lo Oct.. 1 91 2. J 



The Cl/eniistr \,' of L.me. 



607 



Carbonate of Lain. — A good quality carbonate of lime should contain 

 at least 85 per cent, of carbonate of lime, and pass through a sieve of 

 50 meshes to the linear inch. 



Gyfsiim. — A good quality gypsum should contain at lea.st 30 per cent, 

 of calcium oxide. 



All other grades should be sold on a guarantee, stating their calcium 

 oxide content. 



MoNKv Value of Lime to the Farmer. 



On some land the beneficial effect of lime may l>e worth ^3 per 

 ton. On other land it may be worth only ^i per ton. according to the 

 greater or less ill-effect on the crop returns of the defect which it remedies. 

 What, therefore, is the money value of lime delivered on the farm can 

 only be ascertained as a result of experiment and careful record of die 

 cost compared with the increase of crop returns over a period of years. 



Assuming standard lime as above (75 per cent. CaO. and 10 per cent. 

 CaCOg) to be worth £,1 los. per ton on the farm, then — 



Standard slaked lime (75 per cent. CaO and CaH^O^. and 10 per 

 cent. CaCOg) is worth ^i 2s. 3d. per ton on the farm. 



Standard carbonate of lime (85 per cent., finely ground CaC^Oo (ground 

 limestone, &c.) is worth i6s. lod. per ton on tbi farm. 



Standard gvpsitni (30 per cent. CaO) is worth 9s gd. per ton on the 

 farm. 



It does not follow that if a farmer can get gypsum landed at the 

 nearest railway station to him for 9s. 9d. per ton that it would pay 

 him as well as to buy freshly burnt lime landed at the station at 30s. 

 per ton, for the cartage to the farm and the cost of distribution would 

 be three times as much in the former case as it w^ould in the latter. 

 Still less would it pay to buy the bulkier form of lime, paying the above 

 rates at the sending end. for the freight of 3 tons would have to be paid 

 for in the ca.se of gyp.sum additional on the cost, as against the freight 

 charges for i ton in the case of liurnt lime. 



Table showing the Names, Chemical Formula, and Synonyms of 

 THE Different Forms or Lime. 



Note. — Nos. i and 2 are known as hot lime. Xos. 3 and 4. are known as mild lime 

 Hot lime is much stronger in its action in decomposing organic matter than the miUL 

 linifs. 



