A series of studies, each suggested by those that preceded, were first concerned with the movement of water in parenchymatous cells of liver, kidney, submaxillary glands, and other glandular organs. Evidence was soon obtained showing that these cells were isotonic as determined by the osmotic pressure they maintained, not with physiological salt solution (0.15 M), as at that time popularly assumed, but with sodium chloride in approximately twice this concentration. Cells of the liver or of the kidney acted as osmometers and measured the osmotic pressure which they maintained. When various electrolytes were tested, it was found that their osmotic pressures varied with the valence of the basic ions of the salts that were used, being, for example; 1 for monovalent sodium salts, 2 for calcium salt, 3 for lanthanum salts. Solutions of the salts of electrolytes manifest properties so bound together that they are designated colligative. These properties include osmotic pressure, depression of the freezing point, vapor tension, and boiling point of solutions. It is well established that any one of them provides data from which the others can be deduced by appropriate calculation.' The changes which occurred in liver or in kidney were found to be in accord with tables which record changes in the freezing point of graded solutions of salts of electrolytes, on the one hand, or of boiling points on the other. Visible necrosis of the skin of laboratory animals was produced by injection into the dermis, and the molar strength of solutions of various electrolytes needed to