PREPARATION OP COLLODION. 
43 
in a cloth. Pull it out into a loose mass, and dry it in a 
stove at a moderate heat. 
The compound thus obtained is not pure fulminating cot- 
ton; it always retains a small quantity of sulphuric acid, is 
less inflammable than gun-cotton, and it leaves a carbona- 
ceous residue after explosion. It has, however, in a remark- 
able degree, the properly of solubility in ether, especially 
when mixed with a little alcohol ; and it forms therewith a 
very adhesive solution, to which the name of Collodion has 
been applied : 
Preparation of Collodion. 
Prepared cotton - - - .- .8 parts by weight. 
Rectified sulphuric ether - - 125 ie " 
Rectified alcohol - - - - 8 " . " 
Put the cotton with the ether into a well-stopped bottle, 
and shake the mixture for some minutes. Then add the al- 
cohol by degrees, and continue to shake until the whole of 
the liquid acquires a syrupy consistency. It may then be 
passed through a cloth, the residue strongly pressed, and the 
liquid kept in a well-secured bottle. 
Collodion thus prepared possesses remarkably adhesive 
properties. A piece of linen or cotton cloth covered with it, 
and made to adhere by evaporation to the palm of the hand, 
will support, after a few minutes, without giving way, a 
weight of from 20 to 30 lbs. Its adhesive power is so great 
that the cloth will commonly be torn before it gives way. 
The collodion cannot be regarded as a perfect solution of 
cotton. It contains, suspended and floating in it, a quan- 
tity of the vegetable fibre which has escaped the solvent ac- 
tion of the ether. The liquid portion may be separated 
from these fibres by a filter, but it is doubtful whether this 
is an advantage. In the evaporation of the liquid, these 
undissolved fibres, by felting with each other, appear to 
give a greater degree of tenacity and resistance to the dried 
mass. 
