BULLETIN OF THE 
C 
No. 129 
Contribution from the Forest Service, Henry S. Graves, Forester. 
September 10, 1914. 
(PROFESSIONAL PAPER.) 
YIELDS FROM THE DESTRUCTIVE DISTILLATION 
OF CERTAIN HARDWOODS. 1 
By L. F. Hawley and R. C. Palmer, Chemists in Forest Products. 
PURPOSE OF EXPERIMENTS. 
The chief hardwoods used in this country for distillation are beech, 
birch, and maple. Only mill and forest waste and trees unmerchant- 
able for lumber are now ordinarily used, although some material suit- 
able for lumber still finds its way to the distillation plants. Such 
southern hardwoods as the oaks, red gum, tupelo, and hickory have 
not been important in distillation, and no information has existed in 
regard to the amount of the various products which could be obtained 
from them. Nor has information been available on the relative value 
of the commonly used species, or of the different forms of material, 
such as body wood, limbs, and slabs. The investigation here de- 
scribed was undertaken in order to supply this information and to 
aid in this way the utilization of materials now wasted. 
METHOD OF INVESTIGATION. 
GENERAL PLAN. 
Since conditions of distillation influence the yield of products, 
results obtained in the laboratory could not be compared directly 
with those obtained in commercial operations. In order to have a 
direct comparison between the species commonly used and the ones 
which are not, it was therefore necessary to include both classes in the 
investigation. 
The various materials were distilled under similar conditions, and 
their products analyzed by the same methods. In order to avoid 
errors due to differences in yields from different trees of the same 
species, in most cases an average sample of material from two or 
Note.— Gives results of experiments in destructive distillation of hardwoods. Of interest to manufac- 
turers of by-products. 
> The investigation the results of which are given in this bulletin were conducted at the Forest Prod- 
ucts Laboratory, Madison, Wis., maintaine:! in cooperation with the University of Wisconsin. 
51595°— 14 1 
