As language was at its beginning merely oral, all words of necessary
or common use were spoken before they were written; and while they
were unfixed by any visible signs, must have been spoken with great
diversity, as we now observe those who cannot read catch sounds
imperfectly, and utter them negligently. When this wild and barbarous
jargon was first reduced to an alphabet, every penman endeavoured
to express, as he could, the sounds which he was accustomed to
pronounce or to receive, and vitiated in writing such words as were
already vitiated in speech. The powers of the letters, when they
were applied to a new language, must have been vague and unsettled,
and therefore different hands would exhibit the same sound by
different combinations.

From this uncertain pronunciation arise in a great part the various
dialects of the same country, which will always be observed to
grow fewer, and less different, as books are multiplied; and from
this arbitrary representation of sounds by letters, proceeds that
diversity of spelling observable in the Saxon remains, and I suppose
in the first books of every nation, which perplexes or destroys
analogy, and produces anomalous formations, that, being once
incorporated, can never be afterward dismissed or reformed.

Of this kind are the derivatives length from long, strength from
strong, darling from dear, breadth from broad, from dry, drought,
and from high, height, which Milton, in zeal for analogy, writes
highth; Quid te exempta juvat spinis de pluribus una [Horace,
Epistles, II. ii. 212]; to change all would be too much, and to
change one is nothing.

This uncertainty is most frequent in the vowels, which are so