It has been calculated that a space of one cubic millimeter would contain 250,000,000 of these minute organisms, and that they would not weigh more than a milligram.

The Paris Congress decided upon adopting certain units of resistance of electromotive force, of current, and of quantity, and they determined the particular length of a column of mercury that should represent the ohma column of mercury 106 centimeters long and of one square millimeter in section.