26 



COMBINED NITROGEN 



Eothamsted was made by Frankland and published in 1881 and 1882 l 

 by Lawes, Gilbert and Warington. From sixty-nine samples collected 

 in 1869-70 the following numbers were obtained. (Parts per million) : 



In 1888-9 a series of monthly determinations of the amounts of 

 ammonia and nitric acid in the rainfall at Eothamsted was made by 

 Warington.' 2 The results are given in the accompanying table : 



This gives a total of combined nitrogen in the rain of 3 '74 lb. per 

 acre per annum. 



The mean amount from seven Continental agricultural stations 

 between 1864 and 1872 is 0-4:7 parts of nitrogen as nitric acid per million, 

 and 1-26 parts of ammonia per million in the rain, yielding a total fall 

 of 10*18 lb. of combined nitrogen per acre. 



Eesults obtained in New Zealand and in Japan agree better with 

 the Eothamsted results. 



On the other hand, Miintz and Marcano 3 in 1883-5, as the 

 result of over 120 analyses of rain-water in Venezuela, found as a mean 

 2-23 parts of nitric acid per million (equal to 0-578 parts of nitrogen), the 



1 Jour. Hoy. Agric. Soc., 1881 and 1882. 



2 Jour. Chem. Soc., 1889, 537. 



:{ Compt. Kend., 108, 1062; Jour. Chem. Soc., 1889, Abstracts, 923. 



