Page:Zacaton as a paper-making material (IA zacatonaspaperma309bran).pdf/26

 BULLETIN

20

300,

U.

S.

DEPARTMENT OF AGRICULTURE.

This evidence was considered sufficiently complete with regard to the oxycellulose The behavior of Epicampes pulp with the usual solvents of cellulose was

question. tried,

with results

as follows:

Schweitzer's reagent dissolved all but the merest faint trace of the fiber. (6) Concentrated sulphuric acid dissolved the fiber quite rapidly and completely, with a very faint darkening in color not nearly so dark as straw celluloses usually (a)

—

give with sulphuric acid. (c) Zinc chlorid in concentrated hydrochloric acid dissolved the fiber more slowly

than did sulphuric acid, but quite completely. (d) Zinc chlorid solution swelled the fiber, but dissolved it only slowly. The percentages of ash and moisture were also determined, ash being 2.2 per cent and moisture 4.8 per cent. Both determinations are of minor importance, the ash qualitatively and quantitatively being dependent on the previous treatment of the pulp and the moisture on the atmospheric conditions. The fact that they were not extraordinary had, however, to be determined. The moisture was within 0.2 per cent of that of poplar pulp under the same atmospheric conditions, indicating again the close chemical relationship that has been evident throughout in the comparison of poplar and Epicampes pulps, as it is well known that different forms of cellulose have widely differing hygroscopicity. It is, in fact, more closely related to poplar pulp than it is to straw celluloses, like those of wheat or rye. These latter give from 12 to 14 per cent of furfural, for example, while Epicampes pulp gave a 10.8 per cent average, poplar giving 10 per cent. The resistance of Epicampes cellulose to destructive agents in general is correspondingly higher than that of the usual straw celluloses. It was next intended to make a methoxyl determination on the Epicampes pulp, but microscopic examination showed (1) lignified cells still present and (2) cells in bundles that are usually completely separated by cooking, although only a very little A methoxyl determination would be unfair to the sample when thus underof either. cooked, and so was not earned out. Direct determination of cellulose by any of the accepted methods is obviously useless here, (1) because the pulp has already been through processes for lignin removal and (2) because the presence of oxycellulose renders impossible a determination of cellulose accurate to 15 per cent, as it is always attacked much more than lignin by the usual reagents. There is no existing accurate method for these conditions. Carbon and hydrogen determination by combustion would add, perhaps, a little to the already present wealth of evidence of oxycellulose presence, but the relation of furfural yield to carbon percentage is so well known that the carbon could be predicted to a fraction of a per cent. This determination, therefore, seemed needless for the complete characterization of the Epicampes fiber. Hydralcellulose was tested for during the 'copper number' determinations, by Schwalbe's method, and found absent. To sum up the net result of these determinations: Epicampes macroura bleached pulp is a natural oxycellulose closely related to poplar pulp in chemical properties and considerably superior to the usual straw celluloses in power of resisting chemical '

'

attack

by destructive

agencies.

SEMICOMMERCIAL TESTS OF THE PULP. Having experimentally determined the cooking conditions and found them to be reasonable and satisfactory and also having determined that the chemical nature of the pulp was satisfactory, the work was continued on a semicommercial scale and was planned to include the actual manufacture of paper. There is a tendency on the part of many to discount the practical value of results obtained