50 STUDIES IN ELECTRO-PHYSIOLOGY: 



he must become more or less proficient in neurology, in 

 electro-physics, and in electro-physiology. He who has a 

 knowledge of the laws of animal electricity, and the actions 

 and reactions of franklinic, galvanic, and faradic electricity 

 on the brain, spinal cord, and sympathetic ; on the nerves 

 of motion and of common and special sense ; on voluntary 

 and involuntary muscles ; on the skin, and on all the 

 various passages and organs of the body in health, and also 

 of the electro-conductivity of the body, will find the paths 

 of electro-diagnosis and of electro -therapeutics illumined at 

 every step by such knowledge, and will, in the end, make 

 more correct interpretations of disease than he who merely 

 holds electrodes on patients without any higher aim ; and 

 more than that, he will be introduced into a field of thought 

 and experiment a field surpassingly rich and fruitful 

 and lying in close relation to all departments of physiology, 

 of pathology, and of biology, where he can study science 

 for its own sake."* 



To go back to history, it was in 1786 that Galvani 

 discovered that muscular contraction followed the contact 

 of the nerves and muscles of a frog with a heterogeneous 

 metallic arc. He theorised, and his theory was that in the 

 tissues of animals there existed a special independent 

 electricity, which he called animal electricity. Later 

 observers admitted the existence of animal electricity as 

 a force, but explained it by contact of dissimilar substances 

 and by the chemical action of the fluids of the body on the 

 metals. This erroneous and untenable theory is upheld by 

 the average physiologist of to-day. 



Volta's researches followed, and in 1799 Humboldt 

 published a work which went to show that Galvani and 

 Volta were both right and both wrong ; that there was such 

 a thing as animal electricity ; that Galvani was in error in 



* The italics are iriine. 



