The text comprises an exhaustive encyclopedic reference sequence covering various historical, geographical, mineralogical, and biographical subjects between the letters crocoite and cuba. Among the notable entries is crocoite, a lead chromate mineral discovered in the Urals, characterized by its bright hyacinth-red colour and association with gold deposits. Another entry discusses the botanical genus of the crocus, detailing its adaptation to dry climates through the formation of corms and its wide distribution across Europe and Asia.
The historical accounts include the life and reign of Croesus, the last king of Lydia, whose proverbial wealth and conquests brought him into conflict with Cyrus. The narrative covers his alliances, his defeat at Sardis, and the various classical legends associated with his downfall and subsequent relations with the Persian court. Other biographical notices document figures such as Sir Herbert Croft, noting his literary activities and controversies surrounding Chatterton's letters, and Sir James Croft, whose political career under Tudor monarchs involved frequent diplomatic missions and accusations of treason.
The volume further details musical history through the biography of William Croft, an English composer celebrated for his church music and organ appointments at Westminster Abbey and the Chapel Royal. Geographical and regional entries include a comprehensive description of Cromarty, its burgh history, its geographical features along the Cromarty Firth, and its incorporation into Ross-shire. Biographies of contemporaries such as John Wilson Croker, Richard Croker, James Croll, and George Croly provide extensive accounts of their respective careers in politics, literature, and science.
Biographical and anthropological subjects also feature prominently, notably the description of the Cromagnon race, derived from skeletal remains discovered in the Dordogne district of France and identified as an early neolithic type. The articles extend to political and biographical sketches of modern figures, including the first Earl of Cromer and his extensive administrative career in Egypt and the Sudan. Finally, the text covers musical instruments such as the cromorne, detailing its cylindrical bore, double reed, and historical usage in European consort music down to the eighteenth century.
