— 108 — 



maintain the price at about 2000 francs per kilo (the figure which it had 

 reached in September 1911), they were nevertheless compelled, as time 

 went on, to show a more tractable spirit in order not to be left with their 

 stocks on hand. As no orders of any magnitude came forward, prices 

 finally receded to about 1700 francs per kilo. At that level, however, they 

 have remained steady, because in the meantime news has been received 

 from the growing districts, announcing that the plantations have been 

 seriously damaged by the severe winter, and that the prospects of the 

 new crop have again become unfavourable. In any case, however, it is 

 still too soon to express a reliable opinion on the probable development 

 of the flowers. The weather during the months of April and May will be 

 the chief determining factor in this respect. 



In Gildemeister and Hoffmann's book The Volatile Oils (p. 429) the 

 maximum limit of value of the optical rotation of rose oil is stated to be 

 « D — 4°. Afterwards 1 ) we reduced this limit to — 3°. Later, in our Report 

 of October 1910 (p. Ill), we called attention to the fact that Parry had ex- 

 amined six samples of rose oils alleged to be pure, of which the optical 

 rotation ranged from — 4° to — 5°, whereas in our own experience we 

 had only once encountered a sample with « D — 4° 20'. More recently, a 

 few instances have again occurred in which Bulgarian rose oils, when 

 examined in our laboratory, have shown an optical rotation exceeding — 4°, 

 their constants in other respects being normal. Quite lately another such 

 oil came under our notice. Its constants were: d 30 o 0,8608, « D — 4° 32', 

 "D250 1,46565, sol. p. +19°, acid v. 1,5, ester v. 9,5, total geraniol 68,3%. 

 When the oil was washed out with water its specific gravity remained 

 unaltered, but the co-efficient of refraction had risen to 1,46704, a value 

 which had never before come under our notice in rose oil of good quality 

 (compare Report April 1910, 93). 



Our suspicion that the sample under examination represented an 

 adulterated article was confirmed by the striking discovery that the stea- 

 roptene which had separated out from the oil was semi-liquid at ordinary 

 temperature and rotated strongly, whereas the stearoptene of rose oil of 

 normal condition is at most feebly active, and is solid at room-temperature. 

 It was therefore evident that a liquid material possessing strong optical 

 rotatory power had been added to the oil. Upon further examination of 

 the oily constituents, which in each case had again been freed from solid 

 paraffin by freezing, we obtained, among other fractions, one which pos4 

 sessed the following physical characteristics: b. p. 95 to 96° (4 mm.), 

 255 to 260° (756 mm.), d 15 o 0,9203, « D — 63° 55', n D20 o 1,49975. 



After being saturated with hydrochloric acid gas in an absolute ethereal 

 solution the oil afforded no solid hydrochloride even when left to stand 



x ) Report October 1904, 81. 



