By the methods of statistical thermodynamics, it has been proved that a conduction electron cannot be trapped above 45 K in an AgBr microcrystal by a shallow positive potential well with a depth of about 0.05 eV. A trap with a depth of 0.2 eV cannot be effective above 155 K. The direct electron trapping process of the Hamilton nucleation and growth theory, in which an electron is trapped at room temperature by the shallow positive potential well of a silver ion on a surface kink site, without the participation of an interstitial silver ion in the actual trapping process at the trapping site, violates the second law of thermodynamics. This process would result in a decrease in the entropy and an increase in the Helmholtz free energy of the system.