122 PROFESSOR JOHN GIBSON ON 
TABLE I. 
Hydrochloric Acid and Chrome Acid. 
Y= Knee -K. 
Per cent. Tr Time in Time in 
HCl. ; days. months. 
y x 102. 
32 8:78 137 0:25 ‘008 
30 8:23 101 0:3 ‘01 
28 7:68 73 6 ty) 
24 6°58 25 38 1:3 
Pl 5:95. 8 118 3°9 
20 5°49 1 174 5:9 
18:22 5:00 0 > 700 25 circa 
N.B,—With 16 per cent. and 12 per cent. HCl the reduction was not 
nearly complete after four years’ standing. 
In the graph (Fig. I.) the times required for complete reduction of the CrO, are 
plotted as abscisse against the specific conductivities of the respective solutions as 
ordinates. The maximum conductivity of hydrochloric acid is taken as origin, so that 
the ordinates indicate decrements of conductivity from the maximum, that is to say, 
they indicate the values for y= K,,,x. — K. 
123465678 9 10 12 131415 16 17 18 19 20 2 22 23 2% 25 2627 26 
Tite in months —~> 
From this series of experiments and from a number of other cases it appears that 
the tendency towards increased conductivity is greater the greater the possible gain in 
specific conductivity ; or, in other words, the tendency increases with the value of 
Y =Kinax.-K. There is some reason to think that it may also increase with the value 
POP cs 
= ee 
