But a caution is necessary here. We must not regard as certain in every case, or indeed in most cases, that the first rise of a word will have exactly consented in time with its first appearance within the range of our vision. Such identity will sometimes exist, and we may watch i the actual birth of some word, and may affirm with confidence that at such a time and on such an occasion it first saw the light--in this book, or from the lips of that man.