A data set from Oehlert (2000) \emph{A First Course in Design and Analysis of Experiments}, New York: W. H. Freeman. Data originally from Hunt, J.~R. and B.~J. Larson (1990). ``Meal protein and zinc levels interact to influence zinc retention by the rat.'' {\em Nutrition Research\/}~{\em 10}, 697--705. Table of treatment means taken from figure 1. Columns are meal protein level, meal zinc level, diet zinc level, and response (percent zinc retention).