On the Rain and Drainage - Waters at Rothamsted. 
343 
winter of 1879-80, wc arc not disposed to think that the 
general bearing ol" tlie results has been disturbed by the occa- 
sional presence of worms. It must also be recollected that 
animal life is present in all soils, indeed, often to a far greater 
extent than is usually imagined, and that the nitrification of the 
ammonia resulting from decaying animal matter is therefore not 
an abnormal occurrence, but one of the ordinary sources of the 
nitric acid in drainage-water. 
We have just stated that ammonia is not a usual constituent 
of the drainage-water from the gauges. The waters have also 
been from time to time examined for nitrous acid, but nothing 
beyond a minute trace has ever been found. The process of 
nitrification in the soil is clearly very complete. 
Turning now to the determinations contained in Table 
XXXIV. (p. 344) we shall at once remark the much lower 
amount of nitric acid contained in the drainage from the 40-inch 
gauge, as compared with that found in the drainage from the 
other gauges. Taking the average composition of the whole 
amount of drainage irom the three gauges during forty-eight 
months,''we have for the 20-inch gauge, 11-8 ; for the 40-inch 
gauge, 8*9 ; and for the 60-inch gauge, 11'5 parts of nitrogen as 
nitrates per million of water. This considerable deficiency of 
nitrates in the drainage from the 40-inch gauge is apparent in 
Frankland's earliest analyses of these drainage-waters ; it is 
probably, therefore, due to some original difference in the com- 
position of the soils. No such difference is perceived in the 
proportion of chlorides contained in the three drainage-waters, 
which average 3'9, 3*9, and 3'8 parts of chlorine per million. 
There is not much regularity of sequence visible in the pro- 
portion of nitrates and chlorides found from month to month in 
the drainage-waters, and still less in the weights of nitrogen 
and chlorine removed monthly from the soil in this manner. 
The conditions suitable for nitrification — the temperature and 
humidity of the soil, have varied extremely ; the monthly amounts 
of drainage have varied quite as much. Both the production 
and removal of nitrates have thus proceeded very irregularly. 
A reference to Table XV. will show that the supply of chlorides 
in the rain has been equally irregular. The series is too short 
for these irregularities to disappear by taking an average of the 
monthly results ; we must, therefore, confine our attention to a 
few principal points. 
The two facts we have already pointed out in the earlier re- 
sults find here fresh illustration ; thus the drainage-waters are 
seen to be generally richest in nitrates from July to October, 
and poorest from April to June. The extremely wet and cold, 
summer of 1879 forms an exception ; the waters did not here 
VOL. XVII.— S. S. 2 B 
