Artificial Manures for Swedes. 
91 
practices, that a knowledge of the principles on wliicli the 
fertilising effects of manuring matters depend is by no means so 
generally spread amongst the agricultural community as it is 
desirable it should be? Do they not show that the sjiecific 
action even of our standard fertilisers is unknown to many, and 
that consequently the choice of a manure for a particular crop is 
more regulated by chance or habit than by a consideration of the 
peculiar effects on vegetation whicli characterise many manures ? 
How often do we not see a manure which has been employed 
upon wheat with considerable benefit, indiscriminately applied 
on every description of crops ? Do Ave not recognise in some of 
the facts to whicli allusion has been made, a reluctance of many 
to change a manure which hitherto has been used with advantage 
for another, recommended by the best authorities as a superior 
fertiliser ? and on the other hand a willingness in others to 
submit to an experimental test that which is not really worth the 
trouble of trial ? I do not doubt most readers will reply to these 
queries in the affirmative. But, I think, we may recognise still 
more in the proffered observations. It strikes me, that a trial in 
the field with different manuring matters is often considered an 
easy thing, whereas it is in reality a difficult task to perform a 
good field experiment. The reasons of this are obvious. The 
neglect of a single point which ought to have been attended to in 
the execution of an experimental trial in the field, or the com- 
mission of a fault, which cannot in this instance be so readily 
remedied as many other mistakes, or uncontrollable circumstances 
which interfere, but which pass by unnoticed, at once spoil the 
final result of the experiment, and consequently the inferences 
■deduced from it are erroneous and apt to lead astray. Indeed 
a review of most published experimental field trials has convinced 
me, that comparatively speaking few have been undertaken with 
that amount of caution, candour, care, practical and scientific 
skill, premeditation, power of observation and general intelli- 
gence, which is requisite for the performance of a field experiment 
from the result of which trustworthy practical inferences can be 
deduced ; and I have no hesitation in saying that the suppression 
of the majority of our recorded field trials with different manures 
would be a benefit to the agricultural community, inasmuch as 
they are calculated to mislead instead of to direct the practical 
man in his operations on the farm. 
Then again, often no regard is had to the composition and 
physical properties of the soil on which experiments are tried ; 
no notice is taken of the mechanical state of preparation in 
which it is found at the time when the experiment is made ; 
casualties, such as the partial destruction of the crop by insects, 
unpropitious weather, &c., are overlooked ; manures differing 
