Paet III.] PuEAN Singh : Note on Manufr. of Ngai Camfhor. 285 
branches get v/ilted before they are put into the still appears to be un- 
necessary, unless it were in the case of the leaves that have to be 
taken to a long distance. 
The distillation of the plant by means of water or of steam should be 
slowly conducted, and the receiver in which the vapours are conducted 
from the still should be kept as cool as possible. 
It would thus appear that the Chinese system of distilling the plant 
in the winter months is perfectly justified, though of course the distilla- 
tion may be carried on in the hot season if due precautions are taken in 
keeping the receiver cool during the process. 
A few words may here be said about the moot points connected with 
the extraction of Ngai camphor, which have been indicated in a pre\dou 3 
chapter, while reviewing the accounts of the Chinese process of distillation. 
In the first place, it is to be remarked that though the Chinese are not 
stated to obtain any oil as a by-product from the plant, it is nevertheless 
possible to do so, as in the case of other camphor-yielding trees. Secondly, 
to obtain the maximum yield of camphor from the plant there seems no 
need of subjecting it to any preliminary treatment excepting that of 
reducing it to a state in which the steam or the water may have an 
opportunity of rupturing and entering the plant cells and may bring the 
volatile oil contained in them to boiling point. The processes of the 
formation of both the oil and of the camphor in it in the tissue of the 
plant have not yet been understood, and so far it appears, therefore, 
that it is not possible to control the development of these substances in 
the plant with the object of increasing their yield. Thirdly and lastly, 
other species of Blumea can be utilised as well as B. balsamifera for the 
manufacture of Ngai camphor. 
As regards the ready sublimations or crystallisation of camphor in 
the oil by the addition of some substance to the latter or otherwise, 
the question is under investigation and will possibly be dealt with in a 
future note on the subject of the manufacture of Ngai camphor. 
The above notes must be regarded as a preliminary and only very 
partial enquiry into the extraction of Ngai camphor from B. balsamifera 
of Burma. There is no doubt that the results of the assay of the 
plant as given above are decidedly encouraging. But in practice when 
the distillation of the plant is carried on on a large scale, the yield of the 
oil must become, as has already been stated, much smaller than the pre- 
liminary assay has shown. For there are numerous causes at work during 
the process of distillation by which more or less of the volatile oil origin- 
ally present in the plant is very likely to be rendered wholly useless or 
