- 60 - I 



requirements for bergamot oil. In most of the samples, too, the ester- 

 content (calculated from the ester value obtained after one hour's saponi- 

 fication of 1,5 to 2 g. of oil with 10 cc. seminormal liquor), was too low, 

 apart even from the added adulterants, and only in the case of sample 

 No. 1 did it correspond to the ester-content of normal oils. In the last- 

 named the original ester content of about 34 p. c. was increased by the 

 added glycerol ester by about 2p.c. Sample No. 2 also contained glycerol 

 ester. The detection was carried out according to the method described 

 in detail in our Report of April 1911, 151, to which a brief reference will 

 here be sufficient. Of the filtered alcoholic liquid which is obtained after 

 shaking 10 cc. of oil with 20 cc. 5 p. c. alcohol, 10 cc. should only use up 

 about 0,1 cc. of seminormal potash liquor after being neutralised for 

 saponification. The samples referred to above, however, required 0,75 cc. 

 and 0,6 cc. respectively. For the purpose of isolating the glycerol ester 

 about 50 cc. of the oil were extracted three times with an equal volume of 

 5p.c. alcohol, and by subsequent evaporation of the extracts thus obtained 

 the quantity of added ester was estimated. In both cases it was found 

 to be about 0,5 p. c. The presence of the ester was then indisputably 

 established by the determination of the saponification value and the detection, 

 in connection therewith, of the presence of glycerol and acetic acid. In the 

 case of both oils also the difference obtained in fractional saponification 

 (Report October 1911, 116) was excessive, but in the course of a repeated 

 fractional saponification of the steam-distilled oils (comp. Report April 1912, 

 79) it was found that only sample No. 2 contained terpinyl acetate, the 

 excessive difference in No. 1 being due to resinification "of the oil. The 

 quantity of added terpinyl acetate, calculated from the difference of 11,5 

 as determined by us with mixtures of known content, was about 5 p. c. 

 (Report October 1911, 117). 



Sample No. 3 contained about 30 p. c. spirit and, in addition, an ester 

 of a sparingly-volatile acid, the acid value II, as estimated according to 

 our Report of October 1910, 61, being about 35,3 lower than the saponi- 

 fication value of the oil. The available quantity, however, was insufficient 

 for the identification of the ester. When the alcohol had been removed 

 by extraction with solution of common salt the oil gave di 5 0,8984, « D + 18° 6\ 



The next three samples (Nos. 4, 5 and 6), when subjected to fractional 

 saponification showed excessive differences in their saponification values, (Jj 

 and a repeated testing, carried out after the oils had been distilled with 

 steam, showed similar differences, thus proving the presence of terpinyl 

 acetate in the proportions indicated. 



In the case of No. 7 also adulteration with terpinyl acetate was sus- 

 pected, but the quantity of this oil sent to us for examination was insuf- 

 ficient to carry out a steam-distillation and in this case, therefore, the 

 question whether terpinyl acetate was actually present remained unsettled. 

 Apart from this, however, the oil would have to be rejected on account 



