That he should have proceeded to the demonstration of the laws of electrolysis, was the next most natural result. He showed that the amount of any compound decomposed by the electric current is exactly proportional to the whole quantity of electricity which has passed through the electrolyte. Different substances are variously refractory to dissolution under the influence of the electric current, but each one always acts in the same way and requires the same amount of current. Substances that are closely related to one another chemically, are also related to one another in the amount of electricity required to bring about decomposition of their various compounds. He showed, of course, that there are differences of electrical relationship that make the results produced in the decomposition of various compounds very different. Polarization, for instance, sets in to a much greater degree in the decomposition of some substances than of others. One consequence is that the resistance to the passage of the electric current differs markedly, and the opposing electromotive force will stop the current or hamper its effects in many cases, so that, until after actual experiment, the quantitative effect of the passage of the electric current through a solution cannot be determined. Faraday's opinions as to the significance of electricity in the animal economy are very interesting because of his profound knowledge of electrical phenomena and their place in nature. It is all the more interesting because it is so simple, and most scientists would be apt to say that its very simplicity is a very taking argument for its truth. "As living creatures produce heat, and a heat certainly identical with that of our hearths, why should they not produce electricity also, and an electricity in like manner identical with that of our machines? Like heat, like chemical action, electricity is an implement of life, and nothing more."