THE HISTORY OF EXPLOSIVE AGENTS. 
347 
c. Experiments with mercuric fulminate. 
The fulminate employed in these experiments to furnish the initiative detonation 
was enclosed in strong tubes or cases of tinned iron, the openings of which were firmly 
closed by means of the electric fuse used for exploding the charge. The quantity of 
fulminate inserted into the opposite extremity of the tubes was, in all instances, 100 
grains (6 -48 grms.), and was loosely confined by being screwed up in moderately stout 
paper. 
1. Employment of wrought-iron titles of T25 inch (-031 m.) diameter . — The explosion 
of 5 grains (’324 grm.) of the fulminate, in one extremity of a tube 1 foot (‘304 m.) 
in length, detonated the charge which was just inserted in the other extremity; but 
the detonation produced varied in violence, and it appeared as if 1 foot were about the 
limit of distance through which detonation was susceptible of transmission under 
the above conditions, as regards dimensions and force of initiative explosion. The 
explosion of 10 grammes of the fulminate did not induce detonation through a tube 
of double the length (2 feet =-608 m.), and with 15'4 grains (1 grm.) the same 
negative results were obtained. On inserting the fulminate-fuse, containing 15 "4 grains 
(1 grm.) of the substance, to distances of 6 inches, 3 inches, and 2 inches (T5 m., 
•075 m., - 050 m.) into the tube 2 feet long, explosion of the fulminate inserted 
into the other extremity was always induced ; but the effects were those of a violent 
detonation only when the fuse was inserted to the maximum distance (6 inches), 
leaving a length of 18 inches ( - 45 m.) through which detonation was transmitted. 
When tubes of the same diameter, only 18 inches in length, were employed, the fuse 
charged with 15 -4 grains (1 grm.) of fulminate being just inserted into one extremity, 
the explosion induced in the other was not so violent as in the preceding experiments 
when the charges were separated by the same distance, the initiative explosion being, 
however, produced at some distance (6 inches) inside the tube employed. In these 
cases the transmission of the concussion was obviously favoured by the circumstance 
that the tube projected some distance beyond the seat of the initiative detonation, 
the loss of force by dispersion in other than the desired directions being thereby 
much reduced. With 23 grains (T49 grm.) of the fulminate just inserted into one 
opening of a tube 2 feet (-608 m.) long, detonation was induced at the other extremity ; 
and the same result was obtained with the above quantity of fulminate when tubes 
3 feet (’91 m.) long were employed. 
2. With tubes 1 inch (-025 m.) in diameter and 2 feet long , the detonation of 
10 grains ('65 grm.) of the fulminate inserted into one extremity produced explosion, 
though not of a very violent character, at the other end. In one instance, among 
several experiments with these tubes and the above quantity of fulminate, violent deto- 
nation was induced, the conditions of the experiment being evidently just bordering on 
the limits of those essential to the development of detonation by transmission of the 
concussion. 
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