guage, and inseparable from its use. This will be made plain to us by a brief inquiry.
The most rapid and noticeable mode of change in our language is that which is all the time varying the extent and meaning of its vocabulary. English speech exists in order that we may communicate with one another respecting those things which we know. As the stock of words at the command of each individual is an approximate measure of the sum of his knowledge, so the stock of words composing a language corresponds to what is known in the community; the objects it is familiar with, the distinctions it has drawn, all its cognitions and reasonings, in the world of matter and of mind, must have their appropriate expression. That speech should signify more than is in the minds of its speakers is obviously impossible; but neither must it fall short of indicating what they think. Now the sum of knowledge in every community varies not a little from generation to generation. Every trade and handicraft, every art, every science, is constantly changing its materials, its processes, and its products; and its technical dialect is modified accordingly, while so much of the results of this change as affects or interests the general public finds its way into the familiar speech of everybody. As our material condition varies, as our ways of life, our institutions, private and public, become other than they have been, all is necessarily reflected in our language. In these days of railroads, steamboats, and telegraphs, of sun-pictures, of chemistry and geology, of improved wearing stuffs, furniture, styles of building, articles of food and luxury of every description, how many words and phrases are in every one's mouth which would be utterly unintelligible to the most learned man of a century ago, were he to rise from his grave and walk our streets! It is, of course, in its stores of expression for these more material objects and relations, and for the details of technical knowledge, that language changes most notably, because it is with reference to these that the necessity for change especially arises. The central and most indispensable substance of every language is made up of designations for things, properties, acts, the
