

JOURNAL 





OF THE 



WASHINGTON ACADEMY OF SCIENCES 



Vol. VII FEBRUARY 4, 1917 No. 3 



PHYSICS. — Standard substances for the calibration of viscometers. 1 

 Eugene C. Bingham and Richard F. Jackson, Bureau of 

 Standards. (Communicated by C. W. Waidner.) 



For the calibration of viscometers there is a need for one or 

 more liquids which can be easily obtained in pure condition, and 

 which have viscosities that are greater than that of water and 

 that are known with a considerable degree of certainty. The 

 substances selected are mixtures of ethyl alcohol and water, 

 and sucrose and water. Previous work upon water and alcohol 

 being adequate, the present experiments were confined to sucrose 

 and water. The sucrose was purified by repeated recrystalli- 

 zation from water solution, and contained residual impurities 

 of the order of one-thousandth of a per cent. The compositions 

 of the solutions used in the measurements were determined by 

 density measurements and by polariscopic tests. 



The viscometer used in the investigation consisted essentially 

 of a U-tube fitted with a capillary limb surmounted by a bulb 

 with constrictions. The bulb served as a measure of the volume 

 of liquid forced through the capillary. A bulb of similar size 

 and shape was sealed on the other limb. The viscometer was 

 connected to a manometer and an apparatus for the application 



1 To appear in detail as Bureau of Standards Scientific Paper No. 298. 



53 



