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V, — Effects of the Drouyht 0/ 1870 on some of the Experiment<il 
Crops at Rothamsted. By J. B. Lawes, Esq., F.R.S., F.C.S., 
and J. H. Gilbert, Ph. D., F.R.S., F.C.S. 
The rainfall of Great Britain is usually sufficient for the growth 
of a considerable variety of crops, in fairly abundant quantity. 
Indeed, so far at least as the growth of corn is concerned, our 
fears are of injury from an excess rather than from a deficiency 
of rain. It is only occasionally, and generally at long intervals, 
that a season of great drought occurs ; and then it is that we 
forcibly realise how essential for luxuriant vegetation is an 
abundant supply of water. 
Throughout the Midland, Southern, and Eastern portions of 
England, the year 1870, just past, has been characterised by 
a season of drought, commencing with the period when vegetation 
usually becomes active, and extending, with little intermission, to 
the time when its activity has upon the whole greatly diminished, 
and in the case of some crops entirely ceased. To find a parallel 
we must go back to 1844, or more than a quarter of a century. 
The summer of 1868 was, it is true, one of great drought ; and, 
being hotter than that of 1870, it is not improbable that there 
was at some periods of it a greater deficiency of moisture in the 
soil than in the latter year. In fact, those who travelled through 
the Southern and Midland counties of England in July, 1868, 
will not soon forget the almost entire absence of green in the 
meadows, and the intense heat of the atmosphere, resembling 
more what we read of in tropical countries than the usual expe- 
rience of our own summers. Although both the drought and 
heat were more extreme during the months of May, June, and 
July in 1868 than in 1870, the deficiency of rain commenced a 
, month earlier and extended later last year ; and hence, not only 
the first crops of grass and hay, but also the second growth, 
suffered much more in the season just past than in 1868. 
It is only when crops are grown under precisely similar 
circumstances, as to manure and other conditions, for many 
years in succession, that we can obtain satisfactory data for 
studying the influence of variation of season on the amount and 
character of the produce. At Rothamsted, as is known to most 
of the readers of this Journal, numerous experiments on the 
growth of various crops, each grown year after year on the same 
land, with different descriptions of manure, the same description 
being applied year after year to the same plot, have been carried 
on without change for many years ; in some cases reaching back 
as far as the drought of 1844, above referred to. Taking 
