An international system of electro-therapeutics : for students, general practitioners, and specialists . eedle willremain stationary, thus showing that there is no current. This resultwill appear strange to the uninitiated reader, and deserves to be dweltupon. If made to act separately, they cause the needle to deflect, one GALVANISM. A-249 toward the right, the other toward the left. The current furnished bythe larger one is more intense than the current produced by the smallerone, as the deflections of the needle show. But if these two cells beopposed to each other, the effect of one is coun
An international system of electro-therapeutics : for students, general practitioners, and specialists . eedle willremain stationary, thus showing that there is no current. This resultwill appear strange to the uninitiated reader, and deserves to be dweltupon. If made to act separately, they cause the needle to deflect, one GALVANISM. A-249 toward the right, the other toward the left. The current furnished bythe larger one is more intense than the current produced by the smallerone, as the deflections of the needle show. But if these two cells beopposed to each other, the effect of one is counterbalanced by the effectof the other, and no current flows, through the circuit. The conclusionof this experiment is that the electro-motive force of battery cells doesnot depend upon their dimensions. Experiments also show clearly thatthe electro-motive force of batteiy cells does not depend upon theirdimensions, but upon the materials used in their composition. Measurement of Electro-motive Forces.—It has been seen how, bymeans of an ordinary galvanometer, the electro-motive forces of different. Fig. 42. batteries maybe compared. This method,just used and described, iscalled the method of opposition, because it consists in opposing equalor unequal forces. It can be easily understood how the electro-motiveforces of different cells may thus be measured and tables of these forcesmade out. The electro-motive forces inserted between two dissimilarmetals are altered by every change in their temperatures, but the con-nection between the change of temperatures and the change of electro-motive force has not been thoroughly investigated. Electro-motive force may also be produced by electricity in motion,and by magnetism in ways which we cannot even describe, until thesimpler phenomena of electricity in motion and of magnetism have beendescribed ; but it may be said generally that all causes which have the A-250 BLEYER. power of altering the distribution of electricity can produce el
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Keywords: ., bookcentury1800, bookdecade1890, booksubjectuterus, bookyear1894
