336 PAST Him'ottx OF alpinm i'obrbnis, 



their own foliage, or sending out long rootlets into the surrounding earth 

 in search of juices to feed them. 



" The eruptive matter of volcanoes, forbidding as is its aspect, does not 

 refuse nutriment to the woods. The refractory lava of Etna, it is true, 

 remains long barren, and that of the great eruption of 1669 is still almost 

 wholly devoid of vegetation. But the cactus is making inroads even here, 

 while the volcanic sand and molten rock thrown out by Vesuvius soon 

 become productive. Before the great eruption of 1631 even the interior of 

 the crater was covered with vegetation. George Sandys, who visited 

 Vesuvius in 1611, after it had reposed for several centuries, found the 

 throat of the volcano at the bottom of the crater ' almost choked with 

 broken rocks and trees that are falne therein.' ' Next to this,' he 

 continues ' the matter thrown up is ruddy, light, and soft : more removed, 

 blacke and ponderous : the uttermost brow, that declineth like the seates 

 in a theater, flourishing with trees and excellent pasturage. The midst of 

 the hill is shaded with chestnut trees, and others bearing sundry fruits.' " 



He adds in a foot note, — " Even the volcanic dust of Etna remains very 

 long unproductive. Near Nicolosi is a great extent of coarse black sand, 

 thrown out in 1669, which, for almost two centuries, lay entirely bare, 

 and can be made to grow plants only by artificial mixtures and much 

 labour. 



" The increase in the price of wines, in consequence of the diminution of 

 the product from the grape disease, however, has brought even these ashes 

 under cultivation. ' I found,' says Waltershausen, referring to the years 

 1861-62, ' plains of volcanic sand and half subdued lava streams, which 

 twenty years ago lay utterly waste, now covered with fine vineyards. The 

 ash-field of ten square miles above Nicolosi, created by the eruption of 

 1669, which was entirely barren in 1835, is now planted with vines almost 

 to the summits of Monte Eosso, at a height of three thousand feet.' " 



To the spread of vegetation and the growth of trees is attributed the 

 extinction of the primitive torrents,^ — to the destruction of forests, which 

 had protected the land for ages, is attributed the reappearance of them in 

 our day, — to the spread of forests over denuded ground is attributed the 

 extinction of some which seem to have originating in later times, — and to 

 aid in this work is the object of the reboisement and gazonnement which are 

 being carried out. The whole process is thus sketched by Marschand, in 

 his work entitled Les Torrents des Alpes et le Patiirage : — 



"After their elevation, the Alps presented everywhere abrupt crests, 

 separated by deep rents. Physical and chemical agencies disintegrated 

 the rocks everywhere naked, and formed of their accumulated debris the 

 first slopes of crumbled materials. The waters flowing on these extremely 

 steep lower slopes, gnawed them away little by little, and levelled up the 

 bottom of the valleys. At this epoch aU the water-courses must have had 

 a character essentially torrential ; they carried away immense quantities 

 of materials, which have formed the beds of alluvial deposits, the thickness 

 of which is at times so considerable. 



"But soon a powerful vegetation came to cover the upper slopes, and to 

 arrest, or rather to retard, the great work of levelling. When one pictures 

 to himself what must have been then the configuration of these mountains 

 formed of rocks without consistency, he is led to suppose that the power 

 of vegetation must have been then much greater than in our days, for it is 



