ACACIA CATECHU. 
183 
«xtenpr white part of the wood is cut off ; the interior coloured wood is 
cut into chips, which is put into a narrow-mouthed unglazed earthen 
pot, pouring water upon them till the whole is covered ; when this 
is half evaporated by boiling, the decoction, without straining, is 
poured into a flat earthen pot, and boiled to one-third part ; this is 
set in a cool place for one day, and afterwards evaporated by the 
heat of the sun, stirring it several times in a day ; when it is reduced 
to a considerable thickness, it is spread upon a mat or cloth^ which 
has been previously covered with the ashes of cow dung ; this mass 
is divided into square pieces by a string, and completely dried by 
turning them frequently in the Sun, until they are fit for sale.-' 
'* This extract is called cutt by the native^ of India, by the English 
cutch, and by different authors Terra Japonica, catechu,* khaathy 
tnte, cachou, &c. &c." 
" In making the extract, the pale brown wood is preferred, as it 
produces the fine whitish extract ; the darker the wood is, the blacker 
the extract, and of less value." There are two kinds of extract met 
with in commerce, one which comes from Bengal, and the other 
from Bombay. 
Sensible Qualities and Chemical Properties. Catechu,, 
m its purest state, is a dry pulverable substance, which does not de- 
liquesce, or apparently change by exposure to the air : outwardly it 
is of a reddish colour, internally of a shining brown, (more or less 
dark) tinged with a reddish hue ; its specific gravity varies from 1.39 
to 1.28 ; to the taste it is sweet and mucilaginous, accompanied with 
a considerable degree of astringency. It dissolves almost entirely in 
water ; alcohol dissolves about ^ of the pure mass, the residue is an 
almost insipid mucilaginous substance. It is also soluble in vinegar. 
It softens when heated, and then takes fire from a flaming body, and 
burns away with a somewhat grateful smell. The watery solution is 
of a deep red brown, highly astringent to the taste, but has no per- 
ceptible smell; it slightly reddens litmus paper, and forms an inso- 
luble elastic precipitate with gelatin, and green, dark blue or black 
precipitates with iron. The watery infusion is copiously precipitated 
by the sulphuric and muriatic acids, by solutions of Hme, of strontia 
and of barytes. The carbonates of magnesia, of soda, of potash, and 
of ammonia, added to a solution of catechu, deprives it of the power 
of precipitating gelatine, which is restored by the addition of 
* This name is said to be compounded of two Oriental words, c««e which signifies; a 
tree, and cj« juice. 
