384 EESIJLTS OF FOEEST PLANTATION. 



at least five, and, according to some, ten times more rapid than 

 that of the oak — would prove good investments even in an eco- 

 nomical aspect.* 



There is no doubt that they would pay the expenses of their 

 planting at no distant period, at least in every case where irri- 

 gation is possible, and in very many situations, terraces, ditches, 

 or even horizontal furrows upon the hillsides, would answer as a 

 substitute for more artificial irrigation. Large proprietors would 

 receive important indirect benefits from the shelter and the 

 moisture which forests furnish for the lands in their neighbor- 

 hood, and eventually from the accumulation of vegetable mould 

 in the woods.f The security of the investment, as in the case 



back only to 1870, have now a diameter of more than a foot. Their influence 

 on the health of the establishment has been such that, though from 1869 to 

 1874 one-fourth of the frati were generally suffering from fever, and were 

 obliged to leave the Abbey at evening in order to take refuge for the night 

 within the walls of Rome, yet the latest report of the Superior states that the 

 cases of fever do not at present exceed 5 to 100 of the inmates, and pernicious 

 or congestive fevers have disappeared almost entirely. 



The wood of the pauloicnia, a tree which thrives in Northern Italy, is of little 

 worth comparatively, though said to possess some very valuable qualities bo- 

 sides its lightness, such as security against shrinkage, warping or splitting, and 

 a capacity for receiving a fine polish. However this may be, this vigorous 

 tree would serve well as a shelter for seedlings and young plants of more val- 

 uable species, and in other cases where a temporary shade is urgently needed. 

 The young shoots, from a stem polled the previous season, almost surpass 

 even the eucalyptus in rapidity of growth. Such a shoot from a tree not six 

 inches in diameter, which I had an opportunity of daily observing, from the 

 bursting out of the bud from the bark of the parent stem in April till Novem- 

 ber of the same year, acquired in that interval a diameter of between four and 

 five inches and a height of above twenty feet. 



* The economical statistics of Grigor, Arboriculture, Edinburgh, 1868, are 

 very encouraging. In the preface to that work the author says : " Having 

 formed several large plantations nearly forty years ago, which are still stand- 

 ing, in the Highlands of Scotland, I can refer to them as, after paying every 

 expense, yielding a revenue equal to that of the finest arable land in the coun- 

 try, where the ground previously to these formations was not worth a shilling 

 an acre." See also Hartig, Ueier den Wachsthumsgang und Ertrag der Buclie, 

 Eiche und Kiefer, 1869, and especially Bryant, Forest Trees, chap. ix. 



f The fertility of newly cleared land is by no means due entirely to the ac- 

 cumulation of decayed vegetable matter on its surface, and to the decomposi- 

 tion of the mineral constituents of the soil by the gases emitted by the fallen 

 leaves. Sachs has shown that the roots of living plants exercise a most pow- 

 erful solvent action on rocks, and hence stones are disintegrated and resolved 



