ACTION OF NITRIC ACID IN NEUTRALIZING ALKALINE SOIL. 47 



The pot on the left of each photograph, Nos. 1 and 5, 

 contain the alkaline soil untreated; the other three pots 

 contain the same soil in which the injurious effects of the 

 alkali have been corrected by the addition of nitric acid. 

 Nos. 2 and 6 received *2 per cent. Nos. 3 and 7 received *5 

 per cent., and Nos. 4 and 8 received 1 per cent, nitric acid. 



Two grains only of wheat were grown in each pot, con- 

 sequently it is fair to assume that the "stooling " properties 

 of wheat are greatly assisted by the process, and as the 

 pots containing *2°/° HN0 3 show an increase in the yield, 

 practically equal to those containing l°/», it is only reason- 

 able to suppose that the same result would be obtained by 

 the use of a much lower percentage of acid. 



From these experiments, which must be regarded as 

 purely of a preliminary nature, it is quite impossible to 

 attempt to estimate the cost, and until the experiment has 

 been tried in the field on a comparatively large area, I 

 would prefer not to express an opinion on this point. Mr. 

 Guthrie, Ohemist, Department of Agriculture, on seeing 

 the photographs of this experiment, sent to Moree for some 

 alkaline soil, and kindly made arrangements for me to carry 

 out larger pot experiments at the Botanic Gardens; the 

 results of these experiments will form the subject of a 

 paper now in preparation. 



The mechanical power derivable from the pressure given 

 in the outflow from artesian bores could probably be turned 

 to account in producing, on the spot, electro-chemical nitric 

 acid from the atmosphere, a process which is now being 

 successfully carried out in Europe, at a cost of £8 3s. 6d. 

 per ton. As the cost of raw material and power is nil, it is 

 simply a question of plant, working expenses, and intelli- 

 gent supervision. I am certainly of the opinion that this 

 will be of the utmost importance in the future irrigation 

 scheme of New South Wales. 



