David:
 
When I did my global confluence research, I kept an eye out for short, synthetic works that would be useful for undergraduates. One I would recommend is Rudi Matthee, "Exotic Substances: The Introduction and Global Spread of Tobacco, Coffee, Cocoa, Tea and Distilled Liquor, Sixteenth to Eighteenth Centuries," in Drugs and Narcotics in History, ed. Roy Porter and Mikulas Teich (Cambridge: Cambridge University Press, 1995), 24-51. Matthee manages to pack quite a bit of information in a short essay, and it's a good "starter" for undergraduate research projects. If they can't find something in there that interests them, they've signed up for the wrong class.
 
David Courtwright