On the Rain and Drainage - Waters at Rotliamsted. 261 
ences of composition due to season, very few of the samples 
having been collected either in the height of summer or the 
depth of winter. Thus out of the fifty-six samples there is not 
one collected in August, and but one in July ; there is but one 
in December, and there are only two each in November and 
January. The most abundant collections were in May, April, 
and September, among the summer months, and in February, 
March, and October, among the winter months. 
Table XIII. — The Composition of Rain-Water in relation to the 
Amount of Eainfall and Season of the Year. 
Total 
Solid 
Matter. 
Carbon 
Nitrogen as 
Quantity of RaiiifaU. 
Number 
Sample 
in 
Organic 
Matter. 
Organic 
Matter. 
Am- 
monia. 
Nitrates 
and Ni- 
trites.* 
Tokil 
Nitro- 
gen. 
Chlorine. 
In the Whole Yeak. 
Below 
•10 inch .. .. 
22 
38 
2 
0-95 
0 
21 
0-46 
0-12 
0-79 
4 
2 
From 
10 to -20 inch.. 
20 
36 
9 
1-19 
0 
23 
0-44 
0-17 
0-84 
3 
5 
From 
20 to -40 inch.. 
7 
3t 
9 
0-74 
0 
14 
0-23 
0-11 
0-48 
1 
8 
From 
50 to -90 inch.. 
7 
21 
5 
0-71 
0 
12 
0-26 
0-18 
0-56 
1 
5 
In the Summer Months, April to September. 
Below 
•10 inch .. .. 
10 
42 
2 
1-10 
0-17 
0-48 
0-17 
0-82 
3-2 
From • 
10 to -20 inch .. 
14 
41 
9 
1-18 
0-18 
0-43 
0-18 
0-79 
3 6 
From 
20 to -40 inch .. 
4 
42 
6 
1-01 
0-15 
0-25 
0-12 
0-52 
2-3 
From 
50 to -90 inch .. 
4 
26 
3 
0^97 
0-11 
0-35 
0-38 
0-84 
1:9 
In the Winter Months, October to March. 
Below 
•10 inch .. .. 
12 
35 
0 
0-83 
0-25 
0 
44 
0-10 
0-79 
5 
0 
From 
lOto •20inch.. 
6 
25 
1 
1-22 
0-33 
0 
48 
0-16 
0'97 
3 
3 
From 
20 to -40 inch.. 
3 
24 
6 
0-39 
0-13 
0 
20 
0-09 
0-42 
1 
2 
From 
50 to -90 inch.. 
3 
15 
1 
0-37 
0-14 
0 
14 
0^08 
0-36 
0 
9 
Notwithstanding, however, the small number, and partial 
distribution of the samples available for discussion, the result 
* The figures for the nitrogen present as nitrates and nitrites are the means of 
determinations made in the following samples : — 
Below •lO incli Summer, 2; Winter, 8; Whole Year, 10 samples. 
From -10 to -20 inch .. „ 7 „ 6 „ „ 13 „ 
From -20 to -40 inch .. „ 1 „ 1 „ „ 2 „ 
From • 50 to • 90 inch .. „ 1 „ 2 „ „ ?• „ 
