If the Face be smeared with the white of an Egg, It will not be Sun-burnt. With us, women that have to do in the Sun, to defend their Faces from the heat of it, that they may not be black, they defend it with the white of an Egg beaten with a little Starch, and mingled; and when the Voyage is done, they wash off this covering with Barley-water.”
This recipe is interesting, because while you can occasionally find concoctions on how to heal sunburns, this is a rare preventative measure. While there is nothing harmful in it, I doubt it would work; you are much better-off using modern sunscreens. Remember, no matter how dark your skin is, the sun’s UV rays will still do damage.
Source: John Porta, Natural Magick: Of Beautifying Women, 1589, in Latin; English translation 1658.