6.33 
G L U 
GLU 
some outwards, and some sideways: they are 
also of various sizes, the larger ones being 
four or live inches long, and the smaller less 
tlian a quarter of an inch. They are found 
with us in the strata of blue clay, and are very 
plentiful in the clav-pifes of Richmond, and 
some other places ; but they are no where so 
common as in the island of Malta. 
GLO r FIS. See Anatomy. 
GLOV E, a covering for the hand and 
wrist. Gloves, with respect to commerce, 
are distinguished into leathern, silk, thread, 
cotton, worsted, &c. Leathern gloves are 
made of chamois, kid, lamb, doe, elk, buff, 
&c. 1 o throw the glove, was a practice or 
ceremony very usual among our forefathers, 
being the challenge whereby another was de- 
bed to single combat. It is still retained at 
the coronation of our kings, when the king’s 
champion casts his glove in Westminster- 
hall. Favyji supposes the custom to have 
arisen from the Eastern nations, who, in all 
•their sales and deliveries of lands, goods, Ac. 
used to give the purchaser their glove by- 
way of livery or investiture. To this effect 
he quotes Ruth iv. 7. where the Chaldee pa- 
raphrase calls glove what the common ver- 
sion renders by shoe. He adds, that the rab- 
bins interpret by glove that passage in the 
cviiith Psalm, In Idumean extendam calcea- 
mentum raeum, “ Over Edom will I cast 
mv shoe.” Accordingly, among us, he who 
took up the glove declared thereby his ac- 
ceptance of the challenge ; and as a part of 
the ceremony, continues Favyn, took the 
glove off his own right hand and cast it upon 
the ground, to be taken up by the challenger. 
This had the force of a mutual engagement 
on each side, to meet at the time and place 
which should be appointed by the king, par- 
liament, or judges. The same author as- 
serts, that the custom which once obtained 
of blessing gloves in the coronation of the 
kings of France, was a remain of the Eastern 
practice of giving possession with the glove, 
1. xvi. p. 1017, See. Anfiently it was prohi- 
bited the judges to wear gloves on the bench ; 
and at present, in the stables of some princes, 
it is said to be unsafe going in without pulling 
off the gloves. 
GLOW-WORM. See Cicindela. 
GLOXINIA, a genus of the didynamia 
angiospermia class and order. The calyx is 
superior, five-leaved ; corolla bell-shaped, 
with the border oblique; filaments with the ru- 
diment of a fifth inserted into the receptacle. 
There is one species, a herb of South Ame- 
rica. 
GLUCINA, a new earth, discovered in 
1798, in the mountains of Siberia. Accord- 
ing to the experiments ef Vauquelin and Kla- 
proth, we learn that 
1. To obtain glucina pure, the beryl or 
emerald reduced to powder, is to be fused 
with thrice its weight of potass. The mass 
is to be diluted with water, dissolved in mu- 
riatic acid, and the solution evaporated to 
dryness. The residuum is to be mixed with a 
great quantity of water, and the whole thrown 
-on a filtre. The silica, which constitutes 
more than half the weight of the stone, re- 
mains behind ; but the glucina and the other 
earths, being combined with muriatic acid, 
remain in solution. Precipitate them by 
means of carbonat of potass. Wash the pre- 
cipitate, and then dissolve it in sulphuric 
G LG 
acid. Add to the solution sulphat of potass; 
evaporate it to the proper consistence, and 
set it by to crystallize. Alum crystals gra- 
dually form. When as many of these as 
possible have been obtained, pour in the 
liquid carbonat of ammonia in excess, then 
filtre, and boll the liquid fur some time. A 
white powder gradually, appears, which is 
glucina. 
2. Glucina, thus obtained, is a soft light 
white powder, without either taste or smell, 
which has the property of adhering strongly 
to the tongue. It has no action on vegetable 
colours. It is altogether infusible by heat; 
neither does it harden or contract in its di- 
mensions, as is the case with alumina. Its 
specific gravity is 2.967. 
It is insoluble in water, but forms with a 
small quantity of that liquid a paste which has 
a certain degree of ductility. 
3. It does not combine with oxygen nor 
any of the simple combustibles; but sulphu- 
rated hydrogen dissolves it, and forms with 
it a hydrosulphurat, similar to other hydro- 
sulphurats in its properties. 
4. Azote has.no action on it; but muriatic 
acid dissolves it, and forms with it a sweet- 
tasted salt, called muriat of glucina. 
5. Glucina is soluble in the liquid fixed al- 
kalies, in which it agrees with alumina. It 
is insoluble in ammonia, but soluble in car- 
bonat of ammonia, in which respect if agrees 
.with yttria ; but it is about five times more 
soluble in carbonat of ammonia than that 
earth. 
It combines with all the acids, and forms 
with them sweet-tasted salts, as is the case 
also with yttria. 
GLUT, among artificers, a tenacious vis- 
cid matter, which serves as a cement to bind 
or connect things together. See Gela- 
tine. 
GLUTA, a genus of the class and order 
pentandria monogyniu. The calyx is bell- 
shaped, deciduous; petals live; filaments in- 
serted into the tip of the column ; germ sit- 
ting in an oblong column. There is oiie spe- 
cies, a tree of Java. 
GLUT/EUS. See Anatomy. 
GLUTEN. If wheat flour is kneaded 
into paste with a little water, it forms a te- 
nacious, elastic, soft, ductile mass. This is 
to be washed cautiously, by kneading it un- 
der a small jet of water till the water no 
longer carries off any thing, but runs off co- 
lourless ; what remains behind is called glu- 
ten. It was discovered by Beccaria, an 
Italian philosopher, to whom we are indebted 
for the first analysis of wheat flour. 
1. Gluten, when thus obtained, is of a 
grey colour, exceedingly tenacious, ductile, 
and elastic, and may be extended to twenty 
times its original length. When very thin, 
it is of a whitish colour, and has a good deal 
of resemblance to animal tendon or mem- 
brane. In this state it adheres very tenaci- 
ously to other bodies, and has often been 
used to cement together broken pieces of 
porcelain. Its smell is peculiar. It has 
scarcely any taste, and does not lose its te- 
nacity in the mouth. When exposed to the 
air, it assumes a brown colour, and becomes 
• in a manner covered with a coat of'oil. 
When exposed to the air, it gradually 
dries ; and when completely dry, it is pretty 
hard, brittle, slightly transparent, of a dark- 
brown colour, and has some resemblance to 
glue. It break-s like a piece of glass, and 
the edges of the fracture resemble in smooth- 
ness those of broken glass ; that is, it breaks 
with a vitreous fracture. 
It is insoluble in water., though it imbibes 
and retains a certain quantity of it with 
great obstinacy. To this water it owes its 
elasticity and tenacity. When boiled in wa- 
ter it loses both these properties. 
When kept moist, it very soon begins to 
decompose, and to undergo a species of fer- 
mentation. It swells, and emits air-bubbles, 
which Proust has ascertained to consist of 
hydrogen and carbonic acid gases. It emits 
also a very offensive odour, similar to what 
is emitted by putrefying animal bodies. Ca- 
det kept gluten for a week in a damp room. 
Its surface became covered with byssi, the 
fermentation just mentioned had commenced, 
and the odour was distinctly acid. In 24 
days, on removing the upper crust, the glu- 
ten was found converted into a' kind of paste, 
of a greyish-white colour, not unlike bird- 
hme. In that state he gave it the name of 
fermented gluten. If the gluten is still left 
to itself, it gradually acquires the smell and 
the taste of cheese. This curious fact was 
first ascertained by Rouelle junior, to whom 
we are indebted for the most important dis- 
sertation on gluten which has yet appeared. 
In that state it is full of holes, and contains 
the very same juices which distinguish some 
kinds of cheese. Proust ascertained that it 
contains ammonia and vinegar; bodies 
which Vauquelin detected in cheese: and 
ammonia robs botli equally of their smell and 
flavour. 
When moist gluten is suddenly dried, it 
swells amazingly. Dry gluten, when ex- 
posed to heat, cracks, swells, melts, black- 
ens, exhales a fetid odour, and burns pre- 
cisely like feathers or horn. When distilled, 
(here comes over water impregnated with 
ammonia and an empyreumatic oil ; the 
charcoal which remains is with difficulty re- 
duced to ashes. 
2. Gluten is insoluble in water; it is 
equally insoluble in alcohol and in ether. 
But when the fermented gluten of Cadet is 
triturated with a little alcohol int& a muci- 
lage, and then mixed with a sufficient quan- 
tity of that liquid, a portion of it is dissolved. 
This solution constitutes an excellent var- 
nish, possessed of considerable elasticity. It 
may be spread over paper or wood ; and 
when dry resists other bodies as well as most 
varnishes. . In this state too it may be em- 
ployed to cement china ; and triturated with 
paints, especially vegetable colours, it forms 
a very good ground. When this solution is 
mixed with a sufficient quantity of lime, it 
forms a very good lute; and bits of linen 
dipt in it adhere very strongly to other 
bodies. 
All the acids dissolve it, even when very 
much diluted; alkalies precipitate it again, 
but it is deprived of its elasticity, and brought 
nearer to the state of extractive matter. Con- 
centrated sulphuric acid renders it violet- 
coloured, and at last black ; inflammable air 
escapes, and charcoal, water, aiid a portion 
of ammonia, are formed. When nitric acid 
is poured on it, and heat applied, there is a 
quantity of azotic gas emitted, as Berthollet 
discovered; and by continuing the heat, 
some little oxalic acid is formed, and like- 
