64 MATERIA MEDICA. 



Incompatibles. — The alkalies and their carbonates, lime-water, 

 magnesia and its carbonate, sugar of lead, and tartrate of potassa. 



Uses. — A powerful astringent, both general and local. When 

 long used, it is apt to injure the organs of digestion. Large doses 

 occasion irritation of the stomach and bowels, and even inflamma- 

 tion. Given internally, in hemorrhages, particularly of the uterus 

 and lungs ; also in colica pictonum, where it is supposed to do good 

 by a chemical action ; formerly used in intermittents. Its nauseant 

 effect is best obviated by combining it with aromatics and opium. 

 Employed externally, as an astringent to the throat in inflamma- 

 tion ; also to arrest slight hemorrhages, as in epistaxis, and bleed- 

 ing from leech-bites; also as an injection in leucorrhcea and chronic 

 diarrhoea, and as a wash to indolent ulcers. 



Alum-curd is made by rubbing up alum with the white of an 

 egg ; used in conjunctivitis. 



Ahim-whey is made by boiling 3ij of alum in a pint of milk, and 

 straining; dose, f3ij. Dose of powdered alum, 5 to 15 grains, 

 several times a day ; in hemorrhages, the dose must be much 

 increased. 



CLASS v. — REFRIGERANTS. 



So named from the cooling effect upon the surface of the body 

 generally produced by their use. They are sometimes called 

 Arterial sedatives^ from the fact that they reduce arterial action. 

 They are indicated in cases of high vascular action, as the different 

 phlegmasia, and fevers unaccompanied with typhoid symptoms. 

 Although sedative in their general impression upon the system, some 

 of them, as antimony, produce a local stimulant effect upon some of 

 the organs. 



Vegetable Acids. 



Nearly all of them are refrigerant, and are well adapted, when 

 properly diluted, to inflammatory and febrile complaints. Too long 

 used, they enfeeble digestion, and produce symptoms of marasmus. 

 Those most employed in medicine are the Acetic, Citric, and 

 Tartaric. 



Acetic acid, in the form of vinegar, diluted with water, is a re- 

 freshing drink in febrile cases. It is also useful as a cooling appli- 

 cation to the surface. The strong acetic acid is an irritant poison. 



Citric acid exists in the lemon, lime, sour orange, tamarind, and 

 many other fruits. It is used either in the form of lemon juice, or 

 the solid crystalline form. The decomposition of lemon juice may 

 be partially prevented by exposing it to a freezing temperature, 

 whereby all the watery parts are separated, and the juice much con- 

 centrated ; or by making it into a syrup with sugar. 



The crystalline acid is prepared by saturating lemon juice with 

 chalk, and then decomposing the citrate of lime by sulphuric acid, 



