Curiosities of Medical Experience Part 38

III. Arbitrary or fict.i.tious a.s.sociations.

Dr. Abercrombie has admirably treated this subject, and I refer the reader to his interesting work.[44] The poet Simonides is said to have been the founder of the mnemonic art. Cicero informs us, that, supping one night with a n.o.ble Thessalian, he was called out by two of his acquaintance, and while in conversation with them the roof of the house fell in, and crushed to death all the guests he had left at table. When the bodies were sought for, they were so disfigured by the accident that they could not be recognised even by their nearest friends; but Simonides identified them all, by merely recollecting the seats they had held at the banquet.

Cicero and Quintilian adopted his system, connecting the ideas of a discourse with certain figures. The different parts of the hilt of a sword, for instance, might regulate the details of a battle; the different parts of a tree a.s.sociate the relations of a journey. Other mnemonic teachers recommended the division of ideas to correspond with the distribution of a house; while some of them refreshed the memory by a.s.sociations connected with the fingers and other parts of the hand.

Cicero expresses himself plainly on this subject: "Qui multa voluerit meminisse, multa sibi loca comparet: oportet multos comparare locos, ut in multis locis multas imagines collocemus."

The celebrated Feinagle who delivered lectures on memory had adopted the system of aiding the memory by dates, changing the figures in the dates into the letters of the alphabet corresponding to them in number. These letters were then formed into a word to be in some way a.s.sociated with the date to be remembered--for instance--Henry IV., King of England, was born in the year 1366. This date changed into letters makes _mff_ which was very easily changed into the word _m.u.f.f_--the method is not so obvious of establis.h.i.+ng with this a relation to Henry IV., but Hen_ry_ IV., says Mr.

Feinagle, means four hens, and we put them in a m.u.f.f, one in each corner, and no one after hearing this is in any danger of forgetting the date of Henry IV.'s birth.

Learning poetry by heart in infancy and youth is perhaps one of the best methods of improving memory, since it lays the early foundation of a cla.s.sification of words and ideas. Virgil has justly said, "Numeros memini, si verba tenerem." To abridge, resume, and a.n.a.lyze what we have read or heard, is another practice highly beneficial; for, the more clearly we comprehend a subject, the deeper will it remain engraved in our memory. Reading what we wish to recollect before going to bed will materially a.s.sist the memory. We sleep over the impressions we have received, and dreams alone can weaken them. From this very reason we can write with more facility upon subjects that require much mental exertion in the morning, fasting, when the mind has not been disturbed by the events of the day, and when the functions of digestion have not drawn upon our faculties, too frequently with the lavishness of a spendthrift. It is somewhat singular, but, despite the interruption of dreams, our ideas are matured during our sleep. Quintilian expresses himself as follows on this subject: "Mirum dictu est quantum nox interposita adferat firmitatis, sive quiescit labor ille cujus sibi ipsa fatigatio obstabat, sive maturatur ac coquatur, seu firmissima ejus pars est recordatio. Quae statim referri non poterant, contexuntur postero die, confirmatque memoriam idem illud tempus quod esse in causa solet oblivionis."

Memory is subject to be variously disturbed in certain maladies. There is an affection called _amnesia_, in which it utterly fails, and another termed _dysmnesia_, when it is defective. Failure of memory is generally more manifest on some subjects than on others. Salmuth relates the case of a man who had forgotten to p.r.o.nounce words, although he could write them.

Another person could only recollect the first syllables. An old man had forgotten all the past events of his life, unless recalled to his recollection by some occurrence; yet every night he regularly recollected some one particular circ.u.mstance of his early days. A curious anecdote is recorded of an elderly gentleman who had fallen into the meshes of an artful courtesan, and who frequently took his own wife for this insidious acquaintance, frequently saying to her, "Madam, I feel that I am doing wrong by devoting to you so much of my time, for, when a man has a wife and children, such conduct is unpardonable;" and, after this polite observation, he took up his hat, and would have walked off, had not his wife, wise enough not to manifest displeasure, contrived to undeceive him.

Dietrich mentions a patient who remembered facts, but had totally forgotten words; while another could write, although he had lost the faculty of reading. Old men are frequently met with who confound substantives, and will call their snuff-box a cane, and their watch a hat.

In other cases letters are transposed, and a musician has called his _flute_ a _tufle_. Dr. Abercrombie relates the case of a gentleman who uniformly called his snuff-box a hogshead. In Virginia he had been a trader in tobacco, so that the transition from snuff to tobacco, and from tobacco to a hogshead seemed to be natural. Another person, affected in a similar manner, always called for paper when he wanted coals, and coals when he needed paper. Others are known to invent names and unintelligible words. Some curious anagrams have been made by these irregularities. John Hunter was suddenly attacked with a loss of memory, which is thus related by Sir Everard Home: "He was at the time on a visit at the house of a friend. He did not know in what part of the house he was, not even the name of the street when he was told, nor where his own house was. He had not a conception of anything existing beyond the room in which he was, and yet he was perfectly conscious of the loss of memory. He was sensible of impressions of all kinds from the senses, and therefore looked out of the window, although rather dark, to see if he could be made sensible of the situation of the house. The loss of memory gradually went off, and in less than half an hour his memory was perfectly recovered." Such momentary accidents I have frequently observed in gouty patients; and for a second or two I have myself experienced the sensation, which was for the moment of a most alarming nature. Hunter was subject to arthritic attacks.

Corvinus Messala lost his memory for two years, and in his old age could not remember his own name. This is an occurrence by no means uncommon; and I knew a person in perfect health who could only recollect his name by writing it. We frequently see individuals who, although they are generally correct orthographers, cannot sometimes spell a simple conjunction. An anecdote is related in the Psychological Magazine of a German statesman, who having called at a gentleman's house, the servants of which not knowing him, was asked for his name, which he had, however, so totally forgotten, that he was under the necessity of turning round to a friend and saying with great earnestness, "Pray tell me who I am, for I cannot recollect."

Cases are recorded of the forgetfulness of a language constantly spoken, while one nearly forgotten from want of practice was recovered. A patient in St. Thomas's Hospital, who had been admitted with a brain-fever, on his recovery spoke an unknown language to his attendants. A Welsh milkman happened to be in the ward, and recognised his native dialect; although the patient had left Wales in early youth, had resided thirty years in England, and had nearly forgotten his native tongue. Boerhaave relates a curious case of a Spanish poet, author of several excellent tragedies, who had so completely lost his memory in consequence of an acute fever, that he not only had forgotten the languages he had formerly cultivated, but even the alphabet, and was obliged to begin again to learn to read. His own former productions were shown to him, but he could not recognise them.

Afterwards, however, he began once more to compose verses, which bore so striking a resemblance to his former writings, that he at length became convinced of his having been the author of them.

Dr. Abercrombie relates the case of an aged gentleman, who, in an attack of the head, had almost forgotten the English language, and expressed himself in a mixed dialect of French, Italian, Spanish, German, and Turkish. Having been some time afterwards severely burnt about the head, by setting fire to the curtains of his bed, he was observed to make use of some English words; this being followed by a course of blistering, he continued to speak more English, but only occasionally and in very short sentences. These were sometimes correctly applied, but at other times most erroneously; for instance, having been taken to see a small house, he observed, "it is very neat, but it is a very little child."

Dr. Beattie mentions the case of a clergyman who, on his recovery from an apoplectic attack, had exactly forgotten a period of four years; and Dr.

Abercrombie records a lady who had thus forgotten ten or twelve years of her life. Wepfer mentions a gentleman, who on recovery from an apoplectic attack, was found to know n.o.body and remember nothing. After several weeks he began to know his friends, to remember words, to repeat the Lord's Prayer, and to read a few words of Latin, rather than German, his native language. When urged to read more than a few words at a time, he said that he formerly understood those things, but now did not. After some time he began to pay more attention to what was pa.s.sing around him, but while thus making slight and gradual progress, he was, after a few months, suddenly cut off by another attack of apoplexy. Dr. Beattie relates the case of a gentleman who, after a blow on the head, lost his knowledge of Greek, and did not appear to have lost any thing else.

Loss of memory has been observed as a frequent occurrence after the prevalence of pestilential diseases. Thucydides relates, that after the plague of Athens several of the inhabitants forgot their own names and those of their parents and friends. After the disastrous retreat of the French army in Russia, and the disease which swept away so many of their troops at Wilna, many of the survivors had no recollection of country or of home. Injuries of the head appear to occasion different results. This circ.u.mstance was observed by the ancients. Valerius Maximus relates the case of an Athenian, who, being struck on the head with a stone, forgot all literary attainments, although he preserved the recollection of other matters. A man wounded with a sword in the eye completely forgot Greek and Latin, in which he had formerly been a proficient. A young man, having fallen off his horse and contused his head, lost his memory to such an extent, that he would repeat a question a hundred times over, although the very first interrogation had been answered. He had not the slightest recollection of his accident. Epileptic and paralytic attacks frequently usher in this melancholy result, which has also been often observed after child-birth.

Dr. Abercrombie knew a lady who was seized with an apoplectic fit while engaged at cards; the attack took place on a Thursday evening--she lay in a state of stupor on Friday and Sat.u.r.day, and recovered her consciousness rather suddenly on Sunday. The first words she then uttered were, "What is trump?"

Dr. Conolly mentions a young clergyman who, when on the point of being married, suffered an injury of the head, by which his understanding became impaired. He lived in this condition to the advanced age of eighty, and to the last day of his existence, spoke of nothing but his approaching wedding, expressing impatience for the arrival of the happy day.

A singular instance of forgetfulness is related of a lady who had been united to a man she loved, after much opposition on the part of her family, and who lost her memory after the birth of a child. She could not be made to recollect any circ.u.mstance that had occurred since her marriage; nor could she recognise her husband or her infant, both of whom she maintained were utter strangers to her. At first she repulsed them with apparent horror, but was at last, by the entreaties of her family, induced to believe that she was a wife and a mother; and although she yielded to their solicitations, yet for years she could not persuade herself that their a.s.sertions were correct, as she actually was convinced "against her will." In this instance disease not only destroyed memory, but affection.

The case of Dr. Broussonnet was remarkable. An accident he had met with in the Pyrenees brought on an apoplectic attack. When he recovered, he could neither write nor p.r.o.nounce correctly any substantives or personal names either in French or Latin, while adjectives and epithets crowded in his mind. Thus, when speaking of a person, he would describe his appearance, his qualities, and, without p.r.o.nouncing the word "coat," would name its colour. In his botanical pursuits he could point out the form and colour of plants, but had not the power of naming them. A Parisian merchant, after severe losses, experienced such a failure in recollection, that he was constantly guilty of the most absurd anachronisms;--would talk of the battles of Louis the Fourteenth with Alexander the Great, and describe Charles the Twelfth ascending triumphantly Mount Valerian; and one night, after witnessing the performance of Talma, could not be persuaded that he had not applauded Lekain.

Sudden fright has also obliterated this faculty. Artemidorus lost his memory from the terror inspired by treading on a crocodile. Bleeding has produced the same effects; while, on the other hand, blood-letting has restored an absent man to perfect recollection. Various venenose substances have also been said to produce amnesia. History records several instances of the kind. The soldiers of Anthony, on their return from the Parthian war, were attacked with loss of memory after eating some poisonous plants on their march. Bamba, king of the Goths, was suddenly deprived of all recollection after taking a draught presented to him by Eringius. Plater and Baldinger attributed a similar accident to the use of hemlock and a.r.s.enic. Narcotics, no doubt, may produce similar effects, but they will be of a transient nature; I do not know that this injurious power has been detected in any other productions, as the cases related by writers are not supported by sufficient authority to be ent.i.tled to unqualified belief.

The cause of these affections will most probably ever be unknown. Equally futile have proved all the endeavours to ascertain in what part of the brain memory is seated, since we have found some physiologists lodging this wonderful faculty in the posterior, and others in the anterior portion of the cranium. I apprehend that we might torture the brute creation, from the elephant down to the lowest reptile, for centuries, without being able to ascertain this point; and even could we attain this information, _cui bono_? Would it protect this privileged quarter of the cerebral organ from the action of external agency, or restore it to its healthy functions when diseased? The mode in which our mental faculties are developed is an impenetrable mystery; and, instead of vainly endeavouring to raise the mystic veil to gratify our curiosity, or rather our vanity, let us endeavour to apply these functions to the use for which they were intended by the allwise Creator, and exert them for the purpose of increasing the prosperity, or at any rate in endeavouring to diminish the sum of sufferings of his creatures, whether they be our fellow-men or the divers races that are submitted to our capricious power.

AFFECTIONS OF THE SIGHT.

The different terms applied to the various morbid affections of vision have been frequently misconceived, and consequently have occasioned much confusion in their application. Those vitiated conditions which are usually noticed may be cla.s.sed as follows:

I. Night sight.

II. Day sight.

III. Long sight.

IV. Short sight.

V. Skew sight.

VI. False sight.

_Night sight_, specifically called _Lucifuga_, was also termed _Nyctalopia_, from [Greek: nyx], _night_, and [Greek: ops], _eye_; it was also known as the _Noctem amans_. This affection was thus named in consequence of the person labouring under it being only able to see at night, or in a deep shade; hence the first name: while nyctalopia has been used by most modern writers in the opposite sense of _night-sight ache_, agreeably, according to Mason Good's observations, to the technical or implied meaning of _opia_, in which case it always applies to a diseased vision; whence nyctalopia has been made to import day sight, instead of night sight.

This disease appears to be dependent upon a peculiar irritability of the retina, produced by two different causes,--a sudden exposure to a stronger light than the eye has been accustomed to bear, or a deficiency of the black pigment which lines the choroid tunic. If the iris be weak and torpid, it is enlarged; if strong and contracted, diminished. Thus, those who from peculiar circ.u.mstances reside in dark caverns and subterraneous abodes, or who have long been confined in obscure dungeons, labour under the first of these causes; instances of which were observed in two of the captives liberated from the Bastille in 1789.

Ramazzini informs us that this affection is commonly observed among the Italian peasants, amongst whom he was not able to trace any other peculiarity than an enlargement of the pupil. This state of the vision, however, has been attributed to the peculiar brightness of the Italian sky, its clear atmosphere, and the relaxing warmth of the temperature.

The Italian peasants are therefore constantly exposed to all those causes that tend to debilitate the iris, while they irritate the retina. We thus find these causes acting with renewed power at the season when the disease usually makes its attack,--the vernal equinox, when an increased flood of solar rays breaks on them. Such is the dimness that this brightness produces, that the peasantry frequently lose their way in the fields in the glare of day; but on the approach of night they can see distinctly.

Hence are they obliged to remain for some weeks in the shade to recover their sight.

A deficiency of the black pigment of the eye is occasionally found in persons of a very fair complexion and light hair. This affection is therefore common in the Albinoes. This circ.u.mstance arises from the whiteness of the eyelashes and hair, whereby the retina is deprived of the natural shade that softens the light in its descent. This debilitated race generally inhabit warm and damp regions; they are seldom long-lived, and frequently low-spirited and morose. The iris is of a pink colour, and this circ.u.mstance, added to the constant winking that the weakness of the organ occasions, gives them a distressing appearance. In horses, this want of the dark pigment const.i.tutes what is called the _wall eye_.

Acuteness in night vision is natural to most, if not to all, animals that prowl in the dark. In the feline genus we observe that the iris can be contracted much closer than in mankind, when exposed to a vivid glare; but they also expand to a much greater degree when obscurity sets in. Owls, bats, and many insects, possess a similar faculty.

_Day sight_, the nyctalopia of some authors, is said to be endemic in some countries,--Poland, the West Indies, Brazil, and various intertropical regions. This affection arises from causes totally different from the former one. Here the eye is habitually exposed to too great a flood of light, whence the retina becomes torpid. It has been said to be endemic in some districts of France, particularly in the neighbourhood of Roche Guyon, on the banks of the Seine; but here the soil is of a dazzling white: and as it makes its attacks in the spring, and continues for three months, it is supposed to arise from the keenness of the reflected light, after the dreary winter months.

This disease has also been commonly observed in Russia, especially in the summer, when the eye is exposed, with scarcely any intermission, to the constant action of light, as the sun dips but little below the horizon, and there is scarcely any interval of darkness. Hens are subject to this affection, and cannot see to pick up their food in the dusk of the evening. The complaint is, from this circ.u.mstance, called _hen blindness_.

Dr. Heberden has communicated the following curious case of this species of affection: "A man about forty years old had in the spring a tertian fever, for which he took too small a quant.i.ty of bark, so that the returns of it were weakened without being removed. Three days after his last fit, being then employed on board a s.h.i.+p in the river, he observed at sun-setting that all objects began to look blue, which blueness gradually thickened into a cloud; and not long after he became so blind as hardly to perceive the light of a candle. The next morning about sunrising his sight was restored as perfectly as ever. When the next night came on, he lost his sight again in the same manner, and this continued for twelve days and nights. He then came ash.o.r.e, where the disorder of his eyes gradually abated, and in three days was entirely gone. A month after he went on board another s.h.i.+p, and after three days' stay in it the night blindness returned as before, and lasted all the time of his remaining in the s.h.i.+p, which was nine nights. He then left the s.h.i.+p, and his blindness did not return while he was upon land. Some little time afterwards he went into another s.h.i.+p, in which he continued for ten days, during which time the blindness returned only two nights, and never afterwards." It appears, however, that this individual had previously laboured under an affection produced by the use of lead, which had left him in a state of much nervous debility. Notwithstanding this circ.u.mstance, this case clearly proves that the affection is liable to be increased and brought on by local influence.

_Long sight._ In this species of vision the iris is habitually dilated, and not easily stimulated into contraction. Several varieties of this affection have been observed. Dr. Wells, in the Philosophical Transactions, relates the case of a young person who, from a permanent dilatation of the pupil, saw near objects with much difficulty and confusion, but remote bodies with singular accuracy. The power of moving the upper lid was completely lost. This dilatation of the pupil, which may be artificially produced by the application of belladonna, can be remedied by the use of convex gla.s.ses.

_Short sight._ In this case the iris is contracted, and the cornea, which in long sight is too much flattened, is too convex or polarised; therefore spectacles of an opposite character, and with concave gla.s.ses, become necessary. Mice are said to be short-sighted; hence the affection has been termed myopia or myopiasis, literally "mouse-sight."

_Skew sight_, or _sight askew_, is a condition of our vision only accurate when the object is placed obliquely, in consequence of some partial obfuscation of the cornea, frequently from slight scars, scarcely, if at all, observable. In this lateral vision the axis of the eye affected usually coincides with that of the sound eye. In squinting, on the contrary, the two axes do not coincide.

In _false sight_, imaginary objects float before the sight; or, at other times, objects a.s.sume imaginary forms and qualities. The latter species has been divided in cases where the objects that are supposed to be seen have no real existence, and in cases where actual objects have a.s.sumed qualities that do not appertain to them. The first are termed ocular phantasms or spectres; the latter, ocular trans.m.u.tations or illusions.

These spectres sometimes form dark spots, called by physicians _muscae volitantes_. In another species, a net-work seems to be spread before the eyes; hence called _visus reticularis_. In a third form sparks scintillate, and this appearance is experienced when the eye has been struck. The eye is also troubled with an imaginary sense of dazzling, const.i.tuting the _myrmaryge_ of the Greek writers; at other times, an iridescent appearance, exhibiting the colours of the rainbow, is experienced, although sometimes this impression is confined to a single colour. Dr. Heberden relates the case of a lady of advanced age, lodging on the eastern coast of Kent, in a house that looked immediately upon the sea, and exposed to the glare of the morning sun. The curtains of her room were white, a circ.u.mstance which added to the intensity of the light. When she had been there about ten days, she observed one evening, at the time of sunset, that first the fringes of the clouds appeared red, and soon after the same colour was diffused over all the objects around her, especially if they were white. This lasted the whole night, but in the morning her sight was again perfect. This alternation of morbid and sound sight prevailed the whole time the lady resided on the coast, which was three weeks; and for nearly as long after she left it, at which time it ceased suddenly of its own accord.

There exists another variety of false sight, that Plenk has denominated _metamorphopsia_, and in which objects appear changed in their natural qualities, producing error of form, error of motion, error of number, and error of colour. I had a patient in Lisbon who fancied that all the horses he saw carried horns or extensive antlers. A young lady whom I attended beheld every one of a gigantic height. Dr. Priestley has given a curious case of error of colour in five brothers and two sisters, all adults. One of the brothers could form no idea whatever of colours, though he judged very accurately of the form and other qualities of objects; hence he thought stockings were sufficiently distinguished by the name of stockings, and could not conceive the necessity of calling them white or black. He could perceive cherries on a tree; but only distinguished them, even when red-ripe, from the surrounding leaves by their size and shape.

One of the brothers appeared to have a faint sense of a few colours, but still a very imperfect notion; and, upon the whole, they did not seem to possess any other distinguis.h.i.+ng power than that of light and shade, into which they resolved all the colours presented to them,--so that dove or straw colour were regarded as white; and green, crimson, and purple, as black or dark. On looking at a rainbow, one of them could distinguish that it consisted of stripes, but nothing more. Dr. Nicholl relates the case of a boy who confounded green with red; and called light red and pink, blue.

His maternal grandfather and one uncle had the same imperfection. The latter was in the navy, and having a blue coat and waistcoat, purchased a pair of red breeches to match. The same physician knew a gentleman who could not distinguish green from red; a cuc.u.mber and a boiled lobster did not offer the least difference in colour. His brother and his niece laboured under a similar affection.

Some philosophers are of opinion, that in the power of conceiving colours there is a striking difference in individuals, and are inclined to think that in many instances the supposed defects of sight ought to be ascribed to a defect in the power of conception, arising probably from some early habit of inattention. This theory is scarcely tenable. The utmost inattention and indifference regarding surrounding objects could never lead to a delusive view of any colour; also, it is more than probable that, in the case of a child in whom such a defective vision was observed, his attention would be incessantly called on by those around him, to correct, if possible, so strange a delusion. Moreover, this defect of vision, as we have seen, appears in some instances to be hereditary; and to prevail in families.

Phrenologists of course are of opinion that the judgment of colours resides in a particular organ, remarkably full and prominent in painters distinguished by the perfection of their colouring. According to Gall, a local deficiency of brain is observable where the power of distinguis.h.i.+ng colours is wanting.

The sense of vision exhibits more variety in the different cla.s.ses of animals than any of the others. In man, and the greater number of quadrupeds, this organ is guarded by an upper and a lower lid, both of which in man are fringed with lashes. This is not the case in most quadrupeds. In the elephant, opossum, seal, cats, other mammalia, birds, and all fishes, we find a third eyelid, or nict.i.tating membrane, as it is called, arising from the internal angle of the eye, capable of covering and protecting the eye from danger, either wholly or in part. In the dog this membrane is narrow; in oxen and horses it extends half over the eyeball. It is by means of this veil that eagles are capable of fixing their eyes on the noon-day sun. The largest eyes in proportion to the size of the animal are found in birds,--nearly the smallest in whales; but the most diminutive are those of the shrew and mole, the latter's not exceeding the size of a pin's head.

The situation of the organs of vision differs materially. In man and monkeys they are placed directly under the forehead; in some fishes, such as the turbot and flounder tribes, both eyes are placed in the same side of the head. In the snail they are situated on the horns; and in the spider, distributed over various points of the body, and in different arrangements.

Eyes, however, are not indispensable to become sensible of the presence of light. Several zoophytes, that do not possess the organs of vision, are perfectly alive to its influence. A distinct organ is not always indispensable for a distinct sense. It is probable that in those animals that appear to be endowed with particular senses, without displaying particular organs relating to them, the senses are diffused like that of touch, over the whole surface. This subject has been admirably commented on by Cuvier.