George W. Matsell's “Vocabulum; or The Rogue's Lexicon” serves as an intriguing exploration of the vernacular of 19th-century American criminals. This lexicon captures the colorful and often clandestine language employed by rogues, thieves, and outlaws, offering a linguistic snapshot of an era defined by societal challenges and countercultures. Matsell meticulously arranges the terms with humor and scholarly precision, providing a window into a subculture simultaneously fascinating and repelling, while also addressing broader themes of morality and legality in a rapidly changing society. Matsell, a figure steeped in the cultural dynamics of his time, worked as a police officer in New York City, lending him unique insights into the criminal mind and its lexicon. His experience on the streets informed his curiosity about criminality, enabling him to capture the nuance of language used by those operating outside the law. The intersection of his professional life and personal interests fuels this lexicon, positioning it as both a study of language and a reflection of societal attitudes toward crime. “Vocabulum” is not merely an etymological curiosity; it is an essential read for linguists, historians, and enthusiasts of American literature. This book will enrich your understanding of the complexities of language and culture, offering a rare glimpse into the underbelly of society while inviting readers to ponder the implications of words that reflect truth and deception.