252 Mr. Prideaux 07i the Kauri Resin, 



h. The same oil, in the water-bath four hours, dissolved 

 nearly 9 grains; the residue not elastic, (as that of c and d 

 from alcohol,) and when dry was partially soluble in cold an- 

 hydrous alcohol, the undissolved part then acquiring some 

 elasticity. 



i. The elastic deposit from alcohol (c, d) was digested in 

 oil of turpentine on the water-bath, by which almost the 

 whole was dissolved ; a small portion separating when cold 

 in a soft bulky jelly. 



h. To another alcoholic portion, as d^ was added one third 

 of its volume of turpentine solution, as li, with the residuum, 

 both being warm ; the solutions mixed freely and clear, and 

 the heat being continued other four hours, the residue com- 

 pletely dissolved. The solution retained its transparency and 

 deposited nothing on cooling. Thus the kauri resin is com- 

 pletely soluble in four times and a half its weight of alcohol 

 with one and a half its weight of oil of turpentine, and acts as 

 a medium to combine the menstrua. 



/. Pyroacetic spirit was tried with oil of turpentine in the 

 same manner, but refused either to combine with the turpen- 

 tine, or to act effectively on the resin. 



m. Coal-tar naphtha dissolved the greater part readily in 

 the cold, leaving a soft gelatinous residue, hke caoutchouc 

 digested in that liquid. 



n. Linseed oil did not dissolve it by digestion, nor by gently 

 heating together in an iron ladle. On increasing the heat, 

 combination takes place, but not till the hardness and elasti- 

 city of the resin are destroyed (w). The case is not amended 

 by combining either the oil or the resin previously with oil 

 of turpentine. 



It was stated above that this resin v^ 2iWi'& fimhilityx for al- 

 though it easily softens and agglutinates, it refuses to liquefy, 

 and even burns away without dropping. 



To try how far this property could be induced : 

 r, A portion of the powder was mixed with half its weight 

 of volatile oil of turpentine and gradually heated in an iron 

 ladle. The resin softened as usual ; the oil acquired consist- 

 ence ; but the combination was only partial, though kept con- 

 stantly stirring. The oil gradually evaporated, leaving the 

 resin in its original clammy state, from which it did not change 

 at any period of the experiment. 



5. Another portion was mixed with half its weight of oil of 

 turpentine, left in the cold for a night, and then digested six 

 hours in a very gentle sand-bath. There were, as before, 

 partial combinations between the mass of the resin and a part 

 of the oil, and between the bulk of the oil and a part of the 



