What follows is a lightly edited version of the author's unpublished master's essay, submitted in partial fulfillment of the requirements of the degree of Master of Arts at the Pennsylvania State University, dated June 1994, written under the supervision of Professor George E. Andrews. It was retyped by the author on November 23, 2022. Obvious typographical errors in the original were corrected without comment; hopefully not too many new errors were introduced during the retyping. Explanatory text added by the author in 2022 is notated by \emph{Remark added in 2022}. After the initial posting on the arXiv on November 29, 2022, the author received email from Wadim Zudilin and George Andrews, pointing out some typos and making some interesting comments. These comments have been incorporated in this revised submission to the arXiv. The bibliography in this version is more extensive than that of the original.