Scientific Intelligence. — Arts. 417 
the banks of the Orinoko. The natural oil obtained from it is 
similar to other volatile oils obtained by chemical processes, and 
although rectified it is heavier than alcohol. It remains trans- 
parent, its taste is warm and pungent, its smell aromatic. It is* 
very inflammable, and burns entirely. Acids and alkalies have 
little action upon it. It is soluble in alcohol and ether, and dis- 
solves camphor, caoutchouc, wax, resin, &c. It is employed 
externally as a discutient, and internally as a diaphoretic, diu- 
retic, and resolvent. The Indians regard it as an infallible re- 
medy against rheumatisms and pains of the kidneys* The decoc- 
tion of the root of the tree is also employed for the same pur- 
pose. — Journ. de Pharm. No. xi. p. 547. 
28. Chica^ a Pigment used hy the Indians of the OrinoJco to 
stain the Shin red. — The native Americans on the banks of the 
Orinoko, use two species ol’ dye for the purpose of staining the 
skin red. One of these is the product of the Bixa Orellana ; 
, the other is the extract of the leaves of Bignonia Chica, which 
is cut into round cakes five or six inches in diameter, and two 
or three in thickness, and dried. Experiments have been made 
upon this substance, from which it appears, that the chica has 
some peculiar properties, by which it is distinguished from other 
vegetable principles ; and though it approaches in nature to the 
resins, it differs from them in being infusible by heat, without 
decomposition ; it not being separable by water from its solution 
in alcohol and sulphuric acid, and in being readily soluble in am- 
monia, which does not touch the true resins. The chica is be- 
gun to be used for dyeing cotton, to which it gives an orange- 
red. — J. B. BoussingauU. 
29. Brown's Pneumatic Engine. — The principle of this en- 
gine appears to be nothing more nor less than a very sudden 
expansion and condensation, not of the gases used in the opera- 
tion, but of the small quantity of water formed from the com- 
bustion of the hydrogen with the oxygen of the atmospheric air, 
admitted into the cylinder at every stroke of the engine. When 
the union of these two gases takes place at a very high tempe- 
rature, as is the case in Mr Brown’s model, exhibited in Print- 
ing-house Square, London, the water generated is instantly con- 
verted into steam of a high degree of elasticity, filling the capa- 
city of the cylinder with an elastic fluid capable of instantaneous 
