and nicety of usage, so as to become fairly good substitutes for modifying constants on the one hand, and inflectional change on the other. Nevertheless, although inflectional change is wholly absent, modifying constants in the form of auxiliary words are not so. In Chinese, for example, there are what the native grammarians call “full words,” and “empty words.” The full words are the monosyllabic terms, which, when standing by themselves, present meanings of such vague generality as to include, for instance, _a ball_, _round_, _to make round_, _in a circle_: that is to say, the full words when standing alone do not belong to any one part of speech more than to another. Moreover, one such word may present many totally different meanings, such as _to be_, _truly_, _he_, _the letter_, _thus_. In order, therefore, to notify the particular meaning which a full word is intended to convey, the empty words are used as aids supplementary to the devices of intonation and syntax. It is probable that all these empty words were once themselves full words, the meanings of which gradually became obscured, until they acquired a purely arbitrary use for the purpose of defining the sense in which other words were to be understood—just as our word “like,” in its degenerated form of “ly,” is now employed to give adjectives the force of adverbs; although, of course, there is the difference that in isolating tongues the empty or defining words are not fused into the full ones, but themselves remain isolated. In the opinion of many philologists, however, “the use of accessory words, in order to impart the required precision to the principal terms, is the path that leads from monosyllabic to the agglutinative state.”[149] This _Agglutinative_, or, as it is sometimes called, _Agglomerative_ state belongs to languages of the second order. Here the words which serve the purpose of modifying constants, or marks of relationship, become fusible with the words which they serve to modify or define, so as to constitute single though polysyllabic compounds, as in the above example, “_un-cost-li-ness_.” I have already remarked that by long usage many of these modifying constants have had their own original meanings as independent words so completely obscured as to baffle the researches of philologists.