JUNCTION OR SEPARATION OF STREAMS.

There are several river-names which contain the idea, either of the junction of two streams, or of the separation of a river into two branches. The Vistula, Visula, or Wysla, (for in these various forms it appears in ancient records), is referred by Müller,[63] rightly as I think, to Old Norse quisl, Germ. zwiesel, branch, as of a river. A simpler form of quisl is contained in Old Norse quistr, ramus, and the root is to be found in Sansc. dwis, to separate, Gael. and Ir. dis, two. The Old Norse name of the Tanais or Don, according to Grimm (Deutsch. Gramm. 3, 385), was Vana-quisl. The word whistle, found as the ending of some of our local names, as Haltwhistle in Northumberland, and Osbaldwhistle in Lancashire, I take to be = the Old Norse quisl: the sense might be that of the branching off of two roads or two streams. In an account of the hydrography of Lanarkshire, for which I am indebted to the kindness of a Friend, there is a burn called Galawhistle, which compares with the above Old Norse Vana-quisl. In connection with the Vistula Jornandes introduces a river Viscla, which has been generally considered to be merely another form of the same word—Reichard [64] being, as I believe, the only writer who considers it to be a different river. It seems to me a curious thing that it has never occurred to any one to identify it with the Wisloka, which joins the Vistula near Baranov. The modern name must contain the correct form, for Wisloka = an Old High Germ. Wisilacha, from acha or aha, river, and is the same as the Wisilaffa or Wislauf, from afa or apa, river. The following names I take to be all variations of the same word.

1.	France.	The Oust. Dep. Côtes-du-Nord.
	Germany.	The Twiste. Joins the Diemel.
		The Queiss. Pruss. Silesia.
	Russia.	The Uist. Joins the Tobol.
		The Uste. Joins the Dwina.
2.	With the ending en.
	Germany.	Quistina, 11th cent., now the Kösten.
3.	With the ending er.
	France.	The Vistre. Dep. Gard.
	Belgium.	The Vesdre. Joins the Ourt.
	Germany.	The Veistr(itz). Pruss. Silesia.
4.	With the ending rn.
	Germany.	Quistirna, 8th cent., now the Twiste, joins the Oste.
5.	With the ending el = O. N. quisl.
	Germany, &c.	Vistula, 1st cent., Germ. Weichsel.
		Wisl(oka), joins the Vistula. (See above.)
		The Wisl(ok). Joins the San.
		Wisil(affa), 11th cent., now the Wisl(auf).
	France.	The Vesle. Joins the Aisne.

The following seem also to contain the Germ. zwei, Eng. two, and to have something of a similar meaning to the foregoing.

1.	Germany.	The Zwitt(awa) or Zwitt(au) in Moravia.
2.	With the ending el.
2.	Germany.	The Zwettel in Austria.

I include also here the Scheldt or Schelde, (the Scaldis of Cæsar), which I think is to be explained by the Old Norse skildr, Dan. skilt, separated, in allusion to the two mouths by which it enters the North Sea. And to the same origin may be also placed the Schilt(ach) of Baden, which falls into the Kinzig.

From the Gael. caraid, duplex, may probably be the two Carts in the County of Renfrew, the united stream of which enters the Firth of Clyde near Glasgow.