— 5i — 



Mandarin oil. d 15 o 0,854 to 0,858. «d —f- 67 to -f- 73 . 



«d of the first half of the distillate averages 3 more than a D of 

 the original oil. 



Orange oil, bitter. di 5 o 0,852 to 0,856. « D 20° -f- 88 to -j- 96 . 



«p of the first half of the distillate at least 3 higher than a^ of 

 the original oil. 



Orange oil, sweet 1 ). d 15 o 0,847 to 0,852 «D20°+96 to -{-98°. 



a D of the first half of the distillate at least i° 30' higher than 

 a D of the original oil. 



Beginning of boiling at 176 to 1 77 (normal press.); 79 to 8i° 

 (20 to 30 mm. press.). 



Lemon Oil. When criticizing the Swiss Pharmacopoeia 2 ) we 

 pointed out, inter alia, that the statements there as to the determination 

 of boiling points were insufficient. In order to obtain correct results, 

 it ought to have been laid down that the entire mercury column 

 must be surrounded by the vapours of the liquid. Fleissig 3 ), by 

 a series of most careful researches, has now experimentally established 

 what are the differences shown in the case of oil of lemon according 

 to whether the mercury column has or has not been wholly exposed 

 to the vapours. He found that a thermometer protruding from the 

 flask registered up to 5,5° less than one wholly exposed to steam, 

 and that the requirement of the Pharm. Helv. IV that not more 

 than 30% of the oil of lemon must pass over at 170 , is fulfilled 

 only in the latter case. As a result, he arrives at our own conclusion, 

 that either a shortened thermometer must be used or the necessary 

 corrections must be carried out. Fleissig also points out that the 

 barometric pressure should be taken into account. The difference in 

 the boiling point of water at Basle and St. Moritz, for instance, 

 amounts to 5,3 °. 



Sophisticators have taken advantage of the enormous advance in 

 the price of oil of lemon to throw upon the market oils which are 

 adulterated to an almost incredible extent. E. J. Parry 4 ) reports on 

 a whole series of such oils of lemon, the chief adulterants of which 

 were mineral oil, castor oil, turpentine oil and also the terpenes of 

 oil of lemon. Upon evaporation the samples adulterated with mineral oil 

 left a residue of 30 to 5O°/ (specific gravity 0,878) showing the 

 characteristics of paraffin. Normal oil of lemon leaves a residue 



x ) For the properties of this, and of bitter orange oil, as determined in our 

 laboratories, see Report October 1906, 35. 



2 ) Report April 1908, 127. 



* 3 ) Schweiz. Wochenschr. f. Chem. and Pharm. 1909, No. 5. From a copy 

 kindly sent to us. 



4 ) Chemist and Druggist 74 (1909), 121. 



