Nov. 18, 1881.] 



KNOWLEDGE 



45 



^ifiuent good and increase of its race. Thirdly, it appears 

 possible to account for these curious ti-ansformations and 

 disguises, by finding an initial step. It is the old story of 

 /■ premier pan qui route, applied to natural history 

 n search ; and this first step is found in tlie solid axiom, 

 that every living species is liable to variatiun and change. 

 Xi'.\t succeeds the consideration that such varieties as 

 :irc produced have to "struggle for existence." Suppo.se 

 a numWr of white varieties produced in a cold, snowy 

 r.-irion, along with varieties of more conspicuous colours. 

 It is evident that, whilst the white varieties would escape 

 fidui their enemies, the darker-coloured individuals would 

 succumb. Thus the white race comes to the front, and 

 holds its own, and its perpetuation and increase becomes a 

 mutter of surety. Summing up the argument, we find that 

 t«o factors are at work in bringing about these wonderful 

 (dour likenesses in the animal world. The one is varia- 

 tion, producing the colour - varieties ; the other is the 

 ( ircumstances of life, which weed out the weak and give 

 the battle to the strong, which latter are those whose 

 colours best suit theii- surroundings. This is the philosopliy 

 which natural history to-day lays down for our acceptance. 

 Xay more, it is a philosophy which explains far more 

 important facts of life than mere mimicry. It is "evolu- 

 tion and development" reduced to their plainest and 

 fundamental terms — in a word, Darwinism in a nutshell, 

 lis illustrated by the variation and change that all life 

 knows, and by the warring of that life bringing the best of 

 its units to the front of the battle. 



BRAIN TROUBLES. 



Impaired Memory. 



ri"^HE first mind trouble we propose to consider is the 

 JL apparent temporary impairment of the memory. The 

 gradual progressive decay of the power of memory with 

 advancing years is, of course, a change which all may 

 expect who attain great length of years ; tliough, as Cicero 

 long since pointed out, and as has been repeatedly exemplified 

 by modem instances, the change is to some degree under 

 control, and those matters in which an aged person takes 

 special interest may be well remembered, when others about 

 which he cares little are easily forgotten. " I never heard," 

 says Cicero, "of any old man that had forgotten where he 

 had hid his treasure ; things which they regard, old men 

 remember — the securities the}' have out, and who are 

 indebted to them, as well as to whom they are indebted." 

 And so forth. The points to be noticed here are, first, 

 that memory is seen to be in large degree a question of at- 

 tention as well as of retention ; and, secondly, that decay 

 of memory implies a change in the mind analogous to that 

 which makes the old incapable of great bodily efforts. So 

 that when the memory of a person who is not old becomes 

 impaired, we may infer that unless there is actual disease, 

 the symptom indicates overwork of the mind, precisely as 

 bodily weariness indicates that the body haa been over- 

 \vrought We may, perhaps, be led to inquire here whether 

 a distinction should be drawn between loss of memory, as 

 shown bj' a weakening of the power of committing to mind 

 new matter (of whatever kind) which we may wish to re- 

 member, and the passing away from the mind of matter 

 which had been already committed to it, and retained so 

 long and so recently that its being forgotten can be ex- 

 plained only as due to some marked and recent change in 

 the state of the mind. Suppose, for instance, that after 

 carefully noting a number of facts, which under ordinary 

 conditions we should remember thenceforward for weeks. 



we find that they liave left no suthcient impression on the 

 mind ; liere wo obviously have evidence that the power of 

 attention on which, in the first instance, memory depends, 

 is for the time being enfeebled. Can we, liowever, infer 

 tliat it is weakened in the same way and in the same degree 

 as we should judge- it to be if we found that numbers, dates, 

 names, or words which we had had occiision to refer to 

 daily for years, were suddenly clean forgotten ? Making 

 use, as we conveniently may (tliough we must not place too 

 much stress on the method), of the analogy between bodily 

 and mental relations, we may compare a change of the 

 former kind to a diminution of the jiower of accjuiring some 

 new feat ; a change of the latter kind, to the sudden loss 

 of a feat already acquired and long practised. It can 

 hardly be doubted that an athlete who should find liimself 

 unable to perform some n(>w gymnastic trick, which lie had 

 supposed well within liis powers, would not be so much 

 struck by the circumstance, as he would be if he should 

 suddenly find himself unable to achieve a feat in which he 

 had hitherto found no difficulty. 



Let us inquire, however, whetlier known cases of loss of 

 memory of either kind atibrd any means of answering the 

 question which has thus arisen. Of course, those cases in 

 which the trouble has been only temporary, though far more 

 numerous than those in which loss of memory has been 

 symptomatic of actual disease, stand far less chance of being 

 kept on record, so that we may have to consider cases of 

 the latter kind to discover the relative importance of the 

 two forms in which loss of memory may be noticed. The 

 reader must not judge fi-om cases thus cited that either 

 class of symptoms is necessarily, or even probablj-, indica 

 tive of serious brain mischief. 



We will begin, however, with a case in which the trouble 

 was only temporary, and, moreover, its cause obviously 

 indicated. 



Sir Henry Holland gives the following suggestive account 

 of a transient loss of memory due to fatisfue. It will be 

 seen that the failure of memory belongs to the second class 

 above referred to, that, viz., in which what had been long 

 and well known is suddenly forgotten. " I descended," 

 he says, " on the same day, two very deep mines in the 

 Harz Mountains, remaining some hours undergi-ound in 

 each. While in the second mine, and exhausted both from 

 fatigue and inanition, I felt the utter impossibility of 

 talking longer with the German Inspector who accompanied 

 me. Every German word and phrase deserted my recol- 

 lection, and it was not until I had taken food and wine, 

 and been some time at rest, that I regained thea." This 

 case would seem to show that transient loss of memory, 

 even of this kind, need not be regarded as necessarily an 

 alarming symptom. 



The following case points in the same direction even 

 more decisively. "A gentleman," says Dr. Winslow, 

 " well known for his intense passion for field spoiis (living, 

 it may be said, upon the saddle during the greater part of 

 the year), frequently complained of transient attacks of 

 loss of memory after a hard day's run with the hounds. 

 His remedy for this affection was half'-a-pint to a pint of 

 port wine at a draught ! The effect of this heroic dose of 

 vinous stimulant upon the depressed energy of the brain 

 was evidenced by the memory immediately recovering its 

 vigorous activity." It would, however, be unwise to infer 

 tliat this sportsman, in thus prescribing for these attacks, 

 showed himself the " physician " of the proverb relating to 

 fools and physicians. The remedy was a dangerous one. 

 His was specially a case where prevention was better than 

 cure. The transient attacks of loss of memory showed that 

 the hard days run with the hounds overtaxed his strength. 

 He would have done wisely to have limited his exertions 



