Page:Zacaton as a paper-making material (IA zacatonaspaperma309bran).pdf/23

 ZACATON AS A PAPER- MAKING MATERIAL.

17

the losses ran about 20 per cent, while with the more dilute they were from 8 to 10 per cent, with, as was noted, a large factor of possible error. The ordinary bleaching practice would give results nearer the lower limit, if anything. The blow-pit stock from which the pith had not been separated did not bleach to a good color, even on long treatment. The loss in weight in one case which was weighed

—

12.5 per cent, but the stock was not up to a pure white rather a light cream color. This was due partly to the depth of coloring of the cooked pith and its resistant nature. The strongly resistant nature of the pith is seen by comparison of the results of dilute alkali and acid treatment with their effect on the original straw. The loss on boiling the pith 1 hour with 1 per cent caustic soda was 18.5 per cent in one case and 17.8 per cent in another. The straw lost 45 per cent under similar treatment, and the pure bleached fiber 20 per cent. The loss on heating the pith 7 hours at 70° with 10 per cent nitric acid was 18.3 per cent in one case and 17.9 per cent in another, while the straw lost 61 per cent and the pure bleached fiber lost 10 per cent under the same treatment. The necessity of removing the pith, even at the expense of some fiber, is apparent. There was quite a Httle fiber in the sample of pith, as shown by shaking up a sample with an excess of water, but no method of quantitatively separating the two has as yet suggested itself, unless fractional levigation or filtration may succeed in some form later. Chemically, there is not enough difference to effect even an approximate separation. The black liquor resulted from cooking Epicampes straw in an 3. Black liquor. autoclave at 90 pounds for 7$ hours, using 23 per cent caustic on the straw weight, at concentration of 23.9 grams per liter. It was investigated for specific gravity, per-

was

—

centage of dissolved solids, saccharine matter, nitrogenous matter, ash, and total organic matter.

The

specific gravity of the liquor

by one determination, and

was

1.046.

It

had

9.9 per cent total solids dis-

Of this, 2.89 per cent should be the original caustic soda (of course, somewhat altered by combination with silica, etc.). A determination of the ash of the evaporated residue corroborated this; 6.2 per cent of the residue burned away in the blast, leaving 3.8 per cent ash, the 6.2 per cent being, then, total organic matter. The amount of ash does not by any means account for the silica of the straw, even assuming that half of it is It is probable that much of it is loosened by the cook and left in the finished paper. solved

10 per cent according to a second.

washed away

as a fine suspension. Kjeldahl analysis of an evaporated residue showed 2.1 per cent "proteid," using the usual factor in calculation from the ammonia found; that is, there was about 0.2 per cent proteid in the liquor before evaporation. The addition of mineral acid to the black liquor gave a voluminous precipitate, consisting of acid cellulose, lignic acids, and some silicic acid. The amount of the is

A

precipitate

was

matter in the

4.8 per cent of the black liquor, leaving, then, 1.4 per cent organic

filtrate.

was examined for sugars. In 100 c. c. of the filtrate only 33 milligrams were present, calculated to dextrose. Probably the remainder in solution was levulinic acid, humic acids, acid-soluble modifications of cellulose, and similar products of the breaking down of the complex substances in the straw, but then-

The

filtrate

of sugar

small quantity and lack of value after identification argued against the necessarily long and laborious task of isolating them, even if they could be identified. Conclusion—The result of an investigation like the present one on substances of this nature gives necessarily only a general impression rather than a summary of definite and precisely measurable constants. In general, it may be said that Epicampes

macroura gives a commercially practical yield of rather unusually high-grade paper silica in the fiber, with no particular trouble to be expected except from pith and process of manufacture.