304 THE OWALA SEED AND OIL. 
oil be spread in thin layers over the surfaces of different substances, 
and left for several days exposed to the air, it still preserves its original 
fluid state. This property the oil of Owala possesses in common with 
the oil of Moringa aptera, and is valuable for diminishing friction in 
clockwork. 
The oil which I obtained was rather acrid ; but this might have been 
the result of the age of the seeds, and the damage they received by the 
voyage. It has rather a marked odour, which, however, is by no means 
disagreeable ; it resembles very much that obtained from various pulses. 
The flavour, too, which it possesses, is an agreeable one; indeed, I 
have little doubt but that this oil will some day be an acceptable ad- 
dition to those already in use for comestible purposes; in fact, the 
Boulons or Bushmen, a tribe in Senegal, employ it in the preparation 
of their food. 
` Ifan attempt be made to dissolve the oil in alcohol without heat, 
the improbability of success soon becomes apparent; the spirit, however, 
carties off a peculiar matter as well as a part of its aroma. 
One of the most remarkable properties of the oil is the colour which 
. it developes under the influence of sulphuric acid. If the farina, or the 
oil obtained from the kernel, be dissolved in concentrated sulphuric acid, 
the mixture takes first an olive, then a violet, and finally a bright crim- 
son-red colour, which will, however, sometimes disappear on the addi- 
tion of a certain quantity of water. I was induced by the appearance 
of this phenomenon of colour to seek for the producing cause, and en- 
deavoured to find in what part of the seed this property displayed itself 
in its maximum of intensity, To accomplish this I commenced by dis- 
solving part of the kernel in water. Upon this solution, the moisture 
being all drained off, I poured a quantity of concentrated sulphuric acid, 
and it became slightly brown, but no trace of the red colouring matter 
appeared. From this experiment I concluded that the part of the ker- 
nel wherein lay the power (when aided by sulphuric acid) of producing 
a red colour was insoluble in water. ‘The same operation was performe 
upon another portion of the kernel dissolved by the aid of heat m 
alcohol. This experiment produced a magnificent red colour, and proved 
that the colouring matter is soluble in alcohol. When ether was sub- 
stituted for alcohol, the colour produced was no longer red, but violet, 
which became less intense upon the admixture of ether or alcohol, and 
‘this led me to infer that the application of ether changed in a great 
