ON THE PROBABLE UTILITY OF PEAT-SOIL, ETC. 2G9 



But, to come nearer home, the bogs in Ireland and some parts of Scot- 

 land would furnish an abundant supply of peat-soil, if it were once 

 found how to turn it to profitable account. I am not aware that this kind 

 of soil has ever been made much of as arable land ; I have seen oats and 

 flax on it on the Continent, but in all cases the crops were poor. However, 

 in the Hebrides they get, on a small scale, very fair crops of oats from it by 

 the following mode of culture : — They first set fire to the heather, and then 

 spread seaweed in strips of six or eight feet width on the ground ; on each 

 side of the seaweed-covered patches they dig a trench two to three feet deep, 

 throwing the soil from the trenches over the seaweed ; when this soil 

 is hacked a little with a spade, it is ready for the seed. 



It appears, from what I heard, that the seaweed in this case exercises 

 a great influence in making the peat-soil productive ; yet it seemed strange 

 that a soil of this kind, composed almost entirely of vegetable matters, 

 should require more vegetable matter as manure. 



Now, the principal use of manure undoubtedly is, to furnish the 

 minerals required by vegetation in a soluble state. In the Channel Islands, 

 where vraic (the name of seaweed in those islands) is extensively used as 

 fuel, it is found that the ashes are more beneficial as manure than the fresh 

 weed ; and peat-ashes are considered of great value for rye-land on the Con- 

 tinent. We find that where water percolates the soil, it renders it unfruit- 

 ful ; it evidently washes away dissolved minerals, and robs the vegetation of 

 it? nutriments. Where the land is too wet, and the contained water 

 stagnant, the dissolved minerals may be too largely diluted : besides, the 

 water will prevent the air from acting on the soil, and thus prevent farther 

 solution. Land in this state therefore requires draining. The quantity of 

 suitable mineral substances that water ought to hold in solution to sustain 

 vegetation may be extremely small, but one can conceive that the supply 

 ought to be continuous. 



Manure may furnish mineral matters suitable to nourish plants, in the 

 first place, when it contains them in such a state that they are acted on 

 directly by air, moisture, temperature, &c, so that they by degrees become 

 soluble ; secondly, by acting chemically on the minerals composing the soil ; 

 and thirdly, by facilitating the decomposition of organic substances, setting 

 free their contained minerals : the action of ammonia as manure is, perhaps, 

 of this latter kind. 



Now, peat-soil is evidently not prone to spontaneous decomposition ; 

 hence its sterility per se : but if it were laid up in heaps, mixed with sea- 

 weed, refuse fish, &c, the action of these substances on each other might 

 tend to produce a most valuable manure. In the case of fish, the peat-soil 

 would probably absorb evolved ammonia, and other volatile products, the 

 greater part of which might otherwise have gone to waste. Quicklime and 

 many other substances might perhaps also be found useful. But it is vain to 

 speculate in details ; I have only attempted to throw out hints of a general 

 nature, and experiments alone can test their value. 



Glasgow. 



