A series of lead/tin alloys have been examined in order to determine how alloy composition affects some important electrochemical characteristics. The behaviour is complex. Tin modifies the well-defined double layer structure of lead in a non-linear manner. A progression towards the double layer structure of tin is not observed, rather the interphase structure of the alloys appear always to be complicated by adsorption. Tin increases the reactivity of alloyed lead under certain conditions and transpassive dissolution of the alloy occurs in regions where pure lead itself would be expected not to dissolve. Exchange currents also behave in a rather anomalous manner. For the present the experiments can only be regarded as preliminary, however definite trends are indicated which themselves highlight further areas of worthwhile study.