Boiler Deposits

These are formed from substances di olved or suspended in the water used. They are diminished by frequent blowing off. The most common ingredients are sulphates and carbonates of calcium and magnesium. The former can be removed from the feed-water by precipitation with carbonate of sodium and the latter by heating with the exhaust steam, which also causes precipitation. The following mixture has been used, a small quantity being introduced into the boiler every day, the above-named impurities being thus kept in solution or in suspension, and blown out the waste-pipe. The mixture is ground logwood 8, sal ammoniac 1, chloride of barium 1.