external characters of lustre,
softness, and translucency, but the all-important quality of uniformity
of thread. The collodion-spinning is a process still very defective in
this respect, and the defect is no doubt referable to the difficulty of
securing absolute physical invariability of the collodion. It is to be
regretted, in the interests of scientific development, that none of the
technologists who have published investigations of these processes have
entered into the discussion of the fundamental factors of the spinning
processes; we are, therefore, unable at this stage to discuss these
elements of a full comparison in greater detail. We cannot, for this
reason, say how far the cuprammonium process diverges in point of
control from the standard of the collodion processes. Of the 'viscose'
product we have a more intimate knowledge, and it certainly reaches a
higher general standard than the older and now well-known artificial
silks. The process is also sufficiently developed to enable the total
costs of production to be estimated at a figure less than one-half that
of the 'collodion' processes. This would assure to this system an
_entree_ in this country, and a basis of expansion limited only by the
ordinary laws of supply and demand.

This prospect is opened up precisely at the moment when, for various
reasons connected both with the difficulties of manufacture and the
narrowing of the margin of profit, the proprietors of the two systems of
collodion-spinning have decided to abandon all idea of manufacturing by
these systems in this country.[15] We leave the discussion of the
industrial problem at this point.

In regard to other developments based upon the exceptional character and
properties of the sulphocarbonate, their further discussion will
exemplify no general principles; and as regards technical detail they
have been dealt with in the papers previously noticed.

As a purely general question, if there is to be any industry in these
'artificial' forms of cellulose, commensurate with the magnitude that
usually belongs to the cellulose industries, it must come by way of a
plastic or soluble form prepared at low cost, and conserving the
essential molecular properties of the cellulose aggregate. These are the
particular features of the sulphocarbonate. The obvious difficulties in
the way of its industrial applications are those caused by the presence
of alkali and sulphur compounds. These are dealt with by app