Collection consists of correspondence written by Albert F. McGuinn, SJ primarily to Donald I. MacLean, SJ. Many of the letters were written when MacLean was a Jesuit scholastic. They concern matters related to chemistry and MacLean's vocation. The collection also includes a letter from McGuinn to MacLean's parents, two letters from McGuinn to Anthony J. Eiardi, SJ, a Boston College mathematics professor, and letters written following McGuinn's death concerning his relationship with Donald I. MacLean, SJ.