If 0.2 c.c. of an 0.8 per cent, aqueous solution of sodium chlorid is injected intracutaneously in a normal child, a circumscribed snow-white elevation, in which the pores are accentuated, is immediately produced at the point of injection. Although the extreme whiteness disappears in from one half to one minute, the elevation persists for a considerable time. In some instances there is an area of erythema about the raised area which usually disappears in a few minutes. It occurred to us that a study of the time required for the disappearance of the elevation, which we assume to be largely the injected salt solution, might give an indication of the tissue's avidity for water. We tested this out in a number of normal and diseased persons, most experiments being carried out under the observation of two. TECHNIC Two-tenths cubic centimeter of an 0.8 per cent aqueous solution of sodium chlorid