320 PLANTS PRODUCING GUMS AND RESINS 



Pterocarpus indicus. — This tree yields a tanniferous gum appar- 

 Liuly similar to that produced by Pterocarpus Marsnp'iuni. According 

 to dc Cordemoy, the kino of the East Indies and the Amboyna kino of 



tlu' druggists arc supi)licd by these two species. 



Pterocarpus erinaceus. This member of ihe Pa])ilionace3e produces 

 the Gambian kino. This gum contains a large amount of tannin, 

 which colours it red. 



Exudation is rarely spontaneous, but is stimulated by any damage 

 to the tree. 



Pterocarpus Draco — This tree is a native of Guadeloupe and the. 

 East Indies, and supplies the resin or kino gum known as dragon's- 

 blood. When the bark is cut there flow out drops of a clear, blood- 

 red liciuid, which solidify quickly. They are then collected under the 

 name of sanguis dracoiiis (dragon's-blood). Large quantities of this 

 resin were formerly exported from Cartagena, an Spain. It is still 

 imported into Portugal, where it is known as sangue de drago 

 (dragon's-blood). It is a red resin, tasteless and odourless, used as 

 an astringent., 



Sesbania grantJiflora.- A small tree which occurs in India and the 

 Sandwich Isles; it has been introduced to the Antilles, and is known 

 there as Colihri vegetal. 



After the trunk has been cut there flows out a white juice slightly 

 tinged with rose. When dry it takes on a violet tone and appears as 

 glassy tears. When dissolved in water the liquid becomes turbid and 

 a white resin is precipitated. 



This solution turns litmus paper red. When alcohol or ether is 

 added there is released a gum which floats at the surface with the 

 ether. M. Cuzent has extracted two colouring principles from this 

 product : one red, which he calls agathin; and the other yellow, which 

 he calls xantlinagatliin. The following ina'tters are also found : arabin, 

 a little bassorin, a resinous matter, tannin, and various salts. 



C/ESALPINIE/E. 



BauhJnia retusa — Yields a gum called Semla gum, which bears 

 considerable resemblance to gum arable. It is eaten by the lower 

 classes, and Roxburgh refers to it as a sweet biownish gum appearing 

 on injured portions of the bark. 



According to a report by Professor Dunstan this gum was submitted 

 to several experts, who declared it to have but little commercial value. 



The tears gathered were opaque, brittle, and l^rown in colour. 

 The taste is sweet and the gum feels mucilaginous to the palate, 

 although it is not very soluble. AMien mixed with twice its weight of 

 water it swells up, absorbs all the water, and forms a firm gelatinous 

 mass. The solution gives the usual reactions of acacia gum and has 

 only a slight reducing action on Fehling's solution; it is eight times 

 as viscous as gum arable. It is used in medicine. 



