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Show 76 THE PlUNCIPLE OF THE DIRECT CnAP. III, strong tendency to various purposeless movements, and to the utterance of various sounds. vVe see this in our young children, in their loud laughter, clapping of hands, and jutnping for joy; in the bounding and barking of a do()' when O'Oino- out to walk with his n1aster; and in the 0 b 0 frjsking of a horse when turned out into an open field. ,Joy quickens the circulation, and this stimulates the brain which ao·ain reacts on the whole body. The ' 0 above purposeless n1oven1ents and increased heart-action 1nay be attributed in chief part to the excited state of the sensoriutn/0 and to the consequent undirected overflow, as Mr. I-Ierbert Spencer insists, of nerve-force. It deserves notice, that it is chiefly the anticipation of a pleasure, and not its actual enjoyment, which leads to purposeless and extravagant n1ovements of the body, and to the utterance of various sounds. We see this in our children when they expect any great pleasure ot· treat; and dogs, which have been bounding about at the sight of a plate of food, when they get it do not ~how their delight by any outward sign, not even by wagging their tails. Now with anin1als of all kinds, the acquirement of almost all their pleasures, with the 10 How powerfully intense joy excites the brain, aud how the brain reacts on tho body, is well shown in the rare cases of Psychical Intoxication. Dr. J. Crichton Browne(' Medical Mirror,' 1865) records the case of a young man of strongly nervous temperament, who, on hearing by a t elegram that a fortune had been bequeathed him, first became pale then exhilarated, and soon in the highest spirits, but flushed and very restless. He then took a walk with a friend for the sake of tranquillising himself, but returned staggering in his gait, uproariously laughing, yet irritable in temper, incesaantly talking, and singing loudly in the public streets. It was positively ascertained that he had not touched any spirituous liquor, though every one thought that he was intoxicated. Vomiting after a time came on, and the half-digested contents of his stomach were examined, but no odour of alcohol could be detected. Ho then slept heavily, and on awaking was well, except that he suffered from he:1dnche1 11at1.sen,, and prostration of strengtl). · CtrAl'. III. ACT!ON OF TiiE NERVOUS SYSTEM. 77 .oxeeption of those of warmth and rest, are associated, and. have long been associated with active Inovements as 111 ~he hunting or search for food, and in thei;. cour~shlp. 1\Ioreover, the mere exertion of the muscles a~ter l~~g rest or confinenlent is in itself a pleasure, as "e. our~elves feel, and as we see in the play of youn()' a~Imals. Therefore on this latter principle alone w; Inight p~rhaps expect, that vivid pleasure would be apt to sh.ow Itself conversely in muscular movements. , , 'Vrth all or almost all animals, even with LirJ~, lon·or causes the body to tremble. ~rhe skin becomes pale, .sweat breaks out, and the hair bristles. The ~ec~etrons of the aliinei~tary canal. and of the kidneys are Increas~d, and they are Involuntanly voided; owing to the relaxation .of the sphincter muscles, as is known to be the case With 111an, and as I have seen with cattle doo-s cats, and ~onkey~. ~rhe breathing is hurried. Th~ he~·t beats qurcldy, Wildly, and violently; but whether it pnm ps the blood n1ore efficiently through the body may be doubted, for the surface seems bloodless and the strength of the muscles soon fails. In a frightened horse I have. felt through the saddle the beating of the he~1rt so plainly that I could have counted the beats. ~rhe In ental faculties are 1nuch disturbed. Utter prostration soon follows, and even tainting. A terrified canary-bird has been seen not only to tren1ble and to turn white about the base :of the bill, but to faint· 11 and I once caught a ro?in in a rootn, which fainted 'so completely, that for a time I thought it dead. . 1\iost of these syrnptoms are probably the direct result" Indep~ndently of habit, of the disturbed state of th~ sensornnn; but it is doubtful whether they-ought to be wholly thus accounted for. When an animal is alarmed ---- ----- - -- 11 Dr. Durwin, ' Zoonomia,' 17tH, vol. i. pj 1481 |