About an hour from Thusis, on the Splagen road, "opens the awful chasm of the Nolla which a hundred years ago poured its peaceful waters through smiling meadows protected by the wooded slopes of the mountains. But the woods were cut down and with them departed the rich pastures, the pride of the valley, now covered with piles of rock and rubbish swept down from the mountains. This result is the more to be lamented as it was entirely compassed by the improvidence of man in thinning the forests."--Morell, Scientific Guide to Switzerland, p. 100. The recent change in the character of the Mella--a river anciently so remarkable for the gentleness of its current that it was specially noticed by Catullus as flowing molli flumine--deserves more than a passing remark. This river rises in the mountain-chain east of Lake Iseo, and traversing the district of Brescia, empties into the Oglio after a course of about seventy miles. The iron-works in the upper valley of the Mella had long created a considerable demand for wood, but their operations were not so extensive as to occasion any very sudden or general destruction of the forests, and the only evil experienced from the clearings was the gradual diminution of the volume of the river. Within the last thirty years, the superior quality of the arms manufactured at Brescia has greatly enlarged the sale of them, and very naturally stumulated the activity of both the forges and of the colliers who supply them, and the hillsides have been rapidly stripped of their timber. Up to 1850, no destructive inundation of the Mella had been recorded. Buildings in great numbers had been erected upon its margin, and its valley was conspicuous for its rural beauty and its fertility. But when the denudation of the mountains had reached a certain point, avenging nature began the work of retribution. In the spring and summer of 1850 several new torrents were suddenly formed in the upper tributary valleys, and on the 14th and 15th of August in that year a fall of rain, not heavier than had been often experienced, produced a flood which not only inundated much ground never before overflowed, but destroyed a great number of bridges, dams, factories, and other valuable structures, and, what was a far more serious evil, swept off from the rocks an incredible extent of soil, and converted one of the most beautiful valleys of the Italian Alps into a ravine almost us bare and as barren as the savagest gorge of Southern France. The pecuniary damage was estimated at many millions of francs, and the violence of the catastrophe was deemed so extraordinary, even in a country subject to similar visitations, that the sympathy excited for the sufferers produced, in five months, voluntary contributions for their relief to the amount of nearly $200,000.--Delle Inondazioni del Mella, etc., nella notte del 14 al 15 Agosto, 1850.