Page:The Book of the Aquarium and Water Cabinet.djvu/71

Rh artificial preparation of sea-water. In the fictitious preparation the component salts were reduced to four, so that no less than three of the original ingredients were dispensed with. If the reader will note in what minute quantities the bromide of magnesium, the sulphate and carbonate of lime occur, and at the same time bear in mind that river and spring waters always contain a considerable proportion of the last-mentioned ingredient, it will be easily understood that the absence of those materials in the preparation does not materially affect its value. The preparation on Mr. Gosse’s plan is composed as follows:—

The recipe may be given in another form to avoid the perplexity of avoirdupoise and troy weights, thus:—

Management of Artificial Water.—When the salts are ready, it is best to mix them in an earthernearthen [sic] pan or jar, and allow them to settle and refine for a day or two. To dissolve them in the tank is decidedly a bad plan, though it is daily recommended by the dealers. Any one who will dissolve a portion in a clean bell glass, and allow it to stand for a week, using the clearest water, and adding nothing but the salts, will observe, at the end of that time, a minute gritty deposit, similar to iron rust, mixed