Dedicated to "Sophronia" (Robert Boyle's "dearest sister," Lady Ranelagh), this is a compendium of moral essays that Boyle had previously written in Stalbridge and Oxford. The work draws parallels between natural phenomena (e.g., the slaking of quicklime) and his spiritual philosophy. His observations often developed into meditations with a moral message. The work displays Boyle's wide-ranging interests, with topics including angling, glowworms, meteorology, horses, apples, syrups, the singing of larks, candles and lanterns, and astronomy.

The title page of this work and dedication are digitized here.