[MCN-L] looking for images of slavery

[Adele HOARAU]

Hi all,
Sorry to jump in with another subject. 
I'm just having some troubles to find digitized images on-line about 
slavery (i.e. period 9th to abolitions), focusing, if possible, on indian 
ocean trade.
I was hoping that someone could share some information about high-quality 
(and free?) databases.
Many thanks
Ad?le Geoffroy
Reunion Island