Burning Land for Manure. 



53 



paper in question. I do so the more readily, as I conceive it 

 contains the best account of kilns for clay-burnino:, together with 

 their economical management, of any yet published. My imme- 

 diate object in drawing attention to the paper here is only to show 

 that a considerable discrepancy of opinion exists as to the state of 

 humidity in which clay should be placed in kilns or clamps, in 

 order to be burned for manure. There can be no doubt that 

 both the remarks of Mr. Long and Mr. Pym are founded upon 

 actual experience and after due deliberation, yet how opposite 

 their conclusions respecting the state of humidity in which clay 

 should be prior to being placed in kilns or clamps for burning ! 

 From the above- quoted description of each process, it must be 

 apparent to all that, reversing their order, there would be the 

 strongest probability that Mr. Long's process would not be adapted 

 to the soil of Mr. Pym, nor Mr. Pym's process to the soil of Mr. 

 Long — in fact, a complete illustration of a previous assertion, that 

 the best mode of burning clay lands for manure can only be 

 ascertained by actual experiment. 



A few other remarks may also be made on the above quotations. 

 Mr. Pym states that the great art is to burn the soil so that the 

 ashes shall turn out black, as they are then much better than 

 when they are red or clinking. With respect to clay being formed 

 into clinkers, there can only be one opinion, viz. their worse than 

 uselessness; yet if the burning process is not carried further than 

 merely to char the vegetable matter in the clay, and thus form 

 black ashes, it will be quite evident that the benefit derivable 

 from an application of such ashes will be slight indeed, being 

 merely that arising from the small portion of the inorganic consti- 

 tuents of plants set free from the charring of the vegetable matter 

 existing in the torrefied clay, and probably a slight amelioration 

 of the mechanical condition of the soil, rendering a stiff soil some- 

 Avhat more porous, and consequently permitting a freer access of 

 the atmosphere to the roots of plants. It may with safety be 

 averred that any mode of burning clay for manure which stops 

 short of converting the protoxide (black oxide) of iron into the 

 red, or peroxide, is incomplete, and will not produce any strikingly 

 beneficial results. I am aware that some change may have been 

 made in the nature of the clay by the process described by Mr. 

 Pym ; but all the evidence tends to show that this m.ust be 

 mainly mechanical. Whether, however, it is possible for the 

 process to be conducted further with safety on soils such as 

 Mr. Pym's, is a question that can only be decided by actual ex- 

 periment. 



In ]Mr. *Long's case it would appear that his soil consisted of 

 decayed minerals and flints in the state of rubble, but not inti- 



