“Dr. Tibbits, who is known as an authority upon electricity, has written a concise book upon this subject for the general practitioner, embracing only the valuable part of the existing knowledge. The work is written in a condensed style, and is well adapted for the practitioner who does not make a specialty of electrical treatment.”--_The New York Medical Journal._ LONDON: J. & A. CHURCHILL. * * * * * _DIRECTIONS FOR USING THE_ HAMMOND Wall Cabinet MANUFACTURED BY _THE WAITE & BARTLETT MAN’F’G CO._, 143 East 23d Street, New York. TO USE THE GALVANIC CURRENT. To use the galvanic current place the ends of the conducting cords in the two binding posts marked =13-13=. Place the socket of current selector (=20=) on the pin marked O, and turn the lever of selector on pin No. =1=, or on any number, according to the number of cells desired; at the same time see that all the switch levers are on their blank buttons, except the one at left of current selector, which should be on its left-hand button marked Constant. If it is desired to use cells from any other part of the series, place the socket on the pin from which it is desired to begin, and having previously moved the lever ahead of this pin move it along until the desired number of cells intervenes between socket and lever. The number of cells in circuit when the socket is not on O, but on a pin with a number, is the difference between the number of the pin and number on which the lever rests, for instance, if socket is on pin =12= and lever on pin =22=, then =10= cells are being used, the starting point being =12= cells from any part of the series may thus be brought into the circuit. If socket be placed on pin =39= and lever on pin =40= then the =40=th cell would be in use only. _Always keep the socket on the lowest number and the lever on the highest, as putting socket ahead of lever would reverse the current._ Should, through any accident, a cell become disconnected or run down, or should it get out of order from any cause, it is only necessary to short-circuit the cells and throw the milli-ampere-meter in circuit by adjusting the switch =10=. By placing the socket on the pin marked O and selecting cell after cell with the lever, the defective cell is easily found by the milli-ampere-meter failing to deflect when the pin corresponding to the defect is reached. TO OBTAIN THE INTERRUPTED GALVANIC CURRENT. To obtain the interrupted galvanic current, move the switch at left of selector on to button marked interrupted, then turn the switch just above the vibrator on to its button marked =11=, by adjusting the screws at =14= and =15= the proper degree of vibration will be obtained. It is necessary that the point of the screws at =15= should touch the plate with every vibration as the current passes through at this point and unless it touches, connections would not be made. TO MEASURE THE RESISTANCE OF THE PATIENT.