38 



PHYSICAL CHEMISTRY 



in solution as follows, beginning with least effective: mannite 

 <glycerine < glycol <meth. ale. <eth. ale. < acetone <prop. 

 ale. <ether. (Abl, 1907.) 



Fig. 7. Method of connecting the apparatus for determining hydrogen 

 ion concentration (from MRR). 



Determination of Hydrogen Ion Concentration with Hydrogen 



Electrodes 

 The apparatus, Fig. 7, consists of a hydrogen electrode, a vial, 

 filled with a saturated solution of KC1, and electrolytically con- 

 nected with the hydrogen electrode, a calomel electrode elec- 

 trolytically connected with the vial by means of a syphon, a 

 capillary electrometer, ce, with compound reading microscope, 



Fig. 8. Tenth normal calomel electrode (from MRR). 



