| The forests yield cinchona bark, caoutchouc, sarsaparilla, and vegetable ivory. |
| A caoutchouc tube passes through the cap, and is connected inside the bottle with a straight glass pipe. |
| By adding a concentrated acid, the conversion of isoprene into caoutchouc artificiel, or artificial rubber, was speeded up a lot. |
| The bark of the tree is so thick that the latex does not run off like caoutchouc when the bark is cut. |
| Dr Rollfs advises melting a piece of caoutchouc at the end of a wire, and introducing it while warm. |
| A solution of the dichloride with excess of sulphur in crude benzol is used for vulcanising caoutchouc. |
