*Hydrargyrum Ammoniatum (Hydrarg. Ammon.), Ammoniated Mercury, U.S.P.

White, odorless lumps or powder, with an earthy, afterward styptic and metallic taste. Insoluble in water or alcohol.

ACTION AND USES: The ointment is extensively used as a cutaneous antiseptic especially for impetigo contagiosa and other pustular dermatoses and ringworm of the scalp. Also used for removing scales of psoriasis. It may cause salivation.

DOSAGE: From 2 to 10 per cent. ointment.

_*Unguentum Hydrargyri Ammoniati (Ung. Hydrarg. Ammon.), Ointment of Ammoniated Mercury, U.S.P._ (White Precipitate Ointment).--Ammoniated mercury (10%) in white petrolatum and hydrous wool fat.

Hydrastina (Hydrastina), Hydrastine, U.S.P.=--An alkaloid obtained from hydrastis or prepared synthetically.

White crystals or powder. Almost insoluble in water, soluble in alcohol (1:170).

ACTION AND USES: Used in the treatment of urethral and vesical catarrh and as a systemic hemostatic, especially in excessive menstruation. Its efficiency and the mechanism of its action are doubtful.

DOSAGE: 0.01 Gm. or 1/6 grain (U.S.P.).

Hydrastinae Hydrochloridum (Hydrastin. Hydrochl.), Hydrastine Hydrochloride, U.S.P.= (Hydrastine Chloride).

White, odorless, bitter powder. Very soluble in water and in alcohol.

ACTION AND USES: Those of hydrastine.

DOSAGE: 0.01 Gm. or 1/6 grain (U.S.P.).

_Liquor Hydrastinae Compositus (Liq. Hydrastin. Co.), Compound Solution of Hydrastine, N.F._ (Colorless Hydrastine Solution).--Hydrastine hydrochloride (0.3%), aluminum chloride, calcium chloride, and magnesium chloride (each 0.3%), potassium chloride (0.1%) in glycerin and water.

USES: Complex and irrational astringent.

DOSAGE: 4 Cc. or 1 fluidrachm (N.F.).

Hydrastininae Hydrochloridum (Hydrastinin. Hydrochl.), Hydrastinine Hydrochloride, U.S.P.= (Hydrastinine Chloride).--The hydrochloride of hydrastinine, an alkaloid obtained synthetically from hydrastine.

Yellowish, odorless crystals or powder. Soluble in chloroform (1:195); very soluble in water and alcohol.

ACTION AND USES: Hydrastinine resembles hydrastine in its action but is said to be less depressing. Hydrastinine has a pronounced pressor effect on peripheral vessels, causing a rise of blood pressure.

DOSAGE: 0.03 Gm. or 1/2 grain (U.S.P.)

*Hydrastis (Hydrastis), Hydrastis, U.S.P.= (Golden Seal).--Rhizome and roots, yielding not less than 2.5 per cent. of ether-soluble alkaloids, chiefly hydrastin.

ACTION AND USES: Hydrastis is an unpleasant bitter; it possesses no advantages over other simple bitters (gentian). It has been asserted to have a special influence on mucous membranes favoring their nutrition and return to a normal condition. There is little or no experimental evidence to bear out the claim for any special action.

DOSAGE: 2 Gm. or 30 grains (U.S.P.).

_Extractum Hydrastis (Ext. Hydrast.), Extract of Hydrastis, U.S.P._ (Extract of Golden Seal, Powdered Extract of Hydrastis).--One Gm. extract represents about 4 Gm. hydrastis. Yields about 10 per cent. of alkaloids.

DOSAGE: 0.5 Gm. or 8 grains (U.S.P.).

_*Fluidextractum Hydrastis (Fldext. Hydrast.), Fluidextract of Hydrastis, U.S.P._--Hydrastis (100%), yielding about 2 per cent. of alkaloids. Absolute alcohol content about 55 per cent.

DOSAGE: 2 Cc. or 30 minims (U.S.P.).

_Glyceritum Hydrastis (Glycer. Hydrast.), Glycerite of Hydrastis, U.S.P._ (Glycerite of Golden Seal).--Hydrastis (100%) yielding not less than 1.245 per cent. of alkaloids.

DOSAGE: 2 Cc. or 30 minims (U.S.P.).

_Tinctura Hydrastis (Tr. Hydrast.), Tincture of Hydrastis, U.S.P._ (Tincture of Golden Seal).--Hydrastis (20%), yielding about 0.4 per cent. of hydrastin; in alcohol and water. Absolute alcohol content about 60 per cent.

DOSAGE: 4 Cc. or 1 fluidrachm (U.S.P.)

*Hydrogenii Dioxidum, Hydrogen Dioxide= (Hydrogen Peroxide).--H{2}O{2}.

_*Liquor Hydrogenii Dioxidi (Liq. Hydrog. Diox.), Solution of Hydrogen Dioxide, U.S.P._ (Aqua Hydrogenii Dioxidii, U.S.P. VIII, Solution of Hydrogen Peroxide).--H{2}O{2} (not less than 3%).

ACTION AND USES: Nontoxic and fairly efficient local antiseptic and detergent, useful mainly for the destruction of pus. Used on suppurating wounds and as a mouthwash and gargle; also as a bleaching agent. Should not be injected into a wound unless free drainage is present.

DOSAGE: 4 Cc. or 1 fluidrachm (U.S.P.). For external application should be diluted about 1:4.

Hyoscyaminae Hydrobromidum (Hyoscyamin. Hydrobr.), Hyoscyamine Hydrobromide, U.S.P.= (Hyoscyamine Bromide).--Obtained from hyoscyamus and other plants of the nightshade family.

White, odorless crystals. Freely soluble in alcohol (1:2.5) and in chloroform (1:1.7); very soluble in water.

ACTION AND USES: Similar to those of atropine; is usually more sedative to the brain, but at times produces acute delirium. The drug is very uncertain.

DOSAGE: 0.3 mg. or 1/200 grain (U.S.P.).

*Hyoscyamus (Hyosc.), Hyoscyamus, U.S.P.= (Henbane, Hyoscyami Folium, P.I.).--Leaves and tops, yielding not less than 0.065 per cent. of alkaloids.

ACTION AND USES: Similar to those of belladonna.

DOSAGE: 0.25 Gm. or 4 grains (U.S.P.).

_Extractum Hyoscyami (Ext. Hyosc.), Extract of Hyoscyamus, U.S.P._--One Gm. extract represents about 4 Gm. hyoscyamus. Yields about 0.25 per cent. of alkaloids.

DOSAGE: 0.06 Gm. or 1 grain (U.S.P.).

_Fluidextractum Hyoscyami (Fldext. Hyosc.), Fluidextract of Hyoscyamus, U.S.P._ (Fluidextract of Henbane).--Hyoscyamus (100%) yielding about 0.065 per cent. of alkaloids, chiefly hyoscyamine. Absolute alcohol content about 60 per cent.

DOSAGE: 0.2 Cc. or 3 minims (U.S.P.).

_Oleum Hyoscyami Compositum (Ol. Hyosc. Co.), Compound Oil of Hyoscyamus, N.F._ (Balsamum Tranquillans).--Infused oil of hyoscyamus (hyoscyamus 10%) flavored with oils of lavender, peppermint, rosemary and thyme.

_*Tinctura Hyoscyami (Tr. Hyosc.), Tincture of Hyoscyamus, U.S.P._ (Tincture of Henbane, Hyoscyami Tinctura, P.I.).--Hyoscyamus (10%), yielding about 0.0065 per cent. of hyoscyamus alkaloids; in diluted alcohol. Absolute alcohol content about 47 per cent.

DOSAGE: 2 Cc. or 30 minims (U.S.P.).