8(5 NATURAL HISTORY OF PLANTS. 



The Rataiihias contain tannin in abundance, a red extractive principle 

 and a kind of sugar supposed to be produced by some chemical 

 change in the tannin, amylaceous and gummy matter, salts and an 

 acid.^ The tannic principle is varied in character, according to the 

 sorts and varieties ; it gives to these roots their active properties as 

 tonics, astringents, hemostatics, antiblennorrhagics, antidiarrhsetics, ' 

 antiputrids, and odontalgics. The wood and bark of the root are 

 used, as is also a dry extract very similar to kino. The plants are 

 also applied to industrial purposes. An infusion of seve Kramerias, 

 of a blood-red, has been employed in adulterating port wine, and 

 it may be used also in preparing skins. In tropical Asia several 

 species of Xanthoj^hyllum are valued for the qualities of theu- wood, 

 especially AT. J.r«oif^M«MTO^ from India, and X. vitelUmun^ from Java. 

 Some Pohj galas are cultivated as ornamental. These are generally 

 Cape species, often with opposite leaves, and large violet 

 flowers (fig. 104-106), which usually open towards the end of the 

 winter in oiu' green-houses and hot-houses. 



I Satanldnc (C ™ H i- AzO "), contained in « Wight, III. i. 50.— Rosenth. op. cit. 790.— 



several American extracts is said not to e.\ist in X.Jlin-ncciis Wight ct Arn. (neo Eoxb.). 



the root (Cotton). The existence of lu-araeric ■' Walp. Sep. i. 248. — Kosenth. up. cit. 1153, 



acid is actually considered doubtful (Geu- Jackia vihilliia Bl. Bijdr. 61. 



HilUDT). 



