— 94 - 



When freshly-distilled turpentine oil is left exposed to the air in a 

 beaker, the peroxide-content gradually increases until at last a maximum 

 is reached. French turpentine oil has shown the highest peroxide-formation; 

 the values for dipentene and terpinolene are considerably less, while the 

 power of activity of sylvestrene is much lower than that of pinene. 



Some years ago, Frey 1 ) published a method of testing turpentine oil 

 for petroleum by shaking with three times its volume of aniline. The 

 practical usefulness of this test, which in our reference we had only 

 admitted under reserve, has recently been commented upon by H.S.Shrews- 

 bury 2 ), who only admits it so far as concerns additions of petroleum of 

 not less than 30 or more than 70%, this limitation having been con- 

 firmed by special experiments with mixtures of known petroleum-content. 

 Moreover, the accurate values which came within these limits can only 

 be arrived at by errors compensating each other. 



An article by George Walker 3 ) on methods for the utilisation of wood- 

 waste deals in the first place with the exploitation of such waste in the 

 United States by means of fire-distillation for the purpose of gas- and 

 tar-manufacture, and next with the utilisation of soft-wood waste by steam- 

 distillation. We have repeatedly referred 4 ) to the properties of the puri- 

 fied distillate obtained by the last-named method, the so-called wood 

 turpentine oil. Walker gives a short description of a plant installed by 

 him for treating "light-wood", i. e., the heart-wood of dead turpentine-tree§ 

 in which, when the bark and the sap-wood have decayed, nearly the 

 whole of the resin concentrates. This wood is treated in cylindrical retorts 

 holding about 1 cord (about 128 cubic feet) each, and is first subjected to 

 simultaneous distillation with live steam, and with fire, the product of 

 this operation being "turpentine oil". Afterwards it is again distilled with 

 fire only, when it yields "heavy oil". At the end of the distilling, when 

 the retort is opened, steam is again injected, with the object of blowing 

 the oily matter out of the condenser and of quenching the glowing charcoal. 

 The heavy oil is again subjected to distillation, when it first yields a 

 resinous oil, sp. gr. about 0,88, and subsequently a heavier oil containing 

 about 20% creosote and a large proportion of paraffin. A residue of 

 about 25% is left, consisting of an elastic glossy black pitch. Walker 

 also describes a method which he has worked out for isolating the resin 

 from finely divided light-wood from which the oil has been removed by 

 steam-distillation, by extracting it with volatile solvents. In a plant working 

 by this method 200 barrels of resin are made weekly, and as this process 



!) Comp. Report November 1908, 123. 



2 ) Analyst 36 (1911), 137. Quoted from Chem. Zentralbl. 1911, I. 1560. 



3 ) Journ. Soc. chem. Industry 30 (1911), 934. 



*) Comp. Report April 1907, 98; October 1907, 94, 95; October 1909, 122, 124; this Report p. 90. 



