sorrow_ of thine own, the brook might tell thee
of it.--HAWTHORNE

In the first sentence, instead of the general abstract notion of
delight, which cannot be singular or plural, _a delight_ means one
thing delightful, and implies others having the same quality.

So _a sorrow_ means one cause of sorrow, implying that there are
other things that bring sorrow.

[Sidenote: _Become pure class nouns._]

NOTE.--Some abstract nouns become common class nouns with the
indefinite article, referring simply to persons; thus,--

If the poet of the "Rape of the Lock" be not _a wit_, who
deserves to be called so?--THACKERAY.

He had a little brother in London with him at this time,--as
great _a beauty_, as great a dandy, as great a villain.--_Id._

_A youth_ to fortune and to fame unknown.--GRAY.

[Sidenote: _Changes material to class nouns._]

191. _An_ or _a_ before a material noun indicates the change to a
class noun, meaning one kind or a detached portion; as,--

They that dwell up in the steeple,...
Feel a glory in so rolling
On the human heart _a stone_.
--POE.

When God at first made man,
Having _a glass_ of blessings standing by.
--HERBERT.

The roofs were turned into arches of massy stone, joined by _a
cement_ that grew harder by time.--JOHNSON.

[Sidenote: _Like the numeral adjective_ one.]

192. In some cases _an_ or _a_ has the full force of the numeral
adjective _one_. It is shown in the following:--

To every room there was _an_ open and _a_ secret
passage.--JOHNSON.

In a short time these become a small tree, _an_ inverted pyramid
resting on the apex of the other.--THOREAU.

All men are at last of _a_ size.--EMERSON.

At the approach of spring the red squirrels got under my house,
two at _a_ time.--THOREAU.

[Sidenote: _Equivalent to the word_ each _or_ every.]

193. Often, also, the indefinite article has the force of _each_ or
_every_, particularly to express measure or frequency.

It would be so much more pleasant to live at his ease than to
work eight or ten hours _a day_.--BULWER

[Sidenote: _Compare to Sec. 184._]

Strong beer, such as we now buy for eighteenpence _a gallon_, was
then a penny _a gallon_.--FROUDE

[Sidenote: _With_ such, many, what.]

194. _An_ or _a_ is added to the adjectives _such_, _many_, and
_what_, and may be considere