Note 103 — Chapter IV · NITRIFICATION.

As much of the nitric acid in this solution was present as nitrate of lime, it was usually treated with a solution of potassium carbonate, the result being the precipitation of the lime as carbonate, pure saltpetre being left in solution, according to the following equation—

K₂CO₃ + Ca(NO₃)₂ = 2 KNO₃ + CaCO₃.

Under the French mode of manufacture, the process was considered to have developed satisfactorily when 1000 lb. of earth, at the expiration of two years, yielded 5 lb. of nitre.