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waters into the Arve, a tributary joining the river a little be- 

 low the Lake of Geneva, and which receives the waters of the 

 glaciers of the valley of Chamouni. The waters of the Rhone 

 are considerably augmented during the heats of summer, by 

 the melting of the snow ; and during this season, the waters of 

 the Lake of Geneva rise, notwithstanding its vast extent, to be- 

 tween six and eight feet, as the maximum. This circumstance 

 distinguishes the rivers of high mountains from those which 

 take their rise in less elevated regions ; whose increase occurs 

 in the rainy seasons, and their greatest subsidence at the pe- 

 riod of the summer's heat. 



The Rhone, at its egress from the Lake of Geneva, where 

 it deposits all the sand and mud with which it is loaded during 

 its impetuous course in Le Valais, is perfectly pure and trans- 

 parent. Its colour, — a fine blue, somewhat tinged with green, 

 — as is well known, has often engaged the attention of philo- 

 sophers, and several explanations of the phenomenon have 

 been attempted. This lovely hue it soon loses. Immediately 

 after passing the town of Geneva, it receives the waters of the 

 Arve, the torrent which, as we have already hinted, comes 

 from Mont Blanc, and which, in its rapid course, passing over 

 a bed of rather decomposible schist, is soon loaded with fine 

 mud, which, in summer especially, darkens its waters, and 

 confers on the Rhone a very deep greyish tint. Somewhat 

 further down, the Rhone receives also the Ain, which, durino- 

 its floods, brings down the marls and clays of La Bresse, and 

 contributes not a little to alter its original limpid purity. Ac- 

 cording to the appearance and the quantity of these different 

 tributaries, the Rhone, in passing Lyons, varies in its physical 

 (malities. If the Arve predominates, it holds suspended a 

 greyish sediment ; on the contrary, when the Ain, swollen by 

 the rains, manifestly augments the size of the river, its waters 

 contain a calcareous argillaceous earth, which communicates 

 to it a yellowish tint. 



In winter, the water of the Rhone is clear and almost lim- 

 pid ; in spring, as soon as the melting of the Alpine snows 

 commences, it increases in size and becomes more muddy 

 every day till well on in autumn, from which time it again de- 

 creases, and gradually becomes clearer. But its chemical 



