1. 1. The osmotic coefficients of aqueous solutions of 10 different anionic and cationic colloidal electrolytes have been measured by freezing point depression, now bringing the total number of those investigated to 64. Conductivities were also measured for these and two other materials too insoluble at 0°C. for freezing point determinations. 2. 2. The relative lowering of conductivity with increasing concentration is less than that of osmotic coefficient. In the case of polycyclic structures, such as a bile salt or sodium abietate, the latter measurement shows the presence of colloid with a critical concentration, whereas this does not appear in the conductivity curve. 3. 3. Addition of dimethyl phthalate, a substance insoluble in oil and water but solubilized by soap solutions, appears slightly to decrease colloid formation as reflected in osmotic coefficient and equivalent conductivity. 4. 4. The colloidal behavior of the laurate of several complex organic bases has been compared with that of potassium laurate. 5. 5. An ordinary molecule, sucrose, lowers the freezing point of water to the same extent as it lowers the freezing point of a solution of the colloidal electrolyte, potassium laurate.