the Royal Agricultural Society. 
41 
this first idea by the no less important inquiry: If these mate- 
rials will not do, what will? 
It would far exceed the limits of this article to attempt any 
description of Lawes's extensive series of experiments. It would 
also be a work of supererogation, as they have been described by 
himself and Dr. Gilbert in this Journal, from time to time. But 
whilst endeavouring to describe the agricultural progress realised 
during the last twenty-five years we wish to record our deliberate 
conviction that there has not during that time been any addition 
made to our knowledge which approaches in importance to the 
insight obtained into the true princij)les of cropping and manuring 
on the experimental farm at Rothamsted. 
It will probably not be considered unpardonable egotism in the 
writer to place next in importance to the Rothamsted results the 
discovery which he first had the pleasure of announcing to agri- 
culturists, viz., the absorbent power of soils, or the power possessed 
by the soil of decomposing and retaining for the sustenance of 
plants the ammoniacal and other salts which form the most 
valuable constituents of manure.* This principle, which was 
further investigated and much extended by Professor Way, 
formed the subject of several valuable papers in the Journal, 
from his pen.| 
The true principles of land drainage have been keenly dis- 
cussed during the period under consideration, and have to a 
great extent been settled by common consent, the exceptions 
being chiefly due to peculiar geological combinations or irre- 
gularities confined to particular localities. Our increased know- 
ledge of the art of draining will be best appreciated by again 
referring to Mr. Pusey's Address of March, 1839. Speaking 
of Smith of Deanston's system, he says, " it is impossible to pass 
it over, although, of course, its introduction is too new to be 
placed already altogether beyond the reach of disappointment. 
Mr. Smith's mode of dealing with a clayey subsoil which holds 
up in the soil the water that has fallen in rain, and thus exerts 
some unexplained evil influence on plants fitted for the food of 
man or of cattle, is as follows." . . . After describing the plough 
and its mode of action, he continues : " The share of the subsoil- 
plough following, passes through and splits the whole of the sub- 
soil to the depth of 18 or 20 inches, and the rain-water sinks, of 
course, so much lower. Mr. Smith, however, does not allow the 
rain to lodge here ; he has previously dug covered drains about 
3 feet deep, made thus deep in older that his underground plough 
may have room to pass over the covered channel." ... It thus ap- 
* ' Journal,' -vol. xi. p. 68. 
t Ibid. vol. xi. p. 313; vol. xiii. p. 123 ; vol. xv. p. 491. 
