
$4 Mr. Kemp’s Experiments on Galvanism. 
In performing this experiment, the wires should be placed into 
the three tubes of the siphon vessel as nearly as possible at the 
same time. | 
(To be continued. ) 

ART. III. Description of the Landes of Acquitania. By W1LL1AM 
ArnswortH, Esq. M.R.C.S.E. &c. 
; (Continued from Page 11.) 
THE existence of these lagune is a fact of much interest ; and 
to explain their origin, we must enter into a notice of the other hy- 
drographical features of the Landes. 
The rivers and rivulets supplying the Dordogne, coming from 
the volcanic rocks of Auvergne and the Cevennes, and the streams 
descending from the central Pyrenees, giving rise to the Garonne, 
form, in the part of a sphere which they describe, one of the most 
extensive hydrographical basins of France. The two rivers unite a 
few miles beyond Bordeaux, and the firth (fleuve) formed by their 
union, is called La Gironde. 
This basin is divided into departments, whose nomenclature is 
after an admirable system founded on the natural position of these 
divisions, partly after the river or its branches, partly after the ele- 
vated sites, or hydregraphical plateaux from which they originate. 
The course of the Garonne is, generally speaking, direct. Rising 
from the Pyrenees, it runs part of its course in a direction nearly 
due north, till sweeping round, it pursues for nearly two hundred 
miles a north-westerly direction, often tortuous, but, except at its 
origin, seldom precipitous; it in no place forms chains of small 
lakes, though’ cennecting ponds sometimes occur at its sides. Its 
slope is not very rapid, the elevation of the bed of the river being 
at Thoulouse not more than 460 feet. Like that ef the Adour, its 
bed is seldom expanded ; shoals, islands, and sand-banks, are there- 
fore not very frequent. 
The Parisian limestone, as we have already stated, forms cliffs 
in the vicinity of Bordeaux of about 200 feet high, following at a 
-small distance the direction of the river, between which are some 
excellent. natural pastures. Some parts are also devoted to the cul- 
tivation of the vine; and nearer the river, are small plantations of 
basket willows. The same land, more sandy on the Acquitanic 
side, is occupied by willow plantations and the gardens which sup- 
ply the town of Bordeaux with esculent vegetables. More towards 
the bank of the river, the ground is overgrown with the Arundo 
phragmites, Lythrum salicaria, &c. The Scirpus maritimus de- 
scends almost half way to low water mark. 
It has been remarked of rivers in general, that as they approach 
the sea, their course becomes more tortuous, and this circumstance 
