The Merz Collection is the mathematical library of John Theodore Merz (1840-1922), an electrical engineer. Merz also had an interest in philosophy, and the collection also includes books amassed by him during the writing of his work The History of European Thought in the Nineteenth Century. These 4000 volumes are strongest in Mathematics and the History of European Thought, but also include notable works on science, European history and German Literature.A particular highlight is An investigation of the laws of thought: on which are founded the mathematical theories of logic and probabilities (1854) by George Boole, the English mathematician and philosopher, and inventor of Boolean logic, the basis of modern digital computer logic.The collection is also of interest for its book-bindings: mostly leather or half-leather bindings by Zaehnsdorf of London.