172 MENTAL, CONSTITUTION OF ANTMALS. 



this great system of things we are only beginning to have 

 a right conception. It has been found that simple elec- 

 tricity, artificially produced, and sent along the nerves of 

 a dead body, excites muscular action. The brain of a 

 newly-killed animal being taken out, and replaced by a 

 substance which produces electric action, the operation 

 of digestion, which had been interrupted by the death of 

 the animal, was resumed, showing the absolute identity 

 of the brain with a galvanic battery. Nor is this a very 

 startling idea, when we reflect that electricity is al- 

 most as metaphysical as ever mind was supposed to be. 

 It is a thing perfectly intangible, weightless. Metal may 

 be magnetized, or heated to seven hundred of Fahrenheit, 

 without becoming the hundredth part of a grain heavier. 

 And yet electricity is a real thing, an actual existence in 

 nature, as witness the effects of heat and light in vegeta- 

 tion — the power of the galvanic current to reassemble 

 the particles of copper from a solution, and make them 

 again into a solid plate — the rending force of the thun- 

 derbolt as it strikes the oak; see also how both heat 

 and light observe the angle of incidence in reflection, as 

 exactly as does the grossest stone thrown obliquely against 

 a wall. So mental action may be imponderable, intangi- 

 ble, and yet a real existence, and ruled by the Eternal 

 through his laws.* 



Common observation shows a great general superiority 

 of the human mind over that of the inferior animals. 

 Man's mind is almost infinite in device ; it ranges over 

 all the world ; it forms the most wonderful combinations ; 

 it seeks back into the past, and stretches forward into the 

 future ; while the animals generally appear to have a nar- 

 row range of thought and action. But so also has an in- 

 fant but a limited range, and yet it is mind which works 



* If mental action is electric, the proverbial quickness of thought 

 — that is, the quickness of the transmission of sensation and will — 

 may be presumed to have been brought to an exact measurement. 

 The speed of light has long been known to be about 192,000 miles 

 per second, and the experiments of Wheatstone have shown that 

 the electric agent travels (it I may so speak) at the same rate, 

 thus showing a likelihood that one law rules the movements of 

 all the " imponderable bodies." Mental action may accordingly 

 be presumed to have a rapidity equal to one hundred and ninety- 

 two thousand miles in the second— a rate evidently far beyond 

 what is necessary to make the design and execution cf any of our 

 ordinary muscular movements apparently identical an point of 

 time, which they are. 



