136 STATES OF THE RIVEB PLATE. 



by diligent tillage, and by heat generating applications, 

 such as quickhme, or decomposing vegetable matter, as 

 manure, &c. &c. 



There are conditions, however, which cannot be pro- 

 vided or supplemented ; for instance, plants wliich can 

 only be grown at a very low temperature cannot well be 

 produced in a warm climate ; as vegetation will not grow 

 without sunlight, and from that heat is inseparable ; there- 

 fore in the warm or hot climates of the tropics, both agri- 

 culturist and horticulturist must fail in the attempt to 

 raise the plants of the frozen zone or cold latitudes ; 

 whereas the vegetation of warm climates can be grown 

 in cold ones by means of artificial heat. 



Agriculture comprises the cultivation of the mandioca, 

 tobacco, sugar, rice, &c. &c., as well as oats, wheat, maize, 

 turnips, &c. &c. On this broad basis it must be under- 

 stood, and selection of plants made best suited to the 

 climate, requirements of the country, and other con- 

 ditions. 



Our chmate, however, at least, in the southern pro- 

 vinces, does not present any great disparity of feature 

 with that of parts of Europe ; and even for the main pro- 

 ducts of the British Isles it offers congenial conditions ; 

 and some that are wanting, or are precarious, can and will, 

 in many districts, be provided by art, as necessities become 

 greater, and knowledge of the science more general. 

 Meanwhile, we have ample compensation in those plants 

 which find more favourable conditions here than there, 

 and these primarily claim attention. 



Again, certain conditions which may be supposed 

 generally wanting, probably from the circumstance of 

 their not having been foimd in one or other locality or 

 tract of land, will undoubtedly be found in other situa- 

 tions or other varieties of soil, of which many varieties 



