510 
ME. E. A. ABEL’S CONTRIBUTIONS TO 
complished, although the charge of nitroglycerine was gradually increased to 1 grm. 
The disk of compressed gun-cotton which rested upon a support of wood was shattered 
almost to dust, portions being driven deeply into the wood, which exhibited an indenta- 
tion corresponding to the form of the disk. In order to compare the mechanical effect 
of the detonation of nitroglycerine with that of the strongly confined fulminates, 
065 grm. (10 grains) of the liquid were placed in the small tin tube upon stout sheet 
copper and detonated by means, of 0T4grm. (2 grains) of mercuric fulminate; the work 
done upon the copper resembled in extent that accomplished with a corresponding 
charge of the confined fulminate (double the amount required to effect the detonation 
of gun-cotton). It appeared evident, therefore, that some power, apart from violence of 
explosion, was wanting in nitroglycerine to produce the result obtained with the fulmi- 
nate. With a view to obtain still more decided evidence on this point, the experiments 
were continued upon a larger scale. Some four-ounce (124 - 5 grms.) disks of compressed 
gun-cotton were placed upon thick supports of wood, and confined charges of nitrogly- 
cerine, weighing about 0‘ 75 ounce (23‘3 grms.), were placed upon these disks and succes- 
sively exploded. The pieces of wood were more or less shattered ; they were deeply in- 
dented (the circumference of the disk being clearly imprinted upon them), and the 
gun-cotton was pulverized and violently scattered, portions being driven firmly into the 
wood, but the desired result was not in any instance accomplished. As a last experi- 
ment, the wooden support bearing the disk of gun-cotton with the vessel containing 
(23 - 3 grms.) O’ 75 ounce of nitroglycerine, was buried about 6 inches in the ground, the 
.stiff clay soil being firmly pressed over the whole. The explosion of the nitroglycerine 
'threw the earth up violently, the piece of timber was split across the fibre and shattered 
in the centre, and the gun-cotton, in a fine state of division, was found disseminated in 
the earth and partly forced into the wood *. 
In contrast to the foregoing results, it may be mentioned that small perforated 
cylinders of compressed gun-cotton, weighing 7'75 grms. to 15‘5 grms. (0'25 oz. to 0’5 oz.), 
with the usual small confined charge of mercuric fulminate inserted into the perforation, 
have frequently been employed, and invariably without failure, for effecting the detona- 
tion of a large disk or slab of gun-cotton, or of a number arranged side by side in open 
air, by simply placing them upon or against any one of the surfaces of the larger mass of 
gun-cotton. It should also be stated that the detonation of a small quantity of nitro- 
glycerine has been found to accomplish the simultaneous explosion of surrounding 
charges of that substance closely confined in small vessels of sheet tin, and placed at 
distances of 2 or 3 inches from the central charge. Lastly, it was found that the deto- 
nation of 7*75 grms. (0-25 ounce) of gun-cotton determined the explosion, simultaneously 
with it, of a charge of nitroglycerine confined in a vessel of sheet tin and placed at a 
distance of 1 inch from the gun-cotton, while 15‘5 grms. (0-5 ounce) of the latter pro- 
duced the same result when separated from the confined nitroglycerine by a space of 
3 inches. All these experiments were so conducted that indisputable evidence was 
* These experiments were repeated with 1 ounce of nitroglycerine, with the same results. 
