The mineral-water saits of commerce are compounds of the various constituents that are necessary for the imitation of a certain spring; they are mixtures of different salts. Reliable mineral waters may be produced from such salts, provided they are compounded reliably. But few can be so compounded in a single mixture to give a perfect imitation. All the salts should be added to the fountain in filtered solutions, to insure clearness of the beverages, and, what is the principal aim, to ease and promote their mutual decomposition, their re-arrangement in the fountain. From the different formulae given for the artificial combinations of the various mineral waters, and from what is stated about compounding of the different salts, their chemical properties and mutual actions, it is evident that but few formulas can be prepared in one package. Most "compounded salts "require two or three separate compounds, if the proper manipulations are followed; otherwise, when all the compounds would be united in a single one, the occurring precipitates would separate and be left on the filter. The separation of the different salts, as grouped in this chapter, is an absolute necessity. There are some ingredients which can never be kept in packages, and some others which should be kept single and out of contact with air, in bottles, and again others which should be expressly and separately prepared and precipitated for immediate use. All these facts prove, that any package, pretending to contain all the necessary ingredients in a single mixture, is suspicious. Acids are components, and, like certain solid constituents, must be kept in bottles. We have analyzed packages of "mineral-water salts "which contained mixtures, the solutions of which have not even a faint taste of that mineral water they pretend to produce. There is no use for the manufacturer of artificial mineral waters to buy compounded salts at all. Why not buy the different salts and make the separate compounds yourself, in advance or for immediate use? Follow directions given for imitating artificial mineral waters and true substitutes are the result. Make, if desired, "compound solutions" for stock - that is, dissolve the different salts of each group separately and keep ready for use, or keep the various salts of a group mixed ready, each group separately, in packages or bottles, as the ingredients permit, and the "compound mineral-water salt" is made in the bottler's laboratory; which has then the advantage of having the assurance that every component, and in proper proportion, is used. The chemical ingredients should be bought from a reliable wholesale supply house. The wholesale supply houses for the mineral-water trade have their laboratories generally under the direction of a scientific and practical chemist, and we trust their salt compounds are what they pretend to be.