Bless You

Whenever someone sneezes, you say " Bless you " or hear someone else say these words.

Why? Why are these words spoken ?
When? When did this saying originate ?
How ? How did this saying originate ?
Where? Where did this saying originate ?

1. You use the words bless you because the Romans would say " Jupiter preserve you " or " Salve" which meant good health to you.

2. The practice of blessing someone when they sneeze started way back at least AD 77, however is far older than most specific explinations can account for.

3.