(i8) 
ON CERTAIN PHENOMENA PRODUCED BY THE DETONA¬ 
TION OF GUN COTTON. 
PROF. CHARLES E. MUNROE, S. B., F. C. S., 
Chemist to the Torpedo Corps, U. S. Navy. 
Gun-cotton is, as its name implies, an explosive substance, 
produced from cotton. It is necessary only to immerse pure dry 
cotton for twenty-four hours in a mixture of the strongest nitric 
and sulphuric acids to convert the cotton into gun-cotton. The 
subsequent treatment which the gun cotton undergoes is solely for 
the purpose of purifying it. 
This substance was discovered by Schonbein in 1846, but its 
present usefulness as an explosive is dependent upon three subse¬ 
quent discoveries. 1st, Abel’s: That gun-cotton may be com¬ 
pletely freed from acid by converting the gun-cotton into pulp. 
2nd, Nobel’s: That a high explosive may be detonated by the in¬ 
itial detonation of mercury fulminate. 3rd, Brown’s : That not 
only may dry gun-cotton be so detonated but that it may also be 
detonated when wet if only a small initial mass of dry gun-cotton 
is detonated in contact with it. 
Dry gun-cotton may be exploded, if confined, by contact with 
a spark, flame or heated body or by a blow between metals like 
iron, but if unconfined and loose it will be very rapidly consumed. 
The speed of combustion may be very materially diminished by 
compressing the cotton, and the pulping of the material enables us 
to do this very readily, so that it is now always produced in this 
form for use as an explosive. The gun-cotton for the U. S. Navy, 
which is manufactured at the Torpedo Station, is issued in the 
form of cylindrical disks three and a half inches in diameter and 
two inches in height or in rectangular blocks of nearly the same 
dimensions. 
When wet with twenty per cent, of water, gun cotton is practi¬ 
cally incombustible and when exposed to fire in this state the sur¬ 
faces are gradually consumed layer by layer as the water dries out 
from them, hence it is very safe to store and transport when in 
this state, and as it may be exploded by detonation while wet, it 
is issued to the service in this condition. Gun-cotton, therefore, 
