Experiments upon Stoedcs. 
73 
diced. Thus, let a manure be ever so worthless, yet, if it be 
tried under varied conditions, it will for some reason or other 
prove in some few cases suj)erior to fertilizers of recognized 
merits. If we suppose that these accidental successes are 
recorded, and all the preponderating number of failures or ques- 
tionable successes ignored, we see at once how it comes to pass 
that artificial manures, like the British Economical manure and 
many others that possess little or no fertilizing value, arc never- 
theless strongly recommended, and that men of undoubted character 
are found to testify in good faith that such rubbish is superior to 
guano, bone-dust, and other well-known fertilizers. Testimonials 
of manures, even when given by the best and most experienced 
men, have little value ; and, as they are much more apt to lead 
astray than to do good, it would be well if leading agriculturists 
would abstain altogether from giving them. 
Nothing is more difficult than to establish by experiment a 
general truth in agriculture. We not only require to modify 
agricultural experiments in a great variety of ways, but, after we 
have continued them for a number of years and carefully re- 
corded the results, it is necessary to exercise the greatest caution 
in interpreting the results, and to look almost with suspicion on 
everything which at first sight appears plausible or even conclusive. 
The preceding experiments, beyond the lesson which they 
afford of diffidence in accepting points which are said to have 
been proved by practical experiment, teach us absolutely nothing. 
Field Experiments on Swedes made in 1859. 
The field selected for the experimental trials in 1859 was in 
tolerably good condition. It bore clover in 1857, and wheat in 
1858. The soil is moderately deep, and well-drained. A por- 
tion of the soil, taken from a large sample from different parts of 
the field, was submitted to analysis, and the following results 
obtained : — 
Composition of Soil from Experimental Field No. 7 of the Royal 
Agricultural College Farm, Cirencester. 
Moisture (when analysed) 3-960 
Organic matter and water of combination .. .. O-GIG 
Oxides of iron and alimiina 19'G60 
Carbonate of lime 3'805 
Sulphate of lime • .. -345 
Phosphoric acid -075 
Magnesia •783 
Potash 1-239 
Soda -090 
Insoluble siliceous matter (chiefly clay) .. .. 60-525 
100-098 
