Part III.] Puran Singh : Note on Manufr. of N gai Camphor. 277 
(2) By extraction . — About 10 — 20 grams of the leaves broken into 
small fragments or of the stem or roots cut up into fine shavings are ex- 
tracted with dry ether in a Soxhlet’s Extractor for about six to ten hours, 
and the material allowed to be thoroughly exhausted of all material soluble 
in ether. From the extract thus obtained the ether is removed by dis- 
tillation and the residue dried over the water bath and then in a desic. 
cator to a constant weight. The weight of the extract is noted as No. 1. 
The volatile oil contained in the extract obtained by the first operation 
is next separated by steam distillation. The operation takes about 
15 — 20 minutes. The residue is thoroughly dried on the water bath and 
finallv in an air bath till of constant weight. This weight is noted down as 
No. 2. 
The total amount of volatile oil contained in the material taken is then 
calculated by the difference (No. 1 minus No. 2). 
It is easy to see that the method just described gives more accurate 
results than the first method. 
For practical purposes, forty to sixty pounds of the plant are distilled 
in a large copper still with a sufficient amount of water for 8 — 10 hours, and 
the oil separated from the distillate by means of a Florentine flask or other- 
wise. In this way, fairly large quantities of the oil may be obtained for 
investigation of its properties. This process has also been used for the 
quantitative determination of the essential oils in plants. But the two 
methods described above being much more convenient and speedy are 
recommended, when the object of the analysis is merely to get a fairly 
accurate idea as to the expected yield of volatile oil from the plant. 
The Assay of the Blumea op Burma. 
The stearoptene or camphor exists in general dissolved in the essential 
oil, which, it appears to be well established, permeates the entire plant 
which yields it from the roots to the flower. The amount of the solid 
stearoptene suspended or dissolved in the essential oil increases with the 
age of the tree, so that the older trees yield more camphor and less cam- 
phor oil, the exact contrary being the case in the distillation of the younger 
trees. The proportion of camphor oil in the essential oil also varies with 
the season, its yield being as a rule larger in hot than in cold seasons. But, 
whatever be the ratio of solid camphor and camphor oil in the essential 
oil, it is clear that the yield of the camphor from a tree depends on the 
amount of the essential oil which can be extracted from it. Thus, the 
chief thing in the assay of a camphor-yielding plant is the estimation of 
essential oil contained in it. 
1 In very old trees camphor (both Barns and common variety) is found crystallised 
in cavities and dssures of the heart wood. 
