On Manures. 233 



$>r rivers, into which these articles are at present too fre- 

 quently thrown, impure and unwholesome, would enrich the 

 land( a68 ). 



4. Refuse of Coal-Mines. In the neighbourhood of coal- 

 mines, much advantage might be derived from their refuse, 

 which, at present, is not only lost, but is actually an encum- 

 brance, covering much ground that might be rendered fer- 

 tile. In many cases, these hills of coal rubbish ought to be 

 reduced to ashes, which might be applied to grass lands with 

 infinite advantage. Some kinds of schistus, shale, or blaes, 

 mixed with slaked lime, in the proportion of one-third, 

 have been found an excellent manure for wheat and other 

 crops(* 69 ). 



5. Refuse of Lime-Kilns. Mr Monteath of Closeburn, in 

 Dumfriesshire, places a grate at the bottom of his lime-kilns, 

 (which is of great benefit, by increasing the draught of air 

 through the kilns); and he thus acquires many hundred cart- 

 loads of refuse, consisting of coal-ashes, mixed with small 

 pieces of lime, which would have been of little value, had 

 the ashes been mixed and measured with the large pieces of 

 burnt lime. He has employed this refuse, mixed with earth, 

 to great advantage, in top-dressing peat meadows, and grass 

 lands of every description. In many districts, immense 

 heaps of this refuse are left totally neglected, except by a 

 few public-spirited individuals (* 7 ). 



Nothing can be more desirable, than to bring into action, 

 these sources of fertility, which are generally left unheeded. 

 They not only produce immediate profit, but increase and 

 improve the staple of the soil ; and indirectly, are the means 

 of augmenting those putrescent substances, so essential to 

 vegetation. 



6. Composts. 



Every farmer of experience knows, that certain compounds 

 formed of various kinds of manures and soils, have a much 

 greater effect in promoting vegetation, than when applied 

 separately. \Vhen the different soils and manures are ana- 

 lysed, we find, that some of them contain more animal, or 

 vegetable matter, than they do of salts or earths, and vice 

 versa. It is natural, therefore, to suppose, that advantage 

 might be derived from mixing or combining the two kinds 

 together. 



Some farmers object to composts, on account of the ex- 

 pense, and affirm, that dung itself, is a much better manure, 



