lO Davis's video: Legend of sneezing

In England during the seventeenth century, it was the custom for all those within earshot of someone who sneezed to remove their hats, bow, and shout, "God bless you!" In nineteenth-century England, someone originated a rhyme regarding the consequences of sneezing on certain days of the week: Sneeze on Monday, sneeze for danger. Sneeze on Tuesday, kiss a stranger. Sneeze on Wednesday, sneeze for a letter. Sneeze on Thursday, something better. Sneeze on Friday, sneeze for woe. Sneeze on Saturday, a journey to go. Sneeze on Sunday, your safety seek—for Satan will have you for the rest of the week! Many people believe that the custom of uttering the benediction "God bless you!" after a sneeze dates from the Great Plague that swept London in 1665. Other traditions are firm in stating that the practice began much earlier during the pontificate of Gregory the Great (c. 540–604; pope 590–604). During this period a deadly pestilence raged throughout Italy that proved fatal to those who sneezed. The pope issued prayers to be said against the plague, accompanied by signs of the cross. It was during this era, according to some scholars, that the custom of crying "God bless you!" to persons who sneezed became definitely established. http://www.unexplainedstuff.com