382 ODOROGIJAPHIA. 



younger branches, have a very thin periderm (outer layer), which 

 is easily detached. The older pieces are rougher, split lengthways, 

 and have many transverse fissures. The pieces are generally 2 

 to 3 inches long, but often mixed with a great deal of small 

 fragments. The white crustaceous lichen attached to the outer 



o 



surface is generally the Verrucaria albissivia, Ach., and sometimes 

 other varieties of Verrucaria.'^ 



The inner surface of the Ijark is of a brownish-red. It breaks 

 with a short, resinous fracture and has an agreeable aromatic 

 odour. To ihe taste it is warm, bitter and aromatic. It burns 

 readily, and whilst burning emits a remarkably fragrant odour, for 

 which reason it is used as an ingredient in fumigating pastilles. 

 The bark yields on distillation with water, or steam, 1-75 per cent, 

 of a complex volatile oil of fragrant penetrating odour. This oil 

 has a sp. gr. of 0-938 and begins to boil at 180^ C This first 

 fraction is colourless, mobile and refractive : the second fraction 

 is yellowish and rather thick. " It was found by Tromsdorff, that 

 the bark also contains 1 5 per cent, of resin, part of which gave an 

 acid reaction and was soluble in alkalies, and part was neutral. 

 It also contains gum in about the -^ame proportion. The bitter 

 principle contained in the bark is ^^asm?'i7//7z, C, oH^gO^, which 

 is a neutral substance freely soluble in ether and hot alcohol, but 

 sparingly soluble in water, chloroform or dilute alcohol. This 

 body melts at 205*^ C. and is not volatile. It is not a glucoside. 



The barks of other species of croton have sometimes been 

 found mixed with cascarilla bark in the bales as imported. -j* An 

 instance was reported by the Curator of the Pharmaceutical 

 Society's Museum, :|: as follows: — Of 4 serous, imported from 

 Xassau, in the Bahama Islands, and purchased by one of the 

 first London houses, three contained the true bark, but the fourth^ 

 which appeared to contain unusually fine specimens, and which 

 were sent out as such, was afterwards found to consist almost 

 entirely of a spurious bark. At hrst sight this bark strongly 

 resembles cascarilla in appearance, but may be distinguished 

 tlius : — The periderm, or outer layer of bark does not readily 

 peel off, and is of a fawn colour, not white. On the inner surface 



* An eniimeiatiou of these growths on various trees is to he found in 

 " Essai des Cryptoganies des ecorces exotiques ofiicinales," par Fee. 

 + Pharin. Journ. [1], vii., ]). 35. 

 X Pharni. Journ. [8], iv., p. 810. 



