Russian Natural History Expedition in Brazil. ^9 



This bog, in his opinion, may be changed in the time of 

 inundation into a large lake, which afterwards, by drying 

 up again, may exhibit in the lower places, but certainly 

 for a very short time, several small lakes ; and these most 

 likely have caused the tale that " the Paraquay springs out of 

 seven lakes." It flows, a small rivulet, upon the ridge of the 

 mountain for the distance of above two leagues, and falls 

 thence over a high rock into the Valley of Diamonds. In 

 its crystal water were frequently found some precious dia- 

 monds. Its current is here often stopped, and led into the 

 diamond-washes ; and, at a distance of a few leagues farther, 

 it becomes navigable for small canoes. On the south side of 

 these mountains (Serra dos Parcels) is the source of the river 

 Preto, which communicates its waters to the river Tapajos, 

 which, in its turn, is a tributary to the Amazon. A very lofty 

 tree, with beautiful large blue flowers, a species of the genus 

 Qualea^ distinguishes itself here in all the native forests, and 

 is even seen at a considerable distance. In the same elevated 

 plains he found a tree closely related to Pterocarpus, covered 

 entirely with abundance of odoriferous flowers ; it produces 

 a kind of shell, with a single seed in it, from which the in- 

 habitants extract a bitter aromatic oil, which they call Fava 

 de S. Ignacio. This oil is by them highly esteemed for its 

 great power as a remedy in different diseases, particularly 

 in colic, and many other stomachic cases. 



In September, 1827, M. Langsdorf determined to make a 

 voyage upon the rivers Arinos, Tapajoz, and the Amazon ; 

 but, to extend this new enterprise on a larger scale, M. 

 Riedel agreed with him to undertake a separate tour to 

 Matto-Grosso, and thence to take his direction upon the 

 rivers Guapore, Mamore, and Madeira, to the Amazon ; they 

 intended to unite, after a seven to ten months' separation, at 

 the Villa de S. Joze do Rio Negro. Having made their pre- 

 parations, M. Riedel, according to proposal, left the town of 

 Cuyaba in the month of November, crossed the Paraquay by 

 Villa Maria, not far from the mouth of the river Jauru, and 

 at a little distance from the place where the pyramid in com- 

 memoration of the definitely decided boundaries between the 

 dominions of Portugal and Spain is erected. Once on shore 

 again, he traversed arid campos, and arrived at the Indian 

 tribe Bororos. Amongst them he noticed, as remarkable, that 

 their principal nourishment consisted of the flesh of the cai- 

 mans (crocodiles), and the fruits of the Acrocomia sclerocarpa 

 Mart, Only a few low hills varied the surface of these vast 

 plains. He arrived at length, in a gently ascending manner, 

 at Matto-Grosso, by which name the principal town and the 



