408 



EEPOET — 1886. 



(5 grammes salt in 100 of water) with 1 

 Fig. 14. 



Plotting of these numbers. 



cc. of baric chloride sol. (BaCl.,, 2Ag 

 centigrammes, or 2*44: of the crys- 

 tallised salt, in 100 cc. water) ; 

 add to this a little phenol-phthal- 

 lein, and just enough NaHO to 

 make it red. The destroying of 

 the colour is the thing observed. 

 No measurements made till the 

 liquid is discoloured round the 

 bends of the tube. At xvii. 4.3 

 the current was started, with an 

 E.M.F. of 45 volts between ter- 

 minals. The galvanometer deflec- 

 tion increased from 41-1° to 44*2° 

 in the first half-houi', and then 

 increased further to 46° in the 

 next hour. By xvii. 51 the de- 

 colorisation had got round the 

 bends, and the first or starting 

 mark was made. The progress of 

 the whole experiment was rapid, 

 and is represented pictorially in 

 figs. 13 and 14. 



In the following summary the 

 column headed, ' Progress of SO4' 

 gives the position of the marks 

 made near cathode end of the 

 tube. The column headed ' Pro- 

 gress of H' gives the position of 

 the marks made near anode end. 

 By these headings it is not in- 

 tended to insist that the full 

 theoretical meaning of the obser- 

 vations is the same as the ob- 

 vious and apparent meaning. All 

 distances are specified in centi- 

 metres. 



