448 
was done in 3-gallon glass jars provided with mechanical agitators. The 
experiments were conducted at ordinary temperatures (about 30° C.), 
and no attempt was made at “souring” by means of acids or of otherwise 
accelerating the action. The endeavor was rather to obtain a slow, 
regulated process which involved the least injury to the cellulose and a 
maximum yield of bleached pulp. After a good, white appearance was 
obtained to the beaten pulp, the stuff was filtered and the residual avail- 
able chlorine determined by titrating an aliquot portion of the filtrate 
with a standard solution of thiosulphate. The filtering and washing 
of the bleached cellulose was performed by means of suction, a large 
Buchner funnel with small perforations, proving a very efficient mold 
in which to wash and press the pulp into dises for a final weighing. 
BLEACHING ABACA PULP. 
Kaperiment No. 1.—The dry residue from digestion No. 2, page 445, amounting 
to 328.4 grams, was placed in the engine and beaten to a homogeneous mass with 9 
liters of water, then 24 liters of clear bleaching powder solution, strength 2.35 per 
cent available chlorine (approximately 10° Bé.) were run in and the stirring 
continued until the pulp was of a light cream color. At this stage 100 cubic 
centimeters of the liquor required 31 cubic centimeters of N/10 thiosulphate, 
equivalent to 0.11 gram of chlorine, or to 12.1 grams of residual chlorine in 
the entire liquor. The amount of chlorine added (24 liters of 2.35 per cent 
chlorine solution) was 58.75 grams. The difference between this quantity and 
the 12.1 grams remaining at the end of the bleach, amounting to 46.65 grams, 
represents the amount used in bleaching 324.8 grams of pulp or 1,000 grams 
of original waste. This is 14.2 per cent of chlorine, calculated on the weight of 
pulp, or 4.66 per cent calculated on the weight of the raw material originally 
taken, Using bleaching powder of 35 per cent available chlorine as a basis for 
calculating into terms of general usage, the above results are equivalent to 
14.2 per cent of powder.’ The dry, bleached residue weighed 304.4 grams, s0 
that there was a loss of 7.3 per cent in the bleaching operation. 
Experiment No. 2.—The residue from digestion No. 3, page 445, weighing 
317 grams was employed. <A bleach liquor of much less strength (1.65 per cent 
available chlorine, approximately 34° Bé.) was used, otherwise the conditions 
were the same as in the preceding experiment. The amount of bleaching powder 
required was 12.22" per cent of the raw material. The dry bleached residue 
weighed 297 grams, so that there was a loss of 6.4 per cent in bleaching. 
CHEMICAL INVESTIGATION OF FIBROUS SUBSTANCES IN GENERAL. 
The schemes which have been used for the analysis of fibrous substances 
and the methods adopted for valuing unknown raw materials for paper 
stock are substantially those of Messrs. Cross, Bevan, and King, whose 
valuable works on fibers,’7 cellulose,ts and paper making*® stand 
%® 13.33 pounds per hundredweight of waste. 
16 12.2 pounds per hundredweight of waste. 
1 Indian Fibers and Fibrous Substances (1887), London, Spon, E. and F, N. 
8 Qellulose (1895), London, Longmans, Green & Co. 
©” Paper Making (1900), London, E. & F. N. Spon. 
