UPPER AMAZON. 335 
Amazon, visiting the ruins of Lactacunga, Ham- 
bato, and Riobamba, in a country the face of which 
was entirely changed by the frightful earthquakes 
of 1797, that destroyed nearly 40,000 of the inha- 
bitants. They then with great difficulty passed 
to Loxa, where in the forests of Gonzanama and 
Malacates they examined the trees which yield the 
Peruvian bark. The vast extent of ground which 
they traversed in the course of their expedition af- 
forded them better opportunities than any botanist 
had ever enjoyed of comparing the different species 
of Cinchona. 
Leaving Loxa they entered Peru by Ayavaca and 
Gouncabamba, traversing the ridge of the Andes 
to descend to the River Amazon. In two days 
they had to cross thirty-five times the Rio de Chay- 
ma. They saw the magnificent remains of the 
causeway of the Incas, which traversed the porphy- 
ritic summits from Cusco to Assouay, at a height 
varying from 7670 to 11,510 feet. At the village 
of Chamaya, on a river of the same name, they 
took ship and descended to the Amazon. 
La Condamine, on his return from Quito to Para, 
embarked on this river only below Quebrada de 
Chuchunga; and Humboldt, with the view of com- 
pleting the map made by the French astronomer, 
proceeded as far as the cataracts of Rentama. At 
Tomependa, the principal place of the province of 
Jaen de Bracamorros, he constructed a map of the. 
Upper Amazon, from his own observations as well 
as from accounts received from the natives. Bon- 
pland employed himself, as usual, in examining the 
subjects of the vegetable kingdom, among which he 
discovered several new species of Cinchona. 
