32 Experiments on the Growth of fVheat. 
been as follows: — In 1853, turnips, dressed witli 2 cwts. <i;uano 
and 3 cwts. superphosphate of lime per acre, and the whole of 
the crop fed on the land ; in 1854, barley ; and a good dressing 
of London dung- for beans in 1855 ; this being the usual pre- 
paration for wheat in that locality. The land was, therefore, to 
use Mr. Eley's words, " in a well-cultivated and fertile state." 
It was, in fact, as the results will show, in higher condition than 
was desirable when the object was to determine the character of 
the exhaustion, and therefore the character of the manures 
required for the crop, in that particular soil, under the ordinary 
system of cropping and management adopted. The action of 
the different manures was, however, sufficiently characteristic 
after the first ciop of wheat had been taken. 
The manures were always mixed at Rothamsted, from the same 
stocks as those employed for the Rothamsted experiments. The 
arrangement of the experiments, and the description and quan- 
tities of manure applied per acre, were as follows : — 
Plot 1. Unmanured. 
Plot 2. Mixed mineral manure, composed of — 
300 lbs. sulphate of potass. 
200 lbs. sulphate of soda. 
100 lbs. sulphate of magnesia, 
200 lbs. bone-ash i o i i ^ r i- 
T rn 11 11 • -1* > ouperphosphate ol hnic. 
150 lbs. sulphuric acid* j i r i 
Plot 3. Ammonia-salts, comprising — 
200 lbs. sulphate of ammonia. 
200 lbs. muriate of ammonia. 
Plot 4. " Ammonia-salts " (as plot 3), and " mixed mineral 
manure " (as plot 2). 
Plot 5. 540 lbs. Peruvian guano. 
Plot 6. 2000 lbs. rape cake. 
Plot 7. 14 tons farmyard manure. 
The above quantities were applied annually for the first three 
years of the experiments ; the arrangement was also the same for 
the fourth year, with the exception that in experiments 2 and 4 
the quantities of sulphate of potass were reduced from 300 lbs. to 
200 lbs., and of sulphate of soda from 200 lbs. to 100 lbs. per 
acre. In the fifth and sixth seasons the crop was grown without 
any fresh application of manure. 
By means of experiment 1, we ascertain the state of produc- 
tiveness of the land without any manure, and so provide a stan- 
dard by which to compare the effects of the different manures. 
By means of experiments 2, 3, 4, 6, and 7, it is ascertained 
whether a specially mineral, nitrogenous, or carbonaceous manure, 
* Sp. gr. 1 • 7. 
