500 ELECTRICAL THEORY 



animal life, unless it undergoes a chemical 

 change in the lungs, by which caloric is evolved 

 and united with the blood. Besides, the quan- 

 tity of life throughout the earth, is not in pro- 

 portion to the amount of oxygen, which is even 

 more abundant in the polar regions than in the 

 climes of perpetual summer. It would therefore 

 be a waste of time to dwell on the absurdity of 

 regarding oxygen as the organizing principle in- 

 dependent of caloric. 



When it was found that electricity is capable 

 of causing the muscles of recently killed animals 

 to contract, philosophers began to imagine that 

 this agent was identical with the unknown ner- 

 vous fluid, and generated in the brain, which 

 some have represented as a galvanic battery.* 

 Mr. Abernethy fancied that it was the materia 

 mice of Hunter; while Lamarck supposed that 

 the vital principle was composed of electricity 

 and light. But it is not in the form of electri- 

 city that the solar fluid warms and vivifies the 

 world. Nor is it in the form of electricity that 



* In a recent work on the Principles of Medicine by Dr. Billing, 

 the author maintains that " the contractile power of the different 

 tissues is called into action by nervous influence, generated in the 

 cineritious portion of the nervous system, and conducted by the 

 white medullary part to all the organs ; that it is analogous to, 

 or depends on, if not identical with the electrical principle, or 

 fluid, whatever that may be ; that the energy of parts depends on 

 a something communicated to them by the nerves, in conjunction 

 with the brain and spinal marrow ; causing the deposition of new, 

 and the absorption of old matter, which keeps up a slow combus- 



