146

ELEMENTS OF MATERIA MEDICA.

sulphured seu hepaiicai). —These waters are impregnated with hydrosul-phuric acid (sulphuretted hydrogen); in consequence of which they havethe odour of rotten eggs, and cause black precipitates (metallic sulphurets)with solutions of the salts of lead, silver, copper, bismuth, &c. Thosesulphureous waters which retain, after ebullition, their power of causingthese precipitates, contain a sulphuret (hydrosulphuret) in solution,usually of calcium or sodium. All the British sulphureous waters arecold, but some of the continental ones are thermal. The most celebratedsulphureous waters of England are those of Harrow gate ; those of Scot-land are Moffatt and Rothsay; of the continent, Enghien , Bareges, Aix,and Aix-la-Chapelle .

The general operation of these waters is stimulant. They are sup-posed to possess a specific power over the cutaneous and uterine systems.They are employed both as external and internal agents ; in chronicskin diseases (as lepra, psoriasis, scabies, pityriasis, herpes, &c.)—in derangements of the uterine functions (amenorrhcea and chlorosis)—inold syphilitic cases—in chronic rheumatism and gout, and in other dis-eases in which sulphur or its compounds have been found serviceable,and which will be noticed hereafter. On account of their stimulanteffects, they are contra-indicated in all plethoric and inflammatory con-ditions of system.

Class 3. Acidulous or carbonated waters. {Aqua miner alesacidulce). —These waters owe their remarkable qualities to carbonic acidgas, which gives them an acidulous taste, a briskness, a sparkling property,and the power of reddening litmus slightly, but fugaciously, and ofprecipitating lime and baryta waters. When they have been exposed tothe air for a short time, this gas escapes from them, and the waters losetheir characteristic properties.

Most mineral and common waters contain a greater or less quantity offree carbonic acid. Ordinary spring and well waters do not usually con-tain more than three or four cubic inches of carbonic acid gas in 100cubic inches of water. Dr. Henry found, in one experiment, 3‘38 inches(Thomson’s System Chem., vol. iii. p. 193, 6th edit.). But the waterscalled acidulous or carbonated contain a much larger quantity. Thosewhich have from 30 or 60 cubic inches of gas are considered rich ;but the richest have from 100 to 200 or more cubic inches (Gairdner,op. cit. p. 30). Alibert ( Nouveaux Elemens de Thcrapeutique , tom. 3 me .p. 517, 5 me . ed.) states, that the waters of Saint Nectaire contain 400cubic inches in 100 of the water. This is the richest of all the aciduloussprings.

Some of the waters of this class contain carbonate or bicarbonate ofsoda: these are termed acidulo-alkaline. Frequently they contain car-bonate of the protoxide of iron also.

The only acidulous or carbonated spring in Great Britain is that ofIlkeston, near Nottingham , and which has been described by Mr. A. F. A.Greeves ( Account of the Medicinal Water of Ilkeston, 1833), and by Dr.T. Thomson {Cyclopaedia of Practical Medicine, art. Waters, Mineral ).

Those acidulous waters which owe their medicinal activity principallyto the carbonic acid which they contain, act chiefly on the digestive andnervous systems, but their effects are transient. They stimulate thestomach and relieve nausea. Sometimes they occasion a sensation offulness in the head, or even produce slight temporary intoxication. They