21 



is contributed by the rain falling from October to March, and 

 the rest (8*3 Ib.) by the spring and summer rains (April to 

 September). This difference is all the more striking as 

 the rainfall of the two six-monthly periods is almost the same. 

 The yearly amounts of chlorine per acre vary considerably, 

 and the variations depend more on the distribution of the 

 rainfall during the year than on the total fall. 



TABLE VIII. Comparison of Maximum and Minimum 

 Precipitation of Rain and Chlorine. 



No recent determinations of sulphuric acid in rain-water 

 have been made at Rothamsted, but a summary of the results 

 obtained in 1881-7 is given here to complete the record. 



Reference to the Table (IX.) will show that the rain 

 contains on the average 2'57 per million of sulphuric acid 



TABLE IX. Sulphuric Acid and Chlorine in Rain-water collected at 



Rothamsted. 



(as SO 3 ), and that the total annual amount per acre is 

 17*41 Ib. The most noteworthy result is the close agreement 

 between the amounts furnished by the summer and winter 

 rain, especially in view of the great variations in the chlorine. 

 In conclusion, it may be pointed out that the rain falling 



