Annual Clicmical Re[:ort. 
337 
tlie addition of muriate of potash to superphosphate, in the 
Escrick exporinients, very materially raised the increase of 
the crop over that produced by muriate of potash alone. 
We may learn from these experiments that a most useful 
fertilising agent like phosphate of lime may in some instances 
remain ineffective, because the soil to which the former has been 
applied is deficient in another equally essential plant-consti- 
tuent, such as potash. The analysis of the soil from the' ex- 
perimental field, indeed, showed only traces of potash, and this 
no doubt is the reason why the artificial supply of muriate of 
potash, especially in conjunction with superphosphate, was at- 
tended with so remarkably good an effect, and also that the latter 
alone did not produce a good result. 
Whilst I have to report favourably on the employment of 
a mixture of superphosphate and muriate of potash in the pre- 
ceding experiments, and also in a similar experiment carried on 
last season in Berkshire, by Mr. Kimber, of Tubney Warren, 
Abingdon, I am bound to state, that in other experiments made 
last season, potash had little or no effect in raising the produce of 
the land. Indeed, my present experience leads me to think, that 
Avhilst potash-salts in conjunction with phosphates are very 
useful in the case of certain poor sandy soils, their special 
application to land in a good agricultural condition, or to soils 
containing an appreciable quantity of clay, does not appear to 
yield results commensurate with the price at which potash-salts 
can at present be bought. 
1 have only briefly alluded to the chief points of interest which 
1 noticed in the field-experiments instituted by me in 1867, as I 
purpose giving a detailed account of them in a future volume of 
the Society's ' Journal.' 
In the past season my attention was occupied with an in- 
vestigation into the chemical composition of drainage-water pro- 
ceeding from land continuously manured with ammoniacal and 
other nitrogenous manures, and from land left continuously un- 
manured or dressed with mineral fertilisers only ; the materials 
for carrying on this investigation having been kindly placed at 
my disposal by Mr. Lawes. Drains were opened by his direc- 
tions in the experimental field at Rothamsted, where wheat was 
grown for more than 25 years in succession with a variety of 
manures, both nitrogenous and mineral, and the drainage-water 
from eleven sections of the field was sent to me at various times 
throughout the year. The investigation which has already yielded 
very interesting results, having an intimate and important bearing 
on the exhaustion of land, and the physiological laws which 
govern the growth of plants, is still in progress, and likely to 
occupy my attention for the next two years, for it has opened 
up quite a mine of theoretical inquirj-. 
