!_ \||;. i I.IVI-: <rTlli;i.KTSON AND MAUDE CUTI1BERTSON ON TIIK 



TABLE V. Dispersion of Hydrochloric Acid. 



Using the SELLMEYER form of equation the refractivity is expressed by 



/ _!\P _ 4-6425 xlO 27 



K76) 10664 xlO 27 -?^' 



Hie values calculated from this expression, in which the constants are calculated 

 from the observations by the method of least squares, are shown in column 3 above, 

 and the differences between columns 3 and 2 are given in column 4. 



HYDKOBROMIC ACID. 



^ Prevwu* Determinations. M.ASGA.KT obtained M - 1 == "000570 for the D line The 

 dispersion has not been attempted. 



/'reparation -The gas was prepared by dropping the purest aqueous solution of 

 . phosphorus pentoxide. After passing through tubes containing red 

 >rus and phosphorus pentoxide, it was condensed in liquid air, sometimes twice 

 >met,mes once only. ! successful experiments the acid was obtained as a pure 

 and a colourless liquid. After an experiment the gas was absorbed over a 

 xia hme , r^o. Only those experiments in which the impurity 

 ras^n. ? lig,t B were used for the determination of the index. 



adopted fo 



Experimnit . . 

 ( M -l)lO'x-- 



of llydrobromic Acid. X = 54G1. 

 l > 2 . 3, 4, 



6167, 6153, 6151, 

 Mean 614y. 



6141, 



5, 

 6139, 



6. 

 6141. 



