CINCHONA OFFICINALIS. 155 
The Bark of the Crown, or Loxa Cinchona, or of the Cinchona 
flava, or Regia. The three first preparations are made by tritura- 
tion, or by infusing the powder with twenty parts of alcohol. 
This latter is not to be recommended. ‘The best Cinchona bark 
is known by the following properties. 
1. The Crown bark consists entirely of quills, simple or 
double, straight or nearly so, from six to fifteen inches long, 
varying in diameter from the size of a crow-quill to that of the 
thumb, or somewhat larger, and in thickness from the thirtieth 
to the sixth of an inch. The epidermis is always entire; the ex- 
ternal surface is crowded with fine longitudinal furrows, and 
crossed with transverse fissures; except in the finest quills, it 
presents various tints of grey, inclining sometimes to liver- 
brown, and it is generally covered irregularly with minute 
white lichens, which give it here and there the appearance of 
silver filagree. ' 
%. The Yellow bark (Cinchona flava) is composed partly of 
quills, partly of flat pieces. The quills, called in Peru, Calisaya 
acolada, are generally from nine to fifteen inches long, from one 
to two inches in diameter, and from an eighth to a third of an 
inch in thickness; a few, however, are considerably smaller and 
thinner, but fine quills are never seen like those which form a 
considerable proportion of crown bark and grey bark; they are 
generally single and clothed with epidermis. They are much 
traversed externally by longitudinal wrinkles and transverse 
fissures, commencing very rough, and in colour greyish-brown, 
mottled with large greyish-white patches, from adhering lichens, 
The inner surface is smooth, longitudinally fibrous, clean, and 
of a yellower cinnamon-brown than the crown bark. ‘The 
transverse fracture is close, but fibrous and splintery, and the 
fibres break under trituration into minute sharp spicule, which 
irritate the skin; the taste and odour are as in crown bark, but 
Stronger. ‘The flat pieces, or Calisaya plancha of the Peruvians, 
sometimes retain their epidermis, but are more commonly striped. 
Both present all the qualities of the quilled variety, except that 
