"The following recipes are taken from an old Roman cookbook: MARCUS GAVIUS APICIUS: DE RE COQUINARIA
The book I have is edited and translated from Latin by Robert Maier. My humble person only translated the German translations into English. I hope the recipes are still rather near to the originals...."
The Virtual Typewriter Museum
ETA: Apparently, you can buy this in book form, but I can only find a German version. Thanks for the head's up, lied_ohne_worte!
ETA2: Even more historical cooking:
as well as 'Feeding America: Historical American Cookbook Project.': http://digital.lib.msu.edu/projects/cookbooks/html/browse.html
Any further links added i'll just say - check out the comments in this post! :)