Mud-lark

a man or woman who, with clothes tucked above the knee, grovels through the mud on the banks of the Thames, when the tide is low, for silver or pewter spoons, old bottles, pieces of iron, coal, or any articles of the least value, deposited by the retiring tide, either from passing ships or the sewers. Occasionally applied to those men who cleanse the sewers, and who wear great boots and sou'-wester hats. Those who are employed in banks and counting-houses, in collecting and other out-door duties, have also this appellation.