S2Q = 560 Iiifluence of Chemical Discoveries on 
salts supplying 82 lbs. of nitrogen per acre, I found on analyi 
in the middle of January 1868, as much as 3f parts of nit 
gen, in the form of nitrates and nitrites, per 100,000 of wai 
For every inch of rain passing through the drains of tl 
plot in January, there was consequently a loss of about 8.;^ I 
of nitrogen, supplied in manure at a cost of about \s. per i 
Assuming that during continued wet weather in winter sevel 
inches of rain pass through the drains, and that, in the cou j < 
of the autumn, winter, and spring, from 7 to 10 inches will p j { 
beyond the reach of the roots, the loss in nitrogen must be vi ' * 
great. Future analyses of drainage-waters, collected under ci • f| 
ditions which allow the exact quantity of water passing throu i i, 
the land to be measured, will probably show that b}- far « \ 
larger proportion of the nitrogen of manure not recovered in i 'i 
crop is lost by drainage. 
Results of My investigations into the composition of waters of lai - 
into rompo-" drainage, embracing full analyses of 70 samples, in addition) 1 
sition of waters the light which they threw on the loss of nitrogen experienc ^ i 
of land- during the growth of corn-crops, disclosed chemical facts wh i i 
drainage. turned to good account by all who desire to apply fai - ( 
yard manure, or artificial fertilisers, in a rational way to ; < 
land, so as to derive the greatest benefit from them. Th? ' 
analyses of the drainage-waters from the different plots of j I 
same field, variously treated as regards the supply of mam , i 
afford striking illustrations of the power of soils to modify s A 
composition of the manure used, and to prepare plant-fo , i 
which is neither so soluble as to injure the crop, nor so - l( 
soluble as to remain inactive. < 
It is remarkable that although large quantities of ammor - t 
salts were applied to some of the plots of the experimental wh< - i 
field, the drainage-water from these plots contained onlyfi .td 
traces of ammonia ; but at all times of the year they contai i « 
nitrates in appreciable quantities, which appears to rcndc t | 
very probable that it is chiefly, if not solely, from nitrates 1 .t 4 
our crops build up their nitrogenous organic constitue 5. | 
Although the drainage-waters were found to contain appreci; e | 
quantities of phosphoric acid and potash, nevertheless these, e i 
more valuable, mineral fertilising constituents supplied in e 
manures were retained in the land almost entirely, whilst iC 
less important, because more abundant and widely distribi d 
mineral matters, such as lime, magnesia, soda, chlorine, sulph ic 
acid, and soluble silica, pass into the waters of land-tlrair ;e 
in considerable quantities. ' 
As may be naturally ex})ected, the loss of fertilising mat ra 
by drainage is greater from highly manured fields, than f n 
land left unmanured, and greater during the autumn and wi Ml 
