196 PHILIPPINE RESINS, GUMS, AND OILS 



* * * To prepare a 1 per cent solution of the oil in alcohol and 

 compare the odor with a similar one of an oil of known quality, as judg- 

 ment is much more certain as to the perfuming power when dilute solutions 

 instead of the pure oils are used. One cubic centimeter of each solution 

 can then be poured on separated pieces of bibulous paper, the odor being 

 compared at the end of twelve, twenty-four, or even a longer number of 

 hours; this test gives some idea in regard to the permanence of the odor. 



DISTILLATION OF OIL IN VACUO 



Bacon found that the distillation of the oil in vacuo provides 

 a good method of ascertaining the quality of an oil and the num- 

 ber of flowers used in preparing it. He also showed that the 

 rectification of oils in vacuo is not very successful. These points 

 are shown in the following quotation : 



* * * the rectification of oils in vacuo is not an entire success, as 

 the distillates, although apparently of the same composition as the oil 

 from which they are distilled, seem to lack in perfuming power; this is 

 especially true of the lasting qualities of the odor. These results suggest 

 that the highest boiling parts of the ilang-ilang oil and even the resins, 

 are very probably important constituents of the whole, possibly they help 

 to fix the more volatile, odoriferous portions. I have always been im- 

 pressed by the peculiarly lasting fragrance of the resinous residues of the 

 distillation of ilang-ilang oils fractioned /n vacuo. 



The distillation of ilang-ilang oils in vacuo has shoviTi that over 50 per 

 cent of the first quality oil will pass over below 100*^ at 10 millimeters 

 pressure, and when I have tested poorer oils in this respect I have found 

 the amount of substance volatile below 100° at 10 millimeters which 

 passed over to be proportional to the quantity of flowers used in preparing 

 the oil. Thus one oil distilled from flowers at the yield of 1 kilo for 206 

 kilos of flowers showed 27 per cent of volatile constituents under the con- 

 ditions named, whereas another prepared in the proportion of 1 kilo to 

 150 kilos of flowers gave 19 per cent. 



It follows from this that the distillation test is also of value both in 

 determining the quality of an oil and the proportion of flowers used in 

 preparing it. The only manner in which poor provincial oils may be 

 improved is by redistillation with steam, and this procedure results in 

 large losses. Fractioning with steam in vacuo also seems quite promising, 

 although the process is very slow. Oils thus obtained are quite colorless, 

 and by taking suitable fractions a very fair oil may thus be prepared from 

 a product which before treatment was almost unsalable. 



EXTRACTION OF PERFUME OIL WITH SOLVENTS 



Bacon * also studied the problem of extracting the oil from 

 ilang-ilang flowers with solvents : 



* * * Many of the constituents of essential oils are very delicate 

 substances and distillation with steam decomposes these compounds to a 



* Bacon, R. F., Philippine terpenes and essential oils. III. Philippine 

 Journal of Science, Section A, Volume 4 (1909), page 129. 



