241 
1906-7.] The Electric Conductivity of Sea-Water. 
The average variation means the mean of the individual differences 
between each recorded observation and the mean of all the observations for 
each value. 
In the case of all the other values for total chlorine we have too few 
samples of water with the same value, and no means can be taken. For 
the sake of comparison, however, the means of all values of all observations 
of waters whose chlorine value is above 22 grams per litre is given. It is 
(i) 22-970 1-03088 -060104 87115" 
In Table IV. are given the differences between the values of the various 
physical constants for variations in the total chlorine. 
TABLE IY. 
Difference 
in Chlorine. 
Difference in 
Relative Density. 
Difference in 
Specific Conductivity. 
Difference in 
Minimum Deviation. 
b — a 
0-141 
0-00024 
0-000370 
18" 
c- a 
•176 
025 
0430 
17 
c-b 
•035 
001 
0060 
d- c 
•141 
0L5 
0301 
16 
e-c 
•177 
023 
0344 
21 
e — d 
•036 
008 
0043 
5 
f-e 
•033 
005 
0170 
4 
9-f 
•037 
006 
0077 
0 
f~c 
•210 
028 
0514 
25 
h-g 
•671 
084 
1525 
36 
h - a 
1-094 
143 
2546 
78 
l-a 
2-531 
341 
5686 
216 
Total 
5-286 
0-00703 
0-012966 
436 
Average 
for 
| 0*100 
0-00013 
0-000238 
8 
From a consideration of the above it is seen that neither the densities, 
conductivities, nor refractive indices (deviations) give values which vary 
exactly with the chlorine values. On the other hand, the variations in the 
physical constants do agree with astonishing accuracy for all variations in 
total chlorine above 0*100 grams per litre. 
In the above tables and remarks the assumption has been made that the 
titrated values for chlorine were absolutely correct. Of course this is not 
warrantable, and since 1 cc. of the silver solution used in titrating was 
equivalent to 0"343 grams of chlorine per litre, the possible error is about 
0*02 grams per litre. If this is taken into consideration, a difference of 
between 2 and 3 in the fifth figure for densities, and of between 4 and 5 in 
VOL. xxvii. 16 
