170 TREUBIA VOL. II, 2—4, 
AEN LE EEE 
Salinity deduced | Salinity determined 
Samples from the amount | by thermometer and Difference 
of chlorine areometer readings 
1 31.46 °/00 Ss ole + 0.671], °/oo 
2 29.85 °/oo 30:02 ie co +) O77 Deo 
3 AND les DISS 2/00 + 0.76 Joo 
4 20.86 °/ 50 2128, Ola + 042 °J 
5 PN) Ola 2254 Ole + 0.7 1e SER 
6 Doses 203050 + 0.54 Joo 
7 29 29 of, QOS iV Fe, + 0.64 Joo 
8 21,92 006 II Ooo + 0.07 Joo 
9 24.20 °/oo DASE So + 0.31 Jo 
10 19.02 °/oo 19:47 olde OA 
5.04! 
Ge > 
the average differ- 
ence = + 0.6 °/oo 
The salinity of this fish-pond water determined by areometer and 
thermometer readings in connection with KNUDSEN’s tables (!°) was conse- 
quently at least 0.31 °/,,, at most 0.77 °/,, and on an average 0.6 °/,, higher 
than the salinity corresponding in those tables with the amount of chlorine 
found in it. 
That this difference is not owing to imperfect calibration of the areo- 
meters used, becomes apparent from the fact that in the comparisons 
quoted above of the salinity of samples of sea-water, determined first by 
means of a KiiCHLER areometer and secondly with a pycnometer or by 
chlorine titration, the differences only amounted to 0.12 °/o9, 0.24 °/o9, 0.09 °/o0 
and 0.08 °/,, respectively. 
| was also able to ascertain that the KüCHLER areometers are on the 
whole correctly calibrated, by determining the salinity of one and the same 
sample of pure sea-water kept in a bottle and a little concentrated by 
evaporation, by means of five different areometers successively; the result 
being as follows: 
