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pact tufts, and even if the water should escape it will continue 

 to grow, and by degrees will cover very dry soils. For we see it 

 in moist climates ; for example, in the mountains of Ireland, in the 

 Vosges, in the Hartz, climbing up slopes of 25° to 30*^, and cov- 

 ering bare granite rocks. A little moisture on the soil in the 

 spring is sufficient to make the spores germinate ; the atmosphere 

 furnishes the necessary moisture for subsequent vegetation. 1 

 remember, in this connection, that one day as I was descending 

 the slope of the Brocken, I slipped on a wet rock, and coming 

 down upon my back, found myself buried under a carpet of 

 Sphagnum more than a foot thick, from which I had some trouble 

 in extricating myself. 



You yourself remark that the pines are not fond of moisture. 

 As these mosses spread, preventing the air from reaching the 

 roots of these trees, the pines die and disappear, whilst a favor- 

 able soil is formed for the cedars, which represent in America 

 the Pinus pumilio of Europe. On the sandy banks of the river, 

 where the slope favors drainage, the Sphagnum cannot grow, 

 and thus the pine and spruce thrive. 



You ask me why it is that the Sphagnum does not form peat. 

 It is because the slow combustion of wood, which forms this 

 substance, can take place only under water, and thus alone 

 where there is a permanent supply of water. As soon as it runs 

 off, the air reaches the lower part of the stalks, the increase of 

 oxygen decomposes and destroys them, so that after ages of 

 these little vegetables, (which nevertheless contain more woody 

 substance in proportion than the hardest oaks and pines,) there 

 remains only a very thin layer of black earth mixed with 

 sand. 



Besides the utility of peat as fuel, it is employed to great 

 advantage as manure, particularly when taken from the banks of 

 rivers, where it contains a much larger proportion of ammonia. 

 But the decomposition must be aided by breaking it up, or by 

 employing it as litter for cattle, where it becomes saturated with 

 their excrements. Thus prepared, I do not hesitate to declare it 

 to be equal in value to guano. But to throw it upon the fields in 

 lumps, as some experimenters have done, is like spreading pieces 

 of coal, or, I may almost say, of stone. For peat is a true coal, 

 and is decomposed only very slowly by the atmosphere. 



