_Tests._—The specific character of these substances is their strongly marked alkalinity, ammonia possessing, over and above, that of volatility. Potash is known from soda by being precipitated of a creamy yellow by platinum perchloride, soda remaining unaffected by that reagent. II.—SIMPLE IRRITANTS. CHAPTER IX. SALTS OF THE ALKALIES AND ALKALINE EARTHS. POTASSIUM NITRATE or NITRATE OF POTASH (_Nitre_, _Saltpetre_, _Salprunelle_) is a more dangerous poison than is commonly supposed, provided the dose be large. It has ordinarily been given in mistake for other salts as a purgative, and in one instance, caused death in about two hours, in another such instance, referred to by Orfila, an ounce proved fatal in three hours. It produces symptoms of irritation in the alimentary canal, vomiting, and diarrhœa. There is generally also severe pain at the pit of the stomach, trembling of the limbs, scanty urine, and collapse. Marks of violent inflammation are found after death in the stomach and along the intestinal canal. POTASSIUM SULPHATE or SULPHATE OF POTASH (_Sal Polychrest_, _Sal de Duobus_, &c.) has proved fatal when taken in a large dose. It has caused death in two or three cases when purposely administered to procure abortion. Taylor quotes an instance of a lady, a week after delivery, being directed by her medical attendant to take ten drachms of this salt, in divided doses as a laxative. After the first dose she was seized with severe pain in the stomach, with vomiting, &c., the symptoms increasing after each dose, and proving fatal in two hours. At the post-mortem examination the mucous membrane of the stomach and intestines was seen to be soft and pale, and the stomach contained a quantity of reddish-colored liquid. This, on being analyzed, was found to contain no other irritant but this salt. BITARTRATE OF POTASS or HYDROGEN POTASSIUM TARTRATE (_Cream of Tartar_, _Argol_.)—This salt has caused death in one case at least, in which about an ounce and a half was taken. The symptoms were those of an irritant poison, with paralysis of the lower extremities. Death occurred within forty-eight hours. SULPHURET OF POTASSIUM (_Liver of Sulphur_) has also caused death as an irritant poison. _Treatment._—As no antidotes are known to these salts the treatment must consist in producing vomiting as speedily as possible by means of emetics; or the stomach-pump may be used. Demulcent drinks should be freely given subsequently, with soothing applications to the bowels. Ice may be given in any quantity. LIME acts as an irritant poison, though a feeble one, when taken into the stomach or applied to a vital part. One fatal instance is reported, where a boy swallowed some lime in an apple-pie. He died in nine days, after suffering from a burning pain in the abdomen, great thirst, and obstinate constipation. Unslaked or imperfectly slaked lime may also prove fatal by being inhaled, and so giving rise to inflammation of the glottis.