PKODUCING SODA PULP FKOM ASPEN. 
47 
Table 9. — Amounts of mechanical, soda, and sulphite wood pulps used in the United 
States. 
Kind of pulp. 
Total pulps. 
Imported pulps. 
1909 1 
1899 
2 
19091 
Tons. 
1,323,000 
304, 000 
1, 200, 000 
Per cent. 
47 
11 
42 
Tons. 
586, 374 
171, 959 
416, 230 
Per cent. 
50 
15 
35 
Tons. 
119, 500 
9,500 
172, 400 
Cost. 
$2, 723, 000 
398, 000 
Sulphite 
8, 142, 000 
Total 
2, 827, 000 
100 
1, 174, 563 
100 
301, 400 
11,263,000 
1 Bureau of the Census— Paper and Wood Pulp Statistics; preliminary report for 1909, issued Apr. 26, 
1911, p. 3. 
2 Bureau of the Census— Bulletin 99 of the Twelfth Census, pp. 10, 12, 1901. 
RECORDS OF THE SERIES TESTS. 
Tables 10 to 14 give the data for the several groups of tests in which the cooking 
conditions were varied in series. 
EXPLANATION OF DATA. 
The following column headings may need explanation: 
Water in chips. — The quantity of water or moisture in the chips as charged is ex- 
pressed in percentage of water based on the calculated bone-dry weight of the chips. 
Initial concentrations of digester liquors. — The caustic soda (NaOH) and the sodium 
carbonate (Na 2 C0 3 ) concentrations are determined by analysis of the stock soda 
solution, and are calculated on the basis of total liquid in the charge, including mois- 
ture in the chips. The total sodium oxide (Na 2 0) is calculated from the proportions 
of NaOH and Na 2 C0 3 , each reduced to the sodium-oxide basis. Grams-per-liter 
concentrations may be converted into the equivalent pounds per gallon by multi- 
plying by 0.00834. What is sometimes erroneously called percentage concentrations 
may be obtained by dividing grams-per-liter concentrations by 10. 
Causticity of liquor. — This represents the ratio of sodium oxide in the caustic soda 
to the total sodium oxide. 
Initial volume of digester liquors. — The digester liquors consist of the stock soda solu- 
tion and water charged, together with the water in the chips as charged. 
Chemicals charged. — The quantities of the several chemicals charged are their dry 
weights based on the chemical formulas indicated. 
Duration of cooking. — Compare data with figure 3. 
Apparent condensation. — This is obtained by subtracting the amount of digester 
liquors at the start of the cook from the amount of liquid in the digester (as read from 
a water gauge) just before relieving the pressure, and blowing the digester at the end 
of the cock. It affords a rough measure of the amount of water condensing from the 
steam used for cooking. 
Yields. — The yields of total crude pulp, screenings, and screened pulp are calcu- 
lated to a bone-dry basis, and are expressed as a percentage of the calculated bone- 
dry weight of the chips. The total crude pulp is the total fibrous material and un- 
cooked chips blown from the digester. 
Yields of pulp per solid cord. — In calculating yields to pounds per cord of wood a 
" solid cord" is considered equivalent to 100 cubic feet of solid wood, green volume, 
knot free. For the aspen tested, the calculated bone-dry weight per " solid cord " was 
2,663 pounds. The yield of bleached pulp, which is given on the air-dry basis (10 per 
cent moisture), is computed by deducting the loss on bleaching and considering 90 
pounds of bone-dry pulp equal to 100 pounds of air-dry pulp. 
