Apostoli’s method of employing intense galvanic currents without discomfort or injury to the patient. The internal electrode, which he calls the _excitateur intrauterin_ is held in the hand of the operator. The _dispersing_ electrode covers the abdomen.] The electricity does not, however, correspond to that which was peculiar to the metallic plates before they were connected by the wire, but the opposite electrical conditions discharge themselves from the wire: the direction of the current in the fluid, being from the positive or copper plate to the zinc or negative plate, and vice versa, so that the wire of the zinc plate is now positive, while that of the copper is negative. Poles and electrodes. The wires or terminals are called the poles of the battery; instead of the term _poles_, the word _electrode_ is now generally used. From what was said of the origin and direction of the current in the fluid, it is important to remember that the positive electrode or wire is connected to the negative plate, while the negative electrode is connected with the positive plate. According to the extent of surface of both zinc and copper plates, exposed to the chemical action of the diluted sulphuric acid, or to the number of cells that are employed, by connecting the copper plate of one cell to the zinc plate of the next, the force and quantity of the electric current is correspondingly increased. Batteries which consist of one solution and two metals rapidly lose their intensity, partly from the decrease in the chemical action owing to the neutralization of the sulphuric acid by its combination with the zinc, and partly from secondary currents, depositing a layer of hydrogen and metallic zinc on the copper plate, which destroys the dissimilarity of the metals, so that the electrical action ceases or the plates become polarized. For this reason these single fluid batteries have almost entirely gone out of use, and batteries with two liquids have taken their place. Electrolysis means to dissolve or decompose, by means of electricity, an organic or inorganic substance into its original elements. If, for instance, a current of electricity of four or five Bunsen’s cells is conducted to two inverted glass tubes, filled with water slightly acidulated to increase its conductivity, gas bubbles rise from the surface of each pole, and upon examination it is found that hydrogen is liberated at the negative pole and oxygen at the positive pole; and as the volume of hydrogen liberated is about twice that of oxygen, the experiment gives at once the qualitative and quantitative analysis of water.