CONTROL OF DECAY IN PULP AND PULP WOOD 
19 
The decayed aspen used in the tests weighed approximately 2 
pounds less per cubic foot than sound wood. To put the matter in 
another way: If 100 solid cubic feet of sound aspen had been pur- 
chased and placed in storage until decay had reduced its density to 
this extent, 200 pounds of wood would have been lost; and even 
though a yield (on the weight basis) were obtained equal to that for 
sound wood, say 40 per cent, the actual loss of 80 pounds per 100 
cubic feet would be there just the same. 
QUALITY OF PULP 
The screened pulps from both the sulphite and the soda cooks were 
converted into waterleaf paper on the experimental paper machine, 
and the papers were tested for strength. The data appear in Table 5. 
Table 5. — Strength tests of sulphite and soda pulps made from sound and from 
decayed vjoods 
Cook 
No. 
Description 
Weight 
of ream, 
24 by 
36—500 
Mullen 
test 
Points 
per 
pound 
per 
ream 
Break- 
ing 
length 
Meters 
5,880 
5,480 
5,630 
6,040 
5,070 
4,370 
6,660 
4,490 
6,170 
5,950 
3,970 
3,760 
5,490 
4,770 
2,790 
6,390 
5,380 
3,290 
Folds 
Stretch 
Atmospheric 
conditions 
Sample 
No. 
Rela- 
tive 
humi- 
dity 
Tem- 
pera- 
ture 
2540 
2547 
560a 
336 
7 
8 
10 
6 
9 
4 
2 
3 
5 
351 
1 
109 
6 
7 
228 
3 
4 
Sulphite pulp: 
Sound spruce . 
Decayed spruce 
Do -. 
Pounds 
43.5 
41.5 
39.5 
38.0 
38.0 
30.0 
47.6 
37.0 
39.5 
38.5 
51.2 
44.5 
40.0 
46.0 
76.5 
43.5 
46.5 
40.5 
Pounds 
32.0 
26.8 
25.4 
25.4 
25.9 
17.8 
32.2 
14.7 
25.8 
21.7 
25.6 
11.4 
28.8 
21.0 
25.2 
37.3 
24.3 
11.8 
0.74 
.65 
.64 
.67 
.68 
.59 
.68 
.40 
.65 
.56 
.50 
.26 
.72 
.46 
.33 
.86 
.52 
.29 
Number 
785 
310 
121 
207 
169 
26 
449 
137 
232 
306 
12 
5 
707 
192 
1 
668 
389 
4 
Per cent 
2.90 
1.58 
1.88 
1.69 
1.83 
1.62 
3.46 
1.90 
2.54 
2.58 
1.87 
1.66 
1.97 
1.44 
1.08 
3.26 
3.32 
1.64 
Per ceni 
65 
64 
64 
64 
64 
64 
66 
67 
65 
66 
65 
66 
65 
65 
66 
68 
64 
65 
O F 
94 
92 
92 
560 
Do. 
77 
2548 
Do-. 
92 
2555 
Do - 
93 
554 
542a 
542b 
Sound hemlock 
Decayed hemlock.. 
Do. 
75 
72 
75 
542c 
Do... 
75 
50 
5521 
540 
2559 
2557 
Sound aspen 
Decayed aspen 
Soda pulp: 
Sound spruce 
Decayed spruce 
Do 
74 
68 
" 79 
82 
40 
542D 
552D 
Sound hemlock 
Decayed hemlock.. 
Decayed aspen 
69 
77 
72 
All of the pulps made from decayed woods show a lower strength 
than those made from sound wood, as indicated by the bursting and 
breaking-length tests. The breaking length for pulp No. 560, from 
decayed spruce, was the only exception to this rule. The low endur- 
ance of folding shown by the pulps from decayed woods is very 
marked, and is indicative of the decidedly deteriorating effect which 
decay in wood has upon the flexibility and wearing qualities of pulps 
made from it. This deterioration is especially marked in sulphite 
pulp No. 2555, made from the badly decayed spruce wood. More- 
over, the pulp was exceptionally dirty. When this same wood was 
cooked by the soda process the strength of its pulp, No. 2557, was 
even lower, and the pulp was again very dirty in color. 
