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SELECTED ARTICLES. 
III. Application of the preceding facts to the analysis of 
Peruvian barks. — M. Andre proposes to apply the above 
facts to the analysis of barks, and considers his results as more 
exact than any means hitherto suggested. He pursues the 
following method; he takes the product of an acid decoction 
of quinia, after having been cooled and filtered, then left in 
contact with animal black, till it has been decolourized; when 
the red tint has disappeared, he states that a blueish zone is 
discoverable on the surface of the clear fluid, and which is vi- 
sible he says as long as gr. 00006 of the alkaloid is present; 
he also treats the acid decoction with chlorine and ammonia, 
and thus obtains more or less distinct green tints; another in- 
dication of the presence of quinia. This plan does not appear 
to us as certain a test as the author supposes. In the first 
place, the opaline blueish colour is not peculiar to quinia alone, 
although this alkaloid possesses the property of exhibiting it in 
the highest degree; solutions of sulphate of morphia, sulphate 
of cinchonia, strychnia, &c. also present it; moreover in the 
filtration of the acid decoction and its decolourization by ani- 
mal charcoal, a large proportion of the quinia remains with the 
insoluble colouring matter and with the animal black, so that a 
trial of the clear liquid only gives a qualitative valuation, but 
not a quantitative. Besides which, how would it be possible 
to determine the proportion of quinia present by the intensity 
of the blue reflection, or of the green colour? We believe 
this to be almost impossible, and hence that the plan of M. 
Andre is not a good one. 
IV. Action of ammonia on a mixture of iodic and hy- 
drochloric acids. — "While endeavouring to separate the qui- 
nia altered by the action of the chlorine and ammonia, I 
thought of the liquid chloride of iodine, spoken of by Serul- 
las, as a mode of separating alkaloids from their alcoholic so- 
lutions; I imagined that the iodic acid which might be formed 
in the liquid perchloride would combine with the altered qui- 
nia, and form a stable and almost insoluble iodate, whilst, the 
hydrochloric acid, would unite to the ammonia. With these 
