CHAPTER XVIII 



ELECTROPHYSIOLOGY 



Scientist, philosopher, and layman have long speculated on a 

 possible relationship between Ufe and electricity. It has been 

 natural to do so, for life and electricity are forces of an ex- 

 traordinary character. Increased knowledge has strengthened 

 rather than weakened this old, half -scientific, half-superstitious 

 belief in electricity as a potent and all-pervading force in life. 

 To be sure, we are in an electric epoch and are likely to become 

 overenthusiastic about electric forces, but there are many experi- 

 ments to support electric interpretations of cellular behavior, 

 and there is the fundamental fact that the ultimate unit of all 

 matter is an electric charge. Relatively little is known of the 

 precise part played by electric forces in organisms, but it has 

 been possible to determine their presence there, to measure them, 

 and to correlate them with certain physiological processes. 



Magnetism and Electromagnetic Forces. — Electric forces 

 may be dealt with under three headings— electromagnetics, 

 electrostatics, and electrokinetics (these overlap more or less). 



With pure magnetism we shall have httle to do. It does not 

 appear that organisms are sensitive to magnetic forces. The 

 story is told that Faraday had a student place his head between 

 the poles of a powerful electromagnet with no noticeable effect. 

 However, some hypotheses have been advanced purporting to 

 explain vital processes on the basis of magnetic forces. 



So closely do the asters of a dividing animal egg (Fig. 17) 

 resemble the distribution of iron filings within the field of influ- 

 ence of a magnet that magnetism was suspected of being the 

 force responsible for the mitotic figure. This suggestion was 

 made by H. Fol, when he first observed the mitotic figure in 1873. 

 Magnetism would thus be the force under the influence of which 

 the chromosomes migrate to the "poles" in a Uving cell. This 

 speculation led to an attempt to disturb the normal process of 

 cell division by placing a dividing animal egg in the field of a 



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