190 ScienHfic Intelligence — Botany. 



concentrated sulphuric acid, is connected with the opposite end of 

 tlic reservoir, and the hottom of the bottle is carefully heated by a 

 spirit-lamp, or by means of sand heated below the melting point of 

 lead. The fluohydric acid gas passes over and through the reeds in 

 the reservoir, and takes up all the silex in the state of lluo-hydro- 

 silic acid gas, which passing into the water is decomposed, and hy- 

 drate of silica is deposited as a gelatinous mass, separable by means 

 of a filter. The vegetable fibre, on being removed from the reser- 

 voir and washed, is destitute of silica. — Proceedings of the Sixth 

 Annual Meeting of the Association of American Geologists and 

 Naturalists, April 1845, p. 44. 



12. Collecting of Peruvian Bark. — In the month of May, the 

 Indians assemble to collect Peruvian bark, for which purpose they 

 repair to the extensive Cinchona \voods. One of the party climbs 

 a high tree, to obtain, if possible, an uninterrupted view over the forest, 

 and to spy out the 3Ianchas, or spots where there are groups of Pe- 

 ruvian bark trees. The men who thus spy out the trees are called 

 Cateadors or searchers. It requires great experience to single out 

 the dark leaf-covered expanse, the Cinchona groups, merely by the 

 particular tint of the foliage, which often differs but very little from 

 that of the surrounding trees. As soon as the Cateador has marked 

 out and correctly fixed upon the mancha, he descends to his com- 

 panions, and leads them with wonderful precision through the almost 

 impenetrable forest to the group. A hut is immediately built, 

 which serves as a resting-place during the night, and is also used 

 for drying and preserving the bark. The tree is felled as near 

 the root as possible, divided into pieces, each from three to four feet 

 long, and with a short curved knife a longitudinal incision is made 

 in the bark. After a few days, if the pieces are found to be getting 

 di-y, the bark already incised is stripped ofi' in long slips, which are 

 placed in the hut, or in hot weather, laid before it to dry. In many 

 parts, particularly in the central and southern districts of Peru, where 

 the moisture is not very great, the bark is dried in the forest, and 

 the slips are packed in large bundles. In other districts, on the 

 contrary, the bark is rolled up green, and sent to the neighbouring 

 villages, where it is dried. Towards the end of September, the Cas- 

 carilleros* return to their houses. 



In the more early periods of South American history, the bark 

 was a principal article of Peruvian commerce. Since the commence- 

 ment of the present century, its value has, however, considerably di- 

 minished, chiefly in consequence of adulterated and inferior kinds, 

 which are supplied from other quarters ; perhaps, also, on account 

 of the more frequent use of quinine ; for, in the production of the 

 alcaloides less bark is employed than was formerly used in substance. 



* Bark-gatherers. The Peruviaps call the bark cascarilla, and they point 

 out the distinction of a great number of species and varieties. 



