Conductivity measurements have been made for very dilute solutions of NaCl,
KCl, HCl and NaOH. They obey the well-known Onsager's formula quite well a
t high concentration, but deviate from it at low concentration in the regio
n of about 10(-4) M. The oscillation of conductivity has also been measured
for very dilute NaCl solution, where a lambda-shape transition is found in
the same region. This possibly indicates a phase transition due to the for
mation of metastable water clusters.