348 VEGETABLE SUBSTANCES. 



diversities of surface, and the vicinity of the sea, 

 keep the air over the former places in continual play 

 and motion, and prevent those intense heats which 

 unquestionably (though by a process which chemistry 

 has not yet fully investigated) render the juices of 

 plants acid, acrid, or saline; while, from the wider 

 extent of Andalusia, and its comparative distance 

 from the ocean, the air over it is, in the warmer months, 

 much more quiescent. 



These considerations will, to a certain extent, ex- 

 plain why there are so many varieties in a fruit, 

 which, according to the authorities, appear all to have 

 come from the same part of the world; and a further 

 extension of these considerations would form a cri- 

 terion of the situations in which it would, or it would 

 not, be desirable to cultivate the orange. 



