62 WOOD TUKPENTINES. 



the objection is that the odor is different from gum turpentines rather than that 

 it is inherently objectionable. 

 The reports follow : 



REPORT 1. 



Referring to the samples of turpentine which you sent us October 24, we 

 have completed the preliminary investigation, and in carrying through the tests, 

 which were made comparatively, we have added to the five samples submitted 

 by you a sample of regular standard gum turpentine, marked A, and a sample of 

 our standard wood turpentine which we are regularly using, marked B. We 

 found the specific gravities to be as follows : 



A, 0.8680. 

 No. 4, 0.8680. 



B, 0.8650. 

 No. 3, 0.8650. 

 No. 1, 0.8650. 

 No. 2, 0.8635. 

 No. 5, 0.8625. 



Flash point: 



A and B, not taken. 



No. 3, 113 F. 



No. 1, 109.4 F. 



No. 5, 105 F. 



No. 4, 103.6 F. 



No. 2, 101.8 F. 

 Staining power (on white paper, least staining power ranked first) : 



No. 5, first. 



A, second. 

 No. 3, third. 



B, fourth. 

 No. 2, fifth. 

 No. 1, sixth. 

 No. 4, sixth. 



Evaporation (on white paper, shortest time ranked first) : 

 No. 5, first. 



A, second. 

 No. 2, second. 



B, fourth. > : f, \ 

 No. 3, fourth. 



No. 1, fourth. 

 No. 4, seventh. 

 Odor: 



No. 5 and A, equal. 



Nos. 1, 2, 4, and B, equal. 



No. 3, objectionable odor and color. 



When used for varnish reducing and carefully watched, we were unable to 

 note any perceptible difference, either in setting or in completed drying after 

 24 hours. What we considered the most delicate test in practical use was in 

 using them for thinning quick-drying black, and the results here were as fol- 

 lows (the time given is in minutes and represents the time when the black 

 had dried sufficiently hard to be varnished over without rubbing up) : 



A 50 minutes. 



B, 1, 2, 5 90 minutes. 



3 and 4 105 minutes. 



After six days the quick-drying black which had been thinned with these 

 various turpentines was examined, and we found that a sample thinned with 

 A showed little or no tendency to thicken up; No. 5 thickened slightly; and 

 the balance had all thickened quite a little, but showed practically no differ- 

 ences. 



In general way I would say that it is our judgment that for the general 

 purposes for which material of this kind is used odor is the most important 



