4 Artificial Manures for Swedes. 



practices, that a knowledge of the principles on which 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 specific 

 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 which 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 we not recognise in some of 

 the facts to which 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 



