THE RESINOUS EXUDATION OF ROSEWOOD. DAYAL 
colouration from the tissues of the heart-wood, and, as a 
rule, lightens the colour of the insoluble deposit in the 
vessels. Ferric chloride caused a darkening of the vessel 
contents, probably due to the presence of tannins, but little 
effect otherwise. The sap-wood which is pale in colour 
also showed numerous oil globules when treated with potash, 
both in the elongated parenchymatous cells and also in the: 
medullary rays. - 
Rosewood felled in April, 1922, was also examined and 
gave practically similar results, as far as the distribution 
and behaviour of the oleo-resin is concerned, to those 
already outlined. The contents of the parenchymatous 
cells, which weresomewhat granular in appearance, rounded 
up in 60% alcohol, the globules being slowly soluble in 70 — 
80> alcohol, and finally went into solution in 90% alcohol. 
Caustic potash showed oil to be present also in the cells of 
the medullary rays. 100% alcohol reduced the colour of the 
vessel contents somewhat, but no solution occurred. 
An examination was made ofasmall branch (about 45mm. 
in diameter) of a tree of D. Fraseranum. Some of the 
vessels contained a light yellow transparent deposit, not 
always completely filling the pore in section, but quite 
insoluble in 100% alcohol or chloroform; no darkening was. 
observed with ferric chloride. A 50” alcoholic solution of 
alkannin stained the contents slightly, but in many cases 
the deposit was unaffected, and subsequent treatment with 
100%° alcohol removed the colour, where stained. There 
was no diminution in volume, thus discounting the possi- 
bility of oil"being present in the vessels. In older branches. — 
the deposit was darker in colour, and more granular in 
appearance, but quite insoluble in glacial acetic acid, petrol- 
ether, benzene, ether, chloroform or acetone. A few oil 
globules measuring about 0°0075 mm. in diameter, were 
found in the elongated parenchyma; these were stained 
bright red with alkannin and were soluble in 100° alcohol. 
