■334 On the Rain and Drainage - Waters at Rothamsted. 
Table XXX. — Results of Percolation after a Double Quantity 
of Nitrate of Sodium had been ai^plied to the Soil. 
Water put 
on. 
Grams. 
Drainage 
obtained. 
Grams. 
Nitrogen as Nitrates and Nitrites, 
in Drainage-Water. 
Per Million. 
120 
118'3 
none 
none 
120 
117-2 
none 
none 
120 
112-2 
noue 
none 
120 
1260 
none 
noue 
120 
126-7 
7-6 
0-00096 
120 
110-9 
119 3 
0-01430 
120 
119-0 
288-3 
0-03457 
120 
119-5 
29i-8 
0-03.523 
120 
120-7 
136-2 
0-01644 
120 
122-4 
11-9 
0-00146 
120 
115-1 
0-8 
0-00009 
1320 
1317-9 
0-10305 
Grams. 
We will now turn to the composition of the drainage-waters 
obtained from the soils of the three drain-gauges. The first 
series of analyses was made by Dr. Frankland ; the analyses 
are published in the ' Sixth Report of the Rivers' Pollution 
Commission, 1874,' p. 62. The results appear in Table XXXI. 
Samples of the drainage-water were thus collected from all 
three gauges on five different occasions ; on each occasion, 
■except the last, drainage was taking place pretty freely when 
the collection was made. 
The first collection (Nov. 20-23, 1870) was made about two 
months after the gauges were completed. The summer had 
been a very dry one. No considerable drainage had taken 
place before the collection of the samples ; this was especially 
true in the case of the 40 and 60-inch gauges. The waters 
analysed were clear. 
The second collection, December 15-17, 1870, was about a 
month after the first ; in the interval between the two collections 
a moderate amount of drainage had occurred. The waters 
analysed were all turbid. 
The third collection, Oct. 30-31, 1872, occurred about two 
years after the first. The preceding summer had been very dry, 
but between two and three inches of drainage had occurred in 
October before the collection of the samples. The waters were 
slightly turbid. 
The fourth collection, February 25-26, 1873, was made under 
very different circumstances. The preceding four months had 
in this case been very wet, about 12 inches of drain-water having 
come through the 20-inch gauge. The waters collected arose 
from the melting of snow ; all were turbid. 
