11 SARTAGE " IN FINLAND. 109 



decayed vegetable mould whicla seemed to hold its mineral 

 particles together, and to retain the water of precipitation, 

 and thus it loosens, pulverises, and dries the earth; it 

 destroys reptiles, insects, and worms, with their eggs, and 

 the seeds of trees and of smaller plants ; it supplies in the 

 ashes which it deposits on the surface important elements 

 for the growth of a new forest clothing, as well as of the 

 usual objects of agriculture industry; and by the changes 

 thus produced it fits the ground for the reception of a 

 vegetation different in character from that which had 

 spontaneously covered it. These new conditions help to 

 explain the natural succession of forest crops, so generally 

 observed in all woods cleared by fire and then abandoned.' 



Thus may be accounted for the abundant crops, for the 

 sake of which the practice is continued. 



Should the ground not be retained permanently under 

 agriculture, whether because it becomes exhausted of such 

 constituents as are required for the crops desired, or from 

 some other cause, it is, as is intimated in the statement 

 quoted, likely to become covered again with a crop of self- 

 sown trees, of the same kind as those destroyed, or of a 

 kind of higher pecuniary value. This I have reported as 

 having been seen by me on the banks of the Saima See, 

 the firs were replaced either by a crop of fir or by a crop 

 of birch. The fir or pine may be of more value for build- 

 ing purposes, but the birch supplies a better firewood; 

 and for this there is, and there is likely to be for a long 

 time to come, an ever-increasing demand in St. Petersburg, 

 to which it can be sent from most places in Finland by 

 water. 



It may be asked next, should it happen in the case 

 supposed, that the crop of trees destroyed be not replaced 

 by another such crop, what will the proximate effect upon 

 the climate be? To this, those whom I consider best 

 qualified to judge, would say : Most probably one bene- 

 ficial for agriculture. 



