THE ACTIVE FORCES OF LIVING ORGANISMS 51 



the ether permeating the cell, we can understand 

 how it happens that the other molecules, for the 

 oxidation of which the supply of oxygen is insufficient, 

 nevertheless become in a certain measure active, and 

 vibrate. Further, if again we suppose that light 

 consists of waves of force transmitted through the 

 ether, we shall see that the very origin of what 

 one may term our chief sense, if not electrical, is very 

 closely allied to electricity. We cannot shut our eyes Electrical 

 to the accumulating evidence of the electrical nature mena. 

 of living tissue. Cutaneous, glandular, muscular, 

 and nerve currents are known to exist, and are, indeed, 

 a constant phenomenon in the functional activity of 

 the corresponding parts. The heart has two electrical 

 areas : there are retinal currents ; there are currents 

 of injury. To produce a current it is sufficient, as 

 Galvani has shown, to make a muscle preparation 

 with a portion of the nerve attached, to raise the 

 latter, and allow it to fall suddenly on another 

 muscle preparation, or even on the same muscle, 

 so that it may unite as far as possible injured and 

 uninjured parts. In this case the current is gene- 

 rated and transmitted through muscle and nerve 

 alone without the aid of electrodes or wire. Thus, 

 it will be seen that variation of potential, or, as 

 one might call it, of ethereal tension coupled with 

 molecular agitation, will, under certain conditions, 

 produce muscular contraction. These facts, to which 

 others might be added, seem to support the view that 

 electricity in living tissue is by no means an inert 



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