1866. ] Agriculture. 387 
pass through it, must not be applied till sprmg. It is thus plain 
that a comparison of ammonia salts with mtrates sown together in 
autumn will give very different results from a similar comparison 
made in spring time. As to mode:—Care must be taken to ensure 
the uniform distribution of the fertilizers. Concentrated manures 
should be mixed with at least three times their bulk of some harm- 
less diluent. The broadcast manure distributor should be employed 
to ensure their uniform application to grass or corn, or they may 
be sown by hand over the drilled fields for roots before the plough 
covers the dung in the drills by splitting the intervening ridgelets. 
4. A careful record must be kept of the composition of the 
manures employed, of the character of the soil, and of its past agri- 
cultural history, in order that the result may be read in the light of 
the information thus preserved. 
5. It is of the greatest importance that the experiment be 
devised so as to reply to a very simple question. If complicated 
mixtures of manures be used, the result cannot be attributed to its 
proper cause with any certainty. Let the experiment be devised so 
as to be sure that it shall answer “ yes” or “no,” as to the effect of 
a single ingredient. 
6. The experiments, moreover, must have regard to the fitness 
of the soil and climate to the plant which is employed to test the 
manures by. It is as useless to try the effect of manures on Indian 
corn in Scotland as it would be to test them by means of mangel 
wurzel in Sweden. So also the soil should be fitted to the habits of 
the plant. The lupine fails on land with a hard, cold subsoil, not 
because the food it requires is not present, but because its deep tap- 
root requires a subsoil in which it can extend. 
7. In reading the results of experiments, regard must be had to 
the character of the season, wet or dry, early or late, cold or warm. 
And extreme diligence should be used in noting all the successive 
appearances of the crop under variations of weather throughout the 
ear. 
Lastly, the operator must not only have unbounded patience— 
waiting long and putting his question frequently before he satisfies 
himself that he has got the answer—but he must have both pluck 
and self-denial enough to throw his results into the waste-paper 
basket, rather than mislead his brother farmers by the publication 
of unsatisfactory conclusions. 
On this same subject Professor Buckman has pointed out that 
careful observation by the farmer of the varying natural conditions 
under which the ordinary rules of farm practice are carried out, will 
often teach as much as can be learned from well-defined experiment, 
provided a careful record be kept of the field-results which are 
obtained under the varying circumstances of early or late farming, 
cold or warm, wet or dry air and soil, and even deep or shallow 
