William Eassie, Cremation of the Dead: Its History and Bearings Upon Public Health
“ When the coffin is not laid in contact with the soil, but entombed in a vault or walled grave, the occupied space is covered by a stone cemented down, air-tight, upon a ledge in the wall, and the raising of which is for ever forbidden. The entombment may also be made by an air-tight surrounding of concrete. The best practice of vault burial is to place some charcoal or disinfectant along with the coffin, so that no foul gas shall escape should reopening be necessary. ”
