SCIENCE IN THE INDUSTRIAL WORLD 



of being almost colorless. For this reason it is a favorite 

 with artists; but it is far too expensive for use in com- 

 mercial paints. This is true also of walnut oil and tung, 

 or Chinese wood oil. 



Turpentine, which is a product of the distillation of 

 the resin of pine trees, is a most useful paint-vehicle 

 for certain purposes. It volatilizes rapidly on exposure 

 in thin layers to the air, but leaves behind a thin layer 

 of resinous substance that acts as a binding medium 

 for the particles of pigment. It mixes with alcohol, 

 ether, and benzine, and is a good solvent of fats, oils, 

 and resins, so that it can be used with almost every kind 

 of paint or varnish. It dries very quickly, and for quick- 

 drying paints, stains, and varnishes is indispensable to 

 the painter. 



The best substitute for turpentine, although inferior 

 as a paint-vehicle, is resin spirit, the product of the 

 distillation of resin. In its most refined forms it can be 

 used as a substitute for turpentine for every purpose; 

 but it has a very offensive odor, and its use is largely 

 confined to making cheap varnishes. 



The two alcohols, methyl alcohol and ethyl alcohol, 

 axe used extensively as vehicles in the manufacture of 

 varnishes and enamel paints. They are good solvents of 

 gums and certain resins. They evaporate rapidly and 

 as vehicles for pigments constitute quick-drying 

 "paints." The most familiar example of one of these 

 is the ordinary commercial shellac varnish. 



Besides the vehicles we have mentioned there are, of 

 course, scores of others, either "patent" or "proprie- 

 tary" mixtures, which are constantly appearing on the 



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