The form in which these thoughts on the doctrine of Purgatory are put forth in this volume is accidental, and I am well aware that it cannot claim to present to the reader a well arranged treatise on the great subject with which it deals. Two or three years ago it fell to my lot, in conjunction with a dear friend and brother in religion, who is now, I trust, at rest with God, to preach during the Octave with which the Society of the Helpers of the Holy Souls is accustomed to celebrate the annual Commemoration of the Faithful Departed. It occurred to me that some of the miracles of our Lord might be usefully applied in illustration of the doctrine of Purgatory, and thus the substance of some few of the chapters of this book was put together. At the beginning of the present year I began a series of papers on the same subject in the Messenger of the Sacred Heart - a religious magazine the existence of which we owe to the zeal and exertions of the widely loved and valued priest of whom I have already spoken.