CORTEX CASCARILL.^. 563 



pieces of a dull brown colour, somewhat rough and irregular, rarely 

 exceeding 4 inches in length by | an inch in diameter. The chief bulk 

 of that at present imported is in very small thin quills and fragments, 

 often scarcely an inch in length, and evidently stripped from very 

 young wood. The j'ounger bark has a thin suberous coat easily 

 detached, blotched or entirely covered with the silvery-white growth 

 of a minute lichen (Verrucaria albiss^ima Ach.), the perithecium of 

 which appears as small black dots. The older bark is more rugose, 

 irregularly tessellated by longitudinal cracks and less numerous 

 transverse fissures. Beneath the corky envelope the bark is greyish- 

 brown. 



The bark breaks readily with a short fracture, the broken surface 

 displaying a resinous appearance. It has a very fragrant odour, 

 especially agreeable when several pounds of it are reduced to coai-se 

 powder and placed in a jar; it has a nauseous bitter taste. When 

 burned it emits an aromatic smell, and hence is a common ingredient 

 in fumigating pastilles. 



Microscopic Characters — The suberous coat is made up of 

 numerous rows of tabular cells, the outermost having their exterior 

 walls much thickened. The raesophloeum exhibits the usual tissue, 

 containing starch, chlorophyll, essential oil, crystals of oxalate of 

 calcium, and a brown colouring matter. The latter assumes a dark 

 bluish coloration on addition of a persalt of iron. In the inner portion 

 of that layer ramified laticiferous vessels are also present. The liber 

 consists of parenchyme and of fibrous bundles, intereected by small 

 medullaiy rays. On the transverse section, the fibrous bundles show a 

 wedge-shaped outline ; they are for the most part built up, not of true 

 liber-fibres, but of cylindrical cells having their transverse walls 

 perforated sieve-like (vasa crihriforinia). The contents of the 

 parenchymatous part of the liber are the same as in the meso- 

 phlceum ; as to the oxalate of calcium, the variety of its crystals is 

 remarkable.^ 



Chemical Composition — Cascarilla contains a volatile oil, which 

 it yields to the extent of 11 per cent. According to Volckel (1840), it 

 is a mixture of at least two oils, the more volatile of which is probably 

 free from oxygen. Gladstone (1872) assigns to the hydrocarbon of 

 cascarilla oil the composition of oil of turpentine. By examining the 

 oil optically we found it to have a weak rotatory power — some samples 

 deviated to the right, some to the left. The resin, in which cascarilla 

 is rich, has not yet been examined more exactly. 



The bitter principle was isolated in 1845 by Duval, and called 

 Cascarillin. C. and E. Mylius (1873) have obtained it from a deposit 

 in the officinal extract, in microscopic prisms readily soluble in ether 

 or hot alcohol, very sparingly in water, chloroform or spirit of wine. 

 It melts at 205° C, is not volatile, nor a glucoside. Its composition 

 answers to the formula C^-ff^O^. 



Commerce — The bark is shipped from Nassau, the chief town of 

 New Providence (Bahamas), and is usually packed in sacks. The 

 quantity imported into the United Kingdom in 1870 was 12,201 c\vt., 



^ For more particulars see Pocklington, Phann. Journ, iii. (1873) 664. 



