n of the
machine the rolled batch of cloth nearly fills the cylindrical space of
what we may call the reaction chamber, and the circulation of the liquid
is maintained by a circulating pump and a differential pressure in the
horizontal plane across and through the folds of the batch. This is in
the meantime kept in slow revolution. For a full description of these
mechanical details the reader is referred to the original patent
specifications [Engl. Pat. 23,400, 23,401; 1900, W. Mather]. If we again
consider the principles involved, they are very much as set forth in
our original work (pp. 288-291). Boiling processes in which a
relatively large volume of liquid is used are wasteful of steam, the
active agent is unnecessarily diluted or used in superfluous quantity,
and the soluble by-products, being continually removed as formed, cannot
so effectively contribute by secondary actions to the chemical work. The
new mechanical appliance enables us to further reduce the volume of
liquid required in the alkaline-hydrolytic treatment of vegetable
textiles, and where advantageous to bring the treatment down (or up) to
a process of steaming with the active agent dissolved in a minimum
proportion of water relative to the cloth. This concentration of effect
is of importance in flax cloth, and especially linen treatment, where
the peculiarly resistant cutocelluloses have to be attacked and a
considerable proportion of waxy by-products to be removed. These points
are the basis of the special process of Cross and Parkes [Engl. Pat.
25,076/ 99] for steaming flax (and cotton) goods with an emulsion
containing, in addition to the special hydrolysing agent--caustic
soda--mixtures of soap with 'mineral' or other oils, the presence of
which effectually aids the removal of the by-products in question.

A complete system on these lines is now working on the industrial scale
in the Belfast district. The results are not merely economical in
largely reducing the number of alkaline boiling treatments required on
the old plan of pan or 'pot' boiling, but are visible in the strength
and finish of the linens so treated.

For cotton bleaching the costs may be put down at a fraction of those of
the Irish linen bleach. The economical advantages of the new system are
obviously less in relation to the lesser total costs. But there are
other points which have come into more prominent influence. The
mechanical wear and tear on the cloth is considerable in