36 WOOD TURPENTINE. 



pentine is nonvolatile at that temperature ; yet, as will be seen subse- 

 quently, the varnishing tests do not indicate that the varnish thinned 1 

 with this turpentine took longer to dry than the others. Some 

 observers reported that this varnish dried more slowly than the 

 other samples, while others stated that it dried fully as fast. The 

 comparatively low acid and saponification numbers of the turpentine 

 refined from soda are to be expected. The steam-distilled sample is 

 of deeper color than the others, but no difference can be detected in 

 the color of the varnishes, which can be ascribed to the color of the 

 turpentine used. While the analyses given indicate that there is a 

 marked difference in the behavior on distillation between the several 

 turpentines, this difference is no greater than that frequently observed 

 between samples of gum spirits. 



Two classes of varnishes were prepared and thinned with these 

 turpentines; a coach finishing varnish to represent outdoor conditions, 

 and a piano varnish to represent those used in interior work. These 

 were prepared by two experienced makers under the writer's personal 

 supervision, in accordance with their regular formulas for such var- 

 nishes. In preparing them the gums and oils were cooked in the usual 

 way, and when sufficiently cooled portions of the batches were thinned 

 to the desired consistency with each of the described turpentines. For 

 comparison, in order that there might be no possible differences due 

 to a variation in manufacture, a portion was also thinned with the 

 turpentine regularly used by the firm. These varnishes were allowed 

 to age for one year at an even temperature, when they were racked 

 off and half-pint samples sent to prominent varnish makers, piano 

 makers, and carriage builders, who had consented to make panel 

 tests of the working qualities and to pass judgment on the merits of 

 the different varnishes. 1 Small quantities of the turpentines were 

 sent with the different varnishes that they might be thinned before 

 using, if necessary, with the same turpentine used in its preparation. 

 The firms which made these tests also prepared a panel with the 

 varnish they regularly used for each class of work. There were thus 

 standard varnishes thinned with gum spirits, two of which were 

 identical, except as to the turpentine, with the three thinned with 

 wood turpentine, while the sixth varnish was that with which the 

 various varnishing workmen were familiar and with which they were 

 securing satisfactory results. Very complete data were requested as 

 to the working, behavior under the brush, tendency to check or peel, 

 time of drying, difference in gloss, behavior when rubbed, disagreeable- 

 ness to workmen, and other pertinent facts, all of which will be found 

 in Table 11, page 69. 



Extended analyses of the varnishes used in these tests has not been 

 attempted because they would possess but little significance. It is in 



1 It was assumed that the finished varnishes made from the same batch of oil and gum would havt 

 practically the same consistency; this was not the case. 



