There is no fact better known to the sanitarian, than that one of the chief sources of danger to life and health, is the contamination of drinking water. I f a malignant form of fever makes its appearance in a family, which cannot b$ explained by the history of actual exposure to contagium, the water supply always comes in for an early and liberal share of attention. The instances are sufficiently numerous in which the investigator is enabled to trace the malady to this source, to warrant every reasonable precaution in procuring a pure water supply.