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was here exhibited to the meeting]. The first of these 

 substances (lime) is almost universally acknowledged to be 

 beneficial, and the second (iron) when in the state of a 

 Peroxide, is likewise stated to be so, when present in 

 the soil in small quantities. On referring to the analysis of 

 fertile soils, made by Sir Humphry Davy, Liebig, and 

 Sprengel, I observe that there is invariably present a 

 portion of oxide of iron, varying from two to eight per 

 cent.; and I find from a table of the fixed constituents of 

 various crops, issued by the latter chemist, (Sprengel), that 

 the same substance is always detected in a greater or less 

 degree, proving it to be essential to the proper development 

 of the plant. From the examination to which I have sub- 

 jected these difibrent kinds of refuse, I believe them to 

 contain also alumina and magnesia, both of which are 

 constituents of fertile soils, and their vegetable products. In 

 fact we have lately had a decided proof of the presence of 

 magnesia in burnt refuse. We were leading upon the land 

 a heap of slack and pyrites which had long been in a state 

 of ignition, and found on removing it, a thick layer of crys- 

 talized salt, which, on examination by a professed chemist, 

 was pronounced to be simple sulphate of magnesia or 

 Epsom salts; [a specimen was here exhibited]. The burnt 

 refuse of a pit hill has been successfully employed by Mr. 

 Forge, steward to Sir Wm. Pilkington, at Chevet Hall, near 

 Wakefield, as a substitute for riddled ashes from houses, 

 mixed with bones, for his turnip crop. He informed me 

 that the portion of land on which this refuse was applied, 

 bore a decidedly better crop than the part where the common 

 ashes were laid. It should likewise be considered that ashes 

 and burnt mining refuse will have a mechanical effect upon 

 a stiff* soil, after the chemical action ceases, and will improve 

 its texture by rendering it more porous and easier to be 

 worked by the plough and harrow. The prevailing character 



