CHAPTER XXXVII

.

Bone-Dust and Superphosphate of Lime.-- Bone furnishes Nitrogen as well as Phosphate of Lime.-- Increasing the Availability of Bone with Sulphuric Acid. 314

## CHAPTER XXXVIII .

Special Manures.-- Liebig’s Views.-- Special Manure for Wheat and Turnips.-- Rothamsted Experiments. 320

## CHAPTER XXXIX .

Value of Fertilizers.-- Cost per pound of the Essential Constituents of Fertilizers.-- Value of Guanos.-- Potash as a Manure. 324

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