h they come, distinct words and different parts of
speech, are made plural in English, by the addition of _e_ or _es_ at the
end. But, in all such cases, I think the hyphen should be inserted in the
compound, though it is the practice of many to omit it. Of this odd sort of
words, I quote the following examples from Churchill; taking the liberty to
insert the hyphen, which he omits: "_Ave-Maries, Te-Deums, camera-obscuras,
agnus-castuses, habeas-corpuses, scire-faciases, hiccius-docciuses,
hocus-pocuses, ignis-fatuuses, chef-d'oeuvres, conge-d'elires,
flower-de-luces, louis-d'-ores, tete-a-tetes_."--_Churchill's Gram._, p.
62.

OBS. 24.--Some nouns, from the nature of the things meant, have no plural.
For, as there ought to be no word, or inflection of a word, for which we
cannot conceive an appropriate meaning or use, it follows that whatever is
of such a species that it cannot be taken in any plural sense, must
naturally be named by a word which is singular only: as, _perry, cider,
coffee, flax, hemp, fennel, tallow, pitch, gold, sloth, pride, meekness,
eloquence_. But there are some things, which have in fact neither a
comprehensible unity, nor any distinguishable plurality, and which may
therefore be spoken of in either number; for the distinction of unity and
plurality is, in such instances, merely verbal; and, whichever number we
take, the word will be apt to want the other: as, _dregs_, or _sediment;
riches_, or _wealth; pains_, or _toil; ethics_, or _moral philosophy;
politics_, or _the science of government; belles-lettres_, or _polite
literature_. So _darkness_, which in English appears to have no plural, is
expressed in Latin by _tenebrae_, in French by _tenebres_, which have no
singular. It is necessary that every noun should be understood to be of one
number or the other; for, in connecting it with a verb, or in supplying its
place by a pronoun, we must assume it to be either singular or plural. And
it is desirable that singulars and plurals should always abide by their
appropriate forms, so that they may be thereby distinguished with
readiness. But custom, which regulates this, as every thing else of the
like nature, does not always adjust it well; or, at least, not always upon
principles uniform in themselves and obvious to every intellect.

OBS. 25.--Nouns of multitude, when taken collectively, generally admit the
regular plural form; which of course is understood with reference to the
individuality of t