As a college freshman, I recall reading an essay by Ralph Waldo Emerson where he discussed the theological reasons for his departure from the Unitarian ministry. Going from my 45-year recollection of this reading, Emerson held that there was no biblical basis for the eucharist; i.e., nowhere in the original Gospel accounts of the Last Supper did Jesus enjoin his disciples to “do this [as oft as you eat/drink] in memory of me”. By contrast, he did argue there was a basis in Jesus’ commands for the washing of feet. 

Can anyone direct me again to this essay? And can Dr Ehrman offer his point of view on whether then, Reverend, Emerson was correct in his citing?