Books of hours were among the most common devotional texts of the Middle Ages. Produced throughout western Europe until the early 16th century, books of hours were important status items, often elaborately illuminated, that might be tailored to the specific tastes of well-heeled clients to reflect interests in particular saints or to incorporate other elements of their personal lives and religious, political, or social commitments. Although the illuminated pages have been removed from this book of hours, the gift of Timothy Matlack in 1811, it remains an elegant and ornate manuscript, with initials and line fillers in prominent gilt, red, and blue. Only one page remains from the calendar (the last), however many of the major elements of the book can be identified, including the prayers to the Virgin, the Stabat Mater Dolorosa and stations of the cross, the penitential psalms, litanies, and prayers, and the office of the dead.

In October 1719, the Yearly Meeting of the Society of Friends for Philadelphia and the Jersies reached consensus on a "book of discipline" governing the "establishment and order of meetings." The regulations covered both the conduct of the Quarterly and Monthly Meetings and the personal comportment of individual members, refining the bureaucratic structure of the meetings and laying out the powers of Overseers and other officials. It touches upon marriage (mandating endogamy), burial, and attendance at meetings, and cautions Friends to plainness of speech and dress, drinking, smoking, backbiting, and gaming. This version of the Book of Discipline is a manuscript copy made for the American Philosophical Society in 1820 "from and antient Copy in the possession of Timothy Matlack, Esqr."

This collection contains minutes of the Society, 1781-1975; minutes of the directors of the Corporation, 1929-1947; membership book (with signatures of early members), 1785; and names of later members. There are also deeds to the meeting house and burying ground; treasurers' accounts; reports of officers and committees; bills and receipts for constructing, maintaining, and repairing the meeting house; cancelled checks; and letters to the Society and its officers, especially Samuel Wetherill, 1883-1884.