PROPOSED SPECIFICATIONS. 25 



turpentine, which, while fully protecting the consumer, recognize the 

 natural variations occurring even in the freshly distilled turpentine. 



This investigation, however, shows clearly that by no means all 

 of the unadulterated turpentine sold can be regarded of the same 

 quality, nor does it comply with the accepted standards. This fact 

 is fully accounted for by natural differences in the crude turpentine, 

 negligence on the part of the turpentine producer, irregularities in 

 distilling, and differences in age and methods of storing. A turpen- 

 tine with a specific gravity of 0.875, only 50 per cent of which distills 

 below 160 C. and 20 mm of which equals in color the No. 1 Lovibond 

 glass, is certainly not of the same grade as one having a specific gravity 

 of 0.865, 90 per cent distilling below 160 C. and 150 mm of which is 

 needed to equal the No. 1 glass in color. Nevertheless the former 

 is turpentine, though its value is somewhat less than the latter. 

 It appears but just and reasonable that several well-defined grades of 

 turpentine should be recognized and standard specifications estab- 

 lished for them. Such standards are accordingly suggested for the 

 consideration and criticism of producers and consumers of turpentine. 



Standard or No. 1 turpentine should have a specific gravity at 20 

 C. of from 0.862 to 0.870; a refractive index at 20 C. of from 1.468 

 to 1.476; 95 per cent should distill below 170 C., and a layer of not 

 less than 200 mm should be required to equal in color the Lovibond 

 yellow glass No. 1. On polymerization with 38 normal sulphuric 

 acid the residue should not exceed 1 per cent, should be reddish in 

 color and viscous, and its refractive index at 20 C. should be from 

 1.500 to 1.520. An unadulterated turpentine which does not agree 

 with these requirements may properly be regarded as not of standard 

 or No. 1 quality. 



Second quality or No. 2 turpentine should have a specific gravity 

 at 20 C. of from 0.862 to 0.875; a refractive index at 20 C. of from 

 1.468 to 1.480; 90 per cent should distill below 170 C. and a depth 

 of not less than 100 mm should be required to equal the Lovibond 

 yellow glass No. 1. The polymerization residue must not exceed 1 per 

 cent and must have a refractive index of not less than 1.50. 



Third quality or No. 3 turpentine should have a specific gravity 

 at 20 C. of from 0.865 to 0.880; a refractive index at 20 C. of from 

 1.468 to 1.485; 60 per cent should distill below 170 C. and a depth 

 of not less than 50 mm should be required to equal the Lovibond 

 yellow glass No. 1. The polymerization residue must not exceed 1 

 per cent and must have a refractive index of not less than 1.500. 



These specifications are applicable to both gum spirits turpentine 

 and to "wood turpentine," and are in general harmony with trade 

 practice. For high-grade varnishes and for medicinal purposes a 

 colorless, light turpentine which evaporates rapidly and will hast (Mi 

 drying, leaving the varnish firm and not " tacky/' is desired. For 



