ANTAGONISTS AND INCOMPATIBLES.--The salts of iron, magnesia, lime, and astringents, are chemically incompatible. The hydroxide of iron, or as it is also known, hydrate sesquioxide of iron, freshly made and in soft magma is the antidote to arsenic. To dogs give from half to one tablespoonful every five or ten minutes. From eight to twenty grains of the antidote are required to each grain of arsenic swallowed (when it can be determined). The stomach should first be emptied by the use of cathartics or stomach pump and then give the antidote, and follow with demulcents as oil, milk and mucilaginous drinks. Also administer diluents, as weak alkaline water. Iodide of potassium is valuable as a antidote of arsenical poisoning and should be administered to promote elimination of the poison. In the absence of the antidote, chalk, magnesia and lime water may be freely given. These agents act mechanically by developing the poison and preventing absorption. Dialysed iron is recommended as efficacious as an antidote in doses of five to fifteen minimums for dogs. ASPIDIUM--MALE FERN DERIVATION.--The rhizome of Aspidium Filix-mas. Collected late in the autumn, divested of its roots, leaves and dead portions, and carefully dried. Male fern should not be kept more than a year. HABITAT.--The male fern grows wild throughout most temperate regions, on the sides of roads and in open woods, especially where the soil is light. PROPERTIES.--Its root stock is perennial, about a foot long and two inches thick; is scaly, tufted, greenish-brown, and firmly fixed in the ground by numerous black root fibers. The dried root has a disagreeable odor, and a sweet, astringent, nauseous taste. Powdered male fern should be freshly prepared and have a bright green color. DOSE.--The powdered male fern is given to horses and cattle in doses of 4 to 6 ozs.; sheep and pigs, 1 to 4 ozs.; dogs and cats, ¹⁄₂ to 2 ozs. The powder is bulky, and less certain than the oleoresin of aspidium. PREPARATIONS OLEORESINA ASPIDII--OLEORESIN ASPIDIUM--OLEORESIN MALE FERN Made by percolation with ether, distillation and evaporation of the ether. DOSE.--Horses and cattle, 3 to 6 drs.; sheep and pigs, 1 to 2 drs.; dogs and cats, 15 ms. to 1 dr. ACTION AND USES.--Male fern is irritant, vermicide laxative, large doses of the drug cause hemorrhagic gastro-enteritis, tremors, weakness, stupor, coma, acute nephritis and cystitis. Oleoresin of male fern is one of the most effectual remedies for tapeworm, particularly those inhabiting dogs. BELLADONNAE FOLIA--BELLADONNA LEAVES