46. ARECA.—ARECA NUT. BETEL NUT. The seed of an East Indian tree, Are'ca cat'echu Linné. Roundish-conical, about 25 mm. (1 in.) long, flattened at the base; externally deep brown, varied with fawn-color, giving it a longitudinally-veined appearance; internally brownish-red with white veins. It abounds in tannin, and contains three alkaloids upon which its taeniafuge properties depend, arecoline, arecaine, and a trace of an undetermined alkaloid. Mixed with the leaves of Piper betel it forms the "betel" chewed so largely by the natives. It is strongly recommended as a taeniafuge and vermifuge. Dose: 2 to 3 dr. (8 to 12 Gm.).