70 



presenl in the oil was but small, the principal constituent being dextro-rotatory 

 pinene, and it is worthy of notice that in practically all the cineol-pinene 

 nils which Eorm a deposit on keeping, the pinene has an optical rotation to 

 the right. The alteration which takes place, however, is not due to the pinene, 

 because the strictly pinene oils like that oi E. dextropinea, for instance, do not 

 Eorm a deposit, and do not increase in cineol content on keeping. (See also 

 the article in this work dealing with this deposit.) Phellandrene does not 

 occur in the oil of this species, nor is it to be expected, judging from the botanical 

 characters. The amount of esters was larger than is usual in oils of this class. 

 Id ic higher boiling portion contained some sesquiterpene. The pinene was 

 separated and its chemical characters determined. 



The crude oil had specific gravity at 15 C. = 0-895; rotation a u + 18-3°; 

 refractive index at 20 = 1-4690, and was soluble in 1 volume 80 per cent, 

 alcohol. The saponification number for the esters and free acid was 19-6. 



On rectification, 2 per cent, distilled below 159 C. (corr.). This portion 

 contained the usual amount of volatile aldehydes. Between 159-169°, 60 per 

 cent, distilled; between 169-178°, 24 per cent, distilled; and between 178-204 , 

 6 per cent, distilled. These fractions gave the following results :— 



First fraction, sp. gr. at 15 C. = 0-879; rotation a B + 23-6°. 



Second ,, ,, ,, = 0-897; ,, + 13-18°. 



Third , : ,, ,, = 0-903; ,, not taken. 



The cineol was not present in sufficient amount to allow of its being 

 determined quantitatively by the phosphoric acid method, and the resorcinol 

 method was not then available. 



The above sample of oil had been stored in the dark, and in April, 1919, 

 was again analysed. An increase in cineol content was shown, and this is more 

 noticeable in the redistilled oil. 86 per cent, distilled below 190° C. The crude 

 oil and the fraction gave the following results : — 



Crude oil, sp. gr. at 15° C. = 0-9144; rotation a D + i7 - 4°; refractive index 



at 20° = 1-4688. 

 Fraction ,, ,, = 0-9140; rotation a D + 18-2°; refractive index 



at 20° — 1-4640. 

 The cineol was determined by the resorcinol method in the rectified portion, 

 and calculated for the crude oil ; the result was 49 per cent. By the rapid 

 phosphoric acid method it was 30 per cent, when calculated for the crude oil. 



28. Eucalyptus hemilampra. 



(F.v.M., Herb. ; R.T.B., Proc. Linn. Soc, N.S.W., 1900, p. 669.) 

 (Syn. E. resinifera, Sm. var. grandiflora, Benth., B.FL, iii, 246.) 



Mahogany. 



Systematic. — A very tall tree, with a red, stringy bark. Abnormal leaves 

 of the same shape as the mature ones. Normal leaves broadly lanceolate, 6 to 

 9 inches long, shining above, pale underneath, of a thick texture; venation 

 indistinct, lateral veins numerous, inclining to transverse, more prominent on 

 the under side of the leaf, intramarginal vein close to the edge ; petiole 2 inches 



