2 Gee, The Electrical Resistance of the Human Body. 



human body with its tissues immersed in fluids may be 

 regarded as an electrolyte of a very complex type. 

 According to the investigations of Dr. G. N. Stewart the 

 current passes almost wholly through the salt solutions in 

 the tissues. The effect of passing a current through the 

 body will then be like the charging of an accumulator 

 or rather a battery of cells arranged in parallel and series. 

 This view of the body has been advocated by Weiss * and 

 others, and more recently Nernst* has shown that many 

 electro-physiological phenomena may be explained by 

 considering the alterations in concentration of the electro- 

 lytes which occur at the surfaces of the membranes of the 

 body. A like explanation applies to the source of E.M.F. 

 in the electrical organ of the torpedo which Bernstein and 

 Tschermak' regard as a concentration battery acting by 

 osmotic forces. In the case of the Melapterurus^ Gotch 

 and Burch ^ find this E.M.F. as high as 200 volts. 



Taking this view of the body the result of passing a 

 direct current through it will be to cause a series of 

 polarisation back-pressures giving an apparent resistance 

 much greater than the true one. The true value can be 

 more nearly approached by using alternating currents. 

 Both methods have been used in our measurements, for hi 

 many medical applications the value of the fictitious or 

 apparent resistance is that which must be considered. 

 This is the case where medicinal substances are passed 

 into the body by endosmose, and whenever direct currents 

 are applied. 



Method of Measurement. Two circular stone-ware 

 vessels V, V^, 10 inches deep and 10 inches in width, were 



' fournal de Physique, 1S97. 



- W. Nernst. Sitz. Ber. Pretiss. Akad. Wiss. Berlin, I, p. 3, 1908. 



" Sitz. Ber. Pretiss. Akad. Wiss. Berlin, 8, p. 301, 1904. 



* Pro. Roy. Soc, 65, p. 434, Jan. 1900. 



