Abstract
Some arguments are advanced to show that the curve representing the apparent constants of the rate of hydrolysis of monoalkyl phosphoric acids as function of the pH offers not only the well known minimum at about pH 0 and maximum at pH 4·5, but a second minimum at high pH. The interpretation of this curve requires the intervention of at least three mechanisms of hydrolysis, such as acidolysis, halolysis and basolysis, as postulated earlier by the authors, apart from hydrolysis sensu stricto.