259 



Magnesian Limestone, subdivided into Knottingley 

 Limestone. 



^Carbonic Acid 42.35 I Carbonate of Lime ... 93.96 



Lime 5L61 J Do. Magnesia ... Trace 



Red Oxide of Iron 1 .42 



Insoluble Matter 4.50 



Loss 0.12 



100.00 



Weldon Limestone (the real Magnesian Limestone.) 



Carbonic Acid 46.00 \ Carbonate of Lime ... 62.12 



Lime 35.04 > Do. Magnesia ... 36.42 



Magnesia 17.50 ) Red Oxide of Iron 0.90 



Insoluble Matter 0.50 



Loss 0.06 



100.00 



Mountain, or Carboniferous Limestone. 



Carbonic Acid 43.00 ( Carbonate of Lime ... 98.50 



Lime 55.50 /Foreign Matter 1.50 



100.00 



You will observe tbat the first and the last of these 

 Limestones contain the greatest amount of pure Lime, 

 and therefore, as far as that mineral is required, are of 

 course the more valuable ; but of what does the foreign 

 matter consist in the other two ? From an analysis made 

 for me by Mr. Haywood, of Worksop, of the Knottingley 

 and Weldon Lime, the foreign matter was found partly 

 to consist of a phosphate, and potash combined with silica, 

 as follows : — 



Knottingley. Weldon. 



Phosphate 087 .100 



Potash combined with Silica ... .128 .196 



.215 .296 



