Prompted by visionary speculation and the hope that a theory might be reduced to facts, Furstenberg, Lashmet and Lathrop1in 1934 undertook water balance studies on patients with Ménière's disease. The speculation suggested the possibility of cerebral hydration or water-logging as the responsible etiologic factor in Ménière's disease, and the theory furnished the concept that the removal of body fluids, dehydration, might eliminate the offending influence and restore the patient to normal equilibrium. The theory proved to be a tenuous one, but its investigation led to an interesting discovery. It was observed, for example, that the quantity of water in the patient's tissues at any given time bore no relation to Ménière's disease but that sodium used in hydrating the patient appeared to initiate the characteristic vertiginous attacks of this disorder. The conclusion reached from these studies was that the tissues responsible for Ménière's disease were sensitized to or had