Abstract
The titration curve of the pH of lake water has been drawn, using BCG and n/200 HCl solution. The titration curve and consequently the buffer value (Cotag α) varies not only with lakes but also with depth in, one and the same lake.
Examining the buffer value on each vertical layer it was found (1) that there is a general tendency that the buffer value of the hypolimnion increases with depth, the Cotag α ranging from 0•70 to 2•70, and (2) that the buffer value in the epilimnion is more or less irregular in vertical distribution, probably because of the effect of other factors such as CO2 tension and alkali reserve of water. The magnitude of buffer value seems to be due mainly to the BHCO3 and H2CO3 contents of water.
No data have previously been made concerning the buffer action of lake water, though numerous data have been available in regard to the pH and its vertical distribution. The method of titration curve enhances the interest of pH study in limnology.
