A chemist of the Department of Agriculture had once occasion to make
experiments with flax fibers, his object being to make them chemically
pure; and to this end he treated them with excess of bleaching agents,
thus rendering them of a beautiful white, silky appearance, to the naked
eye; but when I examined them under the microscope, I found the brown
nitrogenous matter of the joints still present, and on using the chromic
acid test, they became deeply stained. A chemical solution of flax
therefore would prove for some purposes undesirable, owing to the
presence of this ligneous matter. A chemical solution of cotton which is
destitute of ligneous matter will give a chemically pure solution. Cotton
is therefore better adapted than flax for collodion compounds.