296

ELEMENTS OF MATERIA MEDICA.

neutral salts of the alkalies, the continued use of it promotes alvineevacuations. Full doses frequently produce pain in the stomach. As adiaphoretic it is usually given in combination with emetic tartar.

Uses. —It follows from what has been now stated in regard to thephysiological effects of nitre, that this substance is indicated when wewish to diminish preternatural heat, and to reduce the force and frequencyof the pulse, as in febrile disorders, inflammatory affections (exceptperhaps those of the stomach, bowels, kidneys, and bladder), and haemor-rhages (especially haemoptysis.) In continued fever it is frequentlygiven in combination with emetic tartar, and sometimes also withcalomel. It is not often used as a diuretic, because its activity in thisrespect is not very great, but it is adapted for those cases which areaccompanied with arterial excitement. In sore throat it is mixed withwhite sugar and gradually swallowed. A mixture of nitre and powderedgum has long been a favourite remedy for diminishing the scalding ofgonorrhoea. Nitre is rarely employed as an external agent, except as ameans of producing cold. Thus five ounces of nitrate of potash, withfive ounces of muriate ammonia, dissolved in sixteen ounces of water,will reduce the temperature 40° F.; that is, from 50° to 10°, according toMr. Walker. Hence, therefore, we sometimes employ this mixture,placed in a bladder, as an external application (see p. 133.)

On the belief that fever, cholera, and other malignant diseases, wereproduced by a deranged state of the blood, and that this derangementdepended on, or consisted in, a diminution or entire loss of the salineparts of the blood, Dr. Stevens employed nitre, chloride of sodium, andother alkaline salts, in the treatment of these diseases (see his Observa-tions, pp. 296, 298, &c.) Nitre in large doses has been employed in thetreatment of scurvy, and with considerable success, according to thestatement of Mr. Cameron ( Medico-Chirur. Review, March 1830, p. 483.)

Administration. —It may be given in doses of from ten grains to halfa drachm in the form of powder mixed with sugar, or in solution. Ifadministered as a refrigerant, it should be dissolved in water and imme-diately swallowed, in order that the coldness of the solution may assistthe action of the salt. If employed as a diuretic, we ought to give liquidsplentifully, and keep the skin cool.

Antidote. —No chemical antidote is known for this salt. In case ofpoisoning, therefore, we should remove the poison from the stomach asspeedily as possible, and administer tepid emollient drinks. Opiatesperhaps may be advantageously administered. The inflammatory symp-toms are to be combated by the usual antiphlogistic measures.

Potas'see Chlo'ras. — Chlo'rate of Pot'ash .

History. —Chlorate of potash (also called oxymuriate or hyperoxymu-riate of potash) was first procured by Mr. Higgins, who seems to haveconfounded it with nitrate of potash. In 1786 it was distinguished byBerthollet .

Preparation. —It is prepared by passing chlorine gas slowly througha cold solution of carbonate of potash placed in a Woulfe’s bottle. Theliquid is allowed to stand for twenty-four hours in a cool place, and isthen found to have deposited crystals of chlorate of potash. These areto be drained, washed with cold water, dissolved in hot water, and re-crystallized.