They were called blue BLOODs, as they were (relatively) clean enough to see the veins at the wrists, which appear blue. The working folk apparently were not...
i will take into consideration that leaving a silver coin in water will have little if any change but i ask you to explain why the "blue skins" eating off of SILVERware, real silver ware survived plagues? the blue skins nicknamed due to there amount of silver intake causeing the graying of the skin hence blue skins had no battery or any mechanical ways to produce CS or did they?

