28 
NATURAL HISTORY OF THE CINCHONAS. 
the discovery of new districts, and commerce has been en- 
riched by several new species. 
Previously to the year 1775 Loxa bark was the only kind 
of cinchona known in commerce. It was not until 1772 
that Mutis discoved the valuable tree in the neighborhood 
of Santa Fe de Bogota, and at this period Europe began to 
receive cinchonas direct from the ports of New Granada, on 
the Atlantic. Some years later, the authors of Flora Pe- 
ruviana studied the species of lower Peru, to the north of 
Lima, and these also were introduced into commerce. The 
only species, then, which, botanically speaking, still remain- 
ed unknown in Europe, were those growing in the vast ex- 
tent of country extending southward. Notwithstanding the 
efforts of Joseph de Jussieu and the botanist Taddaeus 
Haenke, little was added to the scientific knowledge of the 
cinchonas by their travels. The object of M. Weddell's 
work is to make known the species which have come under 
his observation in these regions during the years 1S45, '46 
'47. The immense commercial demands on the cinchonas 
of these parts, tending to exhaust the forests, rendered it 
necessary that new sources should be discovered. At a 
period when the consumption of these barks was becoming 
more and more considerable, it was desirable that attention 
should be directed to those cinchonas which will have to 
replace the Calisaya bark, the supplies of which are becom- 
ing less abundant. These species although they may be 
less rich in active principles, yet, from their abundance offer 
some security against the prospect of our being deprived of 
one of the most valuable medicines of the vegetable king- 
dom. 
M. Weddell penetrated into Bolivia in the month of Au- 
gust 1845, through the country of the Chiquito Indians. 
The formation of the country in this province is quite in- 
compatible with the existence of the true cinchonas. The 
greater part of its surface is so low and flat, that during the 
rainy season it is completely inundated. In the month of 
