PRODUCTS FROM DISTILLATION OF RESINOUS WOODS. 



19 



products. The "rosin spirits" and " rosin oils" obtained by destruc- 

 tively distilling pine or its soda extract are necessarily contaminated, 

 as is also the turpentine, with empyreumatic constituents derived 

 from the distillation of the cellulose and lignin. They are not, there- 

 fore, strictly speaking, " rosin oils" and " rosin spirits, " but may prop- 

 erly be termed "wood-rosin spirits" and "wood-rosin oils." 



These facts should be borne in mind in considering the tabulated 

 data on yields. It is hoped that more definite data as to the yield of 

 various products from pine will soon be available. The operations in 

 the past at wood turpentine plants have as a rule not been conducted 

 with the care necessary to determine even average yields with exact- 

 ness. The weight of a cord of wood varies greatly, and the amount of 

 water in the wood may also vary. In order that exact data may be 

 had, the wood at turpentine plants should be weighed, a sample 

 analyzed, and all products measured or weighed. The wide values 

 given for the several products are explained partly by variations in 

 the composition of the wood; as has been stated, pine wood differs 

 greatly in the quantity of resin it contains. 



The following figures are taken from the census reports : 



Statistics on the production of wood turpentine and other resin oils from wood 

 (census reports}. 



Though the quantity of wood used in this industry has more than 

 doubled in five years, the quantity of turpentine reported shows some 

 fluctuation and a rather small increase. Owing to the fact that the 

 products of both steam and destructive processes are included in the 

 summary, the only conclusion warranted seems to be that the yield of 

 turpentine per cord has greatly decreased, and this decrease is not 

 balanced by an equivalent increase in the reported heavy oils. It 

 seems probable that the decreased yield per cord reported in 1908 and 

 1909 is partly accounted for by greater care in refining, whereby the 

 heavy oils are more completely separated. The decreasing yields indi- 

 cate either that the wood used in late years is not so rich as that for- 

 merly employed, or that the distillation is less complete, or that a 

 different system of reporting is employed. 



