OBS. 4.—“Holding these things in view,” continues this sharp connoisseur, “the prosodist who rightly examines that which constitutes the external, or most immediately recognisable, form of Poetry, will commence with the definition of Rhythm. Now rhythm, from the Greek [Greek: arithmos], number, is a term which, in its present application, very nearly conveys its own idea. No more proper word could be employed to present the conception intended; for rhythm, in prosody, is, in its last analysis, identical with time in music. For this reason,” says he, “I have used, throughout this article, as synonymous with rhythm, the word metre from [Greek: metron], measure. Either the one or the other may be defined as the arrangement of words into two or more consecutive, equal, pulsations of time. These pulsations are feet. Two feet, at least, are requisite to constitute a rhythm; just as, in mathematics, two units are necessary to form [a] number.[486] The syllables of which the foot consists, when the foot is not a syllable in itself, are subdivisions of the pulsations. No equality is demanded in these subdivisions. It is only required that, so far as regards two consecutive feet at least, the sum of the times of the syllables in one, shall be equal to the sum of the times of the syllables in the other. Beyond two pulsations there is no necessity for equality of time. All beyond is arbitrary or conventional. A third or fourth pulsation may embody half, or double, or any proportion of the time occupied in the two first. Rhythm being thus understood, the prosodist should proceed to define versification as the making of verses, and verse as the arbitrary or conventional isolation of rhythm into masses of greater or less extent.”—Ib., p. 105.