EMPYREUMATIC OILS. 241 



condensed and preserved. The oil, and acid and 

 water, which distil over, do not mix, and may be 

 easily separated by further distillation. The oil is an 

 inferior oil of turpentine, which is useful in coarse 

 painting 1 . The acid is strong and empyreumatic, 

 very closely resembling the pyroligneous acid ob- 

 tained from the distillation of wood. By this method 

 of converting tar into pitch, 600 gallons, or twenty 

 barrels of tar, will produce ten barrels, or 2,200 

 weight of pitch, 176 gallons of oil, and about fatty 

 gallons of acid. 



Besides the British-made pitch, 5,482 cwt. of 

 foreign pitch were retained in 1830 for home con- 

 sumption. It is admitted on a duty of 10c?. per 

 cwt. which is reduced to 9d. when coming from 

 British possessions. Swedish pitch is the best : its 

 price varies from 6s. 6d. to 10s. per cwt. 



