an ordered factor indicating the strip of muscle being measured.
conc
a numeric vector giving the concentration of CaCl2
length
a numeric vector giving the shortening ofthe heart muscle strip.
Details
Baumann and Waldvogel (1963) describe data on the shortening of heart
muscle strips dipped in a CaCl$_2$ solution. The muscle strips are
taken from the left auricle of a rat's heart.