68 MR DAVID RUSSELL ON 
number and contain neither inhabitants nor woods.” And 
according to Torfacus, historiographer to the King of 
Denmark, the condition of the Orkneys in the year 890 
agreed with the description of Solinus. Possibly the Scotch 
areas of woodland date from a time when the land was 
more elevated and the climate, consequently, more continen- 
tal than it is now. Remains of trees occur in situations 
that are now so wet and marshy that it would be impossible 
to have a natural growth of similar trees under present 
conditions. Probably an increase in the humidity of the 
climate has had something to do with the decay of the 
woods, not so much by destroying the trees as by preventing 
young growth where clearances were made, whether by 
wind or by other natural agencies or in later periods by man. 
Mr J. C. Brown gives some interesting particulars (in 
Forests and Moisture) of the drying up of marshes on the 
growth of trees on adjacent dry ground, because of the 
evaporation through the stomata of the leaves, which may 
exceed many times the amount of rainfall. And we have 
evidence of this in the growth of young plantations in 
Ross-shire. Many thousands of acres have been planted 
within recent years. If the soil is wet, ditches must be cut 
and the young trees must be planted sufficiently close 
together to keep the soil dry, otherwise they are unhealthy, 
and many die. Under such conditions a natural growth 
is impossible. 
Mr Brown also gives examples to show that marshes 
sometimes appear on the destruction of forests. Perhaps 
the most interesting of these refers to Russian forests. It 
is stated that in some districts where large areas of forest 
have been destroyed by wind, the trees rot where they fall 
and the ground becomes a marsh, which; he adds, may some 
day have the appearance of a Scotch peat-moss. 
He also states that, on the clearance of pine forests in 
Russia, a growth of natural birch springs up. In Ross-shire 
there is a considerable growth of natural birch—probably 
it dates from the destruction of the pine woods, still in 
existence when the iron smelters came upon the scene. It 
grows in situations not so wet but that pines might still 
grow there; indeed, Scotch firs do occur along with the 
