AND COLLEGE, PUSA, FOR 1914-15. <jl 



favour bacterial action, which would, however, be inter- 

 fered with by accumulation of nitrate beyond a certain 

 concentration. Such a concentration is found in some of 

 the saltpetre earth collected for extraction by the nuniahs 

 and as it is of an order many times greater than that 

 necessary to inhibit nitrification, it is clear that it has not 

 been produced in situ by this process, but has been arrived 

 at by the evaporation of weak solutions of nitrates from 

 the soil surface either in the field or on the walls of houses. 



The nuniah collects nuni-mati or saltpetre earth from 

 haphazard sites selected with reference to the accumula- 

 tions of nitrogen characteristic of village sites and cattle 

 sheds; hence he is dependent on uncontrolled supplies of 

 raw material and any expansion of the industry could only 

 be effected either by introducing the nuniah into hitherto 

 unexploited districts or by artificial nitrification of nitro- 

 genous organic matter which would otherwise serve some 

 other purpose. An attempt is now being made to discover 

 the extent to which the carrying out of this latter alter- 

 native is feasible. Local enquiry has elicited the fact that 

 the nuniah does not generally make his business pay until 

 the second or third year, which he attributes to the fact 

 that the amount of nitrate obtained directly by extraction 

 from the earth collected in the neighbourhood is insuffi- 

 cient on the average to pay expenses, and it is only when 

 the accumulation of residual earth (which after extraction 

 is carefully stored) is sufficient in quantity or suitably 

 matured for a second extraction, that paying quantities 

 of saltpetre are obtained. 



If this information proves to be reliable it is obvious 

 that a great deal can be done for the industry simply by 

 ensuring that the time spent in maturing the store of 

 residual earth shall be employed to the best advantage, 

 i.e., that the optimum percentage of organic matter and 

 moisture shall be present, that no leaching by rain takes 

 place, and that nitrification shall not be interfered with 

 by the addition of excessive quantities of salts in solution 

 in the "mother liquor' remaining after concentration, 



