VARIOUS MANURES. 133 



titles. The nitrogen is absorbed by the root in the 

 state of ammonia or combined with an acid, and forms 

 soUible salts ; which do not all come from the soil, bnt 

 about one-half from the air. Of chemicals to form a 

 nitric fertilizer, we have at our disposal nitrate of soda 

 and potassa and sulphate of ammonia. The advan- 

 tage of the latter is that it can be taken up immedi- 

 ately by the plant, whilst the nitrate has to undergo 

 certain changes, the alkali acting a very secondary 

 part when compared with the nitrogen. 



Mr. Yivien contends that the variation of the action 

 of the nitrates is mainly due to the amount of nitrogen 

 which the air happens to contain, and varies from year 

 to year ; for example, in 1870, with the same amount 

 of fertilizer, the sugar contained in the beet was far 

 less than in years previous. If a large yield of beets 

 is desired it is indifferent in what shape this element is 

 furnished, but when this is of secondary importance, 

 as compared to quality, it is Avell not to surpass 100 lbs. 

 of nitrogen to the acre. If a certain amount of phos- 

 phate of lime is properly united with the same the bad 

 effects of an excess will be much diminished. From 

 what has been said it is easy to understand what an 

 important element the nitrogen is. 



Nitrate of Soda. — For years in France this fertilizer 

 created a great furor, and the importation from foreign 

 countries for a given period, which was very large, all 

 of a sudden fell to a small figure. This was caused 

 by the final exhausting influence which experience 



