1 mars 1000 - 1,000 AD China
Description:
Blew dried small pox scab powder of a weaker case up nose. Observed that if the person the scab came from survived the chance of the person they were giving the scab to was higher.Ajouté au bande de temps:
Date:
1 mars 1000
Maintenaint
~ Il y a 1024 ans
