ETHYL ALCOHOL FROM WOOD WASTE. 15 
The action of hydrogen peroxide would then necessarily be one of 
pure hydration, in which the production of hydrocellulose was facili- 
tated; for, according to Neumann, since the final yield of dextrose is 
dependent upon the amount of hydrocellulose originally present or 
upon the speed of its formation, the production of dextrose from hydro- 
cellulose proceeds at a greater rate than the production of hydrocellu- 
lose from cellulose. 
From the foregoing it is apparent that, since the publication of 
Simonsen's work and the obtaining of patents on his process, the 
production of ethyl alcohol from sawdust has received a very large 
degree of attention practically all over the world, and large sums have 
been spent on its technical development. Of the four plants which 
have been built in this country only two have achieved commercial 
success, but the failure of the others was due apparently to other 
things than the process itself. 
OUTLINE OF INVESTIGATIONS. 
The greatest fault common to all of the work that has been done 
heretofore is that it was aimed chiefly at an increase in the total yield 
of sugars, whereas, as will be shown later, such an increase does not 
necessarily mean a proportionate increase in alcohol yield. Most of 
the fermentation work done was haphazard and not of the same scien- 
tific character as the chemical work. Without accurate fermenta- 
tions, and, consequently, without complete data, the interpretation of 
results led to difficulty, because oftentimes total sugar yields might 
not vary and yet might give different alcohol yields because of varia- 
tions in the proportion of fermentable and nonfermentable sugars. 
Since we have no good quantitative chemical means for separating 
these two classes of sugars and must depend on fermentation, which is 
a biological process, carefully standardized fermentation experiments 
are an absolute necessity. The importance of this point, as will be 
shown later, can not be too strongly emphasized. Simonsen and 
others after him have contented themselves with an occasional fer- 
mentation (usually under conditions that made accurate duplication 
impossible) to show that some of the sugar obtained was actually 
fermentable. A careful study of sugar and alcohol relations, espe- 
cially of the effect of the different variables on that portion of the 
total sugar that is fermentable, has not, to the knowledge of the 
writer, been made public heretofore. 
Simonsen, Neumann, and other investigators obtained contra- 
dictory data because they used as a variable different amounts of 
an acid solution of constant strength, thereby simultaneously vary- 
ing both the ratio of water to wood and that of acid to wood. As 
will be shown in a study of these variables, these ratios are not 
mutually dependent, and the " acidity" of the solution used for 
