Summary The alkaline hydrolysis of quaternary amm0niu. m substituted acetonitrile to the betaine cannot be expressed as a simple second order reaction between positive and negative ions. In excess hydroxide ion the rate is proportional to the 1.3 power of the ammonium ion and to the 1.6 to 1.8 power of the hydroxide ion. When in equal concentrations the sum of the necessary exponents is about 2.4. These facts are ...