31 



further fractionated into a number of portions or fractions. These 

 oils are suitable for use in making varnishes, soaps, disinfectants, 

 paints, inks, etc. 



When, in the distillation of resinous woods, the temperature rises 

 above 250 C., not only is the wood attacked, but the resins in the 

 wood also begin to break up, so that, with the acids, alcohols, ketones, 

 oils, etc., formed from the wood, rosin spirits and rosin oils are formed 

 from the rosin, and, if the latter are allowed to mix with the turpen- 

 tine driven off at lower temperatures (which is always the case in 

 straight destructive distillation), it is impossible to separate them 

 perfectly from the turpentine in subsequent refining, because of the 

 low boiling point of the rosin spirits. For this reason the odor of 

 destructively distilled turpentine differs from gum spirits or steam- 

 distilled wood turpentine and closely resembles that of rosin spirits. 



ROSIN SPIRITS. 



This product has a specific gravity ranging from 0.856 to 0.883 

 and a boiling point varying from 80 to 250 C. It has a peculiar 

 odor, and, with the exception of wood turpentine, is the best substi- 

 tute known for gum turpentine, being much used in the manufacture 

 of the cheaper grades of varnish and as an illuminant. It contains as 

 a characteristic constituent heptine (C 7 H 12 ), which boils at 103 to 

 104 C., has a specific gravity of 0.8031 at 20 C., and absorbs oxygen 

 readily. 



ROSIN OILS. 



Crude rosin oils have specific gravities varying from 0.960 to 1.0, 

 while the refined oils vary from 0.960 to 0.990 and boil at from 300 

 to 400 C. They are -largely used in the preparation of axle grease 

 and other low-grade lubricants; also in the manufacture of printing 

 inks, leather dressing, and cement, and as an adulterant for other 

 oils. 



TAR OILS. 



The tar oils are obtained by distilling tar, and have many proper- 

 ties in common with rosin spirits and rosin oils. Those boiling at 

 from 97 to 240 C. closely resemble rosin spirits, while those boiling 

 above 240 C. contain phenol, creosote, rosin oils, etc., and, when 

 freed from naphthalene and anthracene by cooling and from phenol 

 and creosote by treating with alkali, are used as adulterants of 

 lubricating oils. 



[Cir. 36] 



