THE EOYAL AETILLEEY INSTITUTION. 
381 
Chemical Laboratory of the Engineers' Corps Committee, as may be seen 
in the Keport of the Imperial Academy of Science, Yol. XLYII, p. 59, 
Mathematical and Physical part; and which may be seen in the following 
table, in which the gases of combustion of powder according to Bunsen 
(vide Poggendorf, 4th Series, Yol. XII., p. 131), are cited in comparison 
with those of gun cotton. 
Gases of combustion. 
Volume per cent. 
Bunsen. 
Karolyi. 
Sporting. 
Eifle. 
Common 
powder. 
Gun cotton. 
Nitrogen. N. 
Carbonic acid .C.0. 3 
Carbonic oxide.C.O, 
Hydrogen. H. 
Sulphur and hydrogen H.S. 
Oxygen. O. 
Light carburetted hydrogen gas 
41-1 
62-7 
3-9 
1-2 
•6 
•52 
•00 
35-3 
48-9 
5- 2 
6- 9 
•67 
3-02 
37-6 
42-7 
10-2 
6-9 
•86 
2-7 
12-7 
20-8 
29-0 
3-2 
Carbon) 1*8 
Water ) 25-37 
7-2 
If we compare the gases of gunpowder with those of gun cotton, we easily 
see that the chemical action of the product of combustion of gun cotton on 
the sides of the barrel—if there exists any action at all—must be smaller 
than with the use of gunpowder, because they are less oxidizing gases than 
those of gunpowder. 
Should, therefore, bronze barrels be “burnt out" by the use of gun 
cotton, cast steel may be then used instead of bronze, which, in fact, has 
been successfully done. 
Moreover, bronze gun-barrels have withstood a sufficient number of 
rounds by using an adequate charge of gun cotton with elongated cartridges. 
In this way no alteration of the bore prejudicial to the correctness of aim 
has taken place. 
Prom the steel barrel of a rifle, forty rounds have been fired with gun 
cotton cartridges, which have hit the target 300 yds. distant in an unexcep¬ 
tionable manner. After the said number of rounds, the barrel was internally 
as clean and polished as a mirror. It appears, then, that this problem is 
solved in a general and satisfactory manner. 
Application of Gun Cotton to Mining Warfare. 
17. Gun cotton is also used for mining purposes and mining warfare. On 
this subject nothing but what is favourable has been reported by the Imperial 
Engineers (vide Communications of the It. K. Engineers' Committee, 1861, 
Yol. I., by Moritz Baron von Ebner, Colonel of the Engineers). 
However, it is said that the gases of gun cotton were more poisonous in 
mines than those of gunpowder, and, therefore, the use of gun cotton for 
mining warfare is not to be recommended. 
If we compare the result of Lieutenant Karolyi's analysis of the com¬ 
bustion gases of gun cotton with those of gunpowder as above given, we 
observe that both of them contain irrespirable gases; further, that they 
contain qualitatively the same sort of irrespirable gases; and although the 
