Perhaps also from the root pi we may derive the Ir. buinn, river, bual, biol, water. From the former Mr. Charnock derives the name of the Boyne, a derivation which I think suitable, even if we take the ancient form Buvinda, (Zeuss, Gramm. Celt.,) which might be more properly Buvinna, as Gironde for Garonne in France. For the Bunaha in Germany, the Old Norse buna, scaturire, might also be suggested.

Ireland.The Boyne.
Germany.Bun(aha), 9th cent., now the Baun(ach).

From the Ir. biol, buol, I derive the following, keeping out the rivers of the Slavonic districts, which may be referred to the Slav. biala, white.

1.England.The Beela. Westmoreland.
Ireland.The Boyle, of which, according to O'Brien, the Irish form is Buil.
France.The Bol(bec). Dep. Seine-Inf.
Germany.Boll(aha) ant. Not identified.
Asia Minor.Billæus ant., now the Filyas.
2.With the ending er.
Germany.The Buhler. Wirtemberg.
Russia.The Buller.
3.With the ending et.
Germany.The Bullot. Baden.
Russia.The Polota. Joins the Dwina.

A very obscure root in river-names is gog or cock. The only appellatives I find are in the Celtic, viz., Gael. caochan, a small stream, Arm. goagen, wave; unless we think also of the word jokk, jöggi, which in the Finnic dialects signifies a river; and in that case the most probable root would be the Sansc. yug, to gush forth. To the river Coquet, in Northumberland, something of a sacred character seems to have been ascribed; an altar having been discovered bearing the inscription "Deo Cocidi," and supposed to have been dedicated to the genius of that river. Again, we are reminded of the Cocytus in Greece, a tributary of the river Acheron, invested with so many mysterious terrors as supposed to be under the dominion of the King of Hades. Possibly, however, it might only be the similarity, or identity, of the names which transferred to the one something of the superstitious reverence paid to the other. At all events, I can find nothing in the etymology to bear out such a meaning.

1.England.Cocbrôc (Cod. Dip.) This would seem to have probably been a small stream called Cock, to which, as in many other cases, the Saxons added the word brook.
2.Germany.Cochin(aha), 8th cent., now the Kocher.[33]
3.With the ending er.
England.The Cocker. Cumberland.
The Coker. Lancashire.
India.The Kohary—here?
4.With the ending el.
Transylvania.The Kokel, two rivers.
England.Cockley-beck.[34] Cumberland.
Germany.Chuchilibach, now Kuchelbach.
5.With the ending et.
England.The Coquet. Northumberland.
Greece.Cocytus ant., now the Vuvo.
6.In a compound form.
England.The Cuckmare, Sussex, with the word mar, p. [61].

From the Sansc. mid, to soften, to melt, (perhaps formed on the root mi, p. [59]), come Sansc. miditas, fluid, Lat. madidus, wet. Herein seems a sufficient root for river-names, but there is another which is apt to intermix, Sansc. math, to move, whence, I take it, and not from the former is Old Norse môda, a river. I separate a form med or mid, in which the sense of medius, and also that of mitis, is in some cases clearly brought out; and another, muth or muot, which, though from the same root, as I take it, as môda, a river, (math, to move), has more evidently the sense of speed.

1.Germany.Mota, 8th cent., now the Mede or Mehe.
2.With the ending er.
England.The Madder. Wiltshire.
Germany.Matra, 8th cent., now the Moder.
Italy.Metaurus ant., the Metauro—here?
3. With the ending ern.
France.Matrŏna[35] ant., now the Marne.
Italy.Matrinus ant. in Picenum.
4.With the ending el.
Germany.The Madel.

The only appellative for a river which I find derived from its sound is the Sanscrit nadi, Hind. nuddy, from nad, sonare. Whether the following names should come in here may be uncertain; I can find no links between them and the Sanscrit; perhaps the root nid, p. [54], may be suitable.

1.France.Noda ant., now the Noain.
2.With the ending er.
England.The Nodder. (Noddre, Cod. Dip.)
Hungary.The Neutra. Joins the Danube.
3.With the ending es.
Venetia.Natiso ant., now the Natisone.