|Francesco Salviati, "Portrait of a Man,"|
Metropolitan Museum of Art
"Blowing the nose. We must not blow our nose too lowde, nor open the hand-chercher at all to shewe any nasty filthinesse, nor lay it to the cuppe where another meanes to drinke..."Thomas Gainsford (?), The Rich Cabinet (1616)
Among the smart ideas introduced by the renaissance was the recommendation to not smear your snot on anyone else's drinking glass. Best practices, folks!