knowledge, practical and theoretical, we already possess. 

 A single principle explains and thus recommends or forbids 

 many practices, according to the circumstances of the soil, 

 place, or season. 



Third. To enlarge our actual knowledge by new dis- 

 coveries susceptible of practical application. 



On these several objects of natural science, in its appli- 

 cations to agriculture, it would be out of place at present 

 to dilate. It will be sufficient if I briefly draw your atten- 

 tion to some of the general results, in reference to rural 

 economy, at which science has already arrived. 



With this view I might draw my illustrations from any 

 one of the many different branches of natural knowledge. 

 I might select for example : — 



1st. The general relations of Physical Geography^ to 

 the art of culture — such as 



a. The influence of broad seas and of great lakes and 

 rivers, of tides, of sea currents, and of prevailing winds, on 

 the capabilities of a country and the practices and profits 

 of its cultivators. 



h. The influence of mountain elevations and depres- 

 sions, of high table lands and of low level plains — or 



2d. The general indications of Geology in regard to the 

 fertility of a country, the branches of husbandry to which 

 it is best adapted, and the means by which its fertility may 

 be best promoted. 



The Geological Map of this State and the volumes of 

 the Natural History Survey, afibrd abundant illustrations 

 of the relations of this science to practical agriculture — or 



3d. The relations of Meteorology and Botany conjoined 

 — such as 



a. The adaptation of certain plants to certain climates — 



