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Extractum Calami Fluidum. Fluid Extract of Calamus. By
maceration and percolation with Alcohol, and evaporation.
Dose, 15 to 60 m. ; i. to 4. c.c.


Sweet flag is a simple bitter and feeble aromatic, and is used
with advantage in pain or uneasiness in the stomach or bowels
arising from flatulence, or as an adjuvant to purgative medicines.]


GENTIAN. [The root of Gentiana lutea Linne (nat. ord. Gentianea).
Habitat. Mountains of Central and Southern Europe.

CHARACTERS. In nearly cylindrical pieces or longitudinal slices, about
25 mm. thick, the upper portion closely annulate, the lower portion longitudi-
nally wrinkled ; externally deep yellowish-brown ; internally lighter ; some-
what flexible and tough when damp ; rather brittle when dry ; fracture uneven ;
the bark rather thick, separated from the somewhat spongy meditullium by a
black cambium line ; odor peculiar, faint, more prominent when moistened ;
taste sweetish and persistently bitter.]

COMPOSITION. The chief constituents are (i) Gentiopicrin, an active,
very bitter glucoside, soluble in water and Alcohol. Can be split up into
glucose and Gentiogenin. (2) Gentisic Add, [C U H, O 5 , in yellow, tasteless
needles,] united with Gentiopicrin. (3) A trace of a volatile oil. (4) Gentian-
ose, a sugar. Gentian contains no Tannic Acid, but cannot be prescribed with
iron, because that darkens the coloring matter.

INCOMPATIBLES. Iron salts, silver nitrate, and lead salts.

Dose, 5 to 30 gr. ; [.30 to 2.00 gin.]


1. Extractum Gentianae. [Extract of Gentian. By maceration
and percolation with Water, and evaporation.

Dose, 2 to 10 gr. ; .12 to .60 gm.

2. Extractum Gentianae Fluidum. Fluid Extract of Gentian.
By maceration and percolation with Diluted Alcohol, and evaporation.

Dose, 5 to 30 m. ; .30 to 2.00 c.c.

3. Tinctura Gentianae Composita. Compound Tincture of
Gentian. Gentian, loo ; Bitter Orange Peel, 40 ; Cardamom, 10. By
maceration and percolation with Alcohol and Water to 1000.

Dose, i to 4 fl. 4r. ; 4. to 15. c.c.]



Gentian has the same action as other bitters, such as calumba,
and is employed for the same class of cases. It is more used
than any other bitter, because its taste is pleasant and it is not


QUASSIA. [The wood of Picrana exceha (Swartz) Lindley (nat. ord.
Simarubea). Habitat. Jamaica.

CHARACTERS. In billets of various sizes, dense, tough, of medium hard-
ness, porous, with a minute pith and marrow, medullary rays ; inodorous, and
intensely bitter. In the shops it is usually met with in the form of chips or
raspings of a yellowish-white color.] Resembling Quassia. Sassafras, but
this is aromatic and not bitter.

COMPOSITION. The chief constituents are (i) [Quasstin, C, H,,O S , a
bitter principle occurring in crystalline rectangular plates.] (2) A volatile oil.
No Tannic Acid being present, Quassia can be prescribed with iron salts.


1. [Extractum Quassiae, Extract of Quassia. By percolation
with Water, and evaporation.

Dose, }4 to 3 gr. ; .03 to .20 gm.

2. Extractum Quassiae Fluidum. Fluid Extract of Quassia.
By maceration and percolation with Alcohol and Water, and evapora-

Dose, ' 4 to * fi- dr. ; i. to 4. c.c.

3. Tinctura Quassiae. Tincture of Quassia. Quassia, 100; by
maceration and percolation with Alcohol and Water to looo.

Dose, )4 to 2 fl. dr. ; 2. to 8. c.c.]


Quassia is an aromatic bitter stomachic, acting in the same way
as calumba. As it contains no tannic acid it is often prescribed
with iron. The only objection to it is that some persons find it
too bitter. Injected per rectum, it is an excellent anthelmintic
for Oxyuris vermicularis ; half a pint [250 c.c.] of the infusion
[i to 100 of cold water to avoid extraction of too much of the
bitter principle,] may be given for this purpose, [the patient
being in the knee-chest position.]



CASCARILLA. [The bark of Croton Eluteria Bennett (nat. ord.
Euphorbiacea). Habitat. Bahama Islands.

CHARACTERS. In quills or curved pieces about 2 mm. thick, having a
grayish, somewhat fissured, easily detached, corky layer, more or less coated
with a white lichen, the uncoated surface being dull brown, and the inner sur-
face smooth. It breaks with a short fracture, having a resinous and radially
striate appearance. When burned, it emits a strong, aromatic, somewhat
musk-like odor ; its taste is warm and very bitter. ] Resembling Cascarilla.
Pale Cinchona, which is less white, smooth and small.

COMPOSITION. The chief constituents are (l) Cascarillin, a bitter, neu-
tral crystalline substance. (2) Volatile oil, [1.5 per cent.] (3) Resin. (4)
Tannic acid.

INCOMPATIBLES. Mineral acids, lime water and metallic salts.

Dose, 10 to 30 gr. ; [.60 to 2.00 gm.]

Cascarilla, because of its bitter principle cascarillin, like other
vegetable bitters, improves the digestion, and this stomachic and
carminative action is aided by the volatile oil in it. It is pleasant
to take, and is suitable for the same cases as calumba. The
infusion [i to 20] will not keep good for more than a day unless
the tincture [i to 15] is added to it. Mineral acids precipitate
the resin from the tincture ; therefore the infusion should be

prescribed with them.


CHIRATA. Synonym. Chiretta. [The entire plant, Swertia Chirata
Hamilton (nat. ord. Gentianeae). Habitat. Mountains of Northern India.

CHARACTERS. Root nearly simple, about 7 cm. long ; stem branched,
nearly I meter long, slightly quadrangular above ; containing a narrow wood-
circle and a large yellowish pith. Leaves opposite, sessile, ovate, entire five-
nerved. Flowers numerous, small, with a four-lobed calyx and corolla. The
whole plant smooth, pale brown, inodorous, and intensely bitter.] Resembling
Chirata. Lobelia, which is not bitter.

COMPOSITION. The chief constituents are (I) Chiratin, [CjgH^gO^,] an
active, bitter principle, as a yellow, hygroscopic powder. (2) Ophelic Acid,
CjjH.joOjp] with which it is combined. No Tannic Acid is present.

Dose, ]/i to i dr. ; [2. to 4. gm.]


[i. Extractum Chiratae Fluidum. Fluid Extract of Chirata. By
maceration and percolation with Alcohol and Water, and evaporation.
Dose, y 2 to i fl. dr. ; 2. to 4. c.c.


2. Tinctura Chiratae. Tincture of Chirata. Chirata, loo ; by
maceration and percolation with Alcohol and Water to 1000.
Dose, y z to 2 fl. dr. ; 2. to 8. c.c.]


Chirata has the same actions and uses as gentian, calumba and
other bitters. As it contains no tannic acid, it can be given
with iron. It is more [frequently] used in India.


CUSPARIjE CORTEX. [B. P., not official.] Cusparia Bark. Syn-
onym. Angustura Bark. The bark of Cusparia febrifuga (&%*.. ord. Rutacea).
[Habitat. ]Tropical South America.

CHARACTERS. Flat or curved pieces or quills, [16 cm.] or less long, [4
mm.] thick, obliquely cut on the inner edge. Externally a yellowish-gray,
mottled, corky layer, which can be scraped off, and shows a dirk brown
resinous layer; inner surface light brown, flaky. Fracture short, resinous, and
showing, under a lens, white points or lines. Taste bitter, aromatic. Odor
musty, disagreeable. [Resembling Cusparia. Canella Alba, but this is
darker, and has pared edges. ]

IMPURITY. Bark of Strychnos nux-vomica (false Angustura bark) ; its
inner surface gives bright blood-red color with Nitric Acid, showing Brucine ;
Cusparia does not.

COMPOSITION. The chief constituents are (i) Cusparine, or Angustu-
rine, a crystalline bitter alkaloid. (2) An alkaloid, Galipeine. (3) An alka-
loid, Galipidine. (4) An alkaloid, Cusparidine. (5) An aromatic oil. It is
stated that no Tannic Acid is present, but Iron Salts are incompatible with
Cusparia. .

INCOMPATIBLES. Mineral acids and metallic salts.

Dose, 10 to 40 gr. ; [.60 to 2.40 gm.]


Infusum Cuspariae. [B. P., not official. Infusion of Cusparia],
Cusparia, 5 ; Water at 120 F. ; [48.8 C.] (to avoid extraction of
nauseous principles), 100.

Dose, i to 2 fl. oz. ; [30. to 60. c.c.]


Cusparia bark is an aromatic bitter, having a similar action
to calumba. It is used to make Angustura Bitters. In South
America it is given [in large doses] as an antiperiodic.



SERPENTARIA. Synonym. [Virginia Snakeroot. The rhizome
and roots of Aristolochia Serpentaria Linne, and of Aristolochia reticulata
Nuttall (nat. ord. Aristoloehiacea}. Habitat. United States, in hilly woods.

CHARACTERS. The rhizome is about 25 mm. long, thin, bent; on the
upper side with approximate short stem bases ; on the lower side with numer-
ous, thin, branching roots about 10 cm. long ; dull, yellowish-brown, inter-
nally whitish ; the wood-rays of the rhizome longest on the lower side ; odor
aromatic, camphoraceous ; taste warm, bitterish, and camphoraceous. The
roots of Aristolochia reticulata are coarser, longer, and less interlaced than
those of Aristolochia Serpentaria.} Resembling Serpentaria. [Veratrunc
Viride, (see p. 442),] Arnica, (seep. 530), and Valerian, (see p. 556.)

COMPOSITION. The chief constituents are (l) A bitter principle, Aristo*
lochine [in light-yellow needles. (2) A volatile oil, ^ per cent, containing a
Terpene, and mainly C 15 H 25 O 2 , Borneol Ether. (3) Resin. (4) Tannic
Acid in small quantity.

Serpentaria is used to prepare Tinctura Cinchonae Composita. ]

Dose, 10 to 30 gr. ; [.60 to 2.00 gm.]


[i. Extractum Serpentariae Fluidum. Fluid Extract of Ser-
pentaria. By'maceration and percolation with Alcohol and Water, and

Dose, 10 to 30 m. ; .60 to 2.00 c.c.

2. Tinctura Serpentariae. Tincture of Serpentaria. Serpen-
taria, loo ; by maceration and percolation with Alcohol and Water to


Dose, % to 2 fl. dr. ; 2. to 8. c.c.]


In the small doses in which serpentaria is given in medicine
it is a bitter stomachic, acting just like calumba and cascarilla,
and is used for the same class of cases. It is rarely prescribed
alone. In large doses it produces vomiting and purging. Many
virtues have been attributed to it which it [quite likely] does

not possess.


CIMICIFUG A. [Synonyms. Black Snakeroot. Black Cohosh. The
rhizome and roots of Cimicifuga racemosa (Linne) Nuttall (nat. ord, Ranun-
culacea). Habitat. North America ; in rich woodlands, westward to Eastern


CHARACTERS. -The rhizome is of horizontal growth, hard, 5 era. or more
long, about 25 mm. thick, with numerous stout, upright or curved branches,
terminated by a cup-shaped scar, and with numerous wiry, brittle, obtusely
quadrangular roots, about 2 mm. thick ; the whole brownish -black, of a slight
but heavy odor, and of a bitter, acrid taste. Rhizome and branches have a
smooth fracture, with a rather large pith, surrounded by numerous sublinear,
whitish wood-rays, and a thin, firm bark. The roots break with a short
fracture, have a thick bark, and contain a ligneous cord expanding into about
four rays.

COMPOSITION. The chief constituents are (l) An acrid, crystalline prin-
ciple, soluble in Chloroform and Alcohol. (2) Tannic and Gallic Acids. (3)
Two Resins.]

Cimicifugin or Macrotin is an impure resin deposited from the tincture on
aoding water.


1. Extractum Cimicifugae. [Extract of Cimicifuga. By macer-
ation and percolation with Alcohol, and evaporation.

Dose, i to 5 gr. ; .06 to .30 gm.

2. Extractum Cimicifugae Fluidum. Fluid Extract of Cimici-
fuga. By maceration and percolation with Alcohol, and evaporation.

Dose, 'j to i fl. dr. ; 2. to 4. c.c.

3. Tinctura Cimicifugae. Tincture of Cimicifuga. Cimicifuga,
200 ; by maceration and percolation with Alcohol to 1000.

Dose, YJ. to 2 fl. dr. ; 2. to 8. c.c.]


Cimicifuga has two chief actions. It influences the gastric
secretion like any other bitter, and, to a slight extent, it de-
presses the rate, but increases the force of the pulse, like digitalis.
The arterial tension rises. It is said to cause contractions of the
uterus and to increase the menstrual flow.



It has been used for chorea, dyspepsia, bronchitis, amenor-
rhcea, dysmenorrhcea, rheumatism, neuralgia, and many other
diseases. The evidence that it does much good [beyond thax
accomplished by a simple bitter] , is slight.


TARAXACUM. [Synonym. Dandelion. The root of Taraxa-vm
officinale Weber (nat. ord. Com/>osi/a-), gathered in autumn. Habitat. Grassy
places and roadsides in Europe ; naturalized in the United States.


CHARACTERS. Slightly conical, about 30 cm. long, and i or 2 cm. thick
above, crowned with several short, thickish heads, somewhat branched, bark
brown, longitudinally wrinkled, when dry breaking with a short fracture,
showing a yellowish, porous central axis, surrounded by a thick, while bark,
containing numerous milk vessels arranged in concentric circles ; inodorous ;
bitter.] Resembling Taraxacum. Pellitory, which is pungent when chewed.

COMPOSITION. The chief constituents are [(i) Taraxacin, a crystalline
bitler principle, soluble in water and Alcohol. (2) Taraxacerin, C 8 H 16 O].
(3) Asparagin (found in asparagus, marsh-mallow, liquorice, euonymus) of no
therapeutic value. (4) Inulin. (5) Resin (which gives the juice its milky

[IMPURITY. The root of the Chicorium Intybus, which is paler, and has
the milk vessels in radiating lines.]

Dose, i to 3 dr. ; [4. to 12. gm.]


[i. Extractum Taraxaci. Extract of Taraxacum. By expres-
sion and straining and evaporation.

Dose, 5 to 30 gr. ; .30 to 2.00 gm.

2. Extractum Taraxaci Fluidum. Fluid Extract of Taraxacum.
By maceration and percolation with diluted Alcohol and evaporation.
Dose, i to 4 fl. dr. ; 4. to 15. gm.]


Dandelion is a simple bitter, and acts as a stomachic, just
like calumba. It is also slightly laxative. It was formerly much
more used than at the present day. It has been said to stimulate
the flow of bile, but this is incorrect. [The vulgar name by
which dandelion is known both in England and France suggests
that it may be diuretic.]


[AURANTII AMARI CORTEX. Bitter Orange Peel. The rind
of the fruit of Citrus vulgaris Risso (nat. ord. Rutacea). Habitat. Northern
India ; cultivated in subtropical countries.

CHARACTERS. In narrow, thin bands, or in quarters ; epidermis of a
dark, brownish-green color, glandular, and with very little of the spongy, white
inner layer adhering to it ; it has a fragrant odor, and an aromatic, bitter taste.

COMPOSITION. The chief constituents are (i) A volatile oil, consisting
mainly of Hesperidene, C IO H, 6 , with a small portion of Geraniol, C, H 16 O.
(2)Threeglucosides, Hesperidin, hohesperidin and Aurantiamarin, the bitter
principle. Both Bitter and Sweet Orange Peel contain a substance which re-
acts with iron salts and Tannic Acid.


Bitter Orange Peel is used in preparing Tinctura Cinchonae Composite
and Tinctura Gentianae Composita.

Prepa rations.

1. Extractum Aurantii Amari Fluidum. Fluid Extract of
Bitter Orange Peel. By maceration and percolation with Alcohol and
water, and evaporation.

Dose, y^ to i fl. dr. ; 2. to 4. c.c.

2. Tinctura Aurantii Amari. Tincture of Bitter Orange Peel.
Bitter Orange Peel, 200. By maceration and percolation with Alcohol
and water to looo.

Dose, i to a fl. dr. ; 4. to 8. c.c.

AURANTII DULCIS CORTEX. Sweet Orange Peel. The rind
of the fresh fruit of Citrus Aurantium Linne (nat. ord. Rutaceie). Habitat.
As of the Citrus vulgaris.

CHARACTERS. Closely resembling Bitter Orange Peel, but having an
orange-yellow color. It has a sweetish, fragrant odor, and an aromatic, slightly
bitter taste.

COMPOSITION. As of the Bitter Orange Peel.

Prepa rations.

1. Sympus Aurantii. Syrup of Orange. Sweet Orange Peel,
50 ; Precipitated Calcium Phosphate, 50 ; Sugar, 700. By boiling
with Alcohol, mixture of the tincture (thus formed) in Sugar with Water,
addition of Water and nitration to looo.

Dose, as vehicle.

2. Tinctura Aurantii Dulcis. Tincture of Sweet Orange Peel.
Sweet Orange Peel, 200. By maceration and percolation with Alcohol
to 1000.

Dose, i to 2 fl. dr. ; 4. to 8. c.c.

OLEUM AURANTII CORTICIS. Oil of Orange Peel, a volatile
oil obtained by expression from the fresh peel of either the Bitter Orange,
Citrus vulgarus Risso, or the Sweet Orange, Citrus Aurantium Linne (nat.
ord. Rutacea).

CHARACTERS. A pale, yellowish liquid, having the characteristic, aro-
matic odor of Orange, and an aromatic and, when obtained from the Bitter
Orange, somewhat bitter taste. Sp. gr., about 0.850. Solubility. In four
times its volume of Alcohol.

IMPURITIES. Oil of Turpentine or other oils containing Pinene.

Oil of Orange Peel is contained in Spiritus Myrciae.



1. Spiritus Aurantii. Spirit of Orange. Oil of Orange Peel, 50;
Deodorized Alcohol, 950.

Dose, as vehicle.

2. Spiritus Aurantii Compositus. Compound Spirit of Orange.
Oil of Orange Peel, 200; Oil of Lemon, 50; Oil of Coriander, 20;
Oil of Anise, 5 ; Deodorized Alcohol to 1000.

Dose, as vehicle.

3. Elixir Aromaticum. Aromatic Elixir. Compound Spirit of
Orange, 12; Syrup, 375; Precipitated Calcium Phosphate, 15; De-
odorized Alcohol, Distilled Water, each, a sufficient quantity to make
looo. By solution of the Compound Spirit of Orange in Deodorized
Alcohol, to 250; addition of Syrup and Precipitated Calcium Phos-
phate, and filtering, with Distilled Water to looo.

Dose, as vehicle.

OLEUM AURANTII FLORUM. Oil of Orange Flowers. Syn-
onym. Oil of Neroli. A volatile oil distilled from fresh flowers of the Bitter
Orange, Citrus -vulgaris Risso (nat. ord. Rutacece).

CHARACTERS. A yellowish or brownish, thin liquid, having a very fra-
grant odor of Orange Flowers, and an aromatic, somewhat bitter taste. Sp.
gr., 0.875 to 0.890. Solubility. In an equal volume of Alcohol.


1. Aqua Aurantii Florurn Fortior. Stronger Orange Flower
Water. Synonym. Triple Orange Flower Water. Water saturated
with the volatile oil of fresh Orange Flowers.

Dose, indeterminate.

2. Aqua Aurantii Florum. Orange Flower Water. Stronger
Orange Flower Water, 500; Distilled Water to looo.

Dose, indeterminate.

3. Syru pus Aurantii Florum. Syrup of Orange Flowers. Sugar,
850 ; Orange Flower Water to looo.

Dose, indeterminate.]


The various preparations of the orange are used largely as
flavoring agents. They are slightly bitter and stomachic. [The
aromatic elixir is an excellent flavoring agent and vehicle for
liquid medicines.]


Vegetable Drugs containing Tannic Acid.

These are all astringent.

[Oak Bark,] Nutgall, [Tannic Acid, Gallic Acid, Pyrogallol,] Catechu,

Krameria, Kino, Haematoxylon, Hamamelis, [Rhus Glabra,

Geranium, Rubus, Rumex,] Eucalyptus Gum, [Goto.]

[QUERCUS ALBA. White Oak. The bark of the Qiiercus alba
Linne (nat. ord. Cupulifera). Habitat. North America, westward to Min-
nesota, Kansas, and Mississippi ; in woods.

CHARACTERS. In nearly flat pieces, deprived of the corky layer, about 5
mm. thick ; pale brown ; inner surface with short, sharp, longitudinal ridges ;
tough ; of a coarse, fibrous fracture, a faint, tan-like odor, and a strongly
astringent taste. As met with in the shops it is usually an irregularly coarse,
fibrous powder, which does not tinge the saliva yellow.

COMPOSITION. The chief constituents are (\) Quercitannic acid, [C W 1I M
O u , 6 to II per cent., a variety of Tannic Acid. (2) Quercin, a bitter prin-
ciple. (3) Quercite, a sugar. (4) Resin.

INCOMPATIBLES. See Tannic Acid, p. 593.]

GALLA. [Nutgall. An excrescence on Qucrcus lusitanica Lamarck
(nat. ord. Cupuliferir], caused by the punctures and deposited ova of Cynips
Galla tinctoriie Olivier (class Insecta ; order Hymenoptera. Habitat

CHARACTERS. Subglobular, I or 2 cm. in diameter, more or less tuber-
culated above, otherwise smooth, heavy, hard ; often with a circular hole near
the middle, communicating with the central cavity ; blackish olive-green or
blackish-gray ; fracture granular, grayish ; in the centre a cavity containing
either the partly developed insect, or purulent remains left by it; nearly in-
odorous, taste strongly astringent.]

COMPOSITION. The chief constituents are (l) Tannic Acid, [501060]
per cent. (2) Gallic Acid, 2 to [3] per cent. (3) Sugar. (4) Resin.

INCOMPATIBLES. See Tannic and Gallic Acids, [p. 593 and p. 596.]

Prepa rations.

1. Tinctura Gallae. [Tincture of Nutgall. Nutgall, 200; by
maceration with Glycerin, 100, and Alcohol to looo.

Dose, i to 2 fl. dr. ; 4. to 8. c.c.

2. Unguentum Gallae. Nutgall Ointment. Nutgall, 20 ; Ben-
zoinated Lard, 80.]


ACIDUM TANNICUM. Tannic Acid, [HC U H 9 O 9 =32I.22. Syn-
onyms. Tannin. Gallotannic Acid. Digallic Acid. An organic acid ex-
tracted from Nutgall.]

SOURCE. (i) Expose powdered Nutgall to a damp atmosphere for twenty-
four hours. (2) Add Ether to form a paste, and let it stand, closely coveted,
for six hours. (3) Express this in a close canvas cloth, between tinned plates,
reduce the lesulting cake to powder and mix with sufficient Ether and express
as before. (4) Mix the expressed liquids and allow the mixture to evaporate
spontaneously. Tanmc Acid remains. [2"HC 7 H 5 O 5 H 2 O HC U H 9 O 8 . ]

CHARACTERS. [A light yellowish, amorphous powder, usually cohering
in form of glistening scales or spongy masses, odorless, or having a faint char-
acteristic odor, and a strongly astringent taste ; gradually turning darker when
exposed to air and light. Solubility. In about I part of water, and in 0.6
part of Alcohol ; also in about I part of Glycerin, with the intervention of a
moderate heat ; freely soluble in diluted Alcohol, sparingly in absolute Alco-
hol ; almost insoluble in absolute Ether, Chloroform, Benzol or Benzin.]

INCOMPATIBLES. Mineral acids, alkalies, antimony, lead, silver, and
ferric salts, alkaloids, gelatin, and emulsions.

Dose, i to 20 gr. ; [.06 to 1.20 gm.]


[i. Collodium Stypticum. Styptic Collodion. Tannic Acid,
20 ; Alcohol, 5 ; Ether, 25 ; Collodion, to too. By solution.

2. Trochisci Acidi Tannici. Troches of Tannic Acid. Tannic
Acid, 6; Sugar, 65; Tragacanth, 2 gm.; Stronger Orange Flower
Water, a sufficient quantity to make loo troches. Each troche contains
about I gr. ; .06 gm. of Tannic Acid.

Dose, i to 3 troches.

3. Unguentum Acidi Tannici. Ointment of Tannic Acid. Tan-
nic Acid, 20 ; Benzoinated Lard, 80.

4. Glyceritum Acidi Tannici. Glycerite of Tannic Acid. Tan-
nic Acid, 20; Glycerin, 80.]


External. Tannic acid is one of the most important drugs,
because it coagulates albumin and gelatin with great readiness ;
that is to say, it tans the tissues, for it is by coagulating the in-
terstitial fluid in skins that tannic acid converts them into
leather. The coagulated albumin or gelatin powerfully resists
putrefaction. If an albuminous discharge is taking place from a
sore or mucous surface and tannic acid is applied, the excreted



fluid is coagulated, and the coagulum forms a solid protecting
layer which prevents further discharge. As the tannic acid soaks
into the tissues it coagulates the albuminous fluids there also, and
this still further hinders the discharge of fluid, therefore it is an
energetic astringent. If bleeding is taking place, tannic acid
of course coagulates the blood as it flows and the clots plug the
vessels ; at the same time the coagulum formed within the tissues,
by its contraction, constricts the blood-vessels, and thus tannic
acid becomes a powerful haemostatic. It has no noteworthy
direct effect on the blood-vessels themselves. Tannic acid is
mildly depressant to sensory nerves. Like other acids it is irri-
tant, but it is very feebly so, and consequently its action in this
direction is more than counterbalanced by its strongly astringent

Internal. Gastro-intestinal tract. Because tannic acid co-
agulates the mucous secretions and the fluids in mucous mem-

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