AbstractThe solubility behaviour is reported of long chain carboxylates of lead(II), zinc(II), mercury(II), copper(II), cadmium(II) and manganese(II) in various organic solvents. Two types of behaviour were observed. In dekalin and pentan‐3‐one, the temperature at which 1 % concentration gave a solution was found to be higher than that for higher concentrations. This behaviour is interpreted in terms of solubilisation of a mesophase of the soap. In all other cases, Krafft type behaviour was followed, where the solubility was low up to a certain critical temperature and then increases dramatically. Krafft points have been determined in these cases, and were found to be linear functions of the carbon chain length of the carboxylate. The solubility of lead(II) decanoate and tetradecanoate has been studied in a series of aliphatic alcohols, and Krafft points are found to be linearly related to the alcohol chain length. Values in the branched chain alcohol octan‐2‐ol are higher than in the corresponding straight chain alcohol. The results are interpreted in terms of hydrophobic interactions. Values of Krafft points of the hexadecanoates of various divalent metals in toluene showed a good linear correlation with second ionization potentials of the metals for all cases, except lead. Electronic spectra of copper(II) carboxylate solutions indicate the presence of aggregates, probably reversed micelles. Dilute solutions of copper(II) decanoate in hexan‐1‐ol decomposed on warming to give a black precipitate, whereas concentrated solutions were stable. This unusual concentration effect is interpreted in terms of reaction of soap monomers with