60 
BULLETIN 983, U. S. DEPARTMENT OF AGRICULTURE. 
yielded fermentable sugars and alcohol in proportion to their cellulose 
content. In order to throw additional light on this subject, and also 
to ascertain whether another com m on waste material other than mill 
waste could be used for the production of alcohol, cook No. 50 was 
made on western larch. 
The logging of western larch shows a woods loss of about 8 per cent, 
caused by butting off the lower portion of the tree. 46 The presence 
of shakes in the butt is chiefly responsible for this practice. In addi- 
tion, the base of the tree is usually swollen. This portion is denser 
than the rest of the trunk, and usually sinks, thus preventing rafting. 
The length of the butts left in the woods varies from 4 to 8 feet, 
although a 16-foot piece is sometimes rejected. 
Hitherto the utilization of this waste material has not met with suc- 
cess, and it was hoped that it might profitably be employed as a raw 
material in the production of alcohol. A sample of sawdust from a 
butt log was cooked with 1.8 per cent of sulphuric acid, 125 per cent 
of water, 7.5 atmospheres of pressure, for 10 minutes. A }deld of 
sugars equal to 29.72 per cent and of total solids equivalent to 35.18 
per cent of the dry weight of the wood was obtained. Under the same 
conditions white spruce would yield from 22 to 23 per cent of total 
sugars of which 60 to 65 per cent would be fermentable, making an 
alcohol yield of 6.8 to 7 per cent of the dry weight of the wood. The 
extracts obtained from the hydrolysis of the larch were fermented 
under standard conditions, the fermentation records and the alcohol 
yields being shown in the tables in the Appendix. 
The larch yielded about 35 per cent more of total sugars than did the 
spruce, and yet only 37.9 per cent of that sugar fermented as com- 
pared with 60 or 65 per cent of the total sugar from spruce. A. W. 
Schorger, of the Forest Products Laboratory, has analyzed both of 
these woods with the following results: 
Western 
larch 
(base) 
(per 
cent). 
White spruce (4 samples). 
Range (per cent). 
Mean 
(per 
cent). 
Soluble in ether 
9. 75 ; 0. 90 to 1. 95 
14. 47 ' . 82 to 1. 45 
16. 52 1.88 to 2. 52 
1.36 
Soluble in cold water 
1.12 
Soluble in hot water 
2.14 
Soluble in 1 per cent of NaOH, 10 minutes heating 
32. 72 ! 6. 72 to 8. 84 
38. 58 ' 11. 18 to 13. 87 
6. 99 , 10. 04 to 10. 78 
3. 42 3. 08 to 3. 95 
42. 57 51 - 95 to 58. 47 
7.70 
Soluble in 1 per cent of NaOH^ 60 minutes heating 
12.21 
Pentosan 
10.39 
Methyl pentosan 
3.55 
Cellulose 
56.17 
Volatile oil 
.84 
.36 
Ash 
. 285 to . 326 
.307 
It will be noticed that the larch contained a large amount of 
material soluble in water and a proportionately small amount of eel- 
's u. S. Department of Agriculture, Forest Service, Bulletin 122, " The Mechanical Properties of Western 
Larch," by O. P. M. Goss. 
