This section is from the book "A Treatise On Therapeutics, And Pharmacology Or Materia Medica Vol2", by George B. Wood. Also available from Amazon: Part 1 and Part 2.
The indications which water is capable of fulfilling, either topically or generally, externally or internally used, are to relax and soften the skin when dry and constricted; to diminish arterial excitement, whether general or local; to dilute the blood and other liquids within the body, and thus render them less irritating; to allay thirst, and abate abnormal heat by obviating its causes; and to calm nervous irritation, as shown in the relaxation of spasm, the relief of pain, the soothing of general uneasiness and restlessness, and the promotion of sleep by the removal of the causes of wakefulness.
The remedial uses of water are very numerous; and, within the limits allowed by the plan of this work, it would be impossible to specify each application, with all the rules requisite for its proper government. I must content myself with considering the subject rather in reference to classes than individual diseases.