CHEMISTRY. 209 



ATTAR OF ROSE. BY DR. R. BAUR, OF CONSTANTINOPLE. 



Attar of rose, or rose-oil, is the volatile oil obtained on the 

 southern slopes of the Balkan by distilling the flowers of Rosa 

 damascena. 



Pure attar of rose, carefully distilled, is at first colorless, but 

 speedily becomes yellowish. Its specific o:ravity at 18° R. (72.5'^ 

 F.) is 0.87 ; its boHing-point 229° C. (444° F.). It consists of an 

 elaeoptene and a stearoptene, the former the source of the odor, 

 the latter of the property of congealing into a solid form. 



Pure attar of rose, once distilled, solidifies at a temperature of 

 from 11° C. to 1G° C. (51.8° F. to 60.8'* F.), or still higher. It is 

 soluble amons: other thinofs in absolute alcohol and in acetic acid. 



^ CD 



Its odor is rose-like, with a peculiar honey-like sweetness, agree- 

 able only when highly- diluted. Attar is adulterated chieily with 

 the so-called geranium of Palmarosa oil. 



The Turkish geranium oil is, according to the most credible ac- 

 counts, dei'ived from a grass of the genus Andropogon, from which 

 it is distilled in the months of December and January in tho 

 neighborhood of Delhi. It comes to Turkey by way of Arabia, 

 and is sold here by Arabs in large, bladder-shaped vessels of 

 tinned copper, holding about 120 jjounds each. When recent, it 

 is toleral)ly limpid, bright-yellow to brownish, often colored green 

 through containing copper, and very frequently — indeed mostly 

 — contaminated by the addition of a fatty oil. 



The geranium oil as it arrives is, however, by no means in a 

 proper condition for mixing with attar. Its odor and color must, 

 as far as possible, be assimilated to those of rose oil, and to this 

 end it has to be refined. By this process it loses its penetrating 

 after-smell, and, according to the goodness of the sample treated, 

 acquires, sooner or later, a pale, clear yellow color. It also loses 

 the property, which it possesses in the unrefined state, of acquiring 

 a red color (separation of CuoO) upon long standing. 



Geranium oil does not solidify at — 20^* C. ( — 4° F.), but be- 

 comes at that temperature turbid and thick. Like attar, it takes 

 up ozone from the air, and shows an energetic reaction with 

 iodine; it is easily soluble in ordinary spirit of wine, and affords 

 like attar a well-crystallized compound with CaCl. It is quite 

 inactive to a ray of polarized light. 



Geranium oil is mixed with attar in almost any proportion, from 

 a few parts per cent, up to 80 or 90. The differences in congeal- 

 ing-j^oint are not quite in proportion to the relative volumes of 

 the two oils which are mixed, apart from the variable properties 

 of each. 



Many attempts have been made to discover some chemical re- 

 action which would reveal the falsification of attar with geranium 

 oil, but hitherto mostly in vain. As completely deceptive, may be 

 noticed Guibourt's test with the vapor of iodine ; and also that 

 with K I and starch. The author has had the opportunity of pre- 

 paring a standard attar of rose on the spot, and was also in a po- 

 sition sucli as scarcely another chemist ever had for investigating 

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