and its Application in the Arts, 251 



fracture bright vitreo-resinous. The white and milky pieces 

 odorous, rather fragrant, somewhat resembling fine elemi; 

 taste like the smell, and sweetish. One piece, indeed, had 

 crevices, dividing it into laminae, between which was com- 

 pressed a subsaccharine pasty matter. Sp. gr. r04? to 1*06. 



It is very inflammable, burns away with a clear bright flame, 

 but does not drop. 



By gentle heat it froths and swells, giving out water and 

 aromatic oil, and becoming transparent ; and on increasing the 

 heat runs into a clammy fusion, but does not liquefy. After 

 cooling it is transparent, and nearly as hard and tough as shell 

 lac. This change may be effected without heating it enough 

 to impair its whiteness, even by powdering and heating gently 

 over the sand-bath, when it agglutinates as it gives off" its 

 essential oil, but becomes hard again on cooling. 



To try its solubility, 20 grains, dried as above, were treated 

 with the following liquids, each six times the quantity of the 

 resin. 



a. Cold water for twenty-four hours dissolved very little, 

 but acquired its odour, taste, and sweetness ; lost its transpa- 

 rency, and rendered the resin also opake. 



b. Boiling water four hours on the sand-bath dissolved 

 about 1 grain and became milky, but retained little of the 

 odour and taste, the essential oil having passed off* in the 

 steam. 



c. Rectified spirit of wine, twenty-four hours, cold, dissolved 

 nearly one half, leaving the residue soft and elastic, like bird- 

 lime. 



d. Alcohol (tartarised), four hours, at about 90°, dissolved 

 the whole, but on cooling deposited the elastic matter as left 

 by c ; this dried on the sand-bath, till crisp and beginning to 

 discolour, weighed 8^ grains. 



e. Pyroacetic spirit acted little upon it in the cold, leaving 

 the residue partly pulverulent, partly glutinous and elastic. 



Jl Pyroacetic spirit tartarised (rectified over carbonate of 

 potass) digested four hours in a warm-water bath, dissolved 

 it very partially, acquiring no consistence, becoming milky, 

 but not coagulating when dropped into water, and burnhio- 

 with the same bluish transparent smokeless flame as the pure 

 spirit. No other instance occurs to my recollection in which 

 the distinction between alcohol and pyroacetic spirit is so 

 marked ; the latter leaves the kauri resin even when com- 

 bined with shell lac or common resin. 



g. Volatile oil of turpentine, twenty-four hours in the cold, 

 rendered the resin voluminous, soft, and opake, but dissolved 

 very little. 



