DESCRIPTIONS OF TRIBES AND GENERA. 199 



commerce. Abundant and good drinking-water collects 

 in the hollows of the internodes of many large species. 

 In those of others (Bambusa arundinacea and Mdocanna 

 bambusoides) are formed those remarkable silicic-acid 

 concretions, the " Tabasheer," that are still playing an 

 important part in the superstitious system of medicine 

 among the Orientals. Tabasheer is considered, not 

 merely in India but in the whole Orient and in China, as 

 a medicine of the highest value for bilious fever, dysen- 

 tery, jaundice, leprosy, and lung diseases, as well as an 

 aphrodisiac. As early as the times of the Roman Em- 

 pire physicians ascribed medicinal properties to it, and 

 it attained its world-wide fame through the Arabian 

 physicians of the tenth and eleventh centuries. It occurs 

 in commerce in two forms, the crude and the calcined. 

 The first, in a fresh uninjured condition, is in the form 

 of a more or less perfect cylinder with a rounded convex 

 base, 1-3 cm. in diameter and 1-4.5 cm. long (Fig. 108, 

 B, C ), found in the hollows of the internodes upon one 

 or both sides of the cross-wall, and as there are longi- 

 tudinal furrows in the outer surface corresponding to 

 the course of the fibro- vascular bundles, it represents an 

 exact cast of the cavity of the internode. It is translu- 

 cent, gray, yellowish, bluish, brownish, or blackish in 

 color and greasy in appearance, and covered with a 

 chalky coating. In warm, dry air it becomes opaque 

 and finally falls into little pieces or fine grains like sand. 

 When fresh it contains 58-62$ of water and scarcely 

 1% of organic substance ; the remainder is pure silicic 

 acid, soluble in potassium lrydrate. Calcined Taba- 

 sheer is formed by heating the crude substance red-hot, 

 in consequence of which it is transformed into irregular, 

 milk-white, opaque or bluish opalescent, concavo-convex 

 pieces having an earthy taste. The origin of Tabasheer 

 is not yet thoroughly explained ; the most probable 

 inference is that at the time of most rapid growth 

 great quantities of water are conducted into the bamboo 

 stems from the roots and collect in the hollow inter- 

 nodes. The silicic acid alkalies that are dissolved in it 

 probably become decomposed by carbonic or organic 



