A data set from Oehlert (2000) \emph{A First Course in Design and
Analysis of Experiments}, New York: W. H. Freeman.

Data originally from Peggy Swearigen (personal communication).

Total free amino acids in cheddar cheese aged 56 days.
Treatments are factor/level combinations of strain r50 
not added (1) or added (2), and strain r21 not added (1)
or added (2).  Columns are levels of r50, levels of r21,
and amino acid response.