86 ON TAMANU RESIN AND OIL 



that is sui generis, and an insipid flavour, which is not agreeable. Its 

 density is 8 - 9347. 



When it is boiled, it becomes thick and strongly coloured. It is in- 

 soluble in alcobol. If shaken in a tube with tbat liquid the mixture 

 becomes very green. This colour is owing to the resin, which the spirit 

 separates from the oil and keeps in a state of solution. "When allowed 

 to settle, the oil, which has taken a yellow tint, occupies the lower part. 

 If the alcohol be poured off, and the tube, which now only contains oil, 

 be plunged into warm water, it clears, becomes translucid, and is very 

 much like olive oil. The alcohol having been evaporated, a residuum 

 of green resin is obtained. Such would be the means of purification 

 employed were it not too expensive. This oil is insoluble in ether and 

 chloroform. "When a drop of concentrated sulphuric acid is added to 

 some drops of oil, previously poured upon a lamina of glass placed on 

 a small piece of white paper, a yellow stain is soon seen to form, 

 which continually increases in the intensity of its colour, and finally 

 becomes a reddish brown, but this colour disappears after twelve hours 

 exposure to the air. Concentrated sulphu ric acid, poured into oil of 

 Tamanu, precipitates a resinous substance of a brown red colour, and 

 the oil takes an orange tint without producing a sediment. Azotic acid 

 has no immediate action on it ; but if the mixture be stirred with a glass 

 rod, the oil takes an orange tint without producing a sediment. 

 Clorhydric acid produces the same result on stirring the mixture, except 

 that the colour which the oil takes is yellow, like that of a lemon. 



Corrosive potash with heat forms with this oil a yellow soap, very 

 soluble in water. 



Corrosive soda changes it, in the same manner, into a hard soap of 

 a green colour, very soluble in water. 



Liquid ammonia also produces soap from it ; the combination is 

 greenish and soluble in water. 



The acetate of lead gives a yellowish green soap, quite insoluble in 

 water. 



If 7 grammes of litharge are boiled with 1,000 grammes of oil of 

 Tamanu, a black substance is the result, which very readily dries. 



"When the oil is treated with the Poutet reaction, it grows yellow, 

 and then takes the colour of ochre, which soon changes to a veiy bright 

 green. That colour in time disappears, and the mixture remains of a 

 brown yellow. 



The oil does not congeal at 25° of temperature, it remains fluid ; 

 and at the bottom of the phial a brown, solid, and elastic deposit is 

 formed, and this too is very abundant. If two or three drops of am- 

 monia are poured into the modified oil, which swims on the deposit, it 

 becomes, when stirred, of a very bright orange colour. 



The following results have been noticed in trials to purify the oil by 

 the Thenard process : — 



