IT has already been shown1,2 that the dissociation constants Ka of formic and acetic acid are lower in formamide than in water although the dielectric constant of the former is much larger than that of the latter. The variation of Ka with temperature may, in both solvents, be described by a reduced curve proposed by Earned and Embree3: Here θ is the temperature where the dissociation constant has its maximum value Kθa and p is a constant for all carboxylic acids. However, in formamide p is about ten times larger than in water, expressing the fact that Ka changes faster with temperature in the former solvent.