46 



( )n rectification 38 per cent, of the oil distilled below 167 , and 43 per cent. 

 above 250 C. The specific gravity of the first fraction was 0-8670 at 15 , and 

 ot the other 0-9310. The optical rotation of the first fraction was a D + 33-07°. 



The Walcha sample was stored in the dark, and in December, 1919, was 

 again analysed. Very little alteration had taken place during the twenty years 

 the oil had been kept. On distillation 49 per cent, came over below 190° C, 

 which was separated into two fractions, 155-170° and 170-190°. The crude oil 

 and the two fractions gave the following results : — 



Crude oil, sp. gr. at 15° C. = 0-9082; rotation a u + 15-2°; refractive index at 



20° = 1-4856. 

 First fraction ,, = 0-8684; rotation a B + 34*5° ; refractive index at 



20° = 1-4662. 

 Second ,, ,, ,, = 0-8726; rotation a D + 30-2° ; refractive index at 



20° = 1-4680. 

 The cineol was determined by the resorcinol method in the portion 

 distilling below 190° C. When calculated for the crude oil the result was 6 per 

 cent. 



The Sesquiterpene. — The oil of this Eucalyptus species is one of the best 

 from which to prepare the sesquiterpene in as pure a condition as possible. 



300 c.c. of the crude oil were distilled at 10 millimetres pressure. The 

 following fractions were obtained :— 



50-128 C. gave 56 c.c. = 18-7 per cent. 

 128-140 C. " ,, 153 c.c. = 51-0 

 Residue ,, 91 c.c. = 30-3 ,, 



The second fraction was repeatedly redistilled at the same pressure, finally 

 over sodium, until a fraction representing 20 per cent, of the crude oil was obtained, 

 boiling at 124-125 C. This had specific gravity at 15 C. = 0-9222 ; rotation 

 a n + 4-7° ; and refractive index at 20° = 1-4964. These are, therefore, the 

 constants for the sesquiterpene aromadendrene. (See also the article dealing 

 with this substance.) 



The sesquiterpene alcohol boiling above 140 C. at 10 millimetres was 

 lavo-rotatory. The residue had saponification number after acetylation 115-3, 

 and was laevo-rotatory a a — 15-4°- The refractive index was 1-5124. 



