JUNIPER-TAR OIL 505 



Uses. Juniper-tar oil is used as an application in various skin 

 diseases. 



Adulteration. Pine-tar is best detected by the following test : 

 Shake 1 c.c. of the oil vigorously with 15 c.c. of petroleum spirit and 

 filter ; to 10 c.c. of the filtrate add 10 c.c. of a 5 per cent, solution of 

 copper acetate; allow separation. to take place and dilute 5 c.c. of 

 the upper layer with 10 c.c. of ether. Pure oil of cade gives a pale, 

 brownish yellow colour, pine-tar an intense green. 



When fractionally distilled, from 68 to 80 per cent, should distil 

 between 150 and 300 (pine-tar about 15 per cent.). 



Allied Drug. Birch tar (Oleum Rusci, Oleum Betulae empyreu- 

 maticum) is a nearly black tarry liquid obtained in Russia by destruc- 

 tive distillation of birch wood (Betula alba, Linne). It possesses the 

 characteristic odour of Russian leather and has been used in skin 

 diseases. 



