a 
= 
The determination of the volatile esters in lemon oil will be found described on 
Base: 90 of this Report. 
oj ? €. t 
SSS eo “ 
S “Eucalyptas oil. On page 22 of our Report ‘October 1915 we discussed a paper 
g BY. C. E. Burke and C. C. Scalione on Californian oil of Eucalyptus Globulus. In this 
_ paper the fact was mentioned that the Australian distillate was in conformity with the 
Bea aicnients of the U. S. Pharmacopeceia, but not the Californian oil. P.W. Tompkins’) 
p now deals with this fact more closely.. He has found that the oil distilled from one 
_ year old sucker shoots’) of Eucalyptus Globulus differs very considerably from the oil — 
Bt obtained from leaves of older trees, as will be clear from the following table: meer eee 
s — Oils of Hucalyptus Globuius: 
= oe See eta ee Age of the trees 
e, =. = 1 year - Bene 30 fears 
aa iets ean St 0.09" p.c: 0.21 p.c. 0.84 p.c. | 
a ees ee 8 0.890 0.906 0.908 “3 
2 Solubility in in 20 p p.c. alcohol insoluble 45 vol. 15 vol. 
_ leaves of old trees shows an unsatisfactory solubility, as compared with U. S. P. require- 
= "ment, which is a solubility of 1 vol. of oil.in 3 vol. of 70 per cent. alcohol, such as 
is possessed by Australian oils. Tompkins has now examined an authentic. oil of 
3 Eucalyptus Globulus obtained from Australia and has found that even this oil is soluble 
_ only in 8 vol. of 70 per cent. alcohol. dos50 0.9123; [@]p20 + 3.99; cineole content 
The abnormal properties observed occasionally in Californian oils are probably oe 
~ due to~ young leaves having been used for distillation. But even the oil from normal 
_ 54 per cent. (phosphoric acid method), whereas Californian oils of Eucalyptus Globulus 3 
_ showed the following average properties: doso 0.906; [@]p.50 + 8.0°: soluble in 15 vol. of 
— 
_ 70 per cent. alcohol, cineole content 52 per cent. (phosphoric acid method). The author 
3 Bor Piains the difference in solubility of Californian and Australian oils of Hucalyptus 
_ Globulus by the fact that the Australian oil of commerce is derived in reality from other — 
species, for, as Baker informed him by letter, the oil is rarely obtained from Eucalyptus 
- Globulus in Australia, other kinds being alee which yield oils richer in cineole, such — 
as fii. Eucalyptus polybractea. : 
2 - From this it would appear that, as a matter of fact, oil of ‘Kaci Globulus 
_ does not dissolve readily. Jt would be possible to bring the Californian oil up to the 
U.S. P. solubility standard by means of rectification, but this would entail a loss of 
_ about 15 per cent. of oil. In Tompkins’ opinion it would be better if U.S. P. were to 
_ stipulate a solubility of 1 vol. in 18 vol. of 70 per cent. alcohol; in that case the normal 
_ Califotnian Globulus oils would be covered by the requirements of the Pharmacopceia. 
* 
*) Journ. Ind. Eng. Chemistry 7 (1915), 995. — 7) As will be known, the young foliage of most kinds 
“only sucker Kae are Produced which.are frequently used for distillation in California. 
F. of Eucalypti is differently formed from that of older branches. Wherever new shoots grow fromtree stumps, ~ 
