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Show The Color of Water. It was long ago discovered that the natural color of pure water is blue, and not white, as most of us usually supposed. sup-posed. Opinions have not agreed on the cause of the green and yellow tints; thes, it has been discovered . by W. Spring, are due to extraneous substances. sub-stances. Dissolved calcium salts, though apparently giving a green tint, due to a fine invisible suspension, have no effect ef-fect on the color of the water when adequate ad-equate precautions are taken. . The brown or yellow color due to iron salts is not seen when calcium is present. The green tint is often due to a condition condi-tion of equilibrium between the color effect of the iron salts and the precipitating pre-cipitating action of the calcium salts. Scientific American. |