108 PERMANENT AND TEMPORARY PASTURES 



heat must not be sufficient to create a flame. Gradually the 

 sods will char away to ashes. If the land is suitable, the 

 ashes will be red and powdery, mixed with a few black 

 particles, and when put into water will make it more or less 

 muddy. In the proportion that the water holds the ashes in 

 suspension will the land be benefited by burning. If the land 

 is unsuitable, the ashes will be sandy, and instead of making 

 the water thick they will be precipitated to the bottom, 

 leaving the water almost clear. Supposing this experiment to 

 be in favour of the operation, even then only a small area 

 should be tried until there is conclusive evidence that the 

 proceeding would be advantageous. 



There is no necessity to pare the soil deeper than three 

 or four inches, and instead of the spade or turfing iron, a 

 paring plough made for the purpose is to be preferred, especially 

 as it leaves the slice of soil on its edge, so that a drying wind 

 soon fits it for being gathered into heaps. To economise 

 labour, many small fires scattered over the field have been 

 advocated, and undoubtedly they save much carrying of the 

 turf and facihtate the spreading of the ashes. But small heaps 

 are very wasteful. It is almost impossible to prevent them 

 from flaring, and that is ruinous. Large dense masses, how- 

 ever, can be burned slowly and evenly, and at a comparatively 

 low temperature. This point is worth attention, for it makes 

 an enormous difference in the fertilising value of the ash. 

 The inorganic constituents of the soil are rendered soluble when 

 burned slowly, and become more insoluble when overburned. 



The effect of burning is to get rid of all the organic 

 matter. But the mineral constituents — with the exception 

 of nitrogen — remain, and they are so transformed by fire as 

 to be easily assimilable by future crops. 



The consumption of all the organic matter by fire is of 

 course a destructive process, and in itself involves a consider- 

 able loss, but the effect of fire upon the inorganic substances 

 goes far to neutralise this loss. The soil is rendered capable 



