Page:Popular Science Monthly Volume 66.djvu/445

Rh. In the straw of our wheat and oats crops, which is to-day largely destroyed on the fields, we have another source of cellulose of which we avail ourselves but little. In Europe the production of straw fiber is carried on to some extent, but is capable of great extension should sufficient economy in the process for treating it be introduced. The high content of silica has ever been a source of loss, owing to the fact that the formation of sodium silicate prevents the recovery of the soda now used in the digestion of the straw.

By far the greatest loss of valuable cellulose, however, is found in waste cornstalks and in bagasse, or in the sugar-cane after the soluble portions have been removed. There is a close analogy between these two products in that there is associated with the woody portion carrying the cellulose a large amount of non-usable pith. Rapid progress has been made in the utilization of both of these raw materials within the last few years and the indications are that before long they will prove a source of value rather than a nuisance as is frequently the case at present. The market price of bleached cellulose fiber is to-day from two and a half to three and a half cents per pound. Starch may be bought for from two and a half to four cents, according to its source. It is seen, therefore, that there is little manufacturing margin in the conversion of cellulose into starch or sugar until the cost of the former has been considerably reduced. This can come about only through new processes designed to operate more economically than those at present in use and to use as raw products the cellulose at present wasted on the fields.

It would seem that a more economical step towards the production of food from wood might be through its ligneous or non-cellulose constituents. For every ton of cellulose produced there must be used two tons of wood; that is, an equal weight is wasted. In the soda process as now conducted these non-cellulose materials are burned to recover the soda which is held in combination with them. In the sulphite process this enormous amount of material, aggregating for America alone in a single year almost one million tons, finds its way into the water courses and ultimately to the ocean. This organic matter is most complex in its composition, but consists largely of one class of substances closely allied to the sugars, and another class having the general characteristics of tannins. That these sugar like substances could be made to yield a food material is from their nature quite possible; so far as we know, however, but little has been accomplished in this direction. A number of uses have from time to time been proposed for this waste, but as yet none has been of practical value. Among the more promising may be mentioned a preparation to be used in tanning leather, a sizing material for paper and. a substitute for dextrine in calico printing and as an adhesive.