90 REPORT OF THE AGRICULTURAL RESEARCH INSTITUTE 



It was concluded that the output of saltpetre is limited 

 at present not so much by the available supply of raw 

 material, as by the number of workers (Nuniahs) actually 

 engaged in extraction, this being largely determined by the 

 price of crude saltpetre and the restrictions imposed by 

 landholders, refiners, and the Salt Department. No special 

 soil organisms appear to be associated with saltpetre de- 

 posits which are the result of the nitrification of organic 

 matter accumulated in the neighbourhood of human dwell- 

 ings, the high concentrations of nitrate found in the soil 

 in such sites being due to the upward movement of water 

 carrying dissolved nitrates to the surface where they be- 

 come concentrated by the intense evaporation going on 

 during the dry months of the year. Experiments on a 

 field scale showed the feasibility of adding to the store of 

 nitrates in the country by the use of nitre beds made up by 

 burying a green crop, in this case Crotalaria juncea, in ordi- 

 nary field soil and compacting the heaps sufficiently to en- 

 sure the capillary rise of water from the subsoil to the sur- 

 face, where the nitrate formed accumulates and can be 

 scraped off after the manner of the nuniah. It is suggest- 

 ed that a very large output of saltpetre could be obtained 

 in this way in those parts of India in which soils with suffi- 

 cient lime content and suitable physical texture are found. 

 At the same time the condition of the industry as a whole 

 -could be greatly improved by the introduction of better re- 

 lations between the nuniah and refiner and a revision of the 

 rules of the Salt Department in regard to both of them. 

 It seems clear that the profits of the trade are not equit- 

 ably divided between the nuniah and the refiner, the former 

 class, in consequence of its poverty and lack of business 

 capacity, being entirely at the mercy of the middleman or 

 refiner to the detriment of the industry as a whole. So far 

 as the methods of extraction and refining are concerned the 

 work of the Chemical Section of this Institute, as described 

 in Bulletin No. 24 by Messrs. Leather and Mukerji, has 

 demonstrated the possibility of great improvement in the 

 refining part of the process, and further investigation in 



