856 EXPERIMENT STATION RECORD. 



main stream ami its various tributaries, and the effects which have been produced 

 by industrial and domestic pollution. 



"Of special importance are the statements concerning the effect <>f mine wastes. 

 It is shown that such wastes are not without their beneficial effects, especially in 

 those parts of the river which have been set aside as areas for sewage disposal. The 

 discussion of this matter, together with the consideration of the amount of mine 

 wastes discharged into Susquehanna River, is one of the important features of the 

 paper." 



The amounts of nitrogen as ammonia and as nitric acid, and of chlorin 

 in the rainwater collected at Rothamsted, N. 11. J. Miller (J'ror. Chem. Soc. 

 | London], 18 ( 1902), No. 250, pp. 88, 89'; abs. in < 'entbl. Agr. < 'hem., 34 ( 1905) , No. 1, pp. 

 /, .').-" Results of monthly determinations of nitrogen as ammonia and as nitrates 

 in the rainwater collected during 13 harvest years (September, L888, to August, 

 1901 ) at Rothamsted, showed that the total nitrogen in these forms varied from 3.31 

 lhs. to 4.4.'! lbs. per acre per annum," the average for the year being 3.84 lbs. "Of 

 the total nitrogen 70 per cent was present as ammonia and 30 per cent as nitrates. 

 During the summer months there was an increased production of ammonia, whilst 

 the amount of nitric nitrogen (per acre) was nearly the same in summer as in 

 winter." 



The results of monthly determinations of chlorin during 24 years show that " the 

 yearly amounts of chlorin in the rain vary considerably (maximum 21.19, minimum 

 10.32 lbs. per acre). The variations depend lesson the total rainfall for the year 

 than on the amount of rain during the winter months. The rain falling at Rotham- 

 sted supplies not only sufficient chlorin, hut also enough sulphuric acid for the 

 requirements of most crops." 



The amounts of nitrogen, as nitrates, and chlorin in the drainage through 

 uncropped and unmanured land, N. H. J. Miller (Proc. Chew. Soc. [London], 

 18 {1902), No. 250, pp. 89, 90; abs. in Centbl. Agr. Chem., 34 (190.5), No. 1, pp. 65, 

 66). — The results of studies on this subject are thus summarized by the author: 



"The percolation through the 20, 40, and 00 in. of soil in the three Barnfield drain 

 gages amounted during 24 harvest years (September, 1877, to August, 1901) to 14.:!0, 

 15.30, and 14.41 in. per annum, being 50, 53.2, and 50.1 per cent, respectively, of the 

 rainfall for the same period. The maximum and minimum drainage occur in Novem- 

 ber and June. 



"The average loss of nitrogen, as nitrates, in the drainage is more than 30 lhs. per 

 acre per annum, and about half of this loss takes place during October, November, 

 and December. The yearly losses of nitrogen differ widely, according to the amount 

 and distribution of the rain and drainage. This makes it difficult to form a decided 

 opinion as to whether nitrification is less active at the present time than in earlier 

 years. A very decided falling off is perhaps not to be expected in the near future. 

 The sod of the 20-in. gage is estimated to have contained, in 1870, as much as 6,000 

 lbs. of nitrogen per acre, and of this amount only about 15 per cent has been found 

 in the drainage; in the case of the 60-in. gage, the estimated loss is only 6.5 per cent 

 of the total initial nitrogen of the soil, in addition to loss of nitrogen, there is, 

 however, a considerable loss of lime, amounting to 11 lbs. per acre (or about 20 lhs. 

 of calcium carbonate) per inch of drainage, and this loss may, as time goes on, be 

 expected to influence the changes in the organic matter of the soils. 



"The average yearly amounts of chlorin per acre in the drainage is very similar 

 to the amount found in the rain, but wide differences occur in some individual years. 

 In the 24 years during which the chlorin has been determined, the soils of the 20-in. 

 and 40-in. gages have received from the rain 7 and 14.4 lbs. of chlorin per acre in 

 excess of the amounts lost in drainage. The40-in. gage has lost 17.5 lbs. of chlorin." 



Contribution to the solution of the question of the relation of the water 

 content of the soil to the water requirements of plants, C. von Seeliiorst and 



