Abstract
The acidity and the electric conductivity of rain-water were investigated since November, 1993 until July 1994,in Kochi City, southern Japan, where no remarkable industries exist. The hydrogen ion concentration and electric conductivity of the rain-water were measured especially at first stage of each rainfall. In all rainfalls the rain-water shows more than pH 4.0 and below pH 5.0 at first stage (at 1mm precipitation time of each rainfall) , and according to increase the precipitation it shows higher pH values than that of the first stage. With the communication net-work by using personal computers, the hydrogen ion concentration and electric conductivity of the rain-water were always recorded throughout the Japan, and they are not correlated with any industrial areas.
