24 COMMERCIAL BOTANY. 



grades of African rubber." . It proved to be the produce oi 

 Alstonia plumosa, another apocynaceous plant. 



LIBERIAN RUBBER (Ficus Vogelii). This species was 

 introduced in 1878 by Mr. Thomas Christy from Liberia, 

 It was discovered by Vogel at Grand Bassa, and described 

 in the Niger flora under the generic name of Urostigma, 

 which is now united with the genus Ficus. The rubber, 

 which was formerly made into balls about the size of a 

 large orange, has been valued in the London market at 

 Is. 6d. per pound, and would fetch a higher price if sent 

 home in a cleaner state. 



The trees yielding this rubber are known in West Africa 

 by the name of " Abba," and in the Kew Bulletin for 

 November, 1888, and May, 1890, the subject is discussed 

 in detail. The rubber is described as containing a large 

 amount of resin, which has prevented its general use in this 

 country. Some improvements, however, have recently been 

 made in collecting the fresh milk, so that a better quality of 

 rubber has been obtained. In a note from the District 

 Commissioner at Bndagry to the Colonial Secretary at Lagos, 

 published in the Kew Bulletin for May, 1890, referred to 

 above, the coagulation of the milk is thus described : 



" When the milk is first brought to me in gin-bottles, I 

 at once strain it into perfectly clean bottles through a piece 

 of muslin fixed in a frame. The bottles are then allowed 

 to stand for twenty-four hours for the milk to rise. It is 

 then poured into a large tin, and put on the fire to boil. 

 If much water is seen with the milk, none is added ; but if 

 only a little, about a pint of water is added to every six 

 bottles. As the water and milk begin to boil, lime juice is 

 added in the quantity of one lime to each bottle. This 

 assists the rubber to coagulate. When all the rubber in 

 the water has formed into a large lump, it is taken out and 

 forced into the moulds perforated and fixed in wood euen. 

 Heavy weights are then laid on for twelve or twenty-four 



