Mercury. The official C. S. P. title for mercury is Hydrargyrum. The homeopaths call it crcurius, and they have the better title. We usually abbreviate it to "Hydrarg.," or even to "Hydr." A great many drugs have Hydr. - -and conflict occurs, as witness-hydrastin, hydrangea, hydrated salts, hydriodic acid, hydobromates, and hydrochlorates, hydrocyanic acid, hydrogen, hydrous wool fat, and a long list of synthetic chemicals.

Acetate, antisyphilitic in doses of 1-10 to 1/2 gr. Ammoniated, used in ointments, I to 109'0, as a parasiticide. Hydrargyri chloridu111 corrosivum, U. S. P., antiseptic, alterative, and antisyphilitic. Average dose, I -20 gr. In small doses a tonic (1-100 gr). Hypodermically used by dissolving 11/2 gr. and 15 gr. of sodium chloride in 25 f3 of water and using from 1/2 to I syringeful at a dose. For surgical antiseptic purposes, in solution I :5000 to I :1000. In homeopathic practice, the 3X is used with success in rectal tenesmus. Their ophthalmologists use a I :1000 solution, injected hypo-dermically under the conjunctiva, in choroiditis with progressive myopia and aching pain. Hydrargyri chloridum mite, U. S. P. The tendency now is to use calomel in fractional doses (I 10 gr. triturates), hourly or half hourly, to effect. Large doses are cholagogue. and small ones at long intervals alterative. Quite apt to salivate. A very valuable intestinal antiseptic. The homeopaths call it Mercurius dulcis. Their IX (1-10 gr.) tablet triturates are well made and are yery active. They use the 3x in catarrhal inflammations of the ear and Eustachian tubes and in diarrhea with soreness of the anus. Fumigations of calomel are of great value in membranous croup. Hydrargyrum cum creta,. U. S. P. (389'0), an intestinal antiseptic, cholagogue, and antisyphilitic. Average dose, 4 gr. After saturation with the protoiodide this is a good form of mercury for prolonged administration in syphilis. Cyanide, alterative and antiseptic, in use in I :10,000 to 1:2000 in solution externally, and in 1-10 gr. doses internally. It is similar in action to the bichloride, but is less irritating. Both the regular and homeopathic profession use it in malignant cases of diphtheria, but very small doses should be used. The 3X trituration serves well. Hydrargyri iodum fim'u11!, U. S. P.. or Protoiodide, is used principally in syphilis in the average dose of 1-5 gr. Two things should be remembered with reference to this drug: when purgative effects are produced, it should be conservatively employed, and, as its dose is four times that of the biniodide, it should never be combined with soluble iodides, which convert it into the biniodide. The homeopaths use 1-10 gr. doses when there is a heavy yellow coating upon the tongue, and 1-100 gr. doses (2X) in throat affections with swollen glands. Hydrargyri iodidum rub rum, U. S. P., or Biniodide. Used in obstinate cases of syphilis in an average dose of I -20 gr. Highly toxic. The 2X and 3X are of marked value in ulcerated sore throat and diphtheria. Massa hydrargyri, U. S. P., or Blue Mass (33 % ), is used principally as a purgative. Average dose, 4 gr., usually in pill form. Oxide (Black), or Hahnemann's soluble mercury, is not soluble in water or alcohol, and decomposes upon exposure. Dose, y,; to 2 gr., but is unreliable. Hydrargyri oxidum flavum, U. S. P., is used externally in 10% ointment in chancres, indolent ulcers, ringworm, and for skin parasites, and in 1/2 to I% ointment in ophthalmia. Hydrargyri oxidum rubrum, U. S. P., has the same uses and in the same strength.

Subsulphate is the yellow sulphate or turpeth mineral, and is peculiar in that it possesses emetic properties that render it valuable in croup in doses of 1/4 gr., repeated at intervals. The adult emetic dose is 2 to 5 gr. The Ix or 2X is valued in cases of dyspnea with rapid respiration and burning in the chest and in hydrothorax. Mercurius vivus is the homeopathic preparation of metallic mercury. The globules are in a very much finer state of subdivision than they are in blue mass or mercury with chalk, the excipient being milk sugar. Mercurius vivus is really a very fine pharmaceutic, and, in the Ix trituration, is very useful in syphilis and to take the place of blue mass. Ten grains is a full dose for an adult, and represents I gr. of minutely comminuted mercury. The higher triturations are mildly alterative, but I believe the homeopaths vastly overdo the administration of mercury in a host of chronic conditions. Mercurial inunctions are so valuable as to justify a separate paragraph. In my hands, the U. S. P. Unguentum hydrargyri has served admirably, but it is important that it be well made and not rancid. Squibb makes it up in suitable form, departing slightly from U. S. P. directions. The oleates of mercury are not sufficiently stable to be relied upon.

In employing homeopathic preparations of insoluble mercury, such as calomel or metallic mercury, it must be remembered that they triturate such substances for many hours by means of electrically operated apparatus, and, grain for grain, the actual drug incorporated is much more active than in similar U. S. P. products. The eclectics make very little use of mercury in any form. It is a drug whose action does not differ in large or small dose except in degree. The recent tendency in the treatment of syphilis has been to use it to saturation, and then maintain the effect with small doses. It is proper to say, however, that mercury is a tonic alterative in small doses, and its use for short periods in sore throat and other acute conditions is to be highly commended. It is surprising how quickly many intractable cases of disease yield to small doses of the bichloride or biniodide and old, obscure chronic cases to mercurial inunctions. "When in doubt give mercury" need not apply exclusively to syphilis.