PROSTANTHERA AND ITS ESSENTIAL OIL 109 



such a small quantity was available it was decided to form 

 the phenylhydrazone. This was prepared without difficulty, 

 and after purification melted sharply at 126 - 127°. This 

 result, taken with the other factors, shows the aldehyde 

 to be cuminaldehyde. 



This aldehyde, together with the carvacrol, causes the 

 oil to have a peculiar odour, but when these are removed 

 the odour is that of a Eucalyptus oil of the eucalyptol- 

 pinene class. 



Redistillation. — 125 cc. of the cleared oil were taken, 

 only a few drops of acid water and a little volatile aldehyde 

 came over below 135° 0., the temperature then quickly 

 rose to 167° (temps, corr.). Between 167 - 172° 40 per cent, 

 distilled; between 172-204° 46 per cent.; between 214 — 

 224 3 2*5 per cent. The specific gravity at 15° O. of the first 

 fraction = 0*9063 ; of the second = 0*9174 ; and of the 

 third = 0*9321. The rotation of the first fraction a D = 

 + 3°*7; of the second + 1°*9. The refractive index at 19° O. 

 of the first fraction = 1*4661; of the second = 1*4688; and 

 of the third = 1*4901. 



The cineol was determined in the first two fractions by 

 the resorcinol method, the mean of two closely agreeing 

 determinations being 61 per cent, calculated for the crude 

 oil. The pure cineol was prepared from the phosphoric 

 acid compound and its characters determined. 



Pinene. — The first two fractions were again distilled 

 and the lower boiling portions treated, 20 cc. at the time, 

 with 50 per cent, resorcinol to remove the cineol. The 

 unabsorbed portion was again agitated with fresh resorcinol 

 until the cineol was removed. The oil left, after this 

 treatment, was washed and dried. It had a strong odour 

 of cymene and the following characters: — Specific gravity 

 at 15° C. = 0*8670. Rotation a D = + 7°'7. Refractive 

 index at 20° = 1*4805. 



