"when dey was still drowndin nits in yo pappy’s hair wid coal oil"
An Hour's Search
Public DomainAn Hour's Search - Credit: Robert N. Dennis

Coal tar preparations have long been used as a cheap and effective means of killing and repelling head lice, a common parasite which often targets children.

Head louse
Creative Commons Attribution Share AlikeHead louse - Credit: Gilles San Martin