On the Composition of Waters of Land-Vraincif/c. 143 



The results of the several analyses are incorporated in Table II. 

 (pp. 144, 145). 



By comparing the preceding analytical results with each other, 

 and with the analyses of the drainage-waters collected on the 

 6th December, 18(56, many points of interest are brought out, 

 to some of which I shall now direct attention. 



1. The total amount of fixed solid constituents varies from 

 16 J to 32-| grains per gallon in the several samples. It is smallest 

 in the drainage from the continuously unmanured Plots, No. o 

 and 4, which contained, in round numbers, only 16^ grains per 

 gallon of solid matter in solution. 



On Plot 16 the influence of the application of mixed mineral 

 and ammoniacal manures previous to 1865 is still perceptible in 

 the larger amount of soluble constituents which passed from the 

 land into the drainage, for it will be seen that the drainage from 

 Plot 16 contained 21*41 grains of solid matter per gallon, 

 whereas the drainage-water from the continuously unmanured 

 Plots contained only 16' 65 grains. 



On comparing the relative amounts of solid constituents in 

 the drainage from Plots 5, 6, 7, and 8, it will be seen that rain 

 falling upon land which has been manured with mineral manures 

 only, dissolves less mineral matter than from land upon which 

 both mineral and ammoniacal fertilizing inatters have been used. 

 Thus the drainage from Plot 5, manured with superphosphate 

 and sulphates of potash, soda, and magnesia, and without am- 

 moniacal salts, contained 20'25 grains of solid matter per gallon, 

 whilst the samples from the adjoining Plots 6, 7, and 8, treated 

 like Plot 5 as regards mineral manures, with the addition of 

 200 lbs., 400 lbs., and 600 lbs. of ammonia-salts respectively, 

 yielded 23*15 grains, 25*10 and 31*35 grains of soluble matter, 

 the largest dressing of ammonia-salts causing the largest amount 

 of mineral matters to appear in the drainage. 



The solvent action of ammonia-salts upon the mineral con- 

 stituents of the soil is likewise clearly traceable on Plots 11, 12, 

 13, and 14. 



On Plot 5, which had been manured from year to year with 

 mineral fertilizing matters without aminonia, the drainage con- 

 tained 20*25 grains of solid constituents, composed almost entirely 

 of mineral matter. The addition of ammonia-salts to the mineral 

 manures used on Plots 11, 12, 13, and 14, had the effect of 

 largely increasing the total amount of mineral constituents in 

 the drainage from them. 



At the same time it will be seen that ammonia-salts in a 

 great measure cease to abstract soluble mineral matters from 

 the land when they are applied to it for a great number of years. 

 Thus the drainage from Plot 10, dressed every year with 400 lbs. 



