The great thing which Mr. Horne Tooke has done, and which he has left behind him to posterity, is his work on Grammar, oddly enough entitled THE DIVERSIONS OF PURLEY. Many people have taken it up as a description of a game—others supposing it to be a novel. It is, in truth, one of the few philosophical works on Grammar that were ever written. The essence of it (and, indeed, almost all that is really valuable in it) is contained in his _Letter to Dunning_, published about the year 1775. Mr. Tooke’s work is truly elementary. Dr. Lowth described Mr. Harris’s _Hermes_ as ‘the finest specimen of analysis since the days of Aristotle’—a work in which there is no analysis at all, for analysis consists in reducing things to their principles, and not in endless details and subdivisions. Mr. Harris multiplies distinctions, and confounds his readers. Mr. Tooke clears away the rubbish of school-boy technicalities, and strikes at the root of his subject. In accomplishing his arduous task, he was, perhaps, aided not more by the strength and resources of his mind than by its limits and defects. There is a web of old associations wound round language, that is a kind of veil over its natural features; and custom puts on the mask of ignorance. But this veil, this mask the author of _The Diversions of Purley_ threw aside and penetrated to the naked truth of things, by the literal, matter-of-fact, unimaginative nature of his understanding, and because he was not subject to prejudices or illusions of any kind. Words may be said to ‘bear a charmed life, that must not yield to one of woman born’—with womanish weaknesses and confused apprehensions. But this charm was broken in the case of Mr. Tooke, whose mind was the reverse of effeminate—hard, unbending, concrete, physical, half-savage—and who saw language stripped of the clothing of habit or sentiment, or the disguises of doting pedantry, naked in its cradle, and in its primitive state. Our author tells us that he found his discovery on Grammar among a number of papers on other subjects, which he had thrown aside and forgotten. Is this an idle boast? Or had he made other discoveries of equal importance, which he did not think it worth his while to communicate to the world, but chose to die the churl of knowledge? The whole of his reasoning turns upon showing that the Conjunction _That_ is the pronoun _That_, which is itself the participle of a verb, and in like manner that all the other mystical and hitherto unintelligible parts of speech are derived from the only two intelligible ones, the Verb and Noun. ‘I affirm _that_ gold is yellow,’ that is, ‘I affirm _that_ fact, or that proposition, viz. gold is yellow.’ The secret of the Conjunction on which so many fine heads had split, on which so many learned definitions were thrown away, as if it was its peculiar province and inborn virtue to announce oracles and formal propositions, and nothing else, like a Doctor of Laws, is here at once accounted for,