68 BULLETIN 983, U. S. DEPARTMENT OF AGRICULTURE. 
very low. A large quantity of bark would mean running a large 
volume of inert material through the alcohol plant at considerable 
expense and without return. Moreover, the use of most barks would 
add large quantities of tannin to the solutions to be fermented, and 
this also is undesirable. 
If all waste is disposed of for this purpose, a sawmill could not only 
net the price of 40 cents a cord mentioned above, but it could also 
avoid the cost of burning the waste, which, as given before, ranges 
from 30 to 66 cents a cord. To the sawmill this would mean a net 
gain practically double the figure at which the waste is sold. 
The successful production of ethyl alcohol from sawdust seems to 
depend upon the proper design, equipment, and management of the 
plant, rather than upon the improvement of the chemical or ferment- 
ological features of the process. The problem involves the quick 
and efficient handling of large volumes of low-grade material under 
unusual technical conditions, the perfecting of the necessary acid- 
resisting pieces of apparatus, a study of the experience of the plants 
that have been built and operated, and the efficient utilization of 
material whose mere removal is now an expense. This industry 
unquestionably is worthy the serious study of experimental and 
practical investigators of the utilization of forest products. 
