The powdered seeds which had been treated with ether were then exhausted by cold spirit of wine (·832), which afforded 14·77 per cent. (reckoned on the original seeds) of a red amorphous tannic matter, which after drying, proved to be but little soluble in water, whether cold or boiling. Submitting to destructive distillation, it afforded Pyrocatechin. Its aqueous solution is not altered by ferrous sulphate, unless an alkali is added, when it assumes a violet hue, with separation of a copious dark purplish precipitate. On addition of a ferric salt in minute quantity to the aqueous solution of the tannic matter, a fine green tint is produced, quickly turning brown by a further addition of the test, and violet by an alkali. An abundant dark precipitate is also formed.
The seeds having been exhausted by both ether and spirit of wine, were treated with water, which removed from them chiefly mucilage precipitable by alcohol. The alcohol thus used afforded on filtration traces of an acid, the examination of which was not pursued. After exhaustion with ether, spirit of wine and water, a dark brown solution is got by digesting the residue in ammonia: from this solution, an acid throws down an abundant brown precipitate, not soluble even in boiling alcohol. We have not been able to obtain crystals from an aqueous decoction of the seeds, nor by exhausting them directly with boiling spirit of wine. We have come therefore to the conclusion that Catechin ([p. 243]) is not a constituent of areca nuts, and that any extract, if ever made from them, must be essentially different to the Catechu of Acacia or of Nauclea, and rather to be considered a kind of tannic matter of the nature of Ratanhia-red or Cinchona-red.
By incinerating the powdered seeds, 2·26 per cent. were obtained of a brown ash, which, besides peroxide of iron, contained phosphate of magnesium.
Commerce—Areca nuts are sold in India both in the husk (pericarp) and without it, and the two sorts are enumerated in the Customs Returns under distinct heads. Their widespread consumption in the East gives rise to an enormous trade, of which some notion may be formed by a consideration of the few statistics bearing upon it which are accessible.
Thus, Ceylon exported of areca nuts in the year 1871, 66,543 cwt., value £62,593; in 1872, 71,715 cwt.,—the latter quantity entirely to India; in 1875 of the total export of 94,567 cwt. 86,446 were shipped to India.[2503]
The Madras Presidency largely trades in the same commodity. In the year 1872-1873 there were shipped thence to Bombay 43,958 cwt., besides about two millions of the entire fruit.[2504] An extensive traffic in areca nuts is carried on at Singapore and especially in Sumatra.
Uses—Powdered areca nut may be given for the expulsion of tapeworm in the dose of 4 to 6 drachms, taken in milk. The remedy should be administered to the patient after a fast of about twelve hours; some recommend the previous exhibition of a purgative. It is said to be efficacious against lumbricus as well as tænia.
The charcoal afforded by burning areca nuts in a close vessel is sold as a tooth powder; but except greater density, it possesses no advantage over the charcoal from ordinary wood.
As a masticatory areca nut is chewed with a little lime and a leaf of the Betel Pepper, Piper Betle L. The nut for this purpose is used in a young and tender state, or is prepared by boiling in water; it is sometimes combined with aromatics, as camphor or cardamom.