N. O. PIl'ERAOE/E. 
1095 
interesting studies in the chemistry and physiology of the leaves 
of the Betel-Vine. According to them — 
The younger leaves on the plant contain much more essential oil, much 
more diastase, and much more sugars than those which are older. On the 
nther hand, the taunin does not vary in this direction. The leaves both on 
the middle branches and on the middle part of tho main vine contain 
slightly the largest quantity of ‘ tannin.’ . * * * » 
Nearly all the work done (except that of Eybman) has been done in Europe 
on dried leaves— and all, except the original preparation of Kemp, on Java or 
Siam oils. Our results differ considerably from those published hitherto, and 
we will simply indicate those which we have obtained. 
As to the conclusions regarding the essential oil of betel- 
leaf, they say — 
The essential oil of betel leaf consists essentially of two portions, consist- 
ing respectively of phenols and of terpone-like bodies. The relative pro- 
portion of these varies, and the higher the quality of the leaf, the higher the 
proportion of phenols in tho essential oil. The proportion of phenols in our 
samples varied from 42 per cent. (Poona) to 70 per cent. (Rarntck kapuri) in 
green .leaves of the light green variety, and from 39 per cent, to 45, per cent, 
in green leaves of the dark green variety. The bleaching of the leaves not 
only increases very much tho total quantity of the essential oil, but also the 
proportion of tho phenols in it. In two cases where bleaching was carried 
out, the increase in tho percentage of phenols was from ,17 to 33 per cent. 
t Tho phenols consist essentially of eugcnol in all our cases, mixed with a 
small percentage of betel phenol. The latter can be largely separated by 
washing the phenols with water in which it is very much more soluble than 
eugenol. No sign of any substance having tho properties attributed to chavi- 
col has been found in any of our samples. 
The nonphenolic portion of the essontial oil is a mixture of a number of 
substances as yet univestigated. Over 00 per cent, boils between 240° and 
255°C. This has a light green colour, and a somewhat objectionable smell. 
It is not cadineno or caryophyllene. 
They conclude their interesting studies as follows : — 
We have shown the character of the leaf which is required for chewing, 
and have found more clearly than ever that it is the quantity, and also the 
character, of the essential oil which seems most largely to determine the 
value of any sample of betel vine leaf for this purpose. 
Tho essential oil itself, however, is not always tho same. It consists of 
a mixture of certain phenols and of certain terpene-like constituents. As 
far as the phenols are concerned, eugenol is always tho chief constituent in 
Indian oils, mixed with a small quantity of betel phenol. We have never found 
chavicol in Indian oils. The best essential oil, from a point of view of public 
taste, is that which contains as large a proportion of phenols as possible. 
Those varieties of leaf which give an essential oil containing much terpene, 
are very pungent, but arc looked upon as very coarse. Bleaching not only 
