METHODS The follo\-ing procedures were perfornmed: whole blood (Gb) anid plasma (Gp) specific gravities (2)); micro-hematocrit (Vc)(3); carbon dioxide content of plasma and (feces (4); sodium and potassium conicentrations of plasma, feces and urine bl internal standard flame pho-tometry; and a Fiske osmometer was used for osmo-larity determinations of plasma anid feces. All determinations were done in duplicate and the results averaged. The intravenous treatment schedule recommended by Johnsoin, WJeaver and Phillips (5) was followed using the copper sulfatemethod (2) for determination of Gp. Normal saline wvas infused rapidly in amounts calculated to correct the initial dehydration (200 ml. for each 0.001 increase in (p above 1.025). Following this, fluids wvere given to match measured urine and fecal losses or to correct elevations in Gp. A detailed evaluation anid discussion of this method based on the results of the present study will be presented elsewhere (6). Sodium bicarbonate was infused as a 2 or 4 per cent solutioin to treat acidosis and potassium was given in small amounits. In order to obtaini more iniformlationi on electrolyte exchanige. ideal treatmelnt sclhedcules\were nlot adhered to in all patients. Severalof the later patients were given nonelectrolyte (5 per cent dextrosein dis-tilled water) anid hypertonic (2 per cent saline) or Roger's solution (1.35 per cent saline) infusions in ani attempt to alter fecal electrolyte concentrations. The epidemic subsided before additional planned experiments could be completed.