ass. Various other inventors, e.g. Du Vivier
(10), Cadoret (11), Lehner (12), have attempted the addition of other
substances to modify the thread. These have all failed. Lehner, who
persisted in his investigations, and with success, only attained this
success, however, by leaving out all such extraneous matters. Lehner
works with 10 p.ct. solutions; Chardonnet has continually aimed at
higher concentration up to 20 p.ct. Lehner has been able very much to
reduce his pressures of ejection in consequence; Chardonnet has had to
increase up to pressures of 60 k. per cm. and higher. The latter
involves very costly distributing apparatus. Lehner made next
considerable advance by the discovery of the fact that the addition of
sulphuric acid to the collodion caused increase of fluidity (13), which
Lehner attributes to molecular change. Chardonnet found similar results
from the addition of aldehyde and other reagents (14), but not such as
to be employed for the more concentrated collodions. The author next
refers to his discoveries (15) that alcoholic solutions of a number of
substances, organic and inorganic, freely dissolve the lower cellulose
nitrates. The most satisfactory of these substances is chloride of
calcium (16). It is noted that acetate of ammonia causes rapid changes
in the solution, which appear to be due to a species of hydrolysis. The
result is sufficiently remarkable to call for further investigation. The
chloride of calcium, it is thought possible, produces a direct
combination of the alcohol with a reactive group of the nitrocellulose.
The fluidity of this solution using one mol. CaCl_{2} per 1 mol.
tetranitrate (17) reaches a maximum in half an hour's heating at
60 deg.-70 deg.C. The fluidity is increased by starting from a cotton which has
been previously mercerised. After nitration there is no objection to a
chlorine bleach. Chardonnet has found on the other hand that in
bleaching before nitration there is a loss of spinning quality in the
collodion. The author considers that the new collodion can be used
entirely in place of the ordinary ether-alcohol collodion. With regard
to the properties of the denitrated products they fix all basic colours
without mordant and may be regarded as oxycellulose therefore. The
density of the thread is from 1.5 to 1.55. The thread of 100 deniers
shows a mean breaking strain of 120 grammes with an elasticity of 8-12
p.ct. The cardinal defect of these fibres is their property o