SCIENTIFIC AND OTHER NOTES ON ESSENTIAL OILS. 
Scientific and other Notes on Essential Oils. 
Almond Oil, bitter. Concerning alteration, upon ageing, of amygdalinase and 
amygdalase, see page 69. 
Anise Oil. On page 49 of our previous Report we mentioned a paper by Auguet 
on the determination of essential oils in absinth and other liqueurs, by Hutbl’s iodine 
absorption method. Similar examinations have been carried out since then by E. Morin*) 
and R. Marcille’). 
When determining anise oil in Anisette, Morin invariably obtained figures which 
were too high. In order to ascertain the cause of this difference he determined Hubl’s 
iodine value in solutions containing 0.8, 1 and 1.2 g. of anise oil per litre of 50 p.c. 
alcohol. Calculated on anise oil he found values corresponding with 1.651, 1.7018 
and 1.7350, or an average of 1.0961. This figure differs considerably from the value 
of 1.391 found by Morin in technical literature, but it agrees with the number 1.640 
established for anise oil by Barenthin. The figure 1.6961 found by Morin should only 
be made use of in cases where the liqueurs under examination contain about 1 g. of 
anise oil per litre. 
According to Marcille the determination is influenced not only by the concen- 
tration of the anise oil but also by the strength of the alcohol. He suggests that the 
alcoholic strength of the liqueurs should be brought to 50 p.c., by the addition of more 
alcohol or water, as the case may be. Special care should be taken to add the iodine 
solution in the dark, and to allow the testing vessels to stand in the dark while the 
reaction takes place. 
Bay Oil. In one of ourprevious Reports*) we gave a description of the bay oil 
| industry in St. Thomas. In a complementary way we may here add a few notes on 
the bay leaf industry in the West Indies‘). In order to ascertain whether the time of 
reaping the leaves has any influence on the properties of the oil, leaves were collected | 
monthly from an experimental plot, and distilled separately. It was found that, in 
accordance with experiences collected at earlier dates, the leaves are richest in oil in 
the months of June and July. Phenol content as well as density of the oil are con- 
siderably influenced by the degree of maturity of the leaves; for instance, mature leaves 
distilled in December 1913 yielded an oil of the density of 0.9491, and containing 62 p.c. 
of phenols, whereas an oil obtained in January 1914 from young leaves showed a 
phenol percentage of 33 p.c. and a density of 0.8850. 
To facilitate the reaping of the leaves, bay trees should not be allowed to grow 
higher than about 6 to7 feet. The leaves are dried for a few days in covered sheds, 
before being distilled; whether this is of any use has yet to be ascertained. 
4) Annal. de Chim. anal. 20 (1915), 49. — 7) Ibidem 52. — %) Report April 1918, 31. — *) Perfum. 
kecord % (1914), 425. 
