Dec. 30, 1881.] 



• KNOWLEDGE ♦ 



177 



:u-lueve. Now if an athlete linds that l»Ls bodily strength 



is unequal to a task wliich has hitherto been well witliin 



s powers, he would not think (if he were wise) of trying 



iH'atedly to achieve tlie muscular eflbrt which he has 



und too niueli for him. Or (extending the analogy to 



lior ways in which the power bf attention may fail) if 



1 athlete finds that he is unable to continue some mus- 



1 lar effort so long as usual, he doe^ not compel Nature 



achieve the task which for the nonce has become too 



■at for him. In either case he perceives that for the 



: le being he is not himself, and, by rest or change of 



i.ie kind (diet, mode of training, or the like), he seeks to 



^tore his powers. At any rate, if he is so unwise, in 



her case, as to endeavour to master Nature, he increases 



■ mischief, and may entirelylosethepowers whichhadbeen 



;ikencd, and might otherwise have been soon restored, or 



l^ht at least have been saved from further weakening. So, 



::\embering how close in reality is the analogj- between 



• ■ mental and bodily powers, we can well believe Dr. 



:l)es Winslow, when he tells us that when the attempt 



lix and concentrate the thoughts requires a continuous, 



-inful, and vigorous effort of the will, "serious and irre- 



rable injury may be done to the delicate organisation of 



brain and mind by injudicious attempts to e.xercise, 



niulate, a.nd force into acti^-ity the morbidly flagging and 



_'gish mental faculties." These symptoms show that the 



tin is for the time being unfit for sustained action or 



■ intense action, though not necessarily (or even pro- 



'y) diseased, and that rest is essential to restore its 



!■ ebled energies. Whether such rest should be long- 



:,nntied or not, will depend on the question whether the 



mptoms of weakened powers of attention are marked or 



l.iTwise, and also iii no slight degree on the lengfh of 



1, > during which these symptoms, whatever they may he, 



e been neglected. If they are attended to so soon as 



.- are noticed (in which case they wUl probably be 



.'ht), a very brief rest will generally restore to the 



ir.d its wonted energies. Many a man who, in the 



L'lst of prolonged and arduous mental exertion, has 



ticed signs of flagging in his power of attention, has 



;!id in even half-an-hour of sound sleep a remedy more 



■jtive than a three months' rest would be after such 



jns had been neglected during several successive weeks of 



rital labour. 



Some physiologists assert that defective speech, the next 

 ■iiptom which we have to deal with, has been the first 

 rnptom noticed in cases of cerebral disorder. Dr. Forbes 

 Winslow says : — " The first evidence of approaching 

 apoplexy and paralysis is occasionally a sudden loss of 

 speech." This may have been the first symptom noticed, 

 but we question very much whether it has ever been the 

 first symptom which has existed. 



We ought to distinguish, perhaps, here, between defective 

 speech and defective power of expression (by words indi- 

 cated otherwise than by actual articulation). In fact, an 

 important distinction exists even between the loss of the 

 power of articulation and the aflection of the vocal organs 

 indicative of cerebral disease. Here, however, we consider 

 generally the impairment of the power of linguistic expres- 

 sion which usually precedes serious mental trouble, and is 

 oft«n enough noticed where rest only or change of diet is 

 necessary as a remedy. Usually, however, this symptom 

 IS serious. Indeed, one writer on the subject of cerebral 

 disease remarks that it is a most unusual circumstance 

 for the symptom to exist without being followed by acute 

 cerebral mischief. Possibly the remark refers onlj' to 

 the absolute loss, whether for a short or long period, of the 

 power of expressing ideas by language, spoken or written. 

 That the power of expression may be affected, and even for 



a time affected seriously, while nevertheless there is no 

 serious cerebral mischief, is within the experience of most 

 persons who ha\e occasion to exercise this power freely. 

 The -symptom, like others we have dealt with here, is one 

 to be noticed, and its warning voice sliould bo heeded 

 early. This done, there is usually little occasion for alarm, 

 startling though some of the stories now to be related may 

 appear. 



Dr. Winslow relates that "a literary gentleman, whose 

 vocation in life was that of a public lecturer, noticed for 

 nearly eight weeks before he was seized with paralysis, that 

 occasionally whilst speaking he lost for a second or two all 

 power of articulation. This occurred on five, or six occa- 

 sions previously to an attack of decided hemiplegia. This 

 patient had taxed his powers of mind to their utmost by 

 lecturing twice, and often thrice, a day* ; but independently 

 of this amount of Literary labour, he had been exposed to 

 much anxiety respecting family matters, and this had pro- 

 duced restless, and, in Some instances, sleepless nights." 



INTELLIGENCE IN ANIMALS. 



LET us next examine a few cases in which animals have 

 done things which they have seen done by the 

 persons with whom they live, and more or less obviously 

 with the object of obtaining the result which they had 

 observed to follow from such actions. For this would 

 seem, if the animal can be clearly shown to have had suck 

 a purpose, to be distinctly the result of reasoning. Monkeys 

 may or may not reason when they imitate actions which, 

 when performed by themselves, are of no advantage to 

 them, or are even mischievous. Indeed, it is not impro- 

 bable that they suppose their human fellow-creatures would 

 not perform such actions except for a useful purpose, 

 though what that purpose may be they may have no con- 

 ception. But whatever opinion we may form on this 

 point, we can have, it would seem, no room for rejecting 

 the belief that an animal has reasoned who performs an 

 act dcmonsti-ably for the purpose of producing a certain 

 effect, such as he has observed to follow when human 

 beings have so acted. Now in some of the cases which 

 follow, this does seem to be most clearly made out. 



A writer in Nntitre gives the following case : — " My 

 sister, who lives just opposite to my own house, possesses a 

 cat (now about thirteen years old), whose intelligence is veiy 

 remarkable. He has a habit of making use of the knocker 

 of a side door, which is just within his reach as he stands 

 on his hind legs, whenever he desires admission. A single 

 knock is tried in the first instance ; but if this is not an- 

 swered promptly, it is followed by what is known as the 

 ' postman's knock ; ' if this is not successful, trial is then 

 made of a scientific ' rat-tat ' that would not disgrace a 

 west-end footman. I should say that ' Minnie ' holds the 

 knocker in his paw as we should hold it in our fingers, and 

 not by simply tipping it up. How far this practice involves 

 ' abstract reasoning,' I will not say, but somethiilg like an 

 approach to it is suggested, for he was never taught 4o 

 knock at the door, and adopted the habit some three years 

 ago, evidently to gain admittance, very often to the annoy- 



* The writer of these lines has lectured twice a day for a week, 

 fillii:p; up four or five hoars of each day with literary work, without 

 feeling any effects which seemed to .suggest that he had taxed his 

 powers of mind to their utmost. But, on the other hand, he has 

 noticed that after lecturing only once a, day, or even oaly four times 

 a week, while travelling great distances each d.ay, several of the 

 symptoms of incipient cerebral mischief have appeared; and even 

 less lecturing, accompanied by much mental anxiety, has caused 

 such symptoms to appear. 



