Appendix.

907

d.

but any earthy nitrates and muriates must first be decomposed by sulphuricacid, and the sulphates separated by alcohol and nitrate of barytes. To ascer-tain whether the precipitate be muriate of soda or of potass, evaporate to dry-ness, then dissolve the acetate in alcohol, and again evaporate to dryness. Ifit be acetate of potass the salt will deliquesce, but if acetate of soda, it willeffloresce. To estimate the quantity of these salts, if they be unaccompaniedby other salts, it is only necessary to dry and weigh the precipitate by nitrate ofsilver; setting down for every 100 grains of muriate of silver thus throwndown, 52 of muriate of potass ; and 41 of muriate of soda. If alkaline car-bonates be present, they must be first saturated with sulphuric acid, and sul-phate of silver used to precipitate the muriatic acid.

2. Muriate of Barytes is detected by sulphuric acid. It is rarely found.

3. Muriate of Lime. To detect this salt the water must be first freed fromthe sulphates, then filtered, evaporated to dryness, the dry mass treated withalcohol, and the residue, after evaporating the alcohol, dissolved in water. Ifthis solution yields a precipitate with acetate of silver, the water containedmuriate of lime.

4. Muriate of magnesia is detected by separating the sulphates and proceedingas in the former case. If the aqueous solution of the dry mass treated withalcohol afford no precipitate with carbonate of lime ; and if sulphuric acidand evaporation, with the addition of a little alcohol, occasion no precipitate,the solution contains only muriate of magnesia.

d. 5. Muriate of alumina is detected by first saturating any alkali the water may

contain with nitric acid, and separating any sulphuric acid by nitrate ofbarytes; and then adding carbonate of lime, which produces a precipitate ifthis salt be present. This process also precipitates muriate of iron and ofmanganese, if any be present.

To estimate the quantities of these muriates, which may all be containedin the same water, the earths, after separating any sulphates that may bepresent, are to be precipitated by barytes-water, avid redissolved in muriaticacid. They are then to be separated by the rules already mentioned, andseparately weighed. For every 50 grains of lime, set down 100 of driedmuriate of lime; for 30 grains of magnesia, 100 of muriate of magnesia ;and for 21-8 grains of alumina, 100 of muriate of alumina. The barytesof the muriate of barytes, which the addition of the barytes-water hadformed in the mineral water by precipitating the earths, is now to be separ-ated by sulphuric acid, and its muriatic acid expelled by heat; after whichthe muriate of sod.i, which the water originally contained, is to be obtainedby evaporation.

e. Nitric acio never exists in an uncombined state in mineral waters ; andeven the nitrates are comparatively of rare occurrence.

The nitrates are incompatible with the salts, in the second column of thefollowing table.

C Alkaline carbonates.Nitrate of lime - - < Sulphates, except of lime.

{ Carbonates of magnesia and alumina.Nitrate of magnesia - Fixed alkaline sulphates.

/. 1. Nitrate of Potass may occur in mineral waters in conjunction with sul-phates and muriates ; the former of which must be decomposed by acetate ofbarytes, and the latter by acetate of silver, before the nitrates can be esti-mated. After these previous steps, filter the water, then evaporate it todryness, and treat the residue with alcohol; which dissolves the acetates, andleaves the nitre.

f 2. Nitrate of Lime is detected by first concentrating the water, and separatingthe sulphates by alcohol; then filtering and distilling off the alcohol, andseparating any muriatic acid by acetate of silver ; afterwards, filtering again,evaporating to dryness, and dissolving the residue in alcohol, which mustbe also distilled off, and the dried residue dissolved in water. If oxalic aciddetect lime in this solution, the mineral water contains nitrate of lime; thequantity of which may be estimated by precipitating with sulphuric acid, andcalculating the quantity of lime contained in the sulphate ; and for every 35grains of lime setting down 100 grains of dry nitrate of lime.

/■