"the bell of the nightsoil men"

‘Nightsoil’ was the name given to human excrement which was collected at night. Before the sewage system in London was built, this was the method of waste disposal – cesspits and privies were filled during the day, and the nightsoil men would arrive at a set time of the evening to collect the waste (shouting or ringing a bell as a signal), before disposing of it in common cesspits. In rural areas people were expected to deal with waste themselves, but nightsoil men were prevalent in cities, particularly in slum areas.