250 Mr, Prideaux on the Kauri Resin, 



equally tinctured with it, whilst it may be seen exuding from 

 the tips of the leaves on the highest branches. 



The term " gum " appears to be here misapplied to a sub- 

 stance insoluble in water, and I suppose, with deference to 

 Mr. Yate, that his distinction is unfounded ; that the gum 

 means the more recent exudation, which is white, opake, 

 fragrant, and more or less compressible, from the presence of 

 its essential oil ; the resin that which has lost by time or ex- 

 posure the essential oil and a little moisture, and thus be- 

 come hard and transparent. A piece which was given to me 

 twelve months since in the former state, had become yellow, 

 hard, transparent, and almost inodorous before I repeated 

 my examination of it on the present occasion ; and in look- 

 ing over several cwts. now in this port, I find it in every stage 

 of the difference. 



In Berzelius's Traitc de Chimie (v. 501) is described a 

 jResine Dammara lately introduced, as transparent, colourless 

 or yellowish, insipid, inodorous, sp. gr. 1*097 to 1*123, very 

 fusible, without any odour, dissolving partially in alcohol, 

 almost entirely in aether, and completely in oil of turpentine 

 and fat oils. Brandes found in it traces of gum and succinic 

 acid, and two resins ; one soluble in cold alcohol, amounting 

 to 83*1 percent., the remainder insoluble in that menstruum 

 cold, but dissolving in it hot and precipitating in the form 

 of a voluminous snow-like white powder. It will appear that 

 this is not the same with kauri resin, although possessing con- 

 siderable analogy with it. 



Kauri resin (known here as Cowdee gum) is in pieces of 

 various magnitude, from that of a nutmeg to a block of two 

 or three cwts. Generally they are of irregular shape, with 

 rough powdery surface, and often pieces of bark or occasion- 

 ally even earthy matter attached ; whilst some are shining, with 

 a vitreous fracture. In colour they vary from milk-white to 

 deep amber and even brown; the white having occasional 

 transparent lines and patches; the yellow being generally trans- 

 parent; and the brown sub-opake, apparently from impurity, 

 and perhaps extractive matter. But bits may be found trans- 

 parent and colourless, and every shade afibrds abundant 

 examples of milky opacity. Its hardness is intermediate be- 

 tween that of copal and of resin, so that it cannot be scratched 

 by the nail ; the m ilky pieces more or less tough and elastic ; 



It is black, not quite hard, but friable, breaking like pitch, tasteless and 

 inodorous. On subjecting it to chemical examination, I found it chiefly 

 to consist of asphaltum, containing no kauri resin, as it dissolved entirely 

 in cold oil of turpentine. 



