Ruiz and Pavon then returned to Huanuco, explored the courses of the rivers Pozuzu and Huancabamba, and eventually established themselves at the farm of Macora, near Huanuco, where they resided for two months with Don Francisco Pulgar and Don Juan Tafalla, who, by order of the king, had joined them as pupils and associates in their labours--the first as an artist, the second as a botanist. In August, 1785, a fire broke out in their house, which destroyed all their journals and collections; and they then undertook journeys through the forests of Muña, Pillao, and Chacahuasi, examining new species of chinchonæ.[63] On April 1st, 1788, taking leave of Pulgar and Tafalla, they sailed from Callao, and reached Cadiz in September, when they commenced the publication of their great work the 'Flora Peruviana.'[64] Tafalla continued his researches in the province of Huanuco, and discovered the _C. micrantha_ in 1797, in the cool and shady forests of Monzon and Chicoplaya. Pavon calls him "noster alumnus." The expeditions and discoveries of the Spanish botanists induced the merchants of Lima to speculate in bark, and brought the grey barks of Huanuco into the European markets.[65] In 1785 Don Juan de Bezares, a Lima merchant, devoted 2000 dollars to the exploration of the forests of Huamalies. He penetrated along the banks of the Monzon to Chicoplaya, passing mountains thickly covered with chinchona-trees, and engaged people to collect bark. Thousands of arrobas were thus obtained of the bark of _C. glandulifera_; and having been appointed Governor of Huamalies by the Viceroy Don Teodoro de Croix in 1788, Bezares commenced the construction of a good road down the valley of the Monzon.[66] Up to 1826 the principal supplies of grey bark were derived from _C. nitida_, but since that time they are believed to have come chiefly from _C. micrantha_. Science owes much to the labours of Spanish botanists: the Spanish nation has every reason to be proud of her sons who explored the forests of the Andes with such untiring energy and distinguished ability; and the names of Mutis, Ruiz, Pavon, and Tafalla occupy no unimportant place in the history of botanical research. Nor, in this respect, have the natives of South America been behindhand. Caldas and Zea were worthy successors of Mutis; Franco Davila[67] represents the botanical learning of Peru; while in more modern times the name of the South American Triana is not unworthy to stand side by side with those of the best botanists in Europe. [Illustration: CHINCHONA MICRANTHA. (From Howard's 'Nueva Quinologia de Pavon.') Page 32.]