458 RESINS 



portion consists chiefly of a- and /?-larinolic acids. A factitious 

 mixture of colophony and turpentine is commonly substituted for it. 



Oil of turpentine is chiefly produced by the foregoing method, 

 Lower grades are obtained by the steam- distillation of the wood, 

 roots, stumps, sawdust, &c. (wood turpentine), and also as a by- 

 product in the manufacture of sulphite cellulose. For pharmaceu- 

 tical use it is freed from resinous and other impurities by redistillation. 

 A comparatively small amount of the commercial oil is imported from 

 France. American oil is usually dextrorotatory, though it may be 

 slightly laevorotatory. French is strongly Isevorotatory. It con- 

 sists chiefly of d- and Z-pinene. Specific gravity, 0-860 to 0-870 ; 

 refractive index at 25, 1-465 to 1-480. It should distil almost entirely 

 between 156 and 180 leaving no appreciable residue. It may be 

 adulterated with illuminating petroleum or with rosin oil. 



Colophony distilled at 80 to 250 yields ' rosin spirit ' which is 

 colourless, insoluble in water and in alcohol ; about one-half consists 

 of hydrocarbons boiling below 120. At about 300 the resin yields 

 ' rosin oil ' a viscous, colourless to dark brown oil consisting of a 

 mixture of hydrocarbons of high boiling point together with abietic 

 acid. 



BURGUNDY PITCH 

 (Fix Burgundica) 



Source, &C. Burgundy pitch is a resinous exudation obtained 

 from the stem of Picea excelsa, Link (N.O. Coniferce), melted and 

 strained. 



Burgundy pitch is collected chiefly in Finland, smaller quantities 

 being obtained in the Black Forest and in the Jura mountains. 

 Incisions are made through the bark into the outer layers of wood, 

 and the oleo-resin that slowly collects between the bark and the wood 

 is, after the lapse of some months, scraped out of the incisions, melted 

 under water, and strained. 



Description. True Burgundy pitch is an opaque, yellowish brown 

 or dull reddish brown substance, hard and brittle, but gradually 

 taking the form of the vessel in which it is kept. It is strongly 

 adhesive, breaks with a conchoidal fracture, and has a very agreeable 

 aromatic odour, especially when heated. The taste is sweet and 

 aromatic without bitterness. 



It is soluble in twice its weight of glacial acetic acid, and readily 

 soluble in alcohol. 



Constituents. Burgundy pitch contains resin and a little volatile 

 oil. The latter appears to consist chiefly of a- and /3-picea-pimarolic 

 acids, small quantities of picea-pimarinic and picea-pimaric acids, 

 and resene (juro-resene). 



