44 
BULLETIN 983, IT. S. DEPARTMENT OF AGRICULTURE. 
SIZE OF CHIPS. 
Two cooks were made on chips of two different sizes and under 
the conditions outlined in the table below. 
125 per cent of H 2 0; 2.5 per cent of H 2 S0 4 ; 7.5 atmospheres; 15 minutes. 
Length of 
chip with 
the grain 
(inches). 
Per cent 
of total 
sugars. 
Alcohol yields. 
Per cent 
Cook No. 
of total 
sugars fer- [ Percent 
mentable. ] of dry 
wood. 
Gallons 
absolute 
per ton. 
59 
*to* 
| 
Mixture. 
20.21 
21.005 
20.14 
73.50 < 7.126 
69.07 ; 7. 214 
71.16 7.109 
21.55 
60 
61 
21.82 
21.50 
Even the larger chips were thoroughly penetrated and cooked, and 
the yield obtained from them compares favorably with that obtained 
from sawdust under similar conditions. The chips, however, did not 
extract readily, and while they were being stirred in the leaching tank 
they were ground to a powder. In a commercial diffusion battery 
there would not, of course, be a similar mechanical action, but the 
time of extraction and the capacity of the battery would be decreased. 
A lack of material prevented leaching experiments, and these results 
were obtained primarily to determine whether material of this size 
would give yields similar to those from sawdust. Further work 
along this line is necessary. 
Cook No. 61 was a mixture of sawdust, small chips, and large chips 
in the following amounts : 
Sawdust... 
Large chips 
Small chips 
Moisture. 
Dry 
weight. 
This mixture was cooked at 7.5 atmospheres with 125 per cent of 
water and 2.5 per cent of sulphuric acid for 15 minutes. After it 
was cooked, a sample of the mixture was taken and extracted and the 
extract analyzed in the usual way. Another part of the sample was 
screened through a screen having openings three-eighths of an inch 
square, and the materials passing through the screen and remaining 
on it were also extracted and analyzed in the usual way. The 
following table shows the results of these analyses : 
Digested mixture. 
Moisture 
(per cent). 
Unscreened 70. 26 
Remaining on f-inch screen 70. 54 
Passing through f-inch screen 71.11 
Total 
sugars, 
(per cent 
of wet 
weight). 
Total 
solids 
(per cent 
of wet 
weight). 
6.616 
6.853 
6.688 
7.196 
7.28 
7.32 
Acidity 
of extract 
(C c. N/10 
NaOH). 
7.6 
7.6 
