I actually wondered how such an article got published as late as 1927. That would explain it. I can go find a better one tonight. More broadly, though, here's a Wikipedia page on the subject:

http://en.wikipedia.org/wiki/Scientific_racism

Glancing through the citations, #33 is "Tiedemann, Friedrich (1836). "On the Brain of the Negro, Compared with that of the European and the Orang-outang" (PDF). Phylosophical Transactions of the Royal Society of London 126."