The Resin. 



The solidified resin in tlie flask, after removing the gum solution, was 

 dried as much as possible, and treated with ether, until practicall}- the whole of 

 the resin had been dissolved. The ether solution of the resin was filtered, evaporated 

 to dryness, and heated in thin layers on the water bath until all the ether had 

 been removed. When cold the resin was light coloured, and soon became powdery 

 on the surface ; it broke with a bright fracture, was somewhat soft, but quite 

 brittle, and in appearance strongly resembled sandarac resin. The amount of 

 resin thus obtained from the 680 grams of latex was 320 grams, = 47 per cent. 

 The resin was entirely soluble in 80 per cent, alcohol, and was not precipitated 

 on the addition of a considerable amount of the same alcohol. It was entirely 

 soluble in acetone, but only partly soluble in chloroform or in ether. 



A solution of i gram resin in'io c.c. acetone was Icevo-rotatory — 2-9° in 

 100 mm. tube. (This rotation is in the opposite direction to that of the similarly 

 obtained resin from Agathis robusta.) 



The specific gravity of the resin was i-o6i at 16° C, and the acid number 

 107. It was mostly soluble in a hot aqueous solution of carbonate of soda, but 

 formed a considerable precipitate on cooling. 



For analysis, 25 grams of resin were again treated with ether, but the whole 

 was not soluble ; the insoluble portion weighed 1-52 grams, equal to 6-o8 per cent. 

 When this insoluble portion was dissolved in alcohol and solid potash added, it 

 was almost entirely precipitated as an insoluble potash salt. This salt was dissolved 

 in water, the solution acidified with hydrochloric acid and boiled, and the separated 

 acid dried and heated at 100-105° C. It melted at 233° C, and appeared to be similar 

 to the corresponding acid from Agathis robusta. The ether solution containing 

 the soluble resin was neutralised with alcoholic potash and water added. The 

 solution was then placed in a separator, and the neutral bodies, &c., entirely 

 removed with ether. The aqueous portion was then boiled to remove the ether 

 and alcohol, water added, the solution acidified with hydrochloric acid and boiled. 

 The separated resin melted in the boiling water, but when cold formed a hard, 

 brittle lump of a vellowish resin. It was then dried, powdered, dissolved in alcohol, 

 and solid potash added, when a portion became at once insoluble and eventually 

 formed a thick pasty mass. This insoluble salt was dissolved in water, acidified, 

 and the acid separated and dried. It weighed 2-115 grams, equal to 8-46 per 

 cent. It melted at 232° C, and was identical with the acid insoluble in ether 

 at first, so that both portions were added together for purification. The amount of 

 this acid (Dundathic acid) in the resin of Araucaria Cunninghamii was I4"54 per 

 cent. It was purified by reprecipitating from an alcoholic solution b}' alcoholic 

 potash, and finally dissolving in absolute alcohol, adding a little water, and crystal- 

 lising out. This crystallisation from alcohol was repeated three times, and the 



