b. of the second or ruh-class: vah, sah, mih, rih or lih, guh, ruh, dṛṅh, tṛṅh, bṛh, baṅh, spṛh (?).
c. But muh forms also (not in RV.) the participle mūḍha and agent-noun mūḍhár, as well as mugdhá and mugdhár; and druh and snih are allowed by the grammarians to do likewise: such forms as drūḍha and snīḍha, however, have not been met with in use.
d. From roots of the ruh-class we find also in the Veda the forms gartārúk, nom. sing., and prāṇadhṛ́k and dadhṛ́k; and hence puruspṛ́k (the only occurrence) does not certainly prove √spṛh to be of the duh-class.
e. A number of other h-roots are not proved by their occurring forms to belong to either class; they, too, are with more or less confidence assigned to the one or the other by comparison with the related languages.
f. In derivation, before certain suffixes (216), we have gh instead of h from verbs of either class.
g. The root nah comes from original dh instead of gh, and its reversion is accordingly to a dental mute: thus, natsyā́mi, naddhá, upānádbhis, upānadyuga, anupānatka. So also the root grah comes from (early Vedic) grabh, and shows labials in many forms and derivatives (though it is assimilated to other h-roots in the desiderative stem jighṛkṣa). In like manner, h is used for dh in some of the forms and derivatives of √dhā put; and further analogous facts are the stem kakuhá beside kakubhá, the double imperative ending dhi and hi, and the dative máhyam beside túbhyam (491).
224. Irregularities of combination are:
a. The vowel ṛ is not lengthened after the loss of the h-element: thus, dṛḍhá, tṛḍhá, bṛḍhá (the only cases; and in the Veda their first syllable has metrical value as heavy or long).
b. The roots vah and sah change their vowel to o instead of lengthening it: thus, voḍhám, voḍhā́m, voḍhár, sóḍhum. But from sah in the older language forms with ā are more frequent: thus, sāḍhá, áṣāḍha (also later), sā́ḍhar. The root tṛṅh changes the vowel of its class-sign na into e instead of lengthening it: thus, tṛṇeḍhi, tṛṇéḍhu, atṛṇet (the grammarians teach also tṛṇehmi and tṛṇekṣi: but no such forms are quotable, and, if ever actually in use, they must have been made by false analogy with the others).
c. These anomalous vowel-changes seem to stand in connection with the fact that the cases showing them are the only ones where other than an alterant vowel (180) comes before the lingualized sibilant representative of the h. Compare ṣóḍaça etc.
d. Apparently by dissimilation, the final of vah in the anomalous compound anaḍvah is changed to d instead of ḍ: see 404.
