Electro-physiology and electro-therapeutics : showing the best methods for the medical uses of electricity / By Alfred C. Garratt.

The effect upon the brain in such a case appears to amount to more than exhaustion, as the delicate mass appears to be damaged permanently, and the action through that particular route does not readily, nor yet even always, again take place. It is on this ground, doubtless, that strong moral emotions some- times instantly destroy life; for if each little sub-battery of ganglia, or of periphery, do affect the great central nerve bat- tery, so that a very strong impression made on the brain could influence by reflex action every nerve of the body, then if this action is so great at any given time as to quite exhaust them, vitality is done, and life must necessarily be extinct. See p. 222. It is not a little interesting, says Dr. Smee, in his Sources of Physics, to notice that desire in mental operations is similar in all respects to tension in the voltaic battery. When the desire is gratified, it ceases for a time. This phenomenon is pre- cisely similar to an exhausted battery in which an arrangement exists for replenishing the exciting fluid, as, in this case, after a time the battery would again become active and exhibit ten- sion ; and this is the same as desire ungratified. Hence he con- cludes, that man is perfectly free to act in any manner from external impressions ; but after he has once received those impressions, they also wonderfully influence his future course. Wben the moral law is profoundly impressed on the brain bat- tery, this will predominate, control, and rule each specific instance ; but if feebly impressed, then each immediate impres- sion is not controlled, but is controlling, and then the indi- vidual acts according to the more immediate pleasure or pain. From these considerations man is taught that his mental func- tions proceed from the integrity of his brain organization. If it is incomplete, then the mental phenomena must be imperfect. A skull that is manifestly incompetent in size and proportion to contain the usual entire central electro-nerve battery indicates that the individual is deficient in mental power, unless the con- tained brain is fine and high-toned. True, we sometimes see perfectly-formed skulls, and those of ample size, with atonic or atrophied brains inside ; and the result is a very small mental capacity, or even idiocy. Hence the author cordially concurs in