It is then distributed through pipes of concrete, into which no air can possibly enter, to cisterns equally, air-tight in every house.

The water in these is periodically examined by officers from the waterworks, who ascertain that it has contracted no impurity either in the course of its passage through hundreds of miles of piping or in the cisterns themselves.

The Martialists consider that to this careful purification of their water they owe in great measure their exemption from the epidemic diseases which were formerly not infrequent.

They maintain that all such diseases are caused by organic self-multiplying germs, and laugh to scorn the doctrine of spontaneous generation, either of disease, or of even such low organic life as can propagate it.

I suggested that the atmosphere itself must, if their theory were true, convey the microscopic seeds of disease even more freely and universally than the water.
"Doubtless," replied our guide, "it would scatter them more widely; but it does not enable them to penetrate and germinate in the body half so easily as when conveyed by water.