." A "sad tint," or colour, is one which is
dull. "Sad bread" in the north of England is "heavy" bread which has
not risen properly. Again, we describe as "sad" some people who are
not at all sorrowful. We say a person is a "sad" liar when we mean
that he is a hopeless liar.

The word _tide_, which we now apply to the regular rise and fall of
the sea, used to mean in Old English "time;" and it still keeps this
meaning in the words _Christmastide_, _Whitsuntide_, etc.

One common way in which words change is in going from a general to a
more special meaning. Thus in Old English the word _chest_ meant "box"
in general, but has come now to be used as the name of a special kind
of box only, and also as the name of a part of the body. The first
person who used the word in this sense must have thought of the
"chest" as a box containing the lungs and the heart.

_Glass_ is, of course, the name of the substance out of which we make
our windows and some of our drinking vessels, etc., and this was at
one time its only use; but we now use the name _glass_ for several
special articles--for example, a drinking-vessel, a telescope, a
barometer, a mirror (or "looking-glass"), and so on. _Copper_ is
another word the meaning of which has become specialized in this way
as time has gone on. From being merely the name of a metal it has come
to be used for a copper coin and for a large cauldron especially used
in laundry work. Another example of a rather different kind of this
"specialization" which changes the meaning of words is the word
_congregation_. _Congregation_ used to mean "any gathering together of
people in one place," and we still use the word _congregate_ in this
sense. Thus we might say "the people congregated in Trafalgar Square,"
but we should never think of speaking of a crowd listening to a
lecturer there as a "congregation." The word has now come to mean an
assembly for religious worship in a chapel or church.

Some words have changed their meaning in just the opposite way. From
having one special meaning they have come by degrees to have a much
more general sense. The word _bureau_, which came into English from
the French, meant at first merely a "desk" in both languages. It still
has this meaning in both languages, but a wider meaning as well. It
can now be used to describe an office (a place associated with the
idea of desks). Thus we have "employment bureau," and can get English
money for foreign at a "bureau de