23 



nary pine yielding by steam distillation from 2 to 5 gallons per cord, 

 while good light wood yields from 10 to 20 gallons and averages about 

 15 gallons per cord, and very rich light wood from 20 to 30 gallons. 

 When pine is destructively distilled the yields from good light wood 

 are as follows: Alcohol, from 1J to 4 gallons; acetate of lime, from 50 

 to 100 pounds; turpentine, from 15 to 25 gallons; tar, 30 to 60 gal- 

 lons; charcoal, 25 to 35 bushels; and other wood oils, 30 to 60 gallons. 

 Very few operators recover the acetic acid in any form and so far as 

 is known none of them recover alcohol. 



There is one other type of process applicable to the treatment of 

 resinous woods and a few plants have been built to operate on this 

 principle. The wood is treated, in a closed bath connected with a 

 condenser, with a liquid having as high a boiling point as rosin, such 

 as rosin itself, cotton seed oil, etc. Such a process is applicable for 

 the recovery of turpentine and rosin and industrially depends, of 

 course, on the use of a solvent cheap enough to make it a financial 

 success. 



With reference to the wood turpentine industry in the South it 

 may be said that, from a -careful examination of a large number of 

 plants, the writer is convinced that the distillation industry of the 

 South can not be profitable as a whole until fundamental changes in 

 equipment and in technical and business management are made. In 

 the vast majority of cases the equipment is extremely crude, tech- 

 nical knowledge is lacking, and wasteful labor and business conditions 

 prevail. Both profits and yields of products could be materially 

 increased by improvements in all of these particulars. 



CRUDE PRODUCTS OF DESTRUCTIVE DISTILLATION. 



The crude products from the distillation divide themselves naturally 

 into four classes, as follows: 



Per cent. 



(1) Noncondensable gases 20 to 30 



(2) Charcoaf 20 to 35 



(3) Tar and oils 5 to 20 



(4) Aqueous distillate or crude pyroligneous acid 30 to 50 



As has been said, it is the American practice to burn the gases and 

 tar under the boilers, particularly in the hardwood districts, but it 

 is highly probable that the tar is too valuable to be thus used and 

 that it could be more profitably disposed of for other purposes. 



While the chief and most valuable products of hardwood distilla- 

 tions are charcoal, acetic acid, methyl alcohol, tar, and acetone, a 

 large number of other compounds are produced either primarily or by 

 secondary reactions; and, in the aqueous distillate, formic, propionic, 



[Cir. 36] 



