【医】 糊精

Gum \Gum\, n. [OE. gomme, gumme, F. gomme, L. gummi and commis,
fr. Gr. ?, prob. from an Egyptian form kam?; cf. It.
{gomma}.]
1. A vegetable secretion of many trees or plants that hardens
when it exudes, but is soluble in water; as, gum arabic;
gum tragacanth; the gum of the cherry tree. Also, with
less propriety, exudations that are not soluble in water;
as, gum copal and gum sandarac, which are really resins.

2. (Bot.) See {Gum tree}, {below}.

3. A hive made of a section of a hollow gum tree; hence, any
roughly made hive; also, a vessel or bin made of a hollow
log. [Southern U. S.]

4. A rubber overshoe. [Local, U. S.]

{Black gum}, {Blue gum}, {British gum}, etc. See under
{Black}, {Blue}, etc.

{Gum Acaroidea}, the resinous gum of the Australian grass
tree ({Xanlhorrh[oe]a}).

{Gum animal} (Zo["o]l.), the galago of West Africa; -- so
called because it feeds on gums. See {Galago}.

{Gum animi or anim['e]}. See {Anim['e]}.

{Gum arabic}, a gum yielded mostly by several species of
{Acacia} (chiefly {A. vera} and {A. Arabica}) growing in
Africa and Southern Asia; -- called also {gum acacia}.
East Indian gum arabic comes from a tree of the Orange
family which bears the elephant apple.

{Gum butea}, a gum yielded by the Indian plants {Butea
frondosa} and {B. superba}, and used locally in tanning
and in precipitating indigo.

{Gum cistus}, a plant of the genus {Cistus} ({Cistus
ladaniferus}), a species of rock rose.

{Gum dragon}. See {Tragacanth}.

{Gum elastic}, {Elastic gum}. See {Caoutchouc}.

{Gum elemi}. See {Elemi}.

{Gum juniper}. See {Sandarac}.

{Gum kino}. See under {Kino}.

{Gum lac}. See {Lac}.

{Gum Ladanum}, a fragrant gum yielded by several Oriental
species of Cistus or rock rose.

{Gum passages}, sap receptacles extending through the
parenchyma of certain plants ({Amygdalace[ae]},
{Cactace[ae]}, etc.), and affording passage for gum.

{Gum pot}, a varnish maker's utensil for melting gum and
mixing other ingredients.

{Gum resin}, the milky juice of a plant solidified by
exposure to air; one of certain inspissated saps, mixtures
of, or having properties of, gum and resin; a resin
containing more or less mucilaginous and gummy matter.

{Gum sandarac}. See {Sandarac}.

{Gum Senegal}, a gum similar to gum arabic, yielded by trees
({Acacia Verek} and {A. Adansoni["a]}) growing in the
Senegal country, West Africa.

{Gum tragacanth}. See {Tragacanth}.

{Gum water}, a solution of gum, esp. of gum arabic, in water.


{Gum wood}, the wood of any gum tree, esp. the wood of the
{Eucalyptus piperita}, of New South Wales.


Dextrin \Dex"trin\, n. [Cf. F. dextrine, G. dextrin. See
{Dexter}.] (Chem.)
A translucent, gummy, amorphous substance, nearly tasteless
and odorless, used as a substitute for gum, for sizing, etc.,
and obtained from starch by the action of heat, acids, or
diastase. It is of somewhat variable composition, containing
several carbohydrates which change easily to their respective
varieties of sugar. It is so named from its rotating the
plane of polarization to the right; -- called also {British
gum}, {Alsace gum}, {gommelin}, {leiocome}, etc. See
{Achro["o]dextrin}, and {Erythrodextrin}.


British \Brit"ish\ (br[i^]t"[i^]sh), a. [AS. Brittisc,
Bryttisc.]
Of or pertaining to Great Britain or to its inhabitants; --
sometimes restricted to the original inhabitants.

{British gum}, a brownish substance, very soluble in cold
water, formed by heating dry starch at a temperature of
about 600[deg] Fahr. It corresponds, in its properties, to
dextrin, and is used, in solution, as a substitute for gum
in stiffering goods.

{British lion}, the national emblem of Great Britain.

{British seas}, the four seas which surround Great Britain.