SPECIES OP PEC IT LA EMPLOYED IN PHARMACY. 21 
acid water, or fat water; it is thick and sticky; it contains, 
according to Vauquelin, acetic acid, alcohol, acetate of 
ammonia, phosphate of lime, and gluten. After having 
washed the deposit by decantation, it is suspended in water, 
and the whole poured upon a hair sieve placed over a cask. 
The coarsest bran remains upon the sieve; the finest, with the 
fecula, passes through, and is deposited in a state of mixture. 
Agitation with water is again practised; the fecula by its 
specific weight separates from the bran, which entirely re- 
mains upon the surface of the precipitate, and takes the name 
of black grounds, (grosnoir.) Then the first layer is 
skimmed off, and a second and third by rinsing the upper part 
of the remaining mass; the residue is agitated with water, and 
placed upon a silk sieve, more or less fine. Another propor- 
tion of bran is then separated, and no more is to be done than to 
allow the fecula to deposit, and to wash it to render it pure. It is 
finally dried by moulding the precipitate in wicker baskets, 
lined loosely with linen cloth, after which it is turned out in a 
chamber upon a plaster floor; the blocks or casts should be 
broken by hand. The fragments are exposed to the air for 
some days, their surfaces arc finally scraped, and they are 
dried completely by the heat of a stove. The lumps of starch 
then present little canals, which would appear to indicate a 
coarse state of crystallization, but which arise, in reality, from 
the action of the water in escaping. The amidon thus ob- 
tained is always more tenacious, and less friable than that of 
the potato, on account of a certain quantity of gum and gluten 
which these molecules carry with them on precipitating. 
This method is fitted to the extraction of the fecula from all 
organs that contain gluten, — barley for example, — but the 
starch manufacturers generally employ wheat. 
Rye Fecula. 
(Secale cereale,Yj.) PI. fi.5. Thelargestgrains of this fecula 
attain -fa of a millimetre, but they are distinguished from all 
other feculse, by their flatness and the prominence of their mar- 
gins, resembling disks, and for the most part marked on one 
