300 AGRICULTURAL, ANALYSIS 



the honesty of the dealer, is the only protector of the farmer in 

 guarding against the practice of adulteration of sodium nitrate. 

 Even the honest dealer is compelled to protect himself against 

 fraud, and therefore, the world over, commerce in this fertilizer 

 is now conducted solely on the analyst's certificate. Happily, 

 therefore, adulteration is almost unknown, because it is certain 

 to be detected. Formerly, the saltpeter was adulterated with 

 common salt, or low grade salts from the potash mines; but it 

 is an extremely rare thing now to find any impurities in the salts 

 other than those naturally present. 



In every case the analyst may grow suspicious when he finds 

 the content of nitrogen in a sample to fall below 13 per cent. It 

 must not be forgotten, however, that some potassium nitrate may 

 be present in the sample, and since that salt contains only 13.87 

 per cent, of nitrogen, its presence would tend to lower the value 

 of the fertilizer; but although the potash itself is a fertilizer of 

 value, it is not worth more than one-third as much as nitrogen. 

 In all cases of suspected adulteration, it is advisable to make 

 a complete analysis. The results of this work will, as a rule, 

 lead the analyst to a correct judgment. 



264. The Application of Chile Saltpeter to the Soil. The 

 analyst is often asked to determine the desirability of the use of 

 sodium nitrate as a fertilizer and the methods and times of ap- 

 plying it. These are questions which are scarcely germane to 

 the purpose of this work, but which, nevertheless, for the sake 

 of convenience, may be briefly discussed. In the first place, it 

 may be said that the data of a chance chemical analysis will not 

 afford a sufficiently broad basis for an answer. A given soil 

 may be very rich in nitrogen as revealed by chemical analysis, 

 and yet poor in art available supply. This is frequently the case 

 with vegetable soils, containing, as they do, large quantities of 

 nitrogen, but holding it in practically an inert state. I have 

 found such soils very rich in nitrogen, yet almost entirely devoid 

 of nitrifying organisms. It is necessary, therefore, in reaching a 

 judgment on this subject from analytical data to consider the 

 different states in which the nitrogen may exist in a soil, and 

 above all, the nitrifying power of the soil if the nitrogen be 



