- 110 - f 



their chemical and physical properties. They differ among each other 

 according to method of production, purification, and raw material. With 

 respect to solubility the cellulose oils partly behave similar to turpentine 

 and pine tar oils. For the purpose of distinguishing between cellulose 

 oil on the one hand and turpentine and pine tar oils on the other, Wolff 

 recommends certain colour reactions, into the details of which we cannot 

 enter here. 



H. Wolff 1 ) has also established the toxic action of turpentine oil by 

 experiments on mice. Injections of 0,12 to 0,17 g. turpentine oil in olive 

 oil per 10 g. weight of the experimental animal were fatal; when the dose 

 was gradually raised some of the animals began to accustom themselves to 

 the oil to a considerable extent. The action of turpentine oil would appear 

 to depend largely upon the quantity of oxygen which is absorbed; when 

 oils are rich in oxygen a dose of 0,08 to 0,1 g. per 10 g. weight of the 

 experimental animal is generally fatal. Pine tar oils behave similar to 

 turpentine oils, the limits lay between 0,06 and 0,12 g. 



T. W. Pritchard 2 ) has read a paper before the New York Section of 

 the Society of chemical Industry on a new method of preparing wood 

 turpentine 3 ). In order to. attain a high output it is necessary that the 

 temperature within the retort in which the wood is being distilled should 

 be uniform. To ensure this, the retorts are furnished with double jackets 

 between which oil is pumped in. Outside the retort is a heating-apparatus 

 by means of which the oil can be brought to a given temperature. Before 

 the beginning of the distillation hot steam is blown into the retort to expel 

 the cold air from it. After this the oil is circulated into the space between 

 the inner and outer shells of the jacket; a suitable oil for heating purposes 

 being a certain petroleum residue which is difficult to decompose, and 

 which (air being excluded) can be heated safely to from 315 to 370°. So 

 long as any readily-volatile oils are passing over the temperature within 

 the retort must not exceed 230°, but when all these products have passed 

 over, it may be raised by degrees. One of the great advantages of this 

 process is the comparative freedom from fire-risk, with the consequence 

 of low insurance rates, these being a very considerable factor in other 

 wood-distilling processes. The wood turpentine which is obtained by 

 Pritchard's method is of excellent quality, but it still differs materially 

 from gum turpentine oil by the presence in it of a small proportion of 

 constituents resembling pine-tar oil. Pritchard, however, believes that he 

 has discovered a method by which it will be possible to remove these 

 constituents completely. 



x ) Farbenztg. 17 (1912), 1495. Quoted from Chem. ZentralU. 1912. I. 1919. 



2 ) Journ. Soc. chem. Industry 31 (1912), 418. 



3 ) Comp. Report April 1912, 126. 



