8 BULLETIN 129, *U. S. DEPARTMENT OF AGRICULTURE. 
The average yield from, the beech, birch, and maple wood from 
Wisconsin and Indiana is somewhat higher for acid and considerably 
lower for alcohol than for the same species in Pennsylvania. This 
difference, when figured to commercial products — namely, 82 per 
cent alcohol and 80 per cent acetate of lime — amounts to about 10 
per cent of the alcohol and 1J per cent of the acetate of lime (see 
Table 4). The greatest differences are in the alcohol yield from 
beech and in the acid yield from birch. In the case of maple, the 
yields of both acid and alcohol are slightly higher from the Pennsyl- 
vania than from the Wisconsin wood. In contrast to'tb^se variances 
hi absolute yield, the relative yield of the three ^rjecies in either 
product does not change with the locality. The*, or/ler of yield for 
alcohol is beech, maple, birch; for acid, birch, beech, maple. In the 
case of oak, the largest difference lies in the acid yield, the material 
from the more southern locality giving the lower yield. The yield 
of alcohol from wood cut in different States is very nearly the same, 
but if the runs on lumber are included the average is slightly higher 
for material from the northern localities. 
VARIATION DUE TO FORM OF MATERIAL. 
Although slabs with much bark are usually considered very poor 
material for distillation, the yields of alcohol and acetic acid from 
slabs having as high as 13 to 25 per cent bark by volume are in most 
cases only slightly lower, and in some cases even higher, than from 
heartwood. Distillation of beech bark showed that the higher yields 
of acid from beech slabs were not due to the bark, but to the very 
high yields of the sapwood (slabs without bark). These offset the 
low bark yields sufficiently to account for the fact that slabs with 
13 per cent bark yielded more acid than the heartwood without bark. 
The same or higher yield of acid from the slabs of birch and tupelo 
and from the limbs of chestnut and tupelo is probably due to the same 
cause. The yields of alcohol from the sapwood of beech were prac- 
tically the same as from the heartwood, and since the bark yields 
considerably less alcohol, the slabs with 13 per cent bark yielded less 
than the heartwood. Maple bark yielded very nearly as much alcohol 
as the heartwood, which accounts for the relatively high yields from 
the slabs. 
CHARCOAL, TAR, AND GAS. 
The yields of charcoal, tar, and gas are not included in Table 2, 
since they are influenced very much by the maximum temperatures of 
distillation and therefore are not comparable to the same extent as 
the alcohol and acetic-acid yields. Besides, these products are of 
indefinite composition, which further prevents comparison. There 
are some points of interest, however, in the relations between the yields 
of these products, and in Table 3 the average yields of alcohol, tar, 
and charcoal are shown, the species being arranged in order of the 
