CHEMICAL REMARKS ON CASCARILLA. 30 L 
bark the taste of which is strongly bitter. After having 
been coarsely powdered and placed in a displacement ap- 
paratus, it is treated with water. Solution of acetate of 
lead is added to the mixed liquids, which are filtered and 
freed from excess of lead by sulphuretted hydrogen. They 
are again filtered, evaporated to about two-thirds ; a small 
quantity of animal charcoal is then added, and the mixture 
filtered. The solution is evaporated at the lowest possible 
temperature. At a certain period a pellicle forms. When 
this has acquired a moderate consistence, and before the 
liquid becomes syrupy, the whole is allowed to cool, and 
the substance is carefully removed. Sometimes, however, 
it does not possess the crystalline aspect, but appears resi- 
nous, and adheres to the sides of the evaporating dish. It 
becomes harder by cooling. 
To purify either of these substances, they are pulverized ; 
the powder is placed in a tube, and as much cold alcohol of 
spec. grav. 0-870 is poured over it as is rather more than 
sufficient to moisten it. After a sufficient interval, this al- 
coholic liquid, which is highly coloured, is poured off. The 
greater part of the fatty and colouring matters with which 
the cascarilline was mixed is thus removed ; the remaining 
powder is considerably decolorized. This is then treated 
with boiling alcohol of spec. grav. 0.S35; a little animal 
charcoal is added; it is then filtered and allowed to evapo- 
rate spontaneously. The residue is dried on unsized pa- 
per. To complete its purification, it is powdered, again 
treated with cold alcohol, and subsequently dissolved in 
boiling alcohol, filtered, and allowed to evaporate sponta- 
neously. The bitter matter is thus obtained in a state of 
purity. 
In this state it is white and crystalline ; the crystals, 
under the microscope, appear to be prismatic needles, some- 
times mixed with hexagonal plates. It is inodorous and 
bitter, but this is not immediately perceptible on account of 
its slight solubility in water. When heated in a closed tube, 
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