286 



Selections. [no. 4, new series, 



The same author also states that Wood Oil is afforded by D. costatus( /). 

 angustifolius W. et A.), 7). alatus Roxb. and D. incanus Roxb.» the last 

 mentioned being reputed to furnish the largest proportion of the best sort. 



Closely allied to the Wood Oil of Dipterocarpus is the oleo-rcsin termed 

 Camphor Oil, produced by Dryobalanops Camphora Colcbr., a tree of the 

 same natural order. For a specimen of this oleo-rcsin and of an analogous 

 liquid called Lagam 0/7, both brought from Sumatra by Dr. Junghuhn, I 

 am indebted to the courtesy of Dr. J. E. De Vrij of Rotterdam, 



Wood Oil, as imported from Moulmcin, is after filtration, a transparent, 

 dark brown liquid, of somewhat greater consistence than Olive Oil, a sp. 

 gr. of .904 and an odour and taste like copaiba, though perhaps hardly so 

 strong. One part of it treated with two parts of alcohol sp. gr. .796, is 

 dissolved with the exception of a minute quantity of darkish fiocculent 

 matter, which subsides upon repose. 



But its most curious property (as noticed by Mr. Charles Lowe with re- 

 ference to a liquid which I suppose to have been Wood Oil*) is that exhi- 

 bited when it is heated in a corked vial to about 266° F. (130° C.)f Thus 

 treated, it becomes slightly turbid, and so gelatinous that the vial may be 

 inverted, even while hot, without its contents being displaced ; and on cool- 

 ing, the solidification is still more complete. Gentle warmth and agitation 

 restore to a great extent its fluidity, but solidification is again produced 

 upon the liquid being heated to 2GG°. Copaiba displays no such pheno- 

 menon 



According to Dr. O'Shaughnessy, when Wood Oil is heated in a retort, 

 a yellowish white, crystallizable, solid substance having many of the pro- 

 perties of benzoic acid sublimes into the upper part of the vessel, to the 

 extent of about one per cent, of the Wood Oil taken. In my own expe- 

 riments, I have not detected any of this substance. It is true that when 

 Wood Oil is heated, a scanty, opaque white sublimate condenses in the 

 cooler part of the vessel, but this appears to arise from the condensation of 

 a little water among the minute drops of essential oil, since it is not pro- 

 duced if the Wood Oil has been previously agitated with some fragments 

 of dried chloride of calcium. 



With regard to its medicinal properties, there appears to be no doubt 



* On a new variety of Balsam of Copaiba, Pharmaceutical Journal, vol. xiv. 

 pp. 65, 66. 



t Mr. Lowe says 230 Q F., but a mucb/more striking effect is produced on the 

 Wood Oil by the temperature I have named, 



