Electro-physiology and electro-therapeutics : showing the best methods for the medical uses of electricity / By Alfred C. Garratt.
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cule is only an agglomeration of a greater or less number of atoms. When we take into consideration the general alterations occur- ring in the brain as well as in all the body, it by no means follows that exactly the same change in degree or kind occurs in both. This includes that vastly comprehensive subject of waste and repair; for, as says a philosopher, " wc can no more obtain light without consuming oil, or its equivalent, or heat without the combustion of fuel, and that too with the product of soot and ashes, than we can obtain animal force without the creature receiving food and excreting the debris." Bright arterial blood must flow throughout the whole from pole to pole, i. e., from the centre to the surface corpuscules, and so to the stations of ganglia and to the brain. The electrolyte of both extremities of these nerve routes is liquid, and as healthy serum contains neutral salts, it is under all the better state for exactly such electrical purposes, minus vitality. It is a law of the voltaic circuit that no polarity can occur unless there be some difference in the two poles, either in refer- ence to their individual power of combining with oxygen, or from other circumstances that places them in different relations, such, at least, as variations in temperature, in extent of surface, in state of surface, or in their fluids having a different affinity for the gfo 311 pole. Now, when we have a difference even in any one of these respects, then we as certainly have a voltaic circuit, determined from that pole which renders most capable for com- bining with oxygen. In reference to the changes taking place between the elements of protien, which is largely contained in muscles, Liebig says, the elements of protien, starch, oxygen, and water undergo transformation together, and mutually affect each other. We obtain, as the product of this metamorphosis, urea, choleric acid, ammonia, and carbonic acid; and besides these, no other product whatever. We here have the chief constituents of animal secretions and excretions, viz., carbonic acid, as elimi- nated by the lungs, urea and ammonia by the kidneys, and choleic acid secreted and eliminated by the liver into the