On the Rain and Drainage - Waters at Rothamstccl. 347 
the rain of winter is richer than that of summer. The winter 
drainage contains a larger proportion of chlorides than the 
summer drainage ; and a maximum proportion of chlorides is 
sometimes reached towards the end of winter. The maximum, 
however, generally occurs towards the end of summer, or the 
beginning of autumn, the great evaporation of rain from the 
soil during summer storing up chlorides in a more than usually 
concentrated form. In a cold and wet summer, like that of 
1879, this period of maximum is not perceptible. 
If we look at the quantities of chlorine removed by the 
drainage-waters per acre of soil, we shall find a pretty close 
agreement with the quantities of chlorine already given as con- 
tained in the rain for the same period (Table XV., p. 264). In 
forty-three months the amount of chlorine supplied by the rain 
amounted to 47"601bs. per acre, or really to somewhat more, as 
the method of analysis employed gave rather low results. The 
quantities of chlorine removed in the drainage- waters during the 
same time were respectively 52-90 lbs., 57-34 lbs., and 51-50 lbs. 
for the three gauges. There can, therefore, be little doubt that 
the soil has been completely washed out, and is now dependent 
on the rain for all the chlorides it contains. 
The quantity of nitrogen as nitrates, and of chlorine removed 
by the drainage-water from an acre of soil during each of the 
three drainage years included in the period of the experiment,, 
will be found in Table XXXV. ; the results are arranged in the 
order of the amount of drainage. 
Table XXXV. — Amounts of Nitrogen as Nitrates, and Chlorine as 
Chlorides, contained in the Drainage- Water from the three Drain- 
Gauges in Three Drainage Years (Oct. to Sept.) 
20-Inch Drain-Gauge. 
40-Inch Drain-Gauge. 
60-Inch Drain-Gauge. 
Year. 
Drainage 
Inches. 
Nitrogen 
lbs. 
per Acre. 
Chlorine 
lbs. 
per Acre. 
Year. 
Drainage 
Inches. 
Nitrogen 
lbs. 
per Acre, 
Chlorine 
lbs. 
per Acre. 
Year. 
Drainage 
Inches. 
Nitrogen 
lbs. 
per Acre. 
Chlorine 
lbs. 
per Acre. 
1S79-80 
1877- 8 
1878- 9 
9-743 
14'591 
26-772 
39-78 
43-87 
62-27 
8-13 
15-31 
20-30 
1879-80 
1877- 8 
1878- 8 
10-326 
16-605 
26-907 
'27-44 
38-95 
48-29 
8-94 
17-74 
21-55 
1879-80 
1877- 8 
1878- 9 
9-354 
15-734 
25-186 
28-11 
45-45 
63-29 
7-49 
15-65 
19-96 
Mean 
17-035 
48-64 
14-58 
Mean 
17-946 
33-23 
16-03 
Mean 
16-774 
45-62 
14-36 
These three years fortunately include some very different 
seasons. In 1879-80 we have a year in which the drainage is 
rather below the normal quantity, and in 1878-9 we have a 
year in which the drainage is considerably more than twice the 
normal quantity. We see that an increase in the amount of 
