Dr J. W. Dawson on the Antiquity of Man. 43 



if, in the course of ages, the latter tree proved itself more 

 suitable to the soil, climate, and other conditions. Both 

 oak and beech are of slow extension, their seeds not being 

 carried bj the winds, and only to a limited degree by birds. 

 On the other hand, the changes of forests cannot have 

 been absolute or universal. There must have been oak and 

 beech groves even in the pine woods ; and the growing and 

 increasing beech woods would be contemporary with the 

 older and decaying oak forest, as this last would probably 

 perish not by fire, but by decay, and by the competition of 

 the beeches. In like manner, the growth of peat is very 

 variable even in the same locality. It goes on very rapidly 

 when moisture and other conditions are favourable, and 

 especially when it is aided by wind-falls, drift-wood, or 

 beaver-dams, impeding drainage and contributing to the 

 accumulation of vegetable matter. It is retarded and 

 finally terminated by the rise of the surface above the 

 drainage level, by the clearing of the country, or by the 

 establishment of natural or artificial drainage. On the one 

 hand, all the changes observed in Denmark may have taken 

 place within a minimum time of two thousand years. On 

 the other hand, no one can affirm that either of the three 

 successive forests may not have flourished for that length 

 of time. A chronology measured by years, and based on 

 such data, is evidently worthless. 



Possibly a more accurate measurement of time might be 

 deduced from the introduction of bronze and iron. If the 

 former was, as many antiquarians suppose, a local discovery, 

 and not introduced from abroad, it can give no measure- 

 ment of time whatever ; since, as the facts so clearly de- 

 tailed by Dr Wilson show, while a bronze age existed in 

 Peru, it was the copper age in the Mississippi valley, and 

 the stone age elsewhere ; these conditions might have co- 

 existed for any length of time, and could give no indication 

 of relative dates. On the other hand, the iron introduced 

 by European c(mimerce spread at once over the continent, 

 and came into use in the most remote tribes, and its intro- 

 duction into America clearly marks an historical epoch. 

 With regard to bronze in Europe, we must bear in mind that 

 tin was to be procured only in England and Spain, and in 



