SPECIES OF FECULA EMPLOYED IN PHARMACY. 17 
subjected to a stream of water; the marc alone remains upon the 
sieve; the fecula passes through and is caught in a vessel 
placed beneath. When the operation is terminated, the 
water is decanted, the fecula washed, and the water again de- 
canted, and this is repeated until the water can remove 
nothing more that is soluble. Finally, the fecula is dried in 
the sun, or by a stove. It then presents itself in the form of 
an impalpable crystalline powder, having a light bluish tint; 
under these circumstances it can be affirmed that the grains 
are the least altered. 
Sago Fecula. 
{Obtained from the medulla of certain palms, and in the 
Moluccas from that of the Cycas circinalis, L., and Sago 
farinaria, Rumph.) PI. fig 2. This fecula appears in com- 
merce in the form of globules, which are from four to five 
millimetres in diameter; their surface is reddish and shining, 
their consistence hard, so that, before submitting them to ex- 
amination with the microscope, it is necessary to allow them to 
remain in cold water for some hours. If fragments of the super- 
fices of these globules are then placed under the microscope, 
it is evident, that all the grains of fecula are broken, for their 
integuments, torn and burst open, {fig. 2, a,) are spread in my- 
riads over the stage. Beneath the superficial layer, the grains, 
without having been broken, present internally, and some- 
times upon a point of their surface, a granular arrangement, a 
corrugation, b, which is to be remarked in all the feculse that 
have been momentarily submitted to the action of heat, after 
having been simply dried or hardened. In the centre of the 
globules, on the contrary, there are noticed only entire un- 
altered grains. All these circumstances complete the demon- 
stration of the received opinion, that these globules have been 
torrefied upon a metallic plate, after having been formed by 
passing through a sieve, of which the holes, equal in size, are 
from four to five millimetres in diameter. By manipulating 
in the same way with the fecula of the potato, provided it be 
previously scented slightly with an aromatic substance, as 
vol. v. — no. i. 3 
