ETHERIAL SOLUTION OP PREPARED COTTON. 
183 
ed its preparation. This has been attended with varying 
success from ignorance of the precautions necessary to be 
observed, and from the absence of correct formulae. 
The following observations are the result of a series of 
experiments in making the solution which have several 
times disappointed us : as far as they go they are freely 
offered for the benefit of others who may be disposed to 
attempt it. 
1st. Ordinary commercial gun cotton is not soluble in 
ether. 
2d. The best formula that we have tried for the 
preparation of this solution is as follows : 
Take of Nitric acid sp. gr. i.452, 
Sulphuric acid (Commercial) each, 1 fluid ounce, 
Cleansed and bleached cotton, 2 drams. 
Thoroughly saturate the cotton with the acids, and macerate 
for twelve hours. Then wash the cotton, dry it rapidly by 
artificial heat, in the shade, and dissolve it in 
Sulphuric ether, one and a half pints. 
3d. Gun cotton as thus prepared, will lose its solubility 
entirely, by being kept a few days, or particularly by being 
exposed to the sun's rays. 
4th. The gun cotton prepared as above, is entirely solu- 
ble in the officinal sulphuric ether, though not in the hy- 
drated ether or letheon. 
5th. As many groundless objections to the solution are 
due to its being carelessly or improperly applied, care should 
be taken to saturate the fabric used in making the plaster, 
with the liquid, and to allow it to dry while inclose contact 
with the skin, and where a permanent plaster is required, 
it is well to apply it over the exterior surface with a brush. 
When thus applied, a piece of muslin one inch in breadth, 
and applied over a space of an inch and a half in length, 
will sustain a weight of ten pounds, its adhesion not being 
affected by moisture or temperature. 
6th. Some solutions of cotton, though resembl ng the 
