178 



Anniversary Meeting, 



[Nov. 30, 



"Wheat, for example, was grown year after year upon the same land for 

 twenty-four years ; turnips (with an interval of three years) for twenty- 

 five years ; and in the experiments on rotation (which comprised the " four 

 course" of turnips, barley, leguminous crop [or fallow], and wheat) the 

 last of the fifth *^four course" rotation was completed, comprising twenty 

 years in all. 



Parallel with the field experiments, records relating to the fall of 

 rain, atmospheric pressure, temperature of the air, and of the dew-point 

 were kept or collated, so as to enable the observers to ascertain the 

 effects of the varying season upon the quantity and quality of the field 

 produce. 



It soon became evident that much remained to be done in perfecting 

 the methods of chemical analysis before comparative analyses could afford 

 much assistance in determining the relative productiveness of different 

 soils ; and to this object our medallists addressed themselves both with 

 skill and success. 



The practical value of these experiments may be seen from the fact 

 that, taking the results of twenty years, the annual average produce in 

 bushels of wheat per acre without manure was I65, with farmyard 

 manure exactly double, and with artificial manures 35| bushels, the 

 latter being considerably more than the average produce of Great Britain 

 when wheat is grown in the ordinary course. 



The produce of wheat grown successively on the same plot without 

 manure scarcely altered from year to year, whilst that of the turnips be- 

 came reduced to nothing ; the effect of a manure of superphosphate being 

 most marked upon the turnips, whilst the employment of salts of ammonia 

 mixed with alkaline salts and phosphates was most suitable for wheat, 

 although these are not the manures indicated by a simple analysis of the 

 ashes of the two crops. The authors remark, " Indeed the whole ten- 

 dency of agricultural investigation seems to show the fallacy of alone 

 relying upon the knowledge of the composition of a crop, as directing to 

 the constituents probably more especially required to be provided for it by 

 m.anures ; and rather that the elucidation of agricultural principles must 

 be looked for from a due consideration of Vegetable Physiology, as well 

 as Chemistry, of the special functional peculiarities and resources of dif- 

 ferent plants, as well as their actual percentage composition." 



The investigation into the feeding of animals was even more laborious ; 

 but it was a necessary complement to the experiments upon the growth of 

 crops. It was directed to the solution of the following among other im- 

 portant problems : — 



1. The amount of food consumed, and its several constituents, in rela- 

 tion to the production of a given live weight, for different animals. 



2. The comparative development of the different organs in the fattening 

 of animals, and their composition. 



3. The relation of the manure produced, both in quantity and quality, 

 to the food consumed. 



