57 PICR^NA EXCELSA 



obtained from the trunk and larger branches, are covered by a 

 smoothish bark, which has a dark grey colour externally, and is 

 white and fibrous internally. In the quassia of commerce this 

 bark is commonly removed, and the wood, which is tough, and of 

 a very pale yellowish-white colour, alone employed in medicine. 

 As found in the shops it is in the form of chips or raspings. 

 Quassia wood has no odour, but an intense and pure bitter taste. 



The bitter taste and medical properties of Quassia wood are 

 especially due to the presence of a neutral crystallisable principle, 

 termed quassin or quassite, which exists in it in the proportion of 

 about ~ per cent. Quassin is soluble in dilute alcohol, in chloro- 

 form, and in about 200 parts of water, but is insoluble in ether. 

 Quassia wood contains no tannic acid or other astringent matters. 



Adulterations and Substitutions. The chips of other woods 

 have been sometimes substituted for, or used as adulterants of, 

 those of quassia. The intense and pure bitterness of the genuine 

 drug will generally distinguish it. The infusions of other woods 

 are also commonly changed to black or blueish-black by a persalt 

 of iron, in consequence of the presence in them of tannic acid ; 

 but as quassia chips contain no astringent acid, no such effect 

 is produced under like circumstances on their infusion. 



Besides the official Quassia wood of the British, Indian, and 

 United States Pharmacopoeias, there is another kind of Quassia 

 which is used in France and Germany, and, indeed, the German 

 Pharmacopoeia of 1872 forbids the use of any other quassia. 

 This quassia is the one already alluded to as derived from Quassia 

 amaraj L., and termed Surinam quassia from its geographical 

 source. This kind was the original quassia of the Materia Medica, 

 and the one upon which the reputation of quassia as a medicine 

 was established ; but as the tree yielding it was of small size, the 

 demand for it soon exceeded the supply, and the present official 

 quassia became entirely substituted for it in this country and the 

 United States of America. It is in cylindrical pieces, covered by 

 a thin, easily separable, greyish- white bark. It has no percepti- 

 ble odour, but a pure bitter taste ; and in its chemical and medical 

 properties it closely resembles the Jamaica or official quassia wood. 



