But what, we may ask, are the causes which put a stop to the free growth and development of language? One of these causes is the invention of writing. Language itself is of course spoken language, speech, and as such is subject to no laws save those which belong to our organs of speaking and hearing. No sooner is the word spoken than it is gone, and lives only in the memory; and thus speech, though it may last for centuries, dies, as it were, and comes to life again every hour. It is with language as it is with those national songs and ballads which, among nations that have no writing, take the place of books and histories. The same poem or the same tale passes from mouth to mouth almost unchanged for hundreds of years, and yet at no moment is it visible and tangible, nor for the most part of the time audible even, but for these centuries lives on in men’s memories only. So Homer’s ballads must have passed for several hundred years from mouth to mouth; and, stranger still, stories which were first told somewhere by the banks of the Oxus or the Jaxartes by distant ancestors of ours, are told to this very day, little altered, by peasants in remote districts of England and Scotland. But to return to language. It is very clear that so long as language remains speech and speech only, it is subject to just so many variations as, in the course of a generation or two, men may have introduced into their habits of speaking. Why these variations arise it is perhaps not quite easy to understand; but every one knows that they do arise, that from age to age, from generation to generation, not only are new words being continually introduced, and others which once served well enough dropped out of use, but constant changes are going on in the pronunciation of words. As we have already said, if left to itself a language would not remain quite the same in two different districts. We know, for instance, that the language of common people does differ very much in different counties, so that what with varieties of pronunciation, and what with the use of really peculiar words, the inhabitants of one county are scarcely intelligible to the inhabitants of another.