An accumulator battery is connected to a container full of acid solution. On discharging, an amount of inflammable gas is obtained, such that upon its combustion 35 percent of the energy expended on charging the accumulator battery is given off. If several containers of acid solution instead of one are connected in series, then of course more time will be required for the same amount of electricity to flow through them than in the case of the single container. But the amount of liberated material depends, according to Faraday's law, only on the amount of electricity that passes through the electrolyte. Therefore after a sufficiently long period the same amount of inflammable gas will be liberated in each container as when only one container of acid solution was connected. Then, upon combustion of all the inflammable gas that has formed in all the containers, energy will be liberated which will far exceed the energy expended on charging the accumulator battery. In other words, the law of conservation of energy seems to have been broken. Explain the difficulty.