The doctor no longer practiced, had retired, the landlord believed, but he took a few private patients here the good fellow tapped his forehead knowingly "balmy ones! 
The doctor had come out of retirement and was still practicing, the landlord knew for certain.
mnli hypothesis: The doctor had come out of retirement and was still practicing, the landlord knew for certain. premise: The doctor no longer practiced, had retired, the landlord believed, but he took a few private patients here the good fellow tapped his forehead knowingly "balmy ones! 