This is sometimes a component of mineral waters. It should be preserved in well-stoppered bottles, as it readily absorbs moisture from the air It is best kept in solution, or, still better, prepared for immediate use from calcium carbonate and nitric acid. Wherever possible it is produced by mutual decomposition of chloride of calcium and nitrate alkalies, within the fountain; but when its separate addition is necessary it is best prepared as follows:

Solution

Take 61 parts by weight of calcium carbonate, marble dust, etc., add 658.5 parts by weight of nitrjc acid diluted to 10 ° Baume of 1.069 specific gravity at 15° (J., stir well and add distilled water to make it 1000 parts. Filter and keep in stoppered bottle. This repra sents then a 10 per cent, solution of calcium nitrate, which is kept in stock ready for use. Proportion 10 to 1.

Another Solution

One part by weight of commercial calcium nitrate dissolved in nine parts of distilled water (10 per cent.). Filter. Proportion 10 to 1.