Sodium Compounds.

Sodium, the analogue of potassium, is obtained either from sea weeds, or from common salt–the latter being first made to yield carbonate of soda, as will be described presently. The dry carbonate is mixed with a little hot water, and then with fine charcoal, and some charcoal in small lumps. The mixture is then dried, put into a retort of hammered iron, and heated to whiteness. The sodium distills over through a bent tube dipping into naphtha. It is a silver-white metal, soft, lighter than water, and with an avidity for oxygen similar to that shown by potassium; but it will not decompose cold water with enough energy to ignite the liberated hydrogen, though it will do so instantly with warm water. The majority of its compounds are derived from salt, (chloride of sodium.)

CHLORIDE OF SODIUM. NaCl. Common Salt. This is a leading component of the waters of the ocean, and of great numbers of springs. The better qualities are obtained by evaporating the water from the latter, which usually yields this substance almost free from impurities. Its characteristics are too well known to need repetition. Medically, it is stimulant and antiseptic, and forms a good gargle for putrid sore throat and diphtheria. Small quantities, dry, or in solution, at intervals of a few moments, generally arrests sudden attacks of spitting of blood and bleeding from the stomach, and the risings of worms. From one to two teaspoonsful may be dissolved in a half pint of lukewarm water, or a gill each of water and milk, and given as an enema; which proves an effective and moderately stimulating cathartic, and usually dislodges pin worms. Large doses, as one to two teaspoonsful, are slowly cathartic, and still larger quantities, dissolved in four times its own weight of water, act promptly as an emetic of a moderately stimulating character, and may be used thus in emergencies. Ten grains or more every half hour, in mucilage of slippery elm, make a favorite German prescription for the paroxysms of ague, and for enlarged spleen. Hungarian physicians are especially partial to this use of it; and numerous instances are met where the American people have used it in teaspoonful doses every hour for four hours, with decided success. Externally, its solution is tonic and moderately stimulant, and is much used as a wash for bruises, sprains, and rheumatism; or the dry salt, in thin bags, is well heated and laid over a painful part as a fomentation. A pound of salt in four gallons of water forms a saline solution of about the strength of sea-water; and this makes an excellent tonic bath for rickety and scrofulous children, and for all patients with constitutional debility.

CARBONATE OF SODA. NaO,CO2,+10HO. This was formerly obtained from the ashes of sea-weeds and plants near the seashore. At present, it is obtained from chloride of sodium. This is first heated in a reverberatory furnace, and mixed with an equal weight of sulphuric acid; by which the sulphate of soda is formed, and the chlorine driven off with water, in the form of hydrochloric acid. The sulphate of soda is then powdered, mixed with an equal weight of ground limestone and half its weight of fine charcoal, and the mixture highly heated in the furnace. Sulphate of lime and carbonate of soda result; and the soluble carbonate is washed out with water, and evaporated to dryness. This is one of the most curious, yet simplest and most useful, interchanges of chemistry. The carbonate obtained is in large and nearly white crystals, which in the air effloresce to a fine white powder. It is a strong and harsh alkali, used extensively in making soda soaps, but not used in medicine except to form the bicarbonate.

BICARBONATE OF SODA. NaO, 2(CO₂)+HO. This is prepared by making a cold solution of the above carbonate, and passing into it a stream of carbonic acid gas. Or crystals of carbonate may be placed in an atmosphere of carbonic acid gas. In either case, an extra equivalent of this gas is absorbed, and the bicarbonate results. It forms fine white crystals, soluble in twelve parts of cold water, of a mild alkaline taste, and not deliquescent in the air. It is used in the same manner as the bicarbonate of potassa; and though more commonly employed than the latter alkali, is not usually so acceptable.

BIBORATE OF SODA. NaO,2(BO₃,)+10HO. Borax. This salt occurs in the waters of certain lakes in Tibet and Persia; and is also obtained from the borate of lime, found native in southern Peru. When purified, it is a whitish salt, feebly alkaline in taste and reaction, soluble in twelve times its own weight of cold water, and much more soluble in boiling water. Borax water has the peculiar property of rendering shell-lac soluble in water, and also of rendering cream of tartar much more soluble. Though much used internally for gravel, nephritic difficulties, and lesions of the bowels, it is of doubtful efficacy; and the only use to which it can be put with even a semblance of advantage, is in combination with a strong infusion of sage as a wash in aphthous sores and sore throat, or rubbed up with honey and then mixed with water for the same purpose.

The nitrate of soda is similarly poisonous with the nitrate of potassa. The phosphate, muriate, and sulphate are used in medicine, but are not Physio-Medical agents.

The Physiomedical Dispensatory, 1869, was written by William Cook, M.D.
It was scanned by Paul Bergner at http://medherb.com