The firmly rooted popular belief in the superior excellence of ground water, and especially of spring water, is not difficult to understand. The usual clearness and brilliancy of such waters, together with their coolness, render them highly attractive to the eye and pleasing to the taste. In times of typhoid epidemics "pure spring water" is a shibboleth of undoubted commercial value. A strong and wholly natural preference for ground water as a source of town supply has been evinced on many occasions. The citizens of Ithaca, after becoming fully aware of the origin of the late typhoid epidemic, could not express too deeply their abhorrence of surface water. In France for many years les eaux des sources have held the highest position in the estimation of most municipal authorities, and in that country spring waters have been widely accepted as the most desirable source of municipal supply.
The last decade,