a. The roots unauthenticated by traceable use will be made no account of in this grammar — or, if noticed, will be specified as of that character.
104. The forms of the roots as here used will be found to differ in certain respects from those given by the native grammarians and adopted by some European works. Thus:
a. Those roots of which the initial n and s are regularly converted to ṇ and ṣ after certain prefixes are by the Hindu grammarians given as beginning with ṇ and ṣ; no western authority follows this example.
b. The Hindus classify as simple roots a number of derived stems: reduplicated ones, as dīdhī, jāgṛ, daridrā; present-stems, as ūrṇu; and denominative stems, as avadhīr, kumār, sabhāg, mantr, sāntv, arth, and the like. These are in European works generally reduced to their true value.
c. A number of roots ending in an ā which is irregularly treated in the present-system are written in the Hindu lists with diphthongs — e or āi or o; here they will be regarded as ā-roots (see 251). The o of such root-forms, especially, is purely arbitrary; no forms or derivatives made from the roots justify it.
d. The roots showing interchangeably ṛ and ir and īr or ur and ūr (242) are written by the Hindus with ṛ or with ṝ, or with both. The ṝ here also is only formal, intended to mark the roots as liable to certain modifications, since it nowhere shows itself in any form or derivative. Such roots will in this work be written with ṛ.
e. The roots, on the other hand, showing a variation between ṛ and ar (rarely ra) as weak and strong forms will be here written with ṛ, as by the native grammarians, although many European authorities prefer the other or strong form. So long as we write the unstrengthened vowel in vid and çī, in mud and bhū, and their like, consistency seems to require that we write it in sṛj and kṛ also — in all cases alike, without reference to what may have been the more original Indo-European form.
105. In many cases of roots showing more than one form, the selection of a representative form is a matter of comparative indifference. To deal with such cases according to their historical character is the part rather of an Indo-European comparative grammar than of a Sanskrit grammar. We must be content to accept as roots what elements seem to have on the whole that value in the existing condition of the language.
106. Stems as well as roots have their variations of form (311). The Hindu grammarians usually give the weaker form as the normal one, and derive the other from it by a strengthening change; some European authorities do the same, while others prefer the contrary method; the choice is of unessential consequence, and may be determined in any case by motives of convenience.
107. We shall accordingly consider first of all, in the present chapter, the euphonic principles and laws which govern the combi-
