Solute adsorption to dislocations and cracks is considered in both the Boltzmann and Fermi-
Dirac models. Explicit sums are developed for the integral amount of solute adsorbed in the
defect fields. Examples of the use of the method are presented for the case of hydrogen in
iron and compared with earlier results. The similarity of the condensed atmosphere of
hydrogen to hydride precipitation is noted and its relevancy to hydrogen embrittlement
models is discussed.