CONTENTS. XVII 



ultimate existence of nations depend upon the proper 

 utilization of this fertilizing matter. The calculations of 

 Liebig 730 crores of rupees the value of food- stuffs con- 

 sumed annually in British India. The loss to the com- 

 monwealth by the waste of the inorganic constituents 

 contained in the refuse of f ood, which, if carefully restored, 

 would have enabled the soil to yield another crop worth 

 730 crores. Public opinion awakening to a knowledge of 

 the enormous waste going on. The Times on the Kiver 

 Pollution Commission. The conservation of human and 

 animal refuse in India offers no difficulties. The project 

 of a system adapted for all small towns and villages. Mr. 

 Buck on the utilization of town-refuse at Furrukhabad. 

 Experiments made in the Deccan with human refuse as 

 manure give remarkable results, more than doubling the 

 outturn. Town-refuse adopted as manure for all food- 

 stuffs. Its approximate composition. Its mode of appli- 

 cation... 117 



CHAPTER VII. 



EARTHY PHOSPHATES AND LIME, 



The importance of phosphoric acid as the predominating 

 mineral constituent of the seed. Bones are the principal 

 source of phosphoric acid. Their composition. Bones 

 the chief necessity of high agriculture. Their behaviour 

 to pure water, and to water containing carbonic acid. 

 Their comparative solubility depends upon their state of 

 division. The solvent action of carbonic acid upon bone 

 phosphates in solutions of common salts, saltpetre, and 

 ammonia. Superphosphate] of lime. Coprolites. Phos- 

 phoric acid, the chief loss sustained by the soil of India. 

 Its application to the soil will double the outturn. The 

 use of phosphoric acid in Cheshire. The action of super- 

 phosphate is immediate, and chiefly confined to the upper 

 layers. Bone-dust, on the contrary, penetrates deeper, and 

 requires some years before the maximum result is obtain- 



