and then illustrated some of the points in his paper by an exhibition of electrical apparatus. To arrest the causes that destroy the teeth, fillings of different kinds have been and are being used to repair the loss of continuity of tooth structure, to protect exposed parts, and restore the contour of the organ Prominent among these filling materials are gold, tin, cements and amalgam, or, as it is sometimes called, silver. It is composed in varying proportions of tin and silver, with a small amount of gold or platinum amalgamated, as the term implies, with quicksilver. There are also amalgams of copper, and some containing zinc.
In a general way, I will now introduce the subject of this all-pervading mysterious form of vibration we call electricity. Different qualifying names are employed to designate the kind of electrical manifestations, as magnetic, frictional or static, galvanic, voltaic or dynamic and thermal