— 95 — 



care was exercised to secure uniform superheating. Teeple expects 

 the best result from the use of non-superheated steam, a method first 

 patented to Leffler in 1864, then forgotten, and lately again 

 rejuvenated by Krug. In this case the wood material is first distilled 

 exhaustively with steam, and the wood then worked up further by 

 dry distillation or otherwise. The turpentine oil is consequently not 

 heated to such a degree that it distils out of the retort, — i. e., 

 superheating does not take place here. In plants in which this principle 

 is adopted, great value is attached to the mechanical side of the 

 work, for example the filling and emptying of the retorts, the correct 

 distribution of the steam, the agitation of the wood inside the retorts, etc. 

 The author, who is apparently fully acquainted with all the different 

 methods coming under consideration, as well as with their execution, 

 states the yields in this process to be 6 to 25 gallons of oil per cord 1 ) 

 of wood, or on the average 12 to 15 gallons. There exist in the United 

 States all in all about 80 installations for working up "light wood" and 

 waste wood from the saw mills. If the work is carried out properly, 

 the turpentine oil produced by these processes is said to be at 

 least equal to that obtained from turpentine resin — and possibly 

 superior, owing to its uniform character. With regard to the wood 

 from which the oil has been distilled out, and which has in no way 

 been altered in its structure by the distilling process, its utilisation 

 is still an unsolved question. A portion of it is used as fuel; attempts 

 to destructively distil the rest failed, unless retorts were used in 

 which the wood could be agitated on account of the bad conductivity. 

 Some success has attended the efforts to work up the wood which 

 had been distilled out with steam, into inferior kinds of paper, or 

 to isolate the colophony; but up to the present this has not gone 

 beyond the experimental stage. So much is certain that it is not 

 possible to use the same retort for steam distillation as well as for 

 destructive distillation. 



We read in a Report 2 ) from the German Agricultural Expert 

 in the United States, that in view of the constant clearing of 

 the pine forests there, a substitute for the trees is looked for, and 

 that this has been found to some extent in the stumps of the pines. 

 Successful attempts have been made to work up these stumps into 

 oil by distillation with steam, and a company has been 

 formed at Hinckley, in North Minnesota, which obtains from the 

 farmers against compensation the right to remove the stumps in the 

 denuded forests areas from the ground for the purpose of oil pro- 



*) 1 cord = 8X4x4 feet. 



-) Nachrichten fur Handel und Industrie 1907, no. 33. 



