306 SYLVA 



wish for nothing- further than to have something to 

 say upon a subject, they cannot satisfy the attentive 

 observer of nature. Those decays of the forests 

 have taken place in situations where no invading 

 army ever was or could come. Then as for the con- 

 flagration it would be a powerful flame that could 

 reach from Caithness to Orkney, or from Skye to 

 the Long Island ; nor would it be an ordinary fire 

 that wOuld burn across the summit of a lofty ridge, 

 and down the other side, especially when, as must 

 have been the case when the hill-sides of Scotland 

 were close forests and the bottoms pools of water, 

 the summit of that ridge was clad with perpetual 

 snow. Besides, if the trees had been burnt, the 

 charcoal would have been found, for charcoal is one 

 of the most indestructible of substances. The char- 

 coal of the fires at the signal posts already alluded 

 to, remains in great quantity indeed, it is that 

 which most simply and effectually confounds those 

 who will have it that these trifling fusions of stone 

 by common fires and wood-ashes at the surface are 

 volcanic operations that have long ago taken place 

 in the bowels of the earth ; and if the ashes of a few 

 billets fetched from its skirts have remained, it would 

 be passing strange that the charcoal of the whole 

 Sylva Caledonia, the conflagration of which, if it 

 happened, must have been more recent, should be 

 entirely lost. 



But the fact is, that the pine forests both of Scot- 

 land and the Scottish isles, and of Ireland, have been 

 buried, and not burnt. The remains of them are in 

 the bogs of both countries, so abundant as to serve 

 in many cases both as fuel and as a substitute for 

 candles ; and so sound and fresh as, in not a few, to 

 answer the purposes of domestic economy. 



In the natural history of vegetables, those facts 

 are important in two respects ; first, they show that 

 there are certain periods at which forests fade off, 

 both by the old trees dying and the seeds ceasing 



