670 BOTANY AND PHARMACOGNOSY. 



with concentrated sulphuric acid ; and a light yellow, rather thick 

 ethereal oil (guaiac oil), which cannot be obtained by distillation 

 and possesses a characteristic aromatic odor. Among the other 

 constituents are vanillin and a yellow gum. The yield of ash 

 should not be more than 4 per cent. Guaiac wood yields from 

 20 to 25 per cent, of resin. 



Of particular interest are the decomposition products obtained 

 on heating guaiac resin. On dry distillation the following sub- 

 stances are obtained: Tiglic aldehyde; a colorless, aromatic 

 liquid with the odor of benzaldehyde ; guaiac oil; and a crystal- 

 line substance, pyroguaiacin, which on distillation with zinc yields 

 guaiacene (an aldehyde of tiglic acid). 



PIX BURGUNDICA.— BURGUNDY PITCH.— The resin- 

 ous exudation of the stems of the Norway Spruce Fir, Picea 

 excelsa (Fam. Coniferse), an evergreen tree indigenous to Europe 

 and Northern Asia (p. 81). The resin is obtained by making 

 incisions through the bark into the wood, the resin exuding and 

 solidifying; it is then collected and purified by melting it in hot 

 water and straining the mixture. The chief supplies of the drug 

 come from Finland, the Black Forest (Germany) and the Jura 

 Mountains. It is doubtful if the commercial supplies have ever 

 been derived from the French province. Burgundy, from which 

 it takes its name. 



Description. — Irregular, hard, opaque or translucent pieces, 

 more or less plastic and strongly adhesive, yellowish-brown or 

 reddish-brown, brittle, the fracture shiny, conchoidal ; odor agree- 

 ably terebinthinate ; taste aromatic and sweetish. 



Burgundy Pitch is partly .soluble in cold alcohol (i to 20), and 

 almost entirely soluble in boiling alcohol or in glacial acetic acid. 



Constituents. — Chiefly resin, consisting of two crystallizable 

 resin acids : dextropimaric and laevopimaric acids ; a volatile oil 

 (isomeric with oil of turpentine), about 5 per cent., to which its 

 peculiar fragrance is due ; and about 10 per cent, or less of water, 

 which is included during the preparation. 



Adulterants. — Burgundy pitch is sometimes substituted by 

 various mixtures, as of other coniferous products and palm oil; 

 these are distinguished by being more or less opaque and some- 

 what porous, and not having the characteristic odor of the gen- 



