previous next


A technical term of scientific grammar, applied to the change of a voiced s (z) to r between two vowels. In Greek this change is rare, as in that language the intervocalic s regularly passed into h and then disappeared, leaving no trace of its existence, while in Latin it is regularly changed to r. (Cf. the Gk. μῦς, μυ-ός, Lat. mus, mu-r-is: Gk. νυός, Lat. nu-r-us.) In the dialect of Greek spoken in Elis, rhotacism occurred instead of loss of s, and so in some late Laconian words influenced by the usage of the neighbouring Elis. In Latin rhotacism is a regular law, for though there are many apparent exceptions to it, examination shows that in most of these cases the s was not originally intervocalic or else that the word is of (a) foreign or (b) late origin. For instance, in causa the s is not changed to r because it represents probably ss, Cicero having written it caussa. In many compounds s is not changed to r because it is to be regarded as an initial rather than as an intervocalic consonant—e. g. desilio, positura. In many other words the apparently intervocalic s represents a substitution for another original letter—e. g. esuries (√ed of edo), prosa (provorsa), rosa (cf. ῥόδον), casa (√skad, hence cadta). Such words as basium, casium, gaesum, siser, and probably asinus are non-Latin in their origin. The real exceptions to the operation of the regular change to r do not amount to more than a half dozen, such as vasa, nasus, agaso, caseus; and the exceptions are the basis of a special law known as Conway's Law, first set forth by Mr. R. S. Conway, in 1887, as a sort of corollary to Verner's Law. (See Verner's Law.) Conway's Law is as follows: Medial s between words after an unaccented syllable became r, but after an accented syllable it was retained except when followed by i or u and preceded by i or u or a long vowel or diphthong; while medial s before nasals after an unaccented syllable was lost without compensation; after an accented syllable if arising before the period of rhotacism it was lost with compensatory lengthening of the preceding vowel (e. g. aenus, primus); if arising during the period of rhotacism it became r (e. g. carmen, verna).

Rhotacism in Latin is said to have been effected in the fourth century b. c., as Cicero says (Ad Fam. ix. 21) that L. Papirius, who was consul in B.C. 336, was the first of his family to give up the older spelling Papisius. But the change in general was probably effected earlier, for proper names are notoriously the last to suffer alterations of form.

Rhotacism occurs also in the Teutonic branches of the Indo-Germanic group of languages. (Cf. Germ. eisen, Engl. iron; Germ. blasen, Engl. blare; Engl. sing. was, plur. were.) The unvoiced s first passes into the voiced s (z) and thence to lingual r, for the position of the vocal organs in pronouncing z is substantially the same as that required for r.

See V. Henry, Comparative Grammar of Greek and Latin, pp. 74-76 (Engl. trans. New York, 1890); Roby, Latin Grammar, vol. i. pp. 98 foll.; Joret, De Rhotacismo (1875); Walter, Rhotacism in the Italic Languages (1877); and Conway, Verner's Law in Italy (London, 1887).

hide Display Preferences
Greek Display:
Arabic Display:
View by Default:
Browse Bar: