Part III.] Raitt : Bamboo as Material for Paper-pulp. 
19 
the greater difficulties presented by crushed material as compared with 
scraped, under the limitations of ‘ overhead 5 digestion which compels 
us to deal with pectose and lignin together, will be dealt with in 
Section C. 
22. As a result of analysis and the resolution experiments arising from 
it, we are now in a position to form an approximate estimate of the quan¬ 
tity of NaOH necessary to effect the separation of cellulose from non¬ 
cellulose. It must be understood that we are here dealing with complete 
but bare digestion only, and do not take into account any large excess 
of NaOH which it may be considered advisable to use in order to obtain 
a bleaching effect for the purpose of assisting the subsequent bleaching 
process. But since all chemical reactions require a small excess of the 
reagent in order to ensure complete combination, I include in the last 
column of the following table *5 per cent, for this purpose. This is the 
minimum amount I have found to be necessary. Digestions showing 
*5 per cent, of free NaOH after the operation is complete will usualty be 
found satisfactory. We may estimate on the analyses of 2-year old culms 
which will represent very nearly an average of the whole crop, any slight 
favourable differences in one year old being balanced by corresponding 
unfavourable ones in the culms more than two years old. 
TABLE V. 
Approximate amount of NaOH required to effect the resolution of fat and 
wax, pectose and lignin (starch being previously extracted). 
i. • 
Per cent, of 
pectose, fat 
and wax at 
•32 NaOH for 
each 1 per 
cent. 
! Per cent. 
of lignin at 
•66 NaOH for 
each 1 per 
cent. 
Per cent. 
1 of NaOH 
1 on dry 
bamboo. 
Per cent, 
of NaOH 
on N.A.D. 
bamboo 
+ -5 ex¬ 
cess. 
B. Tulda 
, 
25-34—8-11 
13-80— 9-11 
17-22 
16-00 
B. arundinacea 
• 
25-56—8-18 
15-64—10-32 
18-50 
17-15 
B. polymorpha 
- 
20-60—6-59 
15-74—10-39 
16-98 
15-79 
C. pergracile 
24-01—7-68 
15-30—10-10 
17-78 
16-51 
Melocanna b. 
• 
14-47—4-63 
21-73—14-34 
18-97 
17-58 
[ 199 ] 
