QUASSIA 



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cells composing the rays in the Q. amara are of equal size, and their 

 radial walls appear wavy in tangential section; whereas the corre- 

 sponding cells in P. excelsa are of variable size and exhibit regular 

 walls in tangential section. The true source of Quassia is said, by 

 some authorities, to be a simaruba. 



Powder. Characteristic elements: See Part iv, Chap. I, B. 



PIG. 154. Picrasma excelsa Branch. 



CONSTITUENTS. Pier as' ma excel' sa contains a bitter neutral principle, 

 picrasmin, Quas'sia amar'a, an analogous principle, quassin, both 

 soluble in water, alcohol, and chloroform. The principles can easily 

 be obtained from the precipitated tannate by mixing it with lead car- 

 bonate, drying, and extracting with alcohol. They crystallize from 

 alcoholic solution in needles; purified by recrystallization. Quassia 

 contains no tannin, and therefore can be prescribed with salts of iron. 



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