The Circulation of the Blood and the Distribution of Water.

The Circulation of the Blood and the Distribution of Water.

In a recent paper on “The water supply in cities," M. N. Saunders, of Waco. Tex., says: "By a happy coincidence someone has compared the distribution of drinking water and sanitation of cities to the circulation of the blood in animals. In fact, the arterial system represents the water supply; the arterial blood, which starts from the heart and is distributed throughout the entire system by channels and ramifications of decreasing size until they are converted into capillaries, in which the blood undergoes exosmotic and endosmotic changes, in order to fulfil the life-giving office which is required of it. and having now been transformed into venous, injurious and useless blood by organic refuse, nevertheless continues to circulate, at first through small conduits and afterwards through a smaller number of thicker conduits, until .it last it flows through larger blood vessels, which arc charged with the duty of bringing it in contact with the renovating organs, which purify and restore to it the beneficent qualities which it first possessed. This physiological action is represented by the drainage of the cities, by the lateral and main sewers, and. hence, the necessity of the continuous circulation of the water through the cities, which is all the more necessary in proportion to the extent of population to he supplied.

In a recent paper on “The water supply in cities," M. N. Saunders, of Waco. Tex., says: "By a happy coincidence someone has compared the distribution of drinking water and sanitation of cities to the circulation of the blood in animals. In fact, the arterial system represents the water supply; the arterial blood, which starts from the heart and is distributed throughout the entire system by channels and ramifications of decreasing size until they are converted into capillaries, in which the blood undergoes exosmotic and endosmotic changes, in order to fulfil the life-giving office which is required of it. and having now been transformed into venous, injurious and useless blood by organic refuse, nevertheless continues to circulate, at first through small conduits and afterwards through a smaller number of thicker conduits, until .it last it flows through larger blood vessels, which arc charged with the duty of bringing it in contact with the renovating organs, which purify and restore to it the beneficent qualities which it first possessed. This physiological action is represented by the drainage of the cities, by the lateral and main sewers, and. hence, the necessity of the continuous circulation of the water through the cities, which is all the more necessary in proportion to the extent of population to he supplied.