On the Composition of Waters of Land-Drainage. 135 



The first series of drainage-waters was collected on the 6th 

 December, 1866, at a full flow of the drains. 



From 2 to 3 gallons of each sample of water were received for 

 examination and submitted to careful analyses, which j'ielded 

 the results incorporated in Table I. (pp. 136, 137), showing 

 the constituents in the drainage-water in grains per gallon. 



A careful perusal of the results of these analyses will bring to 

 view a number of important and interesting particulars to which 

 attention may be usefully directed. 



1. In the first place it will be seen that the total amount of 

 solid constituents in a gallon of the several waters of land- 

 drainage varies greatly with the quantities and kinds of manure 

 which the different plots had received. 



The drainage from the continuously unmanured plots, Nos. 3 

 and 4, contained only 21 grains per gallon in round numbers, 

 whilst the plots highly manured both with mineral and am- 

 moniacal manures furnished drainage-waters containing from 48 

 to 56 grains of solid matter per gallon. Thus the drainage from 

 Plot 14 contained nearly three times as much solid constituents 

 as that from the unmanured Plots 3 and 4. 



2. The influence of the application of mineral and ammoniacal 

 manures previous to 1865, after which Plot 16 was left unmanured, 

 is still perceptible in the drainage from that plot, but only in a 

 slight degree ; it contained 23 grains of solid matter per gallon, 

 whilst the continuously unmanured Plots 3 and 4 gave only 21 

 grains. 



3. The application of ammonia-salts to the land increased the 

 proportion of mineral constituents in the drainage-water ; and, 

 as a rule, more mineral matter was found in the drainage from 

 plots which had received a heavier dressing of ammonia-salts 

 than those manured with more moderate quantities. 



Thus the drainage from the unmanured Plots 3 and 4 contained 

 21 grains of solid constituents per gallon ; Plot 5, manured with 

 mineral manures without ammonia-salts, 26*85 grains ; Plot 6, 

 manured with the same mineral manures as Plot 5, with the 

 addition of 200 lbs. of ammonia-salts, gave 37" 1 grains ; and 

 Plot 7, treated like Plot 5, and the addition of 400 lbs of ammonia- 

 salts, furnished land-drainage containing 48^ grains of solid con- 

 stituents per gallon. 



4. By comparing the proportions of lime in the several 

 drainage-waters, it will be seen that in the samples from plots 

 dressed with ammonia-salts it is much larger than in the 

 drainage from the unmanured plots, and from the plots upon 

 which no ammoniacal salts were applied. 



The actual amounts of lime in the different samples varied 

 from 8^ grains per gallon to 26 grains in round numbers. 



