C H E. M 1 
nourifhjng fecula, which they call cajfa-va. They ftrip 
the root, rafp it, and put it into a lack of ruflies, made 
in the form of a cone, and of a very open-texture, which 
they -lufpend to a ftaft", placed acrofs two upright pods. 
At the lower extremity of this fack, they hang a heavy 
veffel, which by its weight prelfes the root, and receives 
the juice which flows out, and is a moll acrid and danger¬ 
ous poifon. When the fecula is well preffed, and de¬ 
prived of its juice, it is dried in the fmoke, flfted, and 
then forms caflava. This farina is fpread on a hot plate 
of iron, and turned till both its furfaces acquire a red- 
difh yellow colour, which denotes that it is fufficiently 
baked. In this ftate it is called caffa-va-bread. When 
the farina is heated in a veffel, and agitated from time 
to time, it takes the form of grains, called couac. A very 
line and mild fecula, called moufache, falls to the bottom 
of the exprefled juice, and is ufed for paltry. 
To prepare the fecula of bryony, the frefh roots are 
deprived of their bark, rafped in .pieces, and fubmitted 
to the prefs. The juice is white, and depolits a very fine 
fecula, from which, at the end of twenty-four hours, 
the liquid is decanted, and it is dried. As this fecula 
contains a certain quantity of extradt, left by the juice, 
it is very acrid, and purges violently : by walking, it 
becomes finer, and whiter, but at the fame time lofes its 
purgative virtue. This method of preparing the fecula 
of bryony affords but a very fmall quantity, but a much 
greater may be obtained, by moiftening, with water, the' 
mafs remaining in the prefs, {training this water through 
a hair fieve, to feparate the groffer fibres, and leaving it 
at reft, and to depofit its fecula, at which time the water 
is to be decanted off, and the powder dried. This laft 
fecula is not purgative, like the former, becaufe it has 
been deprived of its extradtive matter by the water. 
Baume has obferved, that the fecula of bryony is abfo- 
lutely the fame as ftarch, and might be made into hair- 
powder, to the great faving of corn. The fecula of the 
roots of arum, and corn-flag, are prepared in the fame 
way for medical ufes. 
Salep, falop, faiab, See. is the root of a fpecies of orchis, 
prepared by the orientals. They feledt the fineft bulbs of 
this plant, which they peel andboil,afterprevioufly foaking 
them in cold water. They are then ftrung, and dried in the 
air. M. Jean Moult deferibes another procefs for pre¬ 
paring falop, which may be ufed with every kind of or¬ 
chis. The roots, either dry or under water, are rubbed 
with a brufh, to take off the external pellicle; after 
which, by drying in an oven, they become very hard and 
tranfparent. Thefe are very eafily reduced into powder, 
which, with hot water, forms a nourilhing jelly, much 
praifed by Geoffroy, in all diforders arifing from an acrid 
ftate of the lymph, and elpecially in confumptions; and 
the bilious dyfentery. 
The Item or trunk of fome trees contain fecula ; fuch 
are the palm-trees, a numerous family, which grow under 
the equator. Sago is a dry fecula, reduced into grains 
by the adtion of fire, and comes to us from the iflands 
of Molucca, Java, and the Philippines. It is obtained 
from a kind of palm, called lanaan , in the Moluccas. 
The trunk of this tree contains a lweet pith, which the 
inhabitants take out after having fplit the wood: they 
then bruife it, and put it into a kind of cone, or funnel, 
made of bark, and pour on a large quantity of water. 
This fluid carries with it, through the fieve, the fineft 
and whiteft part of the pith, the fibrous part remaining 
behind. The water is received into pots, and gradually 
depofits the fecula. The clear water is then decanted, 
and the depofited matter is paffed through perforated 
plates, which give it the form of fmall grains. The red 
colour on their furface arifes from the adtion of fire, 
ufed in the drying. Thefe grains, or fago, become foft 
and tranfparent in boiling water, and form, with milk 
or foup, a light and nutritive liquid, ftrongly recom¬ 
mended in phthifical diforders. 
Vol; IV, No. aoj. 
S T R Y. - 34 * 
The lichen Iflandicus, furnilhes a fort of fecula from- 
the leaves ; the Icelanders make a very delicate drink of it. 
But it is principally from the Angle feeds, that the 
greateft quantity of fecula are produced. No plant, con¬ 
sidered in whatever light, has the lead, fimilarity 'with 
wheat: it has not only botanical diftindtions from all 
others, but in chemical analyfis alfo. For inllance, no 
meal but that of wheat will formwith water, what is pro¬ 
perly called dough ; for that of rye is very different, and, 
other grain ftill more fo. 
Of FLOUR. 
The fubftance called flour, is in generally dry, friable,, 
infipid, capable of acquiring tafte and digeftibility, by 
the adtion of fire, and compofed of feveral lubftances ea- 
fily leparable from each other. It exifts in the feeds of 
gramineous plants, but more efpecially in wheat, rye, 
barley, oats, rice, buckwheat, &c. Leguminous plants 
likewife appear to contain a compound analagous to 
flour; but the flour of wheat, as above obferved, can 
only be faid to poffefs the requifite properties, becaufe 
it is the only farina in which the different lubftances are 
duly proportioned to each other. Though the economical 
ule of the flour of wheat, as the principal article of nou- 
rifhment, has been eftablifhed from time immemorial, it 
is but lately that chemifts have begun to examine it,- 
Meffrs. Beccari an Italian phyfician, and Kefl'el Meyer, 
in Germany, are the firft chemifts who endeavoured to f&- 
parate the different fubftances contained in flour. Meffrs. 
Rouelle, Spielman, Malouin, Parmentier, Poulletier, 
and Macquer, continued and carried the experiments of 
thefe philofophers much farther. Parmentier, efpecially, 
has profecuted this inquiry with uncommon zeal and 
a&ivity. His refearches into the nature of alimentary 
fubftances, the component parts of flour, the different 
fpecies of fecula, and on all nutritive vegetables, are, with¬ 
out doubt, the moft complete and exadt of any that have 
been made in this way. 
Water is an agent of the greateft utility, and leaft ca¬ 
pable of altering the feveral matters it takes up, or fe- 
parates, in the order of their fclubility. This fluid is 
ufed, with the greateft fuccefs, to obtain the diffeYent fub¬ 
ftances of which wheat flour is compofed. To perform 
this true analyfis, a pafte is made with flour and water, 
and kneaded in a veffel of water, underneath a ftreara 
from a cock; the water carries off a very fine white pow¬ 
der, and the kneading muft be continued till this fluid 
pafles off clear. The flour is then found to be feparated 
into three fubftances ; a greyifh and elaftic matter remain¬ 
ing in the hand, which has been called - the gluten, or <ve- 
geto-animalipa.i t, on account of its properties ; and a white 
powder, depofited by the water, which is the fecula, or 
flarch. The fubftances are held in folution by the water, 
one of which, called albumen, appears after evaporation 
in the form of concrete flocks; if the evaporation be car¬ 
ried to ficcity, another fubftance is difcovered, called the 
mucofo-faccharine matter. Wheat-meal, then, contains 
four diftinft parts: the fecula, the gluten, the albumen, 
and the mucofo-faccharine fubftance : hence it differs 
from all other vegetables. 
Of Starch. —The ftarch obtained by analyfing flour, 
is not that which is ufed in the arts. When prepared in 
the large way, two forts are ufually made, flue and com- 
mon ftarch. The fine fort is made with'bran, and the 
juice of four cherries. The common-is made with da¬ 
maged corn ground on purpofe ; it ferves to. make pafte. 
This fubftance is’very fine, and foft to the touch; its 
tafte is fcarcely fenfible. Its colour is of a grey and dirty 
white, when extracted by the procefs we have deferibed; 
but the ftarch-makers render it extremely white, by fuf- 
fering it to remain in an acid water for a time, which 
they call the four water. It appears from the experiment 
of Poulletier, that the fermentation which takes place in 
this fluid, whitens and purifies the ftarch by attenuating, 
4 S and 
