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XVII. — On the Amount and Composition of the Rain and 
Draina(je -Waters collected at Roihamsted. Parts I. and II. 
By J. "b. Lawes, LL.D., F.R.S., F.C.S., J. H. Gilbert, 
Ph.D., F.R.S., F.C.S., and R. Warington, F.C.S. 
contents : 
Introduction. 
Part I. — The Amount and Composition of the EainfoU (p. 242). 
1. The Rain-gauges (p. 242). 
2. Amount of the Rainfall (p. 244). 
3. Composition of the Rain-water (p. 249). 
Part 11. — The Amount and Composition of the Drainage- 
waters from unmanured fallow land (p. 269). 
1. The Drain-gauges (p. 269). ; 
2. The measured Drainage, and the Evaporation (p. 271).* 
3. Composition of the Drainage-waters.* 
Introduction. 
It is proposed to collect together in the present paper the 
results of all the investigations relating to the Rain and 
Drainage-waters of Rothamsted. A part of these investigations 
has been already published — as the determinations of Ammonia 
in Rain, communicated to the British Association in 1854 ; 
the determinations of Ammonia and Nitric Acid in Rain by 
Prof. Way, published in this 'Journal' in 1857 ; the numerous 
analyses of the Rain and Drainage-waters by Dr. Frankland, pub- 
lished in the Sixth Report of the Rivers' Pollution Commission, 
1874 ; and the analyses of the Drainage-waters published by 
Dr. Voelcker in this ' Journal ' in 1874. Some of these results 
are inaccessible to most readers ; many of them we have never 
yet had an opportunity of discussing fully. f Having there- 
fore a considerable amount of new matter to bring forward, 
it has seemed best to treat the subject as a whole, and to discuss 
as concisely as possible the relation of all the facts hitherto 
ascertained, bringing the record down to the present time. 
The subject will divide itself into Four Parts. The First 
Part will treat of the amount and composition of the Rainfall. 
The Second Part will embrace the results relating to Drainage 
* Section 2 is not completed in the present paper for want of space, and 
Section 3 is for the same reason postponed ; it is hoped that the matter now 
omitted will appear in the next number of this ' Journal.' 
t Some of the bearings of these earlier investigations have been already- 
pointed out in Eothamsted Reports, which have appeared in this ' Journal.' 
See papers on the ' Effects of the Drought of 1870 on some of the Experimental 
Crops at Rothamsted,' 1871 ; 'Report of Experiments on the Growth of Barley 
for Twenty Years in succession on the same Land,' 1873, pp. 367-372 ; ' Our 
Climate and our Wheat Crops,' 1880, pp. 199-210. 
VOL. XVII. — S. S. R 
