The eucalypts are remarkable for the oil secreted in their leaves, and the large quantity of astringent resin of their bark.
The astringent principle is a peculiar kind of tannic acid, called by chemists quercitannic, which, yielding more stable compounds with gelatine than other forms, gives oak bark its high value to the tanner.
They are all, as found in commerce, of a pale yellow-green colour; they emit a peculiar aromatic odour, and have a slightly astringent bitter taste.
When cut open, it displays an infinity of tiny leaf-buds and stems, and at intervals there exudes from it an aromatic resin, which from its astringent properties is used by the shepherds as a vulnerary, but has not been converted to any commercial purpose.
If the latex is warmed or an acid, an alkali or astringent plant juice is added to it, " coagulation " usually takes place more or less readily, the caoutchouc separating in solid flakes or curds.
The Funtumia latex can also be coagulated by the astringent infusion of Bauhinia leaves or by exposing it in shallow dishes, when the liquid " creams."
They are very astringent, haemostatic and sedative; the strong solution of the subacetate is powerfully caustic and is rarely used undiluted.
Lead salts are applied as lotions in conditions where a sedative astringent effect is desired, as in weeping eczema; in many varieties of chronic ulceration; and as an injection for various inflammatory discharges from the vagina, ear and urethra, the Liquor Plumbi Subacetatis Dilutum being the one employed.
Internally lead has an astringent action on the mucous membranes, causing a sensation of dryness; the dilute solution of the subacetate forms an effective gargle in tonsillitis.
The chief use of the preparations of lead, however, is as an astringent in acute diarrhoea, particularly if ulceration be present, when it is usefully given in combination with opium in the form of the Pilula Plumbi cum Opio.
They are soluble in water, have an astringent, acid, and sweetish,, .taste, react acid to litmus, and crystallize in regular octahedra.
As alum and green vitriol were applied to a variety of substances in common, and as both are distinguished by a sweetish and astringent taste, writers, even after the discovery of alum, do not seem to have discriminated the two salts accurately from each other.
The leaves and husk of the fruit are resinous and astringent, and are sometimes used medicinally as well as for dyeing purposes.
The fruit-stalk is very short, bearing a subglobose fruit an inch or rather more in diameter, of an orange-yellow colour, and with a sweetish astringent pulp. It is surrounded at the base by the persistent calyxlobes, which increase in size as the fruit ripens.
An astringent fluid, known as shibu, rich in tannin, is expressed from the green fruit and used in various industries.
The physical properties of the powder also give it a mild astringent action.
Dioscorides refers to it as agallochon, a wood brought from Arabia or India, which was odoriferous but with an astringent and bitter taste.
What are termed " blue," " black," or" green "galls contain the insect; the inferior " white " galls, which are lighter coloured, and not so compact, heavy or astringent, are gathered after its escape (see fig.
Pomet' thought that gall-nuts were the fruit of the oak, and a similar opinion obtains among the modern Chinese, who apply to them the term Mu-shih-tsze, or " fruits for the foodless."2 Hippocrates administered gall-nuts for their astringent properties, and Pliny (Nat.
In British pharmacy gall-nuts are used in the preparation of the two astringent ointments unguentum gallae and unguentum gallae cum opio, and of the tinctura gallae, and also as a source of tannin and of gallic acid.
It contains, in addition to tannin, a peculiar principle called larixin, which may be obtained in a pure state by distillation from a concentrated infusion of the bark; it is a colourless substance in long crystals, with a bitter and astringent taste, and a faint acid reaction; hence some term it larixinic acid.
It has a sweet astringent taste, very soluble in water, but scarcely soluble in alcohol.
Cupri rosa, the flower of copper), green vitriol, or ferrous sulphate, FeSO 4.7H 2 0, having a bluish-green colour and an astringent, inky and somewhat sweetish taste.
Tannin is a hardening and astringent substance, and in large quantities impairs digestion.
Morphine is an analgesic and hypnotic, relieving pain and producing deep sleep. As contrasted with opium it differs in being less astringent and constipating.
The witch hazel is quite a distinct plant, Hamamelis virginica, of the natural order Hamamalideae, the astringent bark of which is used in medicine.
Acacia arabica is the gum-arabic tree of India, but yields a gum inferior to the true gum-arabic. An astringent medicine, called catechu or cutch, is procured from several species, but more especially from Acacia catechu, by boiling down the wood and evaporating the solution so as to get an extract.
They are soluble in water, their solutions having an acid reaction and an astringent taste; the solutions are coloured dark blue or green by ferrous salts, a property utilized in the manufacture of ink.
From tannic acid is also made gallic acid, which resembles tannic acid but has no astringent taste.
It is moreover an astringent to the tissues, hindering the further discharge of fluid.
In the intestine tannic acid controls intestinal bleeding, acting as a powerful astringent and causing constipation; for this reason it has been recommended to check diarrhoea.
But by the addition of some antiseptic to the ointment its defensive action would be converted from passive to active, and its power to prevent infection would become greater; and if inflammation had already set up in the skin, the addition of opium, belladonna, or cocaine would lessen local pain; and an astringent, either metallic or organic, would restrain inflammation and accelerate repair.
If the granulations tend to become too abundant, some astringent, such as sulphate of copper or sulphate of zinc, is added to the water.
Thus in the eye and ear, lotions containing an antiseptic, a sedative and an astringent are very generally used.
The strength of the astringent application and the mode of its administration are varied according to the delicacy and position of the mucous membrane affected.
In cases where diarrhoea is very obstinate and lasts for weeks, sulphuric acid is sometimes more efficacious than alkalis; and in chronic colics it may be necessary to treat the mucous membrane by local application of astringent solutions.
The underground woody stem is astringent and yields a yellow dye.
The effects of the nitrate being both astringent and stimulating as well as bactericidal, solutions of it are used to paint indolent ulcers.