■\ 
GLU 
water ; it is infusible in the flue ; it does 
not contract, like alumina, by great heat, 
and it has no effect on vegetable colours. 
The oxygen, nitrogen, and hydrogen gaSes 
have no action on it ; nor is it acted upon 
by carbon, sulphur, or phosphorus. It com- 
bines with sulphurated hydrogen. It is in- 
soluble in water, but combines with acids, 
making with them soluble salts, distinguished 
by a sweet and slightly astringent taste. 
GLUE, among artificers, a tenaceous 
viscid matter, which serves as a cement to 
bind or connect things together. Glues are 
of different kinds, according to the various 
uses they are designed for, as the Common 
glue, glove glue, parchment glue, isinglass 
glue, &c. 
The common or strong glue is chiefly 
used by carpenters, joiners, cabinet-makers, 
&c. and the best kind is that made in Eng- 
land, in square pieces of a ruddy brown 
colour, and next to this the Flanders glue. 
It is made of tire skins of animals, as oxen, 
cows, calves, sheep, &c. and the older the 
creature is, the better is the glue made of 
its hide. Indeed, whole skins are but 
rarely used for this purpose, but only the 
shavings, parings, or scraps of them ; or the 
feet, sinews, &c. That made of whole 
skins, however, is undoubtedly the best; as 
that made of sinews is the very worst. 
In making glue of parings, they first steep 
them two or three days in water ; then 
washing them well out, they boil them to 
the consistence of a thick jelly, which they 
pass, while hot, through ozier baskets, to 
separate the impurities from it, and then 
let stand some time, to purify it further : 
when all the filth and ordures are settled to 
the bottom of the vessel, they melt and 
boil it a second time. They next pour it 
into flat frames or moulds, whence it is ta- 
ken out pretty hard and solid, and cut into 
square pieces or cakes. They afterwards 
dry it in the wind, in a sort of coarse net ; 
and at last string it, to finish its drying. 
The glue made of sinews, feet, &c. is ma- 
naged after the same manner; only with 
this difference, that they bone and scour 
the feet, and do not lay them to steep. The 
best glue is that which is oldest ; and the 
surest way to try its goodness, is to lay a 
piece to steep three or four days, and if it 
swell considerably without melting, and 
when taken out resumes its former dryness, 
it is excellent. A glue that will hold against 
fire or water may be made thus : mix a 
handful of quick lime with four ounces of 
linseed oil, boil them to a good tluckness, 
GLU 
then spread it on tin plates in the shade 
and it will become exceedingly hard, but 
may be dissolved over a fire, as glue, and 
will effect the business to admiration. 
Glue, method of preparing and using. 
Set a quart of water on the fire, then put in 
about half a poimd of good glue, and boil 
them gently together till the glue be en- 
tirely dissolved, and of a due consistence. 
When glue is to be used, it must be made 
thoroughly hot ; after which, with a brush 
dipped in it, besmear the faces of the joints 
as quick as possible; then clapping them 
together, 'slide or rub them lengthwise one 
upon another, two or three times, to settle 
them close ; and so let them stand till they 
are dry and firm. 
Glue, parchment, is made by boiling 
gently shreds of parchment in water, in the 
proportion of one pound of the former to 
six quarts of the latter, till it be reduced to 
one quart. The fluid is then to be strained 
from the dregs, and afterwards boiled' to 
the consistence of glue. Isinglass glue is 
made in the same way ; but this is improved 
by dissolving the isinglass in alcohol, by 
means of a gentle heat. See Cements. 
GLUME. See Botany. 
GLUTA, in botany, a genus of the Pen- 
tandria Monogynia class and order. Essen- 
tial character: calyx bell-shaped, decidu- 
ous ; petals five, glued at bottom to the 
column of the germ ; filaments inserted into 
the tip of the column ; germ sitting on an 
oblong column. There is only one species, 
viz. G. benghas, a native of Java. 
GLUTEN. With the fecula and saccha- 
rine matter which compose the principal 
part of nutritive grain, is another substance 
approaching more nearly in its characters to 
-animal matter than any other product of 
the vegetable system. From the resem- 
blance in its properties to the animal prin- 
ciple formerly called gloten, but now de- 
scribed under the term Fibrin (which see) 
it has received the name of vegetable glu- 
ten. It is obtained in largest quantities from 
wheat, amounting to the twelfth part of the 
whole grain, by kneading the flour into 
paste, which is to be washed very cautious- 
ly, by kneading it under a jet of water, 
till the water carries off' nothing more, 
but runs off colourless, what remains is glu- 
ten : it is ductile and elastic ; it has some 
resemblance to animal tendon or mem- 
brane ; it is very tenacious, and may be 
used as a cement for broken porcelain ves- 
sels. It has a peculiar smell, with scarcely 
any taste. When .exposed to tlie air it 
