremity in order to set fire to them at the same tirae^ you 

 will be astonished to see the one disappear like lightning, 

 while the other seems to burn exceedingly slow. 



FREPARATIOX OF A FULMINATING OXALATE OF SILVJER. 



Extracted from a Letter of Brugnatelli. 



Take 1 00 grains of lapis infernalis in powder, and having 

 put them into a beer glass pour over them first an ounce of 

 alcohol, and then as much concentrated nitrous acid. Ths 

 mixture becomes heated, enters into ebullition, and there 

 is visibly formed ether, which is changed into a gaseous 

 fluid. The matter gradually becomes milky and opake, 

 and is filled with small very w hite flakes : when the whole 

 gray powder of the lapis infernalis has assumed this form, 

 and when the liquor has acquired consistence, you must 

 immediately add distilled water to suspend the ebullition, 

 and to prevent the matter from being re-dissolved, so that 

 nothing may be found but the solution of silver. Then 

 collexit the white precipitate on a filler, and sufier it to dry. 

 This precipitate is fulminating silver : a little more than 

 half the weight of the lapis infernalis employed is obtained. 

 The detonating force of this preparation even in a much 

 cmaller quantity far surpasses that of i'ldminating mercury 

 prepared according to the process of Mr. Howard. It de- 

 tonates iri a terrible nianner when scarcely touched with a 

 glass tube the extremity of which has been dipped in con- 

 centrated sujpliuric acid, or even that of the shops. A grain 

 of this I'uhiiinating silver put upon a burning coal made so 

 }oud a report that it stunned the by-standcrs. The same 



ctVcc^ 



