40 BULLETIN 983, U. S. DEPARTMENT OF AGRICULTURE. 
Series Va. — Shortleaf pine. 
125 per cent of H2O; 7.5 atmospheres; 10 minutes. 
Per cent 
H0SO4. 
Per cent of 
total sugars 
Per cent of 
total sugars 
. ferment- 
able. 
Alcohol yields. 
Cook No. 
Per cent of 
dry wood. 
Gallons 
absolute 
per ton. 
48 
2.50 
17.15 
14.02 
60.27 
66.59 
5.201 
4.262 
15 73 
49 
4.00 
12.89 
The results of series V and Va for both spruce and shortleaf pine 
are shown graphically in figures 8 and 9. Figure 8 shows the actual 
alcohol yield based on the dry weight of the wood, and figure 9 gives 
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YIELD OF ALCOHOL IN «& OF DRY WEIGHT OF WOOD 
Fig. 8.— Series V and Va, showing variation in alcohol yield with varying concentrations of sulphuric 
acid for spruce and shortleaf pine. 
the variations in total sugars and the portion of total sugars that is 
fermentable. 
Figure 8 shows that the yield of alcohol from spruce increased 
rapidly with the lower concentrations of acid, but that above 1 per 
cent of acid the increase was comparatively small, there being little 
difference between 1 per cent and 3.5 per cent of acid. There was 
an actual decrease in the alcohol yield from shortleaf pine. This was 
because of the decrease of total sugars (fig. 9), although the amount 
of sugars fermentable increased from 60.29 per cent to 66.59 per cent 
of the total. The shortleaf pine used was a mixture of band sawdust 
and hogged slabs and edgings containing about 8 per cent of cypress 
and a considerable quantity of bark. 
Even from spruce a decrease in total sugars is noticeable with 
acidities above 1.4 percent, but here again the percentage of the total 
