CAJEPUT. 851 
present, it immediately forms a deposit on platinum. The liquid 
can then be decanted, the copper dissolved and identified by 
reagents. 
Rectified oil is colourless, but acquires the green colour after 
being a short time in contact with metallic copper. 
All genuine cajeput oil of the Moluccas, Malacca, and India are 
optically levogyre ; several of the Australian cajeput oils are dex- 
trogyre in their action on polarized light. 
Schmidl found * that oil of cajeput consists mainly of di-hydrate 
of cajuputene, C,)H,,+2H,0, which can be extracted from the 
erude oil by fractional distillation between 174° and 178° C.; smaller 
fractions, perhaps products of decomposition, are obtained from 
178° to 250°, at which temperature only a small residue of carbo- 
naceous matter is left in the still, mixed with metallic copper. On 
treating this residue with ether, a green solution is obtained which, 
when evaporated, leaves a green resin soluble in the fraction which 
boils between 174° and 178° and capable of restoring the original 
colour. 
When the di-hydrate is heated to the boiling-point and sulphuric 
acid added by degrees, it becomes coloured, and on fractional dis- 
tillation there passes over, between 170° and 175°, the mono- 
hydrate, C,)H;,+ H,O. 
When the di-hydrate is cohobated with phosphoric anhydride 
for half an hour and distilled, there passes over at 160°-165° the 
hydrocarbon cajuputene, C,)H,,, which is a colourless liquid pos- 
sessing the odour of hyacinths; it is insoluble in alcohol, but 
soluble in ether and in oil of turpentine; its sp. gr. at 15° C. 
is 0°850. It is permanent in the air. With gaseous hydrochloric 
acid it forms a beautiful violet liquid. On continuing the distil- 
lation two isomeric hydrocarbons pass over, iso-cajuputene at 176°— 
178° and para-cajuputene at 310°-316°. 
Chloride of cajuputene, C,)H,.Cl,, is produced by the action of 
nascent chlorine on the di-hydrate (the rectified oil of cajuput). 
When the portion of the oil distilling between 174°-178° is mixed 
with very dilute nitric acid, and hydrochloric acid gas is passed 
into the liquid, a violent action takes place in a few minutes, 
chlorine and nitrous gas being evolved, and if the passage of the 
hydrochloric acid gas is continued, chloride of cajuputene ulti- 
* Trans. Roy. Soc. Ed. xxii. (6) p. 360, and Journ. Chem. Soe. xiv. p. 63. 
