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9.— TAPIOCA. 



Nat. Oed. — Euphorbiacese. 



Manihot utilissima. 



The plant from which this Starch is obtained 

 is the only one of the order which yield a food 

 product that is used to any extent. 



The whole order, almost without exception, 

 possesses acrid properties, and some species are 

 very poisonous. 



The roots and expressed juice of Manihot 

 utilissima are, owing to the presence of Hydro- 

 cyanic acid, of a poisonous nature, but this is 

 destroyed in the process of manufacture. The 

 Tapioca of commerce is prepared by submitting 

 the Starch to heat while moist, by which the 

 granules are broken up, and become agglutinated 

 into little masses. The microscopic characters 

 are therefore lost. The plant is a native of 

 tropical America, where it is known as Bitter 

 Cassava, and the meal made into Cassava bread 

 is extensively used as a food by the inhabitants. 

 The starch is also known as Brazilian Arrowroot. 



The physical characters of the Starch granules 

 partake somewhat of the nature of those of Tacca 

 Starch, but they are rather smaller ; many of the 

 granules are circular, with a distinct hilum in the 

 centre, which sometimes appears as though split 

 into an irregular star. 



