ACTIONS.--Calomel is a cathartic, laxative, alterative, diuretic and vermifuge. Small doses are laxatives when repeated, large doses are cathartics, full doses irritate the stomach and produce emesis in man and dog. By stimulating the urea functions of the liver diuresis are produced, its action on the liver does not directly increase the secretion of bile, but removes it from the duodenum which reflexly increases its secretion. Repeated doses produce mercurial poisoning. It is an alterative when combined with opium, laxative in small repeated doses and cathartic in larger doses. USES.--Calomel is useful in gastric and intestinal catarrh, bilious diarrhoea, influenza lymphangitis and liver disorders which show themselves by a yellowness of the visible mucous membranes. It is a useful adjuvant cathartic conjoined with aloes or other cathartics. As a laxative or cathartic for horses give aloes and calomel; cattle and sheep, magnesium and sodium sulphate; for pigs, dogs and cats with jalap. Pure calomel is a specific for thrush. It is also useful in the treatment of moist skin and raw sores, mixed in equal parts with bismuth subnitrate it quickly dries the flesh and prevents itching. DOSES.--As a laxative vermifuge and alterative horses and cattle take 20 to 40 grs.; sheep and pigs, 5 to 20 grs.; dogs and cats, ¹⁄₁₆ to 1 gr., given two or three times a day with equal weight of opium which prevents griping and a too rapid removal by the bowels. As a cathartic, calomel is best conjoined with other medicines regulated by that of the medicine with which it is conjoined. A full cathartic for horses should consist of calomel 1 to 1¹⁄₂ drs. with aloes 4 to 6 drs.; cattle, 1¹⁄₂ to 2 drs. with magnesium sulphate or sodium sulphate 1 to 1¹⁄₂ pounds; sheep, 5 to 30 grs. with magnesium sulphate 4 to 8 ounces; pigs, 5 to 30 grs. with sodium bicarbonate ¹⁄₂ to 1 ounce; dogs and cats ¹⁄₈ to 10 grs. with jalap 10 to 30 grains. HYDRARGYRI IODIDUM RUBRUM--RED IODIDE OF MERCURY--BINIODIDE OF MERCURY ORIGIN.--Red iodide of mercury is obtained by dissolving in water separately bichloride of mercury and potassium iodide, and pour both solutions slowly and stirring actively. PROPERTIES.--A scarlet-red, amorphous powder; odorless and tasteless; permanent in air, insoluble in water; soluble in one hundred and twenty-five parts of alcohol. ACTIONS.--Red iodide of mercury is a stimulant irritant, resolvent pustulant antiseptic and parasiticide.