ELECTRICAL CONDUCTIVITY OF CERTAIN SALINE SOLUTIONS. 69 
the same as before. The scales are the same as those for sulphate of copper in 
the same figure. 
This curve is also an hyperbola, but the lower asymptote is inclined down- 
wards, unlike those of the two previous salts. For this reason the term 
involving tan 0 is now negative. Substituting its value, as well as the value of 
the intercept /, and then finding ¢ from a known point, we have 
oeede G6 we 
x 
or 34 
R and D having the same meaning as before. 
From this formula we find— 
Specific Resistance. Specific Resistance. 
SSS 2a Le a a eae 
Observed. Calculated. Observed. Calculated. 
118°7 118°4 31°2 31°4 
95°9 96°5 25°6 26°5 
54°5 54°4 19:0 18°9 
41°9 43°4 16°6 16°3 
358 37°3 

We have seen that with some salts the lower asymptote is inclined upwards, 
and that with at least one other it is inclmed downwards ; we might therefore 
expect that salts exist for which it is not inclined at all, in other words, whose 
curves are rectangular hyperbolas. This appears to be the case with bichro- 
mate of potash. The following table gives the results of nine experiments 
with this salt :— 
BicHrRoMATE oF PotasH (COMMERCIAL). 


- Resistance in Specific | - Resistance in Specific | 
soy GE Density at | second tube rehstanie at Fen OH Selly Density at | second tube Paaance at 
to aero 10° 6. at 10° ©. 10° 6. a ie ae 10° C. at 10°C. 10°C. 
ee SAO Winits,|(8. A: Units, |) 5° "2etom B. A. Units. | B. A. Units. 
1 to 100 1:0069 10800 186°9 1 to 25 1:0274 3100 53°6 
Won GW 1:0088 8680 150°2 lL ,, 20 1:0345 2590 44°8 
1 0 1:0137 5560 96°2 eels 1:0452 2040 35°3 
ii; 40 1:0172 4600 79°6 lee kD 
10561 1710 29°6 
a) 1:0231 3490 60°4 Saturated 

See also curve in fig. 3. 
Owing to the sparingly soluble character of this salt, the curve cannot be 
carried far enough to enable its form to be determined with great accuracy. 








As 
we have said, it seems to be a rectangular hyperbola, having this equation— 
