372 MR SCHMIDL ON THE CONSTITUTION OF OIL OF CAJEPUT. 
When exposed in a moist state for a considerable time to atmospheric air, it 
changes into a reddish fluid, showing at last a pretty strong acid reaction to lit- 
mus paper. 
In contact with an aqueous solution of potash a soluble salt is formed, the acid 
of which is precipitated by hydrochloric or sulphuric acid as a resinous substance. 
When dropped into melted potash, a compound is formed which is soluble in 
water and decomposed by a strong inorganic acid ; the precipitate being also a resin. 
When treated at high temperature with sodium, a crystalline mass is produced, 
which is soluble in water and alcohol, and consists of soda and an organic sub- 
stance; the latter being likewise separable by strong acids (organic and inorganic), 
as a resin of a very agreeable smell. 
If the vapours of the oil be passed through a combustion tube filled with soda- 
lime and maintained at a red heat, an oily product is formed, which is obtained in 
a receiver suitably connected with the tube. This product possesses a peculiar 
smell, entirely different from that of the original substance, and a bright yellow 
colour; the soda-lime itself is thoroughly blackened with charcoal, and on the ad- 
dition of an acid, it evolves copiously carbonic acid, thereby indicating that some 
decomposition must have taken place in the oil when passing through the tube; 
the analyses of the changed product will follow afterwards. 
Bihydrate of cajputene does not seem to be changed when digested with per- 
oxide of lead. 
If the oil be distilled over permanganate or bichromate of potash in the presence 
of dilute sulphuric acid, a thick resinous fiuid is produced. 
Fuming nitric acid acts very violently on the oil, red fumes of nitrous acid 
being evolved even in the cold, and an abundance of oxalic acid being formed. 
Commercial nitric acid produces the same effect at boiling temperature; at ordi- 
nary temperature, however, it acts slowly, converting the oil into a thick red fluid. 
Fuming sulphuric acid entirely changes the molecular condition of the oil, even 
if the latter be kept during the operation immersed in ice, a thick brown fluid 
being formed, which boils beyond 360° C. 
Commercial sulphuric acid acts at low temperature very slowly on the oil, so, 
that after four or five hours little or no change is observed if the acid be removed 
and the oil well washed; but if the temperature be allowed to rise, either by 
artificially employed heat, or by continued unchecked chemical action, sulphurous 
acid is given off, blackening of the oil commences, and may even go on to total 
destruction of the substance. This can be avoided by caution, and then a 
sulpho-compound will be formed, which gives with baryta a soluble salt. 
Dilute sulphuric acid acts most curiously on the oil, since, in the opposite 
manner to the fuming and commercial acid, it not only does not deprive the oil of 
its two equivalents of water, but causes the formation of a crystalline substance 
which possesses four equivalents of water in addition to the two original ones. 

