Page:Encyclopædia Britannica, Ninth Edition, v. 2.djvu/693

This page needs to be proofread.
ARR—ARR
631

short manual of moral philosophy, compiled from the lectures of Epictetus, which fur many centuries was regarded both by Pagans and Christians as the best book on the subject. It has been published in a great many editions ; the best is in the collection of Schweighauser mentioned above. Of Arrian s original works the one of greatest importance is his account of the expedition of Alexander the Great in seven books. It contains the most complete and authentic account of that conqueror s career, being based upon the lost works of Aristobulus and Ptolemy, the son of Lagus, both of whom accompanied the king during the expedition. The best modern editions are those of Ellendt, 1832, 2 vols. 8vo ; Kriiger, Berlin, 1835 and 1848, 2 vols. 8vo, and 1851, 1 vol. 8vo; Sintenis, Lips. 1849 ; and Diibner and Miiller, 1846. Connected with his history of Alexander is a treatise on India, in the Ionic dialect, which he wrote separately, in order not to break the continuity of the narrative. He also wrote a work on the chase, a periplus or voyage round the coasts of the Black Sea, and a manual of tactics ; but of many other works ascribed to him by the ancients there are extant only a few fragments. Certain descriptions of the coasts of the Sea of Azov and the Eed Sea, which are ascribed to him, are pro bably the productions of a later period. Arrian s style is simple, lucid, and manly. His imitation of Xenophon is visible, not only in his style and diction, but even in the subjects on which he wrote. His language, though pure Attic, presents some peculiarities which are not found in

the works of his great model.

ARROWROOT. A large proportion of the edible starches obtained from the rhizomes or root-stocks of various plants are known in commerce under the name of arrowroot. Properly the name should be restricted to the starch yielded by two or three species of Maranta, the chief of which is M. arundinacea ; and when genuine or West Indian arrowroot is spoken of, it is understood that this is the variety meant. Maranta arundinacea is origi nally a native of the American continent, but it has long been cultivated in the West Indian Islands, and it has now spread to most tropical countries. The plant produces a scaly, white, tuberous rhizome, and it is at the period when this organ is gorged with starch-cells, immediately before the season of rest, that it is ripe for use. In addition to about 25 per cent, of starch, the fresh roots contain a pro portion of woody tissue, vegetable albumen, and various salts. The arrowroot may be separated on a small scale in the same manner as potato-starch is frequently prepared, that is, by peeling the root and grating it in water, when the starch falls to the bottom. The liquor is then drained off, and the starch purified by repeated washings till it is ready for drying. On a large scale the manufacture of arrowroot is conducted with specially prepared machinery. The rhizomes when dug up are washed free of earthy impurities and afterwards skinned. Subsequently, accord ing to Pereira s Matcria Medica, " the carefully skinned tubers are washed, then ground in a mill, and the pulp washed in tinned-copper cylindrical washing-machines. The fecula is subsequently dried in drying-houses. In order to obtain the fecula free from impurity, pure water must be used, and great care and attention paid in every step of the process. The skinning or peeling of the tubers must be performed with great nicety, as the cuticle contains a resinous matter which imparts colour and a disagreeable flavour to the starch. German-silver palettes are used for skimming the deposited fecula, and shovels of the same metal for packing the dried fecula. The drying is effected in pans, covered with white gauze to exclude dust and insects."


Fig. 2.

Arrowroot Plaiit (Maranta arundinacea). Fig. 1, stem, leaves, and flowers ; fig. 2, roots.

Arrowroot is distinguished by the granules agglomerat ing into small balls, by slightly crepitating when rubbed between the fingers, and by yielding with boiling water a fine, transparent, inodorous, and pleasant-tasted jelly. In microscopic structure the granules present an ovoid form, marked with concentric lines very similar to potato-starch, but readily distinguished by having a " hilum " marking at the thick extremity of the granule, while in potato-starch the same appearance occurs at the thin end (compare figs. 3 and 4 below). In addition to the West Indian supplies, arrowroot is now found in the commerce of Brazil, the East Indies, Australia, Cape Colony, and Natal, in the last of which localities it has become a staple of some im portance. Bermuda arrowroot has always been held in the highest esteem, but on those islands the cultivation is gradually giving way to more profitable crops. In 1872 only 26,710 Ib, of the value of 1323, were exported from the Bermudas, while in 1851 the value of the export trade was more than 10,000. St Vincent is now the chief seat of arrowroot culture in the West Indies.

Tous-les-mois, or Tulema arrowroot, is obtained from

several species of Canna, a genus closely allied to Maranta, and cultivated in the same manner. The granules of tous- les-mois are readily distinguishable by their very large size (fig. 5). East Indian arrowroot is obtained from the root-stocks of several species of the zingiberaceous genus, Curcuma, chiefly 0. angustifolia. Brazilian arrowroot is the starch of the cassava plant, Jatropha Manihot (fig. 6), which when agglutinated on hot plates forms the tapioca of commerce. The cassava is now cultivated in the East

Indian Archipelago as well as in South America.

Fig. 6. Fig. 5.
Tacca,

or Otaheite arrow- root, is the pro duce of Tacca pinna- tifida, the Pia plant of the South Sea Islands. Portland arrowroot was for merly prepared on the isle of Portland from the tubers of the common Cuckoo Pint. Arum maculatum. Various other species of A ru m yield valuable food-starches in hot countries. Under the name of British arrow- starch Granules magnified. Fig. 3, potato ; root the farina of po- fig. 4, arrowroot ; fig. 5, tous-les-mois ; tatoes is sometimes g. 6, jatropba.

sold, and the French excel in the preparation of imi-