ustra-celluloses,' by the collodion processes
also, whilst presenting features of unusual interest attaching to rapid
expansion, has been barren of contribution of fundamental scientific or
technical importance. The tetracetate is now manufactured on the large
scale, but the product has yet to make its market.

The process of mercerising cotton yarns and cloth has been developed to
an industry of colossal dimensions, and the growth has been especially
rapid during the last five years. Significant of the technical progress
in these two industries, with their common aim of appreciating cellulose
in the scale of textiles by approximating its external properties in
those of silk, is the appearance of a monograph of the technology of
each, notices of which have been previously given (pp. 22-26).

There is little doubt, however, that the question of the future
industry in the various forms of cellulose, thread, film, structureless
powder or solid aggregate, obtainable by artificial means, mainly turns
upon cost of production. Irrespective of cost, there would, no doubt, be
a market for all these products, based upon such of their properties or
effects as are indispensable and not otherwise obtainable. As an
illustration, we may cite the extraordinary selling prices of 40-50 fr.
per kilo, for the 'artificial silks' (collodion process) which ruled
some three years ago; and we may note that for a special application of
viscose the dissolved cellulose is paid for at the rate of 10 per
lb. These facts are certainly worthy of mention, and should be borne in
mind as an index of some special features of modern manufacturing
industry. But with a material like cellulose rendered available in a new
shape the question which always arises more prominently than that of
limited uses at high prices is that of consumption on the extensive
scale which marks the older and well-known products. That question is
rapidly solving itself in this country as regards the 'artificial
silks.' There is at present a limited market at 9s.-10s. per lb., a
price which on the one side excludes extensive consumption, and on the
other practically bars manufacture in this country by any of the
collodion systems. It will appear from a very elementary calculation of
what we may call the theoretical costs that the above selling price
would not have a remunerative margin. The theoretical costs are made up
of

Raw materials[14] {Cotton. Nitrating acid. Ether-alcohol