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 1^- 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 these variances 

 in absolute yield, the relative yield of the three species in either 

 product does not change with the locality. The order 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 sap wood (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 



