The present Dictionary of Mr. Richardson is, distinctly, a _new work_, upon a system never attempted before—upon the principles of Horne Tooke, the greatest of philosophical grammarians, and whose developments of an entirely novel theory of language have excited the most profound interest and respect in the minds of all who think. In the _Diversions of Purley_, it is positively demonstrated that a word has one meaning and one only, and that from this one meaning all the _usages_ of the word must spring. “To discover this meaning,” says Mr. Richardson, “etymological research was indispensable, and I have stated the results of such research with conciseness, it is true, yet with a fullness that will enable the more learned reader to form a judgment for himself, and the path of deeper investigation is disclosed to the pursuit of the curious inquirer.” In tracing the _usages_ of words, Mr. R. has availed himself of the materials collected by Johnson and his editors, “the various supplements and provincial vocabularies, the notes of editors and commentators upon our older poets, and of abundant treasures amassed for his own peculiar use.” The quotations are arranged chronologically, and embrace extracts from the earliest to the latest writers of English. The etymology is placed distinctly by itself for the convenience of hasty reference. As an example of the arrangement of the work, we will give the word _Calefy_. CA´LEFY | Lat. _Calefieri_, to be or become hot. CALEFA´CTION | Calere, Vossius deduces from the Doric CALI´DITY | Καλεος for Κηλεος, burning. CA´LIDUCT | To heat, to be, become, or cause to be hot. But crystal will _calefie_ into electricity; that is, a power to attract straws or light bodies and convert the needle freely placed.—_Brown. Vulgar Errours_, b. ii. c. 1. As [if] the remembrance of _calefaction_ can warm a man in a cold frosty night.—_More. Philos. Poems_, c. 2, _Pref._ But ice will dissolve in any way of heat; for it will dissolve with fire; it will colliquate in water, or warm oyl; nor doth it onely submit unto an actual heat, but not endure the potential _calidity_ of many waters.—_Brown. Vulgar Errours_. b. ii. c. 1. Since the subterranean _caliducts_ have been introduced. _Evelyn_. In his prospectus, Mr. Richardson has had occasion to speak in no measured terms of the Dictionary of Dr. Webster. We here repeat his observations because we think them entirely just.