712 
Supplement to the "Tropical Agriculturist." [April 1, 1902. 
The wholesale adulteration of citronella by 
means of kerosene has been tiie downfall of the 
Ceylon trade in the oil. Who could have been 
the ingenious inventor of the fraud ? There is no 
doubt that many a southern fortune that has come 
out of it. It is said that after some trouble 
the chemist found a means of detecting the 
adulterant and the extent of adulteratiiin ; but 
quite lately we have been informed that the test, 
which answered hitherto, fjiila, osring it is 
thought to another adulterant being employed or 
a third substance being bought into reqai-iition 
to effectually disguise the fraud. We have 
not been able to di-iC'iver the suspected tertium 
quid, while a new adulternant, if it could take 
the pliice of kerosene, would not from a ftniincinl 
point of view answer the purpose of the citronella 
planter. Domba oil was suspected to be empl')y6d, 
but it would not pay to employ it even if it be a 
good adulterant. The old method of adulteration 
consisted in mixing the kerosene with the distilled 
citronella ; now, however, the dodge is to pour the 
kerosene over the grass when it is ready to be 
operated on by steam, and distill the vegetable 
and mineral oils together. Could this change of 
tactics account for the confusion of the chemists ? 
Quisgualis indica is not commonly seen outside 
gardens, but Alamanda has long since started on 
its own account. We were surprised, however, to 
see Quisqualis as a veritable escape from cultiva- 
tion on the banks of the Nilwala ganga near 
Atureliya. 
There is no doubt that considerable improve- 
ment is possibled in the method of curing native 
tobacco, as an expert lately remarked ; but tiiose 
who smoke the " fragrant Jaffna" cigar could little 
suspect what ingenious devices are practised by 
the tobacco growers of the North. A late resi- 
dent in that part of the Island assured us that he 
once watched a cultivator working round a 
manure heap which had lately been saturated 
with rain, and saw him fish up a parcel of leaf 
from underneath the midden, explaining, on being 
questioned, that it had been put there to ferment. 
Who will be surprised at the rankuess and pun- 
gency of a Jaffna cigar after that ? 
The tree known as Samadara {Samadera indica) 
found in the Galle district among other places, is 
interesting from the fact that a decoction made 
from tlie leaves has insecticidal properties, and is 
according to Dr. Trimen destructive to white-ants. 
The whole plant which is very bitter is used 
medicinally as a febrifuge. 
IDENTIFICATION OP WOODS. 
[The following is a resumi of a notice in 
Nature (kindly placed at our disposal by Mr. 
Lewis, Assistant Conservator of Forests), from 
which it would ai)pear that it is more difficult to 
identify woods by means of anatomical characters 
than is generally sup])osed, on account of the 
great differences which the structure of the 
primary and secondary wood present. — Ed. A.M.I 
" The grouping of vessels and the medullary rays 
and the arrangement of the wood parenchyma are 
frequently so characteri»tic that various genera can 
be recognized by a glance at the transverse 
section, i.e., horizontally as the tree stands; and 
further it is by no means rare to find the same 
structure runiung through a wh )le genus, or, 
less frequently, through a whole order. A 
hundred genera could be cited which exhibit a 
strong family likeness, and of the Fr-.teacea; 
and Sapiiaceffi it may be said that the description 
of the srructure of the wood of one species will 
practically serve for the whole order. On the 
contrury there are whole orders which appear 
to consist chiefly of exceptions, as in the cise 
of Celastracene, and where it is difficult lo find 
two genera ivith any important feiiture in 
commi.n. The structure of the woody portion 
of Ciyptogiims has been employed for years ia 
the study of fossil plants ; tu^it of the mono- 
cotyledeuous trees and conifers i? notoriously 
uniform, and is assure a guide to- their position 
in the natural system as any external character. 
Why then should not the same rule apply 
to the angiospermous dicotyledons, and for 
what reason should the thread be lost as soon 
as we pass from one division of the vegetable 
world to another? 
It seems a bj'-no-means extravagant idea that 
inasmuch as it is quite indifferent to the welfare 
of a plant what the structure of its woody 
portion may be, so long as it performs the 
mechanical duties imposed upon it, ancestral 
traits should be preserved umlisturbed in the 
wood more than in any other part. 
Ignoring the debatable question, there is no 
doubt whatever of the ecconomic importance 
of this study. 
Mr. Stone points out that with the large number 
of timbers in use and those destined to be turned 
useful, the old rule of thumb methods of 
identification are not likely to answer. He refers 
to the case of the Colonies where those who 
have a knowledge of timbers are few in number 
and vernacular names of trees often confusing! 
Mr. Stone points out that for practical purposes 
it is rarely necessary to use high powers of 
magnification : a pocket lens of a two-inch 
objective being frequently sufficient to display 
the special character of the structure. Higher 
powers tend to obliterate this "individuality" 
which depends on the arrangement or complex 
of the elements. For instance, the radial or 
tree-like arrangement of the vessels in the wood 
of Quercus is recognizable by the naked eye, 
but is not striking under a half inch objective. 
The concentric undulating lines of vessels character- 
istic of the elms is also usually visible to the 
naked eye. But in both these cases the same 
characteristics are shared by many other genera 
often not by any means closely related. 
It will therefore be at once admitted that 
anything like a natural system of classification 
of wood by their structure is quite impossible 
at present. There is too little recorded informa- 
tion and too many glaring exceptions where 
one would not expect to see exceptions. 
