Vocabulum; or The Rogue's Lexicon by George W. Matsell is a fascinating and informative exploration of the language used by criminals and the underworld in the mid-19th century. Matsell's book delves into the intricacies of slang, cant, and jargon specific to the criminal element of society, providing readers with a unique insight into a hidden world. The book is written in a straightforward and accessible style, making it easy for readers to engage with the material and grasp the nuances of the language being discussed. Vocabulum stands out as a valuable resource for scholars of linguistics, history, and criminology, shedding light on a little-known aspect of 19th-century society. The inclusion of colorful illustrations and examples of the language used by rogues adds to the appeal of the book, making it an entertaining and educational read. George W. Matsell, a prominent figure in law enforcement and crime prevention during his time, brings his expertise to bear in this comprehensive study of the language of criminals. His keen insights and firsthand knowledge lend authenticity and credibility to the work, making it a valuable resource for anyone interested in the history of crime and language. I highly recommend Vocabulum; or The Rogue's Lexicon to readers interested in exploring the hidden world of criminal language and gaining a deeper understanding of the subculture of rogues in the mid-19th century.