TRAVELS IN BRAZIL. 5 



lead to conclusions respecting their original coun- 

 try, and their gradual diffusion over the surface of 

 the globe. He proposed connecting these re- 

 searches with climatic and geognostic observations ; 

 and to this end to extend them to the most insig- 

 nificant members of the vegetable kingdom, such 

 as mosses, lichens, and fungi. He was likewise to 

 observe the changes which both the native and 

 exotic plants undergo, when exposed to certain ex- 

 ternal influences ; and to investigate the history of 

 the soil, and the method of cultivation there in use. 

 An examination of the internal structure, and of 

 the development of tropical plants, promised in- 

 teresting solutions of the laws o^ vegetable life in 

 general, as the observation of any traces that should 

 be discovered of an earlier vegetation, now extinct, 

 might afford materials for the foundation of a 

 geognostic theory. Lastly, he conceived he should 

 promote the object of the mission by an accurate 

 investigation of the Brazilian materia medica, 

 drawn from the vegetable kingdom, as well as of 

 all other vegetable substances, the use of which 

 might be interesting to arts and manufactures, and 

 by carefully indicating the manner in which they 

 are employed in their native country. But besides 

 the observations and researches in the departments 

 peculiar to each professor, in which reciprocal 

 assistance and support were presupposed, they 

 were particularly enjoined to complete, as far as 

 possible, the collections of the academy, by send- 



B 3 



