- 56 - 



In recent times there have been many complaints, especially in 

 England, about the want of uniformity of the oils met with in com- 

 merce. Umney and Bennett 1 ) found the following differences: — 







English 



oil 





Foreign oil 



Specific gravity 





0,870 to 0,900 





0,860 to 0,880 



Optical rotation 



(100 mm.) . 



— IO° to 



"H C 



1 



— 3° to —12° 



Index of refraction 



1,4820 to 



1,488 







1,4770 to 1,4830 



On fractional distillation there passed 



over: 









Of English 



oil: 







Of foreign oil: 





freshly distilled 



old dist. 



Hung 



. dist. German dist. 



below 160 



14% 



h% 





22 



% 31% 



» i7o° 



52% 



— 





60 



% 



» 180 



65% 



44% 





72 



% 45% 



„ 200° 



75% 



— 





85% 



„ 2IO° 



— 



54% 







62% 



„ 265° 



— 



75% 







74% 



Similar results were also found by Bird 2 ). 



Umney and Bennett propose the adoption of the following 

 requirements for the British Pharmacopoeia: "d^o 0,860 to 0,885; 

 a D — 3 to — 12 ; below 165 not more than 6o°/ shall distil over. 

 The index of refraction of the oil is of no importance, but it is advis- 

 able to determine the refractive index of the distillation-residue after 

 8o°/ have been distilled off; this index should not be less than 1,49. 

 Freshly distilled oil should dissolve in 10 vol. 90 per cent, alcohol. 

 In older oil the solubility diminishes owing to oxidation, and the 

 specific gravity increases at the same time." 



Parry 3 ) also agrees on the whole with these statements. Bird 

 attributes the differences occurring during fractional distillation to the 

 fact, that the English oils are normal distillates, whilst the Hungarian 

 oils consist of the more readily boiling portions. In our opinion 

 this is explained by the fact that the Hungarian juniper oils are 

 not distilled direct from the berries, but (comp. also Stroecker) 4 ) 

 are obtained as a by-product in the manufacture of juniper brandy, 

 and consequently form the less soluble portions of the total oil. 

 Stroecker estimates the annual production of juniper oil in Hungary 

 at 30000 kilos, but this figure certainly appears to have been taken 

 too high. 



*) Pharm. Journal 79 (1907), 131; Chemist and Druggist 71 (1907), 172. 

 2 ) Pharm. Journal 79 (1907), 130; Chemist and Druggist 71 (1907), 172. 

 8 ) Chemist and Druggist 71 (1907), 355. 

 4 ) Pharm. Post 38 (1905), 236. Accord, to Berichte d. deutsch. pharm. Ges.; 

 Bericht uber die pharmakogn. Lit. aller Lander fur 1905, 67. 



