משתמש:Uri R/caoutchouc

קאוצ'וק

Caoutchouc

• "Of major importance was the distinction between hevea and caucho, the two principle types of rubber gathered from the forest. Hevea rubber was obtained from species of the endemic hevea tree (primarily, Hevea brasiliensis, H. benthamiana). The most valuable rubber latex was extracted from H. brasiliensis which grew at relatively low densities (e.g., 28 trees/km² primary south of the Amazon River... Although the indevidual hevea tree produced only a small quantity of latex upon tapping (i.e., 25 - 50 gms/tree/day), the latex could be extracted every other day for many years and when cured over a smoky fire became the finest rubber in the trade. In contrast to hevea, caucho was not suited for regular tapping. The less valuable rubber was extracted through the felling and bleeding of species of the castilloa tree (C. elastica; C. ulei) found most commonly at low densities or in small stands deep within the upland forests of Upper Amazonia, in an arc from Colombia through Ecuador and Peru to Bolivia."‏‏
• [The French naturalist Charles Marie de] La Condamine observe the natives extracting a milky, viscous liquid from this tree - later designated Hevea brasiliensis - and noted that liquid, upon coagulation, produced a malleable substance of unique elasticity and impermeability that the Indians knew how to fashion into syringes, boots, bottles, and toys. His interest piqued, La Condamine transported a small quantity of this caoutchouc, as the Amazonians called it, back to France in 1745 and published a major study of its peculiar properties.‏‏"
• "The [Peruvian rubber] company was exploiting caucho rubber, which comes from the Castilloa elastica - a type of tree destroyed by the tapping process."‏‏
• "'caucho: an inferior grade of rubber extracted from Castilloa elastica, a tree that is killed in the tapping process."‏‏

ראו גם

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