340 CHE M I 
It ought not to be internally ufcd, but with the greateft 
caution. 
5. Euphorbium is in yellow tears, which have the ap¬ 
pearance of being worm-eaten s it has no fmell. It flows 
front insifions made in the euphorbium , which grows in 
Ethiopia, Lybia, and Mauritania. It contains a very 
acrid refin, and is fo drongly purgative, that it is reckoned 
among poifons. It is not ufed, unlefs externally in 
caries. 
6. Affafetida is fometimes in yellowifii tears, but mod 
commonly in loaves, formed of a number of pieces, ag¬ 
glutinated together. It has a very fetid fmell of garlic, 
with a bitter and naufeous tafte. It is extracted from 
the root of a fpecies of ferula, which glow's in the pro¬ 
vince of Chorafan in Perfia, and is called affafetida by 
Linnaeus. The root of this plant is fleftiy and fucculent. 
By expreffion, it affords a white juice, of an abominable 
fmell, which the Indians ufe as feafoning for food, under 
the name of * food of the gods’. It is internally ufed as 
a powerful antifpafmodic, and is applied externally as a 
difeutient remedy. 
7. Aloes is a juice of a deep red or brown colour, and 
very bitter. It is didinguifhed into three fpecies: fuc- 
cotrine aloes, hepatic aloes, and caballine aloes: thefe 
differ only in their refpeftive degrees of purity, the firit 
being the bed. A. De Juffieu faw the preparation of the 
different kinds of aloes at Morviedro, in Spain, from the 
leaf of the common aloe plant. Deep incifions are made, 
from which the juice flows; this is decanted from its 
fecula, and thickened by the fun’s heat, in which date 
it is packed in leather bags, under the denomination of 
fuccotrine aloes. The juice obtained by preffure from 
the leaves, after it is purified by repofe, and dried, is 
the hepatic aloes. The fame leaves, by dronger preffure, 
afford a portion of juice, which, mixed with the dregs 
of the two foregoing, conditutes the caballine aloes. 
The fird fort contains a much lefs quantity of refin than 
the two lad, which are more drongiy .purgative. It is 
ufed in medicine asadradic purge, and is acknowledged 
fo poflefs the property of exciting the mendrual flux in 
women, or the hemorrhoids in men. It is much edeemed 
as a good hydragogue. 
8. Myrrh is brought to us in the form of reddifli bril¬ 
liant tears, of a drong and rather agreeable fmell, bitter 
tade, and exhibiting white lines, of the form of a nail, 
in their fra#ure. Some of thefe tears are entirely gummy 
and infipid. Myrrh comes from Ethiopia, Egypt, and efpe- 
cially from Arabia, in the country of the Troglodites. 
The plant from which it is extracted does not appear to 
be known. It contains much more extra# than refin. 
It is ufed as an excellent domachic, antifpafmodic, and 
cordial, remedy. Cartheufer advifes literary men, whole 
ftomachs are delicate, to chew this, and fwallow it with 
the faliva. It is ufed in furgery, either in powder, or 
diffolved in ‘'alcohol, to cleanfe foul ulcers, and to dop 
the progrefs of caries. 
9. Gum ammoniac fometimes has the form of tears, 
white within, and yellow without, and is fometimes in 
mafles refembling benzoin. They are eafily didinguifhed 
by their white colour and fetid fmell. It is fuljre#ed, 
from the admixture of feed it contains, that this gum 
refin, which comes from Africa, is extracted from an um¬ 
belliferous plant. The folubility of this fubdance in 
water and in alcohol, and more particularly its inflam¬ 
mability, are properties in which it refembles the refino- 
extraftive matters of Rouelle. Gum ammoniac is me -' 
dicinally ufed as a difeuffive remedy in obdmate obdruc- 
tions; it is given in dofes of a few grains, in pills or 
emulfions, and likewife enters into the compofition of 
many difeuffive and refolvent pladers. 
10. Sarcocolla. This is brought from Perfia or Arabia, 
in tears, or in little friable mafles. 
11. Sagapenum. The plant from which this flows is 
not known; it is brought to us from Perfia, and force 
other parts of the Lm/ant. 
S T R Y. 
is. Bdellium. The tree producing this is not known. 
It is in pieces or tears of different lizes, of a golden yel¬ 
low, or fomewhat red, colour. 
13. Opoponax. This is in tears of various fizes, of 
a fatty confidence, though friable, reddifli without, whit- 
i(h within. 
Caoutchouc, or Elastic Gum. —This has been 
hitherto improperly claifed among gum refins. The tree 
which furnifhes it is called firinga, by the Indians of 
Peru ; in the province of Efmeraldas, in Quito, they call 
it bevca\ and, in the province of Mainas, caoutchouc: 
M. Richard has proved, that the tree is of the family of 
the euphorbia. Horizontal incifions are made quitethrough 
the bark, awhile and fluid juice iflues forth, which is 
applied, in fucceffive coats, on clay moulds, and dried 
by the fun’s heat. Various (ketches of defigns are made 
on the furface with an iron tool. It is then expofed to 
the linoke ; and, when perfectly dried, the clay is cruffied 
and taken out. The bottles, and various utenfils of 
eladic gum, which are imported into Europe, are made 
in this manner, and are vulgarly called Indian rubber. 
The dry caoutchouc, fuch as it is brought to Europe, ex¬ 
pofed to the heat of a fire, foftens, fwells, emits a fetid 
odour, and burns at the fame time that it (brinks. 
Eladic gum is not foluble in water; but water foftens 
it; and, if boiled in a folution of alum, it becomes fo 
loft, that, feveral pieces may be eafily joined together. 
Alcohol has no efte# upon it. Nitric ether is the true 
folvent of caoutchouc. Sulphuric ether, according to 
Berniard, does not diffolve it completely. Weak nitric 
acid a£ts in the fame manner on this fubdance as on cork, 
changing its colour to a yellow. Concentrated nitric 
acid very quickly dedroys it; but the muriatic acid does 
not aft’e# it in the lead. The volatile oil of lavender, 
and likewife thofe of afpic and of turpentine, didolve it 
by the help of a dight heat; it may be then fpread upon 
paper, or ufed as a varnifh for duffs. A mixture of vo¬ 
latile oil and alcohol forms a better folvent than pureoil, 
and the varnifh dries fooner. This fubdance may be dif¬ 
folved alfo in yellow wax melted and boiling; it (hould 
be put in by degrees till the wax is faturated : this folu¬ 
tion, laid upon duffs with a-brufh, makes an elaltic var- 
nilh, not very glutinous, nor apt to fcale off'. 
Thefe various dilutions are rather an alteration of 
caoutchouc than an analyfis ; for after evaporation they 
always remain glutinous. It differs from other vegetable 
fubdances becaufe ammoniac is obtained by didiiling it. 
It is ufed in making probes and fyringes, as a varnifh for 
the duff of which aerodatic machines are made, for rub¬ 
bing out pencil marks, cleaning prints. Sec. 
Birdlime. —This has been generally placed among 
refinous fubdances, but it has never been corre#ly ana- 
lyfed. It is known merely that it is found in the inner 
barks and berries of many plants; that it is inlolubie in 
water, gives by analyfis the fame products as refins, is 
not completely foluble in alcohol, but entirely fo in ether, 
and that water makes the folution turbid. 
Of FECULA. 
All the vegetable matters contained in the juices of 
plants, and not held in folution in them, are in general 
called by this name. There are two fpecies of fecula: 
1. Green fecula, drawn from the juices of plants ; the 
green colour is very uncertain, and not lading, 2. Amy¬ 
laceous fecula, drawn principally from corn and grain. 
There are alfo two kinds of feeds, very different in then- 
nature. 1. Thofe which make emulfions with water; 
they are commonly oily, two-lobed, and furnifh no fe¬ 
cula. 2, Such as make no emulfion; thefe feeds are one- 
lobed or fingle, and abound in fecula. All parts of plants 
may contain fecula. The following contain it in the 
root; orchis, briony, arum, corn-flag, &c. 
The fecula are fometimes found along with the mod 
potent poifon, as in the root of a very acrid plant called 
manioc, whence is drawn, by the Americans, a mild 
nouriftiing 
