'The chief of my results, and which comprehends nearly all the others, is the construction of an apparatus which resembles in its effects, viz. such as giving shocks to the arms, &c, the Leyden phial, and still better electric batteries weakly charged; . . . but which infinitely surpasses the virtue and power of these same batteries; as it has no need, like them, of being charged beforehand, by means of a foreign electricity; and as it is capable of giving the usual commotion as often as ever it is properly touched.'