In a recent issue we announced the death of Professor George Boole, of Queen's College, Cork, a man of varied and profound acquirements, and of singular originality of mind. The work on which his fame will mainly rest is undoubtedly his "Investigation of the Laws of Thought, on which are founded the Mathematical Theories of Logic and Probabilities". We have long purposed to call attention to this remarkable production, though various circumstances have hitherto prevented us from doing so. The present seems a suitable occasion for testifying our admiration of the genius of the deceased philosopher, and, at the same time, endeavouring to give a brief account, inadequate as it must necessarily be, of what may be termed his Mathematico-logical speculations.