GLY 
G L U 
wise malic acid, while a number of yellow- 
coloured oily flakes make their appearance 
in the solution. Acetic acid acts but imper- 
fectly, but it dissolves the fermented gluten 
of Cadet; and the solution may be substi- 
tuted for the solution in alcohol as a varnish ; 
but it does not answer to mix it with colours. 
Alkalies dissolve gluten when they are as- 
sisted by heat. The solution is never per- 
fectly transparent. Acids precipitate the 
gluten from alkalies, but it is destitute of its 
elasticity. Alkalies, when much concentrat- 
ed, form with it a kind of soap, converting it 
into oil and ammonia, which last is dissipated 
during the trituration. 
The action of the metallic oxides and their 
salts upon gluten has not been tried. 
It has a strong affinity for the colouring 
matter of vegetables, and likewise for resi- 
nous bodies. 
3. The properties of this substance clearly 
point out a resemblance between it and ani- 
mal matter; and the phenomena of its fer- 
mentation and destructive distillation shew 
us that oxygen, hydrogen, carbon, and 
azote, are constituents of it. Proust has ob- 
served, that the vapour which it emits, while 
fermenting, blackens silver and lead, and of 
course contains sulphur. 
4. Like all other vegetable principles, 
gluten is susceptible of various shades of 
properties, which constitute so many spe- 
cies. In wheat flour, it occurs in the great- 
est abundance, and from it we can extract 
it with the greatest ease. But the sagacity 
and industry of Rouelle and Proust have de- 
tected its presence in many other vegetable 
substances. Rouelle found it in tbe^ leaves 
of all the vegetable substances which he ex- 
amined. The exactness of this opinion was 
called in question by Fourcroy, who treated 
the experiments of Rouelle with contempt; 
but it has been lately examined and con- 
firmed by very decisive experiments of 
Proust. 
When the juice of cabbage-leaves, cresses, 
Scurvy-grass, and other similar plants, is ex- 
tracted by pressure, and passed through a 
doth, it still continues far from transparent. 
Its muddiness is owing to a fine soft silky 
green powder suspended in it, which sub- 
sides to the bottom so slowly as to take at 
least a week before it is deposited. This 
green powder has been distinguished by the 
name of the green fecula of plants. Rouelle 
first examined it with attention, and ascer- 
tained its properties; and the subject has 
been carried still farther by Proust. The 
slowness with which it subsides shows that 
its specific gravity does not differ much from 
that of water. When once it has fallen, it 
is insoluble. This substance consists chiefly 
of three principles: 1. A green matter to 
which it owes its colour, separated by diges- 
tion in alcohol, and which possesses the pro- 
perties of a resin. 2. A substance which 
consists chiefly of woody fibres, and which is 
left behind when the fecula is digested in 
potass. 3. A species of gluten, which con- 
stitutes the greatest part of it, and to which 
it owes its characteristic properties. 
When the juice of the plants is exposed 
to a heat of about 130°, the green fecula un- 
dergoes a kind of coagulation, concreting 
into large flakes, which subside very quickly. 
At this temperature, albumen is not altered 
GLY 
by heat. This is the method commonly 
taken to clarify these juices. We see from 
it, that the fecula was united to the water 
by a very small force, which the addition of 
heat weakened sufficiently to enable the glu- 
ten to cohere. This coagulation by heat 
takes place how diluted soever the juices are 
with water, which is by no means the case 
with albumen. It is thrown down also by 
the addition of a little alcohol, by all acids, 
by ammonia, by sulphurated hydrogen gas, 
or by throwing into the liquid cry stals of car- 
bonat of potass, magnesia, common salt, mu- 
riat of potass, nitre, sal ammoniac, &c. 
W hen separated from water, it soon dries, 
and becomes elastic, and has somewhat of the 
appearance of horn ; and in that state is scarce- 
ly softened by hot water. When treated 
like gluten, it gradually acquires the cheesy- 
taste and smell. When kept under water, 
it very soon begins to putrefy, and exhales a 
gas which blackens silver and solutions of 
leach This speedy putrefaction in stagnant 
water takes place when flax and hemp are 
steeped. These substances contain green 
fecula in their rind, and the putrefaction 
occasions the separation of the whole, which 
could not otherwise be accomplished. The 
water which has been allowed to remain for 
a whole year over green fecula, contains sul- 
phurated hydrogen, carbonat of ammonia, 
and gluten seemingly held in solution by the 
ammonia. The stench of putrefaction still 
continues even after the water has been 
boiled. 
5.. The number of plants containing gluten 
is very considerable. Proust found it in 
acorns, chesnuts,. horse-chesnuts, rue, bar- 
ley, rye, peas, and beans; and in apples 
and quinces. He found it also in the leaves 
of cabbage, sedums, cress, hemlock, borage, 
saffron, &e. ; in the berries of . the elder, the 
grape, & c. ; in the petals of the rose. &c. It 
occurs also in several roots. Proust could 
find none in the potatoe. 
6. Gluten must be considered as one of 
the most useful of the vegetable principles. 
It constitutes an essential ingredient in wheat, 
and is the substance which renders flour of 
wheat so fit for forming bread. It seems 
also to constitute the essential part of yeast. 
Its uses as a varnish, a ground for paint, &c. 
pointed out by Cadet, likewise deserve at- 
tention. The gluten of wheat is said, in 
many cases at least, to constitute the base of 
the substance called birdlime ; though that 
substance is supposed to be a preparation 
obtained from the bark of the elm, &c. and 
in that case is, accordingrio Proust, a kind of 
turpentine or resin, soluble in alcohol, and 
not in the least resembling gluten. 
GLY CONI AN verse, in antient poetry, 
consists of three feet, whereof the first is a 
spondee, the second a choriambus, and the 
last a pyrrhichius ; or the first may be a 
spondee, and the other two dactyls. 
Minis, Mens re- j gnum bona pos- | sickt.. 
or, Mens re- j gnum bona | possidet . 
GLM CINE, knobbed- rooted liquorice- 
vetch, a genus of the ;decandria order, in the 
diadelphia class of plants, and in the natural 
method ranking under the 32d order, papili- 
onaceae. The calyx is bilabiate ; the carina 
of the corolla turning back the vexiilum with 
its point. There are 25 species, one of which 
is commonly cultivated in our gardens, the 
frutescens, or Carolina kidney-bean tree. 
This has shrubby climbing stalks, twining 
round any support, 15 or 20 feet high, adorn- 
ed with pinnated leaves of three pair of fol- 
licles terminated by an odd one, and from 
the axillas clusters of large blueish-purple 
flowers, succeeded by long pods like those of 
the climbing kidney-bean. It flowers in 
June and July, but tiie seeds do not ripen in 
this country. It is easily propagated, either 
by seeds imported from America, where it is 
native, or by layers. 
The glycine eoccinea is an elegant little 
plant, lately introduced into our stoves, and 
easily propagated by seed, which it perfects 
in this country. 
GLYCIKRIIIZA, liquorice, a genus of 
the decandria order, in the diadelphia class of 
plants, and in the natural method ranking 
under the 32d order, papilionaceae. The 
calyx is bilabiate; the upper lip tripartite, 
and the under one entire; the legumen ovate 
and compressed. There are four species. 
The glabra, -or common liquorice, has a long, 
thick, creeping root, striking several feet 
deep into the ground; upright, firm, herba- 
ceous stalks annually, three or four feet high, 
with winged leaves of four or five pair of oval 
lobes, terminated by an odd one ; and from 
the axillas erect spikes of pale-blue flowers 
in July, succeeded by short smooth podsi 
M he root of this is the useful part, which is 
replete with a sweet, balsamic, pectoral juice, 
much used in all compositions for coughs and 
disorders of the stomach. The echinata, or 
prickly-podded liquorice, is nearly like the 
common sort, only the seed-pods are prickly. 
Both these species are very hardy perennials; 
but the first is the sort commonly cultivated, 
for use, its roots being fuller of juice and 
sweeter than the other. The roots are per- 
ennial; but the stalks rise in spring and de> 
cay in autumn. 
Their propagation is effected by cuttings 
of the small roots issuing from the sides. of 
the main ones near the surface of tire earth, 
dividing them into lengths of six or eight 
inches, each having one or more good buds 
or eyes; and the proper season for procuring 
the sets for planting is any time in open wea- 
ther from October till March, though from 
the middle of February till the- middle of 
March is rather the most successful season 
for planting. An open situation is the most 
suitable for a plantation of these plants. Par- 
ticular regard should also be had to the soil ; 
it ought to be of a light loose composition, 
and three or four feet deep if possible ; for 
the roots of the liquorice will arrive at that 
depth and more, and the longer the roots the 
more valuable they are for sale by weight. 
In three years alter planting, 'the roots ojt 
the liquorice will be fit to take up ; and the 
proper season for this is, any time from the 
beginning of November till' February ; for- 
it should neither be taken up before the' stalks 
are fully decayed, nor deferred till late in 
spring, otherwise the roots will be apt to 
shrivel, and diminish in weight.' In taking 
them up, the small side-roots are trimmed 
off, and the best divided into lengths for fresh 
sets, and the main roots are tied in bundles 
ready for sale. 
Liquorice is almost the only sweet that 
quenches thirst; whence it was called by the 
Creeks adipson. Galen takes notice, that it 
was employed in this intention in hydropic 
