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PAINT TECHNOLOGY AND TESTS 



Use of the Microscope. 4. The microscope is a necessary 

 adjunct of every well-ordered paint laboratory, as has been 

 recognized throughout the whole paint industry. The writer 

 has attempted to collect certain data which may materially 

 assist those manufacturers who employ this instrument to 

 judge of the quality of their raw and finished products. The 

 fineness of grinding considerably affects the quality of the paint, 

 and this can be easily controlled through the intelligent use of 

 the microscope. This instrument may also be used to detect 

 certain adulterations. Appended is a table giving the fineness 



Inside White on White Pine 



of grinding of the various pigments, together with their char- 

 acteristics under the microscope. In this table measurements 

 are given both in millimeters and in inches, in order to accom- 

 modate itself to the use of those chemists employing a millimeter 

 stage micrometer, or those employing the English or inch system. 

 Although it is not yet certain that any and all combinations 

 of pigments may be detected under the microscope the writer 

 is working toward a method which will allow a manipulator to 

 judge of the composition of the paint under observation. 



In order to properly prepare a paint for microscopic examina- 

 tion, the following method is recommended : A microscopic turn- 



