Michael Faraday's experiments showed that the passage of the same quantity of electricity through an electrolyte solution set free equivalent weights of different substances at the electrodes, and that 1 gram equivalent of any substance required the passage of 96,490 coulombs. This quantity , F, is now called the faraday. If the current is carried by ions, that is charged particles of matter, of charge n, and the number of ions in a gram equivalent is N (Avagadro's number), the charge associated with every ion is nF/N