There was once a learned Italian, Galvani. He had an electric machine, and he showed his students what electricity was. He rubbed the glass hard with silk with something smeared over it, and then he approached to the glass a brass knob which was attached to the glass, and a spark flew across from the glass to the brass knob. He explained to them that the same kind of a spark came from sealing-wax and amber. He showed them that feathers and bits of paper were now attracted, and now repelled, by electricity, and explained to them the reason of it. He did all kinds of experiments with electricity, and showed them all to his students. Once his wife grew ill. He called a doctor and asked him how to cure her. The doctor told him to prepare a frog soup for her. Galvani gave order to have edible frogs caught. They caught them for him, killed them, and left them on his table. Before the cook came after the frogs, Galvani kept on showing the electric machine to his students, and sending sparks through it. Suddenly he saw the dead frogs jerk their legs on the table. He watched them, and saw that every time when he sent a spark through the machine, the frogs jerked their legs. Galvani collected more frogs, and began to experiment with them. And every time he sent a spark through the machine, the dead frogs moved their legs as though they were alive. It occurred to Galvani that live frogs moved their legs because electricity passed through them. Galvani knew that there was electricity in the air; that it was more noticeable in the amber and glass, but that it was also in the air, and that thunder and lightning came from the electricity in the air. So he tried to discover whether the dead frogs would not move their legs from the electricity in the air. For this purpose he took the frogs, skinned them, chopped off their heads, and hung them on brass hooks on the roof, beneath an iron gutter. He thought that as soon as there should be a storm, and the air should be filled with electricity, it would pass by the brass rod to the frogs, and they would begin to move. But the storm passed several times, and the frogs did not move. Galvani was just taking them down, and as he did so a frog's leg touched the iron gutter, and it jerked. Galvani took down the frogs and made the following experiment: he tied to the brass hook an iron wire, and touched the leg with the wire, and it jerked.