onoun, and then they are as clearly adjectives; as, "Imagination is like
to work better upon sleeping men, than _men awake_."--_Lord Bacon._ "_Man
alive_, did you ever make a _hornet afraid_, or catch a _weasel asleep?_"
And sometimes the compound governs a noun or a pronoun after it, and then
it is a preposition; as, "A bridge is laid _across_ a river."--_Webster's
Dict._, "To break his bridge _athwart_ the Hellespont."--_Bacon's Essays._

"Where Ufens glides _along_ the lowly lands,
Or the black water of Pomptina stands."--_Dryden._

OBS. 23.--In several phrases, not yet to be accounted obsolete, this old
preposition _a_ still retains its place as a separate word; and none have
been more perplexing to superficial grammarians, than those which are
formed by using it before participles in _ing_; in which instances, the
participles are in fact governed by it: for nothing is more common in our
language, than for participles of this form to be governed by
prepositions. For example, "You have set the cask _a_ leaking," and, "You
have set the cask _to_ leaking," are exactly equivalent, both in meaning
and construction. "Forty and six years was this temple _in_
building."--_John, ii, 20._ _Building_ is not here a noun, but a
participle; and _in_ is here better than _a_, only because the phrase, _a
building_, might be taken for an article and a noun, meaning _an
edifice_.[137] Yet, in almost all cases, other prepositions are, I think,
to be preferred to _a_, if others equivalent to it can be found. Examples:
"Lastly, they go about to apologize for the long time their book hath been
_a coming_ out:" i.e., _in_ coming out.--_Barclay's Works_, Vol. iii, p.
179. "And, for want of reason, he falls _a railing_::" i.e., _to_
railing.--_Ib._, iii, 357. "That the soul should be this moment busy _a
thinking_:" i.e., _at_ or _in_ thinking.--_Locke's Essay_, p. 78. "Which,
once set _a going_, continue in the same steps:" i.e., _to_ going.--_Ib._,
p. 284. "Those who contend for four per cent, have set men's mouths _a
watering_ for money:" i.e., _to_ watering.--LOCKE: _in Johnson's Dict._ "An
other falls _a ringing_ a Pescennius Niger:" i.e., _to_ ringing.--ADDISON:
_ib._ "At least to set others _a thinking_ upon the subject:" i.e., _to_
thinking.--_Johnson's Gram. Com._, p. 300. "Every one that could reach it,
cut off a piece, and fell _a eating_:" i.e., _to_ eating.--_Newspaper._ "To
go _a mothering_,[138] is to visit parents on Mid