OBS. 18.—­Since nouns and adjectives are different parts of speech, the suggestion, that, “Numeral adjectives are also names, or nouns,” is, upon the very face of it, a flat absurdity; and the notion that “the name of a number” above unity, conveys only and always the idea of unity, like an ordinary “singular noun,” is an other.  A number in arithmetic is most commonly an adjective in grammar; and it is always, in form, an expression that tells how many, or—­“denotes how many things are spoken of.”—­Chase, p. 11.  But the name of a number is also a number, whenever it is not made plural in form.  Thus four is a number, but fours is not; so ten is a number, but tens is not.  Arithmetical numbers, which run on to infinity, severally consist of a definite idea of how many; each is a precise count by the unit; one being the beginning of the series, and the measure of every successive step.  Grammatical numbers are only the verbal forms which distinguish one thing from more of the same sort.  Thus the word fours or tens, unless some arithmetical number be prefixed to it, signifies nothing but a mere plurality which repeats indefinitely the collective idea of four or ten.

OBS. 19.—­All actual names of numbers calculative, except one, (for naught, though it fills a place among numbers, is, in itself, a mere negation of number; and such terms as oneness, unity, duality, are not used in calculation,) are collective nouns—­a circumstance which seems to make the discussion of the present topic appropriate to the location which is here given it under Rule 15th.  Each of them denotes a particular aggregate of units.  And if each, as signifying one whole, may convey the idea of unity, and take a singular verb; each, again, as denoting so many units, may quite as naturally take a plural verb, and be made to convey the idea of plurality.  For the mere abstractness of numbers, or their separation from all “particular objects,” by no means obliges us to limit them always to the construction with verbs singular.  If it is right to say, “Two is an even number;” it is certainly no error to say, “Two are an even number.”  If it is allowable to say, “As 2 is to 4, so is 6 to 12;” it is as well, if not better, to say, “As two are to four, so are six to twelve.”  If it is correct to say, “Four is equal to twice two;” it is quite as grammatical to say, “Four are equal to twice two.”  Bullions bids say, “Twice two is four,” and, “Three times two is six;” but I very much prefer to say, “Twice two are four,” and, “Three times two are six.”  The Doctor’s reasoning, whereby he condemns the latter phraseology, is founded only upon false assumptions.  This I expect to show; and more—­that the word which he prefers, is wrong.