WOOD TURPENTINE: 



ITS PRODUCTION, REFINING, PROPERTIES, AND USES. 



INTRODUCTION. 



Wood turpentine, "stump turpentine," or "wood spirits of tur- 

 pentine," as the product is variously known, is turpentine oil made 

 from cut pine, fir, or spruce, by distilling the wood in closed retorts. 

 When properly refined it closely resembles gum spirits of turpentine, 

 obtained by distilling the gum which oozes from the cut surface of 

 the living tree. The turpentine made by distilling the wood with 

 steam below a temperature of 150 C. more closely resembles gum 

 spirits than that obtained by destructively distilling the wood. The 

 latter is always contaminated with other oils derived from the break- 

 ing down of the wood and the resins which it contains. In some 

 cases where the context shows plainly that wood turpentine is meant 

 the term " turpentine " is used to avoid repetition; it should be noted, 

 however, that commercially wood turpentine should always be desig- 

 nated as such and not as "turpentine." 



Wood turpentine is used, chiefly as a varnish and paint thinner as 

 a substitute for, or in the place of, gum turpentine. Its production 

 and use has increased slowly, partly because of its objectionable 

 odor, its physiological effect, its lack of uniformity, and unsatisfac- 

 tory working qualities due thereto, and partly because of the lack of 

 knowledge regarding its ultimate effect on the color and durability 

 of varnishes and paints. 



The recovery of turpentine by distillation from the wood was 

 attempted years ago, and the first patents relating to this subject 

 were granted as early as 1841. The process was not developed, 

 however, and it is only within recent years that any material success 

 has attended its use. There are two primary causes for the numer- 

 ous efforts which have been made during the past 10 or 15 years to 

 recover turpentine from cut pine wood: First, the difficulty of sup- 

 plying the increasing demand for turpentine, owing to the rapid 

 decrease of the supply of live pine timber suitable for even the most 

 advanced system of turpentine orcharding; second, the demand for 

 a profitable method of utilizing the mill and forest wastes of the pine 

 regions, not only that such wastes may be made valuable, but that 



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