Part 2 — PART II. (continued 8)

M. M. Some restraint in exhausting the usual pleasures of the world early in life. The agreeable cares of a matrimonial life. The cultivation of science, as of chemistry, natural philosophy, natural history, which supplies an inexhaustible source of pleasurable novelty, and relieves ennui by the exertions it occasions.

In many of these cases, whence irksomeness of life has been the ostensible cause of suicide, there has probably existed a maniacal hallucination, a painful idea, which the patient has concealed even to his dying hour; except where the mania has evidently arisen from hereditary or acquired disease of the membranous or glandular parts of the system.

12. Pulchritudinis desiderium. The loss of beauty, either by disease, as by the small-pox, or by age, as life advances, is sometimes painfully felt by ladies, who have been much flattered on account of it. There is a curious case of this kind related in Le Sage's Bachelor of Salamanca, which is too nicely described to be totally imaginary.

In this situation some ladies apply to what are termed cosmetics under various names, which crowd the newspapers. Of these the white has destroyed the health of thousands; a calx, or magistery, of bismuth is supposed to be sold in the shops for this purpose; but it is either, I am informed, in part or entirely white lead or cerussa. The pernicious effects of the external use of those saturnine applications are spoken of in gutta rosea, Class II. 1. 4. 6. The real calx of bismuth would probably have the same ill effect. As the red paint is prepared from cochineal, which is an animal body, less if any injury arises from its use, as it only lies on the skin like other filth.

The tan of the skin occasioned by the sun may be removed by lemon juice evaporated by the fire to half its original quantity, or by diluted marine acid; which cleans the cuticle, by eroding its surface, but requires much caution in the application; the marine acid must be diluted with water, and when put upon the hand or face, after a second of time, as soon as the tan disappears, the part must be washed with a wet towel and much warm water. Freckles lie too deep for this operation, nor are they in general removeable by a blister, as I once experienced. See Class I. 2. 2. 9.

It is probable, that those materials which stain silk, or ivory, might be used to stain the cuticle, or hair, permanently; as they are all animal substances. But I do not know, that any trials of this kind have been made on the skin. I endeavoured in vain to whiten the back of my hand by marine acid oxygenated by manganese, which so instantly whitens cotton.

The cure therefore must be sought from moral writers, and the cultivation of the graces of the mind, which are frequently a more valuable possession than celebrated beauty.

13. Paupertatis timor. The fear of poverty is one kind of avarice; it is liable to affect people who have left off a profitable and active business; as they are thus deprived of their usual exertions, and are liable to observe the daily expenditure of money, without calculating the source from whence it flows. It is also liable to occur with a sudden and unexpected increase of fortune. Mr. ——, a surgeon, about fifty years of age, who was always rather of a parsimonious disposition, had a large house, with a fortune of forty thousand pounds, left him by a distant relation; and in a few weeks became insane from the fear of poverty, lamenting that he should die in a jail or workhouse. He had left off a laborious country business, and the daily perception of profit in his books; he also now saw greater expences going forwards in his new house, than he had been accustomed to observe, and did not so distinctly see the source of supply; which seems to have occasioned the maniacal hallucination.—This idea of approaching poverty is a very frequent and very painful disease, so as to have induced many to become suicides, who were in good circumstances; more perhaps than any other maniacal hallucination, except the fear of hell.

The covetousness of age is more liable to affect single men, than those who have families; though an accumulation of wealth would seem to be more desirable to the latter. But an old man in the former situation, has no personal connections to induce him to open his purse; and having lost the friends of his youth, and not easily acquiring new ones, feels himself alone in the world; feels himself unprotected, as his strength declines, and is thus led to depend for assistance on money, and on that account wishes to accumulate it. Whereas the father of a family has not only those connections, which demand the frequent expenditure of money, but feels a consolation in the friendship of his children, when age may render their good offices necessary to him.

M. M. I have been well informed of a medical person in good circumstances in London, who always carries an account of his affairs, as debtor and creditor, in his pocket-book; and looks over it frequently in a day, when this disease returns upon him; and thus, by counteracting the maniacal hallucination, wisely prevents the increase of his insanity. Another medical person, in London, is said to have cured himself of this disease by studying mathematics with great attention; which exertions of the mind relieved the pain of the maniacal hallucination.

Many moral writers have stigmatised this insanity; the covetous, they say, commit crimes and mortify themselves without hopes of reward; and thus become miserable both in this world and the next. Thus Juvenal:

The covetous man thought he gave good advice to the spendthrift, when he said, "Live like me," who well answered him,

14. Lethi timor. The fear of death perpetually employs the thoughts of these patients; hence they are devising new medicines, and applying to physicians and quacks without number. It is confounded with hypochondriasis, Class I. 2. 4. 10. in popular conversation, but is in reality an insanity.

A young gentleman, whom I advised to go abroad as a cure for this disease, assured me, that during the three years he was in Italy and France he never passed a quarter of an hour without fearing he should die. But has now for above twenty years experienced the contrary.

The sufferers under this malady are generally at once discoverable by their telling you, amidst an unconnected description of their complaints, that they are nevertheless not afraid of dying. They are also easily led to complain of pains in almost any part of the body, and are thus soon discovered.

M. M. As the maniacal hallucination has generally arisen in early infancy from some dreadful account of the struggles and pain of dying, I have sometimes observed, that these patients have received great consolation from the instances I have related to them of people dying without pain. Some of these, which I think curious, I shall concisely relate, as a part of the method of cure.

Mr. ——, an elderly gentleman, had sent for me one whole day before I could attend him; on my arrival he said he was glad to see me, but that he was now quite well, except that he was weak, but had had a pain in his bowels the day before. He then lay in bed with his legs cold up to the knees, his hands and arms cold, and his pulse scarcely discernible, and died in about six hours. Mr. ——, another gentleman about sixty, lay in the act of dying, with difficult respiration like groaning, but in a kind of stupor or coma vigil, and every ten or twelve minutes, while I sat by him, he waked, looked up, and said, "who is it groans so, I am sure there is somebody dying in the room," and then sunk again into a kind of sleep. From these two cases there appeared to be no pain in the act of dying, which may afford consolation to all, but particularly to those who are afflicted with the fear of death.

15. Orci timor. The fear of hell. Many theatric preachers among the Methodists successfully inspire this terror, and live comfortably upon the folly of their hearers. In this kind of madness the poor patients frequently commit suicide; although they believe they run headlong into the hell, which they dread! Such is the power of oratory, and such the debility of the human understanding!

Those, who suffer under this insanity, are generally the most innocent and harmless people; who are then liable to accuse themselves of the greatest imaginary crimes, and have so much intellectual cowardice, that they dare not reason about those things, which they are directed by their priests to believe, however contradictory to human apprehension, or derogatory to the great Creator of all things. The maniacal hallucination at length becomes so painful, that the poor insane flies from life to become free from it.

M. M. Where the intellectual cowardice is great, the voice of reason is ineffectual; but that of ridicule may save many from those mad-making doctors; though it is too weak to cure those, who are already hallucinated. Foot's Farces are recommended for this purpose.

16. Satyriasis. An ungovernable desire of venereal indulgence. The remote cause is probably the stimulus of the semen; whence the phallus becomes distended with blood by the arterial propulsion of it being more strongly excited than the correspondent venous absorption. At the same time a new sense is produced in the other termination of the urethra; which, like itching, requires some exterior friction to facilitate the removal of the cause of the maniacal actions, which may probably be increased in those cases by some associated hallucinations of ideas. It differs from priapismus chronicus in the desire of its appropriated object, which is not experienced in the latter, Class I. 1. 4. 6. and from the priapismus amatorius, Class II. 1. 7. 9. in the maniacal actions in consequence of desire. The furor uterius, or nymphomania, is a similar disease.

M. M. Venesection. Cathartics. Torpentia. Marriage.

17. Ira. Anger is caused by the pain of offended pride. We are not angry at breaking a bone, but become quite insane from the smallest stroke of a whip from an inferior. Ira furor brevis. Anger is not only itself a temporary madness, but is a frequent attendant on other insanities, and as, whenever it appears, it distinguishes insanity from delirium, it is generally a good sign in fevers with debility.

An injury voluntarily inflicted on us by others excites our exertions of self-defence or of revenge against the perpetrator of it; but anger does not succeed in any great degree unless our pride is offended; this idea is the maniacal hallucination, the pain of which sometimes produces such violent and general exertions of our muscles and ideas, as to disappoint the revenge we meditate, and vainly to exhaust our sensorial power. Hence angry people, if not further excited by disagreeable language, are liable in an hour or two to become humble, and sorry for their violence, and willing to make greater concessions than required.

M. M. Be silent, when you feel yourself angry. Never use loud oaths, violent upbraidings, or strong expressions of countenance, or gesticulations of the arms, or clenched fists; as these by their former associations with anger will contribute to increase it. I have been told of a sergeant or corporal, who began moderately to cane his soldiers, when they were awkward in their exercise, but being addicted to swearing and coarse language, he used soon to enrage himself by his own expressions of anger, till toward the end he was liable to beat the delinquents unmercifully.

18. Rabies. Rage. A desire of biting others, most frequently attendant on canine madness. Animals in great pain, as in the colica saturnina, are said to bite the ground they lie upon, and even their own flesh. I have seen patients bite the attendants, and even their own arms, in the epilepsia dolorifica. It seems to be an exertion to relieve pain, as explained in Sect. XXXIV. 1. 3. The dread of water in hydrophobia is occasioned by the repeated painful attempts to swallow it, and is therefore not an essential or original part of the disease called canine madness. See Class III. 1. 1. 15.

There is a mania reported to exist in some parts of the east, in which a man is said to run a muck; and these furious maniacs are believed to have induced their calamity by unlucky gaming, and afterwards by taking large quantities of opium; whence the pain of despair is joined with the energy of drunkenness; they are then said to sally forth into the most populous streets, and to wound and slay all they meet, till they receive their own death, which they desire to procure without the greater guilt, as they suppose, of suicide.

M. M. When there appears a tendency to bite in the painful epilepsy, the end of a rolled-up towel, or a wedge of soft wood, should be put into the mouth of the patient. As a bullet is said sometimes to be given to a soldier, who is to be severely flogged, that he may by biting it better bear his punishment.

19. Citta. A desire to swallow indigestible substances. I once saw a young lady, about ten years of age, who filled her stomach with the earth out of a flower-pot, and vomited it up with small stones, bits of wood, and wings of infects amongst it. She had the bombycinous complexion, and looked like a chlorotic patient, though so young; this generally proceeds from an acid in the stomach.

M. M. A vomit. Magnesia alba. Armenian bole. Rhubarb. Bark. Steel. A blister. See Class I. 2. 4. 5.

20. Cacositia. Aversion to food. This may arise, without disease of the stomach, from connecting nauseous ideas to our usual food, as by calling a ham a hog's a——. This madness is much inculcated by the stoic philosophy. See Antoninus' Meditations. See two cases of patients who refused to take nourishment, Class III. 1. 2. 1.

Aversions to peculiar kinds of food are thus formed early in life by association of some maniacal hallucination with them. I remember a child, who on tasting the gristle of sturgeon, asked what gristle was? And being told it was like the division of a man's nose, received an ideal hallucination; and for twenty years afterwards could not be persuaded to taste sturgeon.

The great fear or aversion, which some people experience at the sight of spiders, toads, crickets, and the like, have generally had a similar origin.

M. M. Associate agreeable ideas with those which disgust; as call a spider ingenious, a frog clean and innocent; and repress all expressions of disgust by the countenance, as such expressions contribute to preserve, or even to increase, the energy of the ideas associated with them; as mentioned above in Species 17. Ira.

21. Syphilis imaginaria. The fear that they are infested with the venereal disease, when they have only deserved it, is a very common insanity amongst modest young men; and is not to be cured without applying artfully to the mind; a little mercury must be given, and hopes of a cure added weekly and gradually by interview or correspondence for six or eight weeks. Many of these patients have been repeatedly salivated without curing the mind!

22. Psora imaginaria. I have twice seen an imaginary itch, and twice an imaginary diabætes, where there was not the least vestige of either of those diseases, and once an imaginary deafness, where the patient heard perfectly well. In all these cases the hallucinated idea is so powerfully excited, that it is not to be changed suddenly by occular sensation, or reason. Yet great perseverance in the frequently presenting contrary ideas will sometimes slowly remove this hallucination, or in great length of time oblivion, or forgetfulness, performs a cure, by other means in vain attempted.

23. Tabes imaginaria. This imaginary disease, or hallucination, is caused by the supposed too great frequency of parting with the semen, and had long imposed upon the physician as well as the patient, till Mr. John Hunter first endeavoured to shew, that in general the morbid effects of this pollution was in the imagination; and that those were only liable to those effects in general, who had been terrified by the villainous books, which pretend to prevent or to cure it, but which were purposely written to vend some quack medicine. Most of those unhappy patients, whom I have seen, had evidently great impression of fear and self-condemnation on their minds, and might be led to make contradictory complaints in almost any part of the body, and if their confessions could be depended on, had not used this pollution to any great excess.

M. M. 1. Assure them if the loss of the semen happens but twice a week, it will not injure them. 2. Marry them. The last is a certain cure; whether the disease be real or imaginary. Cold partial bath, and astringent medicines frequently taken, only recal the mind to the disease, or to the delinquency; and thence increase the imaginary effects and the real cause, if such exists. Mr. —— destroyed himself to get free from the pain of fear of the supposed ill consequences of self-pollution, without any other apparent disease; whose parents I had in vain advised to marry him, if possible.

24. Sympathia aliena. Pity. Our sympathy with the pleasures and pains of others distinguishes men from other animals; and is probably the foundation of what is termed our moral sense and the source of all our virtues. See Sect. XXII. 3. 3. When our sympathy with those miseries of mankind, which we cannot alleviate, rises to excess, the mind becomes its own tormentor; and we add to the aggregate sum of human misery, which we ought to labour to diminish; as in the following eloquent lamentation from Akenside's Pleasures of Imagination, Book II. 1. 200.

A poet of antiquity, whose name I do not recollect, is said to have written a book describing the miseries of the world, and to have destroyed himself at the conclusion of his task. This sympathy, with all sensitive beings, has been carried so far by some individuals, and even by whole tribes, as the Gentoos, as not only to restrain them from killing animals for their support, but even to induce them to permit insects to prey upon their bodies. Such is however the condition of mortality, that the first law of nature is, "Eat or be eaten." We cannot long exist without the destruction of other animal or vegetable beings, either in their mature or their embryon state. Unless the fruits, which surround the seeds of some vegetables, or the honey stolen from them by the bee, may be said to be an exception to this assertion. See Botanic Garden, P. I. Cant. I. l. 278. Note. Hence, from the necessity of our nature, we may be supposed to have a right to kill those creatures, which we want to eat, or which want to eat us. But to destroy even insects wantonly shews an unreflecting mind or a depraved heart.

Nevertheless mankind may be well divided into the selfish and the social; that is, into those whose pleasures arise from gratifying their appetites, and those whose pleasures arise from their sympathizing with others. And according to the prevalence of these opposing propensities we value or dislike the possessor of them.

In conducting the education of young people, it is a nice matter to inspire them with so much benevolent sympathy, or compassion, as may render them good and amiable; and yet not so much as to make them unhappy at the sight of incurable distress. We should endeavour to make them alive to sympathize with all remediable evils, and at the same time to arm them with fortitude to bear the sight of such irremediable evils, as the accidents of life must frequently present before their eyes. About this I have treated more at large in a plan for the conduct of a boarding school for ladies, which I intend to publish in the course of the next year.

25. Educatio heroica. From the kinds and degrees of insanities already enumerated, the reader will probably recollect many more from his own observation; he will perceive that all extraordinary exertions of voluntary action in consequence of some false idea or hallucination, which strongly affects us, may philosophically, though not popularly, be termed an insanity; he will then be liable to divide these voluntary exertions into disagreeable, pernicious, detestable, or into meritorious, delectable, and even amiable, insanities. And will lastly be induced to conceive, that a good education consists in the art of producing such happy hallucinations of ideas, as may be followed by such voluntary exertions, as may be termed meritorious or amiable insanities.

The old man of the mountain in Syria, who governed a small nation of people called Assassines, is recorded thus to have educated those of his army who were designed to assassinate the princes with whom he was at war. A young man of natural activity was chosen for the purpose, and thrown into a deep sleep by opium mixed with his food; he was then carried into a garden made to represent the paradise of Mahomet, with flowers of great beauty and fragrance, fruits of delicious flavor, and beautiful houries beckoning him into the shades. After a while, on being a second time stupified with opium, the young enthusiast was reconveyed to his apartment; and on the next day was assured by a priest, that he was designed for some great exploit, and that by obeying the commands of their prince, immortal happiness awaited him.

Hence it is easy to collect how the first impressions made on us by accidental circumstances in our infancy continue through life to bias our affections, or mislead our judgments. One of my acquaintance can trace the origin of his own energies of action from some such remote sources; which justifies the observation of M. Rousseau, that the seeds of future virtues or vices are oftener sown by the mother, than the tutor.

ORDO II.

Decreased Volition.

GENUS I.

With decreased Actions of the Muscles.

Our muscles become fatigued by long contraction, and cease for a time to be excitable by the will; owing to exhaustion of the sensorial power, which resides in them. After a short interval of relaxation the muscle regains its power of voluntary contraction; which is probably occasioned by a new supply of the spirit of animation. In weaker people these contractions cease sooner, and therefore recur more frequently, and are attended with shorter intervals of relaxation, as exemplified in the quickness of the pulse in fevers with debility, and in the tremors of the hands of aged or feeble people.

After a common degree of exhaustion of the sensorial power in a muscle, it becomes again gradually restored by the rest of the muscle; and even accumulated in those muscles, which are most frequently used; as in those which constitute the capillaries of the skin after having been rendered torpid by cold. But in those muscles, which are generally obedient to volition, as those of locomotion, though their usual quantity of sensorial power is restored by their quiescence, or in sleep (for sleep affects these parts of the system only), yet but little accumulation of it succeeds. And this want of accumulation of the sensorial power in these muscles, which are chiefly subservient to volition, explains to us one cause of their greater tendency to paralytic affection.

It must be observed, that those parts of the system, which have been for a time quiescent from want of stimulus, as the vessels of the skin, when exposed to cold, acquire an accumulation of sensorial power during their inactivity; but this does not happen at all, or in much less quantity, from their quiescence after great expenditure of sensorial power by a previous excessive stimulus, as after intoxication. In this case the muscles or organs of sense gradually acquire their natural quantity of sensorial power, as after sleep; but not an accumulation or superabundance of it. And by frequent repetitions of exhaustion by great stimulus, these vessels cease to acquire their whole natural quantity of sensorial power; as in the schirrous stomach, and schirrous liver, occasioned by the great and frequent stimulus of vinous spirit; which may properly be termed irritative paralysis of those parts of the system.

In the same manner in common palsies the inaction of the paralytic muscle seems not to be owing to defect of the stimulus of the will, but to exhaustion of sensorial power. Whence it frequently follows great exertion, as in Sect. XXXIV. 1. 7. Thus some parts of the system may cease to obey the will, as in common paralysis; others may cease to be obedient to sensation, as in the impotency of age; others to irritation, as in schirrous viscera; and others to association, as in impediment of speech; yet though all these may become inexcitable, or dead, in respect to that kind of stimulus, which has previously exhausted them, whether of volition, or sensation, or irritation, or association, they may still in many cases be excited by the others.

SPECIES.

1. Lassitudo. Fatigue or weariness after much voluntary exertion. From the too great expenditure of sensorial power the muscles are with difficulty brought again into voluntary contraction; and seem to require a greater quantity or energy of volition for this purpose. At the same time they still remain obedient to the stimulus of agreeable sensation, as appears in tired dancers finding a renovation of their aptitude to motion on the acquisition of an agreeable partner; or from a tired child riding on a gold-headed cane, as in Sect. XXXIV. 2. 6. These muscles are likewise still obedient to the sensorial power of association, because the motions, when thus excited, are performed in their designed directions, and are not broken into variety of gesticulation, as in St. Vitus's dance.

A lassitude likewise frequently occurs with yawning at the beginning of ague-fits; where the production of sensorial power in the brain is less than its expenditure. For in this case the torpor may either originate in the brain, or the torpor of some distant parts of the system may by sympathy affect the brain, though in a less proportionate degree than the parts primarily affected.

2. Vacillatio senilis. Some elderly people acquire a see-saw motion of their bodies from one side to the other, as they sit, like the oscillation of a pendulum. By these motions the muscles, which preserve the perpendicularity of the body, are alternately quiescent, and exerted; and are thus less liable to fatigue or exhaustion. This therefore resembles the tremors of old people above mentioned, and not those spasmodic movements of the face or limbs, which are called tricks, described in Class IV. 1. 3. 2. which originate from excess of sensorial power, or from efforts to relieve disagreeable sensation, and are afterwards continued by habit.

3. Tremor senilis. Tremor of old age consists of a perpetual trembling of the hands, or of the head, or of other muscles, when they are exerted; and is erroneously called paralytic; and seems owing to the small quantity of animal power residing in the muscular fibres. These tremors only exist when the affected muscles are excited into action, as in lifting a glass to the mouth, or in writing, or in keeping the body upright; and cease again, when no voluntary exertion is attempted, as in lying down. Hence these tremors evidently originate from the too quick exhaustion of the lessened quantity of the spirit of animation. So many people tremble from fear or anger, when too great a part of the sensorial power is exerted on the organs of sense, so as to deprive the muscles, which support the body erect, of their due quantity.

4. Brachiorum paralysis. A numbness of the arms is a frequent symptom in hydrops thoracis, as explained in Class I. 2. 3. 14. and in Sect. XXIX. 5. 2.; it also accompanies the asthma dolorificum, Class III. 1. 1. 11. and is owing probably to the same cause in both. In the colica saturnina a paralysis affects the wrists, as appears on the patient extending his arm horizontally with the palm downwards, and is often attended with a tumor on the carpal or metacarpal bones. See Class IV. 1. 2. 10.

Mr. M——, a miner and well-sinker, about three years ago, lost the power of contracting both his thumbs; the balls or muscles of the thumbs are much emaciated, and remain paralytic. He ascribes his disease to immersing his hands too long in cold water in the execution of his business. He says his hands had frequently been much benumbed before, so that he could not without difficulty clench them; but that they recovered their motion, as soon as they began to glow, after he had dried and covered them.

In this case there existed two injurious circumstances of different kinds; one the violent and continued action of the muscles, which destroys by exhausting the sensorial power; and the other, the application of cold, which destroys by defect of stimulus. The cold seems to have contributed to the paralysis by its long application, as well as the continued exertion; but as during the torpor occasioned by the exposure to cold, if the degree of it be not so great as to extinguish life, the sensorial power becomes accumulated; there is reason to believe, that the exposing a paralytic limb to the cold for a certain time, as by covering it with snow or iced water for a few minutes, and then covering it with warm flannel, and this frequently repeated, might, by accumulation of sensorial power, contribute to restore it to a state of voluntary excitability. As this accumulation of sensorial power, and consequent glow, seems, in the present case, several times to have contributed to restore the numbness or inability of those muscles, which at length became paralytic. See Class I. 2. 3. 21.

M. M. Ether externally. Friction. Saline warm bath. Electricity.

5. Raucedo paralytica. Paralytic hoarseness consists in the almost total loss of voice, which sometimes continues for months, or even years, and is occasioned by inability or paralysis of the recurrent nerves, which serve the muscles of vocality, by opening or closing the larynx. The voice generally returns suddenly, even so as to alarm the patient. A young lady, who had many months been affected with almost a total loss of voice, and had in vain tried variety of advice, recovered her voice in an instant, on some alarm as she was dancing at an assembly. Was this owing to a greater exertion of volition than usual? like the dumb young man, the son of Crœsus, who is related to have cried out, when he saw his father's life endangered by the sword of his enemy, and to have continued to speak ever afterwards. Two young ladies in this complaint seemed to be cured by electric shocks passed through the larynx every day for a fortnight. See Raucedo catarrhalis, Class II. 1. 3. 5.

M. M. An emetic. Electric shocks. Mustard-seed, a large spoonful swallowed whole, or a little bruised, every morning. Valerian. Burnt sponge. Blisters on each side of the larynx. Sea-bathing. A gargle of decoction of seneca. Friction. Frequent endeavours to shout and sing.

6. Vesicæ urinariæ paralysis. Paralysis of the bladder is frequently a symptom in inirritative fever; in this case the patient makes no water for a day or two; and the tumor of the bladder distended with urine may be seen by the shape of the abdomen, as if girt by a cord below the navel, or distinguished by the hand. Many patients in this situation make no complaint, and suffer great injury by the inattention of their attendants; the water must be drawn off once or twice a day by means of a catheter, and the region of the bladder gently pressed by the hand, whilst the patient be kept in a sitting or erect posture.

M. M. Bark. Wine. Opium, a quarter of a grain every six hours. Balsam of copaiva or of Peru. Tincture of cantharides 20 drops twice a day, or repeated small blisters.

7. Recti paralysis. Palsy of the rectum. The rectum intestinum, like the urinary bladder in the preceding article, possesses voluntary power of motion; though these volitions are at times uncontrollable by the will, when the acrimony of the contained feces, or their bulk, stimulate it to a greater degree. Hence it happens, that this part is liable to lose its voluntary power by paralysis, but is still liable to be stimulated into action by the contained feces. This frequently occurs in fevers, and is a bad sign as a symptom of general debility; and it is the sensibility of the muscular fibres of this and of the urinary bladder remaining, after the voluntarity has ceased, which occasions these two reservoirs so soon to regain, as the fever ceases, their obedience to volition; because the paralysis is thus shewn to be less complete in those cases than in common hemiplegia; as in the latter the sense of touch, though perhaps not the sense of pain, is generally destroyed in the paralytic limb.

M. M. A sponge introduced within the sphincter ani to prevent the constant discharge, which should have a string put through it, by which it may be retracted.

8. Paresis voluntaria. Indolence; or inaptitude to voluntary action. This debility of the exertion of voluntary efforts prevents the accomplishment of all great events in life. It often originates from a mistaken education, in which pleasure or flattery is made the immediate motive of action, and not future advantage; or what is termed duty. This observation is of great value to those, who attend to the education of their own children. I have seen one or two young married ladies of fortune, who perpetually became uneasy, and believed themselves ill, a week after their arrival in the country, and continued so uniformly during their stay; yet on their return to London or Bath immediately lost all their complaints, and this repeatedly; which I was led to ascribe to their being in their infancy surrounded with menial attendants, who had flattered them into the exertions they then used. And that in their riper years, they became torpid for want of this stimulus, and could not amuse themselves by any voluntary employment; but required ever after, either to be amused by other people, or to be flattered into activity. This I suppose, in the other sex, to have supplied one source of ennui and suicide.

9. Catalepsis is sometimes used for fixed spasmodic contractions or tetanus, as described in Sect. XXXIV. 1. 5. and in Class III. 1. 1. 13. but is properly simply an inaptitude to muscular motion, the limbs remaining in any attitude in which they are placed. One patient, whom I saw in this situation, had taken much mercury, and appeared universally torpid. He sat in a chair in any posture he was put, and held a glass to his mouth for many minutes without attempting to drink, or withdrawing his hand. He never spoke, and it was at first necessary to compel him to drink broth; he recovered in a few weeks without relapse.

10. Hemiplegia. Palsy of one side consists in the total disobedience of the affected muscles to the power of volition. As the voluntary motions are not perpetually exerted, there is little sensorial power accumulated during their quiescence, whence they are less liable to recover from torpor, and are thus more frequently left paralytic, or disobedient to the power of volition, though they are sometimes still alive to painful sensation, as to the prick of a pin, and to heat; also to irritation, as in stretching and yawning; or to electric shocks. Where the paralysis is complete the patient seems gradually to learn to use his limbs over again by repeated efforts, as in infancy; and, as time is required for this purpose, it becomes difficult to know, whether the cure is owing to the effect of medicines, or to the repeated efforts of the voluntary power.

The dispute, whether the nerves decussate or cross each other before they leave the cavities of the skull or spine, seems to be decided in the affirmative by comparative anatomy; as the optic nerves of some fish have been shewn evidently to cross each other; as seen by Haller, Elem. Physiol. t. v. p. 349. Hence the application of blisters, or of ether, or of warm fomentations, should be on the side of the head opposite to that of the affected muscles. This subject should nevertheless be nicely determined, before any one should trepan for the hydrocephalus internus, when the disease is shewn to exist only on one side of the brain, by a squinting affecting but one eye; as proposed in Class I. 2. 5. 4. Dr. Sommering has shewn, that a true decussation of the optic nerves in the human subject actually exists, Elem. of Physiology by Blumenbach, translated by C. Caldwell, Philadelphia. This further appears probable from the oblique direction and insertion of each optic nerve, into the side of the eye next to the nose, in a direct line from the opposite side of the brain.

The vomiting, which generally attends the attack of hemiplegia, is mentioned in Sect. XX. 8. and is similar to that attending vertigo in sea-sickness, and at the commencement of some fevers. Black stools sometimes attend the commencement of hemiplegia, which is probably an effusion of blood from the biliary duct, where the liver is previously affected; or some blood may be derived to the intestines by its escaping from the vena cava into the receptacle of chyle during the distress of the paralytic attack; and may be conveyed from thence into the intestines by the retrograde motions of the lacteals; as probably sometimes happens in diabætes. See Sect. XXVII. 2. Palsy of one side of the face is mentioned in Class II. 1. 4. 6. Paralysis of the lacteals, of the liver, and of the veins, which are described in Sect. XXVIII. XXX. and XXVII. do not belong to this class, as they are not diseases of voluntary motions.

M. M. The electric sparks and shocks, if used early in the disease, are frequently of service. A purge of aloes, or calomel. A vomit. Blister. Saline draughts. Then the bark. Mercurial ointment or sublimate, where the liver is evidently diseased; or where the gutta rosea has previously existed. Sudden alarm. Frequent voluntary efforts. Externally ether. Volatile alcali. Fomentation on the head. Friction. When children, who have suffered an hemiplegia, begin to use the affected arm, the other hand should be tied up for half an hour three or four times a day; which obliges them at their play to use more frequent voluntary efforts with the diseased limb, and thus sooner to restore the dissevered associations of motion.

Dr. J. Alderson has lately much recommended the leaves of rhus toxicodendon (sumach), from one gr. to iv. of the dried powder to be taken three or four times a day. Essay on Rhus Toxic. Johnson, London, 1793. But it is difficult to know what medicine is of service, as the movements of the muscles must be learned, as in infancy, by frequent efforts.

11. Paraplegia. A palsy of the lower half of the body divided horizontally. Animals may be conceived to have double bodies, one half in general resembling so exactly the other, and being supplied with separate sets of nerves; this gives rise to hemiplegia, or palsy of one half of the body divided vertically; but the paraplegia, or palsy of the lower parts of the system, depends on an injury of the spinal marrow, or that part of the brain which is contained in the vertebræ of the back; by which all the nerves situated below the injured part are deprived of their nutriment, or precluded from doing their proper offices; and the muscles, to which they are derived, are in consequence disobedient to the power of volition.

This sometimes occurs from an external injury, as a fall from an eminence; of which I saw a deplorable instance, where the bladder and rectum, as well as the lower limbs, were deprived of so much of their powers of motion, as depended on volition or sensation; but I suppose not of that part of it, which depends on irritation. In the same manner as the voluntary muscles in hemiplegia are sometimes brought into action by irritation, as in stretching or pendiculation, described in Sect. VII. 1. 3.

But the most frequent cause of paraplegia is from a protuberance of one of the spinal vertebræ; which is owing to the innutrition or softness of bones, described in Class I. 2. 2. 17. The cure of this deplorable disease is frequently effected by the stimulus of an issue placed on each side of the prominent spine, as first published by Mr. Pott. The other means recommended in softness of bones should also be attended to; both in respect to the internal medicines, and to the mechanical methods of supporting, or extending the spine; which last, however, in this case requires particular caution.

12. Somnus. In sleep all voluntary power is suspended, see Sect. XVIII. An unusual quantity of sleep is often produced by weakness. In this case small doses of opium, wine, and bark, may be given with advantage. For the periods of sleep, see Class IV. 2. 4. 1.

The subsequent ingenious observations on the frequency of the pulse, which sometimes occurs in sleep, are copied from a letter of Dr. Currie of Liverpool to the author.

"Though rest in general perhaps renders the healthy pulse slower, yet under certain circumstances the contrary is the truth. A full meal without wine or other strong liquor does not increase the frequency of my pulse, while I sit upright, and have my attention engaged. But if I take a recumbent posture after eating, my pulse becomes more frequent, especially if my mind be vacant, and I become drowsy; and, if I slumber, this increased frequency is more considerable with heat and flushing.

"This I apprehend to be a general truth. The observation may be frequently made upon children; and the restless and feverish nights experienced by many people after a full supper are, I believe, owing to this cause. The supper occasions no inconvenience, whilst the person is upright and awake; but, when he lies down and begins to sleep, especially if he does not perspire, the symptoms above mentioned occur. Which may be thus explained in part from your principles. When the power of volition is abolished, the other sensorial actions are increased. In ordinary sleep this does not occasion increased frequency of the pulse; but where sleep takes place during the process of digestion, the digestion itself goes on with increased rapidity. Heat is excited in the system faster than it is expended; and operating on the sensitive actions, it carries them beyond the limitation of pleasure, producing, as is common in such cases, increased frequency of pulse.

"It is to be observed, that in speaking of the heat generated under these circumstances, I do not allude to any chemical evolution of heat from the food in the process of digestion. I doubt if this takes place to any considerable degree, for I do not observe that the parts incumbent on the stomach are increased in heat during the most hurried digestion. It is on some parts of the surface, but more particularly on the extremities of the body, that the increased heat excited by digestion appears, and the heat thus produced arises, as it should seem, from the sympathy between the stomach and the vessels of the skin. The parts most affected are the palms of the hands and the soles of the feet. Even there the thermometer seldom rises above 97 or 98 degrees, a temperature not higher than that of the trunk of the body; but three or four degrees higher than the common temperature of these parts, and therefore producing an uneasy sensation of heat, a sensation increased by the great sensibility of the parts affected.

"That the increased heat excited by digestion in sleep is the cause of the accompanying fever, seems to be confirmed by observing, that if an increased expenditure of heat accompanies the increased generation of it (as when perspiration on the extremities or surface attends this kind of sleep) the frequent pulse and flushed countenance do not occur, as I know by experiment. If, during the feverish sleep already mentioned, I am awakened, and my attention engaged powerfully, my pulse becomes almost immediately slower, and the fever gradually subsides."

From these observations of Dr. Currie it appears, that, while in common sleep the actions of the heart, arteries, and capillaries, are strengthened by the accumulation of sensorial power during the suspension of voluntary action, and the pulse in consequence becomes fuller and slower; in the feverish sleep above described the actions of the heart, arteries, and capillaries, are quickened as well as strengthened by their consent with the increased actions of the stomach, as well as by the stimulus of the new chyle introduced into the circulation. For the stomach, and all other parts of the system, being more sensible and more irritable during sleep, Sect. XVIII. 15. and probably more ready to act from association, are now exerted with greater velocity as well as strength, constituting a temporary fever of the sensitive irritated kind, resembling the fever excited by wine in the beginning of intoxication; or in some people by a full meal in their waking hours. Sect. XXXV. 1.

On waking, this increased sensibility and irritability of the system ceases by the renewed exertions of volition; in the same manner as more violent exertions of volition destroy greater pains; and the pulse in consequence subsides along with the increase of heat; if more violent efforts of volition are exerted, the system becomes still less affected by sensation or irritation. Hence the fever and vertigo of intoxication are lessened by intense thinking, Sect. XXI. 8; and insane people are known to bear the pain of cold and hunger better than others, Sect. XXXIV. 2. 5; and lastly, if greater voluntary efforts exist, as in violent anger or violent exercise, the whole system is thrown into more energetic action, and a voluntary fever is induced, as appears by the red skin, quickened pulse, and increase of heat; whence dropsies and fevers with debility are not unfrequently removed by insanity.

Hence the exertion of the voluntary power in its natural degree diminishes the increased sensibility, and irritability, and probably the increased associability, which occurs during sleep; and thus reduces the frequency of the pulse in the feverish sleep after a full meal. In its more powerful state of exertion, it diminishes or destroys sensations and irritations, which are stronger than natural, as in intoxication, or which precede convulsions, or insanity. In its still more powerful degree, the superabundance of this sensorial power actuates and invigorates the whole moving system, giving strength and frequency to the pulse, and an universal glow both of colour and of heat, as in violent anger, or outrageous insanities.

If, in the feverish sleep above described, the skin becomes cooled by the evaporation of much perspirable matter, or by the application of cooler air, or thinner clothes, the actions of the cutaneous capillaries are lessened by defect of the stimulus of heat, which counteracts the increase of sensibility during sleep, and the pulsations of the heart and arteries become slower from the lessened stimulus of the particles of blood thus cooled in the cutaneous and pulmonary vessels. Hence the admission of cold air, or ablution with subtepid or with cold water, in fevers with hot skin, whether they be attended with arterial strength, or arterial debility, renders the pulse slower; in the former case by diminishing the stimulus of the blood, and in the latter by lessening the expenditure of sensorial power. See Suppl. I. 8. and 15.

13. Incubus. The night-mare is an imperfect sleep, where the desire of locomotion is vehement, but the muscles do not obey the will; it is attended with great uneasiness, a sense of suffocation, and frequently with fear. It is caused by violent fatigue, or drunkenness, or indigestible food, or lying on the back, or perhaps from many other kinds of uneasiness in our sleep, which may originate either from the body or mind.

Now as the action of respiration is partly voluntary, this complaint may be owing to the irritability of the system being too small to carry on the circulation of the blood through the lungs during sleep, when the voluntary power is suspended. Whence the blood may accumulate in them, and a painful oppression supervene; as in some hæmorrhages of the lungs, which occur during sleep; and in patients much debilitated by fevers. See Somnus interruptus, Class I. 2. 1. 3. and I. 2. 1. 9.

Great fatigue with a full supper and much wine, I have been well informed by one patient, always produced this disease in himself to a great degree. Now the general irritability of the system is much decreased by fatigue, as it exhausts the sensorial power; and secondly, too much wine and stimulating food will again diminish the irritability of some parts of the system, by employing a part of the sensorial power, which is already too small, in digesting a great quantity of aliment; and in increasing the motions of the organs of sense in consequence of some degree of intoxication, whence difficulty of breathing may occur from the inirritability of the lungs, as in Class I. 2. 1. 3.

M. M. To sleep on a hard bed with the head raised. Moderate supper. The bark. By sleeping on a harder bed the patient will turn himself more frequently, and not be liable to sleep too profoundly, or lie too long in one posture. To be awakened frequently by an alarm clock.

14. Lethargus. The lethargy is a slighter apoplexy. It is supposed to originate from universal pressure on the brain, and is said to be produced by compressing the spinal marrow, where there is a deficiency of the bone in the spina bifida. See Sect. XVIII. 20. Whereas in the hydrocephalus there is only a partial pressure of the brain; and probably in nervous fevers with stupor the pressure on the brain may affect only the nerves of the senses, which lie within the skull, and not those nerves of the medulla oblongata, which principally contribute to move the heart and arteries; whence in the lethargic or apoplectic stupor the pulse is slow as in sleep, whereas in nervous fever the pulse is very quick and feeble, and generally so in hydrocephalus.

In cases of obstructed kidneys, whether owing to the tubuli uriniferi being totally obstructed by calculous matter, or by their paralysis, a kind of drowsiness or lethargy comes on about the eighth or ninth day, and the patient gradually sinks. See Class I. 1. 3. 9.

15. Syncope epileptica, is a temporary apoplexy, the pulse continuing in its natural state, and the voluntary power suspended. This terminates the paroxysms of epilepsy.

When the animal power is much exhausted by the preceding convulsions, so that the motions from sensation as well as those from volition are suspended; in a quarter or half an hour the sensorial power becomes restored, and if no pain, or irritation producing pain, recurs, the fit of epilepsy ceases; if the pain recurs, or the irritation, which used to produce it, a new fit of convulsion takes place, and is succeeded again by a syncope. See Epilepsy, Class III. 1. 1. 7.

16. Apoplexia. Apoplexy may be termed an universal palsy, or a permanent sleep. In which, where the pulse is weak, copious bleeding must be injurious; as is well observed by Dr. Heberden, Trans. of the College.

Mr. ——, about 70 years of age, had an apoplectic seizure. His pulse was strong and full. One of the temporal arteries was opened, and about ten ounces of blood suddenly taken from it. He seemed to receive no benefit from this operation; but gradually sunk, and lived but a day or two.

If apoplexy arises from the pressure of blood extravasated on the brain, one moderate venesection may be of service to prevent the further effusion of blood; but copious venesection must be injurious by weakening the patient; since the effused blood must have time, as in common vibices or bruises, to undergo a chemico-animal process, so to change its nature as to fit it for absorption; which may take two or three weeks, which time a patient weakened by repeated venesection or arteriotomy may not survive.

Mrs. ——, about 40 years old, had an apoplectic seizure after great exertion from fear; she had lain about 24 hours without speech, or having swallowed any liquid. She was then forcibly raised in bed, and a spoonful of solution of aloes in wine put into her mouth, and the end of the spoon withdrawn, that she might more easily swallow the liquid.—This was done every hour, with broth, and wine and water intervening, till evacuations were procured; which with other means had good effect, and she recovered, except that a considerable degree of hemiplegia remained, and some imperfection of her speech.

Many people, who have taken so much vinous spirit as to acquire the temporary apoplexy of intoxication, and are not improperly said to be dead-drunk, have died after copious venesection, I suppose in consequence of it. I once saw at a public meeting two gentlemen in the drunken apoplexy; they were totally insensible with low pulse, on this account they were directed not to lose blood, but to be laid on a bed with their heads high, and to be turned every half hour; as soon as they could swallow, warm tea was given them, which evacuated their stomachs, and they gradually recovered, as people do from less degrees of intoxication.

M. M. Cupping on the occiput. Venesection once in moderate quantity. Warm fomentations long continued and frequently repeated on the shaved head. Solution of aloes. Clysters with solution of aloe and oil of amber. A blister on the spine. An emetic. Afterwards the bark, and small doses of chalybeates. Small electric shocks through the head. Errhines. If small doses of opium?

17. Mors a frigore. Death from cold. The unfortunate travellers, who almost every winter perish in the snow, are much exhausted by their efforts to proceed on their journey, as well as benumbed by cold. And as much greater exercise can be borne without fatigue in cold weather than in warm; because the excessive motions of the cutaneous vessels are thus prevented, and the consequent waste of sensorial power; it may be inferred, that the fatigued traveller becomes paralytic from violent exertion as well as by the application of cold.

Great degrees of cold affect the motions of those vessels most, which have been generally excited into action by irritation; for when the feet are much benumbed by cold, and painful, and at the same time almost insensible to the touch of external objects, the voluntary muscles retain their motions, and we continue to walk on; the same happens to the fingers of children in throwing snow-balls, the voluntary motions of the muscles continue, though those of the cutaneous vessels are benumbed into inactivity.

Mr. Thompson, an elderly gentleman of Shrewsbury, was seized with hemiplegia in the cold bath; which I suppose might be owing to some great energy of exertion, as much as to the coldness of the water. As in the instance given of Mr. Nairn, who, by the exertion to save his relation, perished himself. See Sect. XXXIV. 1. 7.

Whence I conclude, that though heat is a fluid necessary to muscular motion, both perhaps by its stimulus, and by its keeping the minute component parts of the ultimate fibrils of the muscles or organs of sense at a proper distance from each other; yet that paralysis, properly so called, is the consequence of exhaustion of sensorial power by exertion. And that the accumulations of it during the torpor of the cutaneous vessels by exposure to cold, or of some internal viscus in the cold fits of agues, are frequently instrumental in recovering the use of paralytic limbs, or of the motions of other paralytic parts of the system. See Spec. 4. of this genus.

Animal bodies resist the power of cold probably by their exertions in consequence of the pain of cold, see Botan. Gard. V. 1. additional note xii. But if these increased exertions be too violent, so as to exhaust the sensorial power in producing unnecessary motions, the animal will probably sooner perish. Thus a moderate quantity of wine or spirit repeated at proper intervals of time might be of service to those, who are long exposed to excessive cold, both by increasing the action of the capillary vessels, and thus producing heat, and perhaps by increasing in some degree the secretion of sensorial power in the brain. But the contrary must happen when taken immoderately, and not at due intervals. A well attested history was once related to me of two men, who set out on foot to travel in the snow, one of whom drank two or three glasses of brandy before they began their journey, the other contented himself with his usual diet and potation; the former of whom perished in spite of any assistance his companion could afford him; and the other performed his journey with safety. In this case the sensorial power was exhausted by the unnecessary motions of incipient intoxication by the stimulus of the brandy, as well as by the exertions of walking; which so weakened the dram-drinker, that the cold sooner destroyed him; that is, he had not power to produce sufficient muscular or arterial action, and in consequence sufficient heat, to supply the great expenditure of it. Hence the capillaries of the skin first cease to act, and become pale and empty; next those which are immediately associated with them, as the extremities of the pulmonary artery, as happens on going into the cold bath. By the continued inaction of these parts of the vascular system the blood becomes accumulated in the internal arteries, and the brain is supposed to be affected by its compression; because these patients are said to sleep, or to become apoplectic, before they die. I overtook a fishman asleep on his panniers on a very cold frosty night, but on waking him he did not appear to be in any degree of stupor. See Class I. 2. 2. 1.

When travellers are benighted in deep snow, they might frequently be saved by covering themselves in it, except a small aperture for air; in which situation the lives of hares, sheep, and other animals, are so often preserved. The snow, both in respect to its component parts, and to the air contained in its pores, is a bad conductor of heat, and will therefore well keep out the external cold; and as the water, when part of it dissolves, is attracted into the pores of the remainder of it, the situation of an animal beneath it is perfectly dry; and, if he is in contact with the earth, he is in a degree of heat between 48, the medium heat of the earth, and 32, the freezing point; that is, in 40 degrees of heat, in which a man thus covered will be as warm as in bed. See Botan. Garden, V. II. notes on Anemone, Barometz, and Muschus. If these facts were more generally understood, it might annually save the lives of many.

After any part of the vascular system of the body has been long exposed to cold, the sensorial power is so much accumulated in it, that on coming into a warm room the pain of hotach is produced, and inflammation, and consequent mortification, owing to the great exertion of those vessels, when again exposed to a moderate degree of warmth. See Sect. XII. 5. Whence the propriety of applying but very low degrees of heat to limbs benumbed with cold at first, as of snow in its state of dissolving, which is at 32 degrees of heat, or of very cold water. A French writer has observed, that if frozen apples be thawed gradually by covering them with thawing snow, or immersing them in very cold water, that they do not lose their taste; if this fact was well ascertained, it might teach us how to preserve other ripe fruits in ice-houses for winter consumption.

ORDO II.

Decreased Volition.

GENUS II.

With decreased Actions of the Organs of Sense.

SPECIES.

1. Recollectionis jactura. Loss of recollection. This is the defect of memory in old people, who forget the actions of yesterday, being incapable of voluntary recollection, and yet remember those of their youth, which by frequent repetition are introduced by association or suggestion. This is properly the paralysis of the mind; the organs of sense do not obey the voluntary power; that is, our ideas cannot be recollected, or acted over again by the will.

After an apoplectic attack the patients, on beginning to recover, find themselves most at a loss in recollecting proper names of persons or places; as those words have not been so frequently associated with the ideas they stand for, as the common words of a language. Mr. ——, a man of strong mind, of a short necked family, many of whom had suffered by apoplexy, after an apoplectic fit on his recovering the use of speech, after repeated trials to remember the name of a person or place, applauded himself, when he succeeded, with such a childish smile on the partial return of his sagacity, as very much affected me.—Not long, alas! to return; for another attack in a few weeks destroyed the whole.

I saw a child after the small-pox, which was left in this situation; it was lively, active, and even vigorous; but shewed that kind of surprise, which novelty excites, at every object it viewed; and that as often as it viewed it. I never heard the termination of the case.

2. Stultitia voluntaria. Voluntary folly. The absence of voluntary power and consequent incapacity to compare the ideas of present and future good. Brute animals may be said to be in this situation, as they are in general excited into action only by their present painful or pleasurable sensations. Hence though they are liable to surprise, when their passing trains of ideas are dissevered by violent stimuli; yet are they not affected with wonder or astonishment at the novelty of objects; as they possess but in a very inferior degree, that voluntary power of comparing the present ideas with those previously acquired, which distinguishes mankind; and is termed analogical reasoning, when deliberatively exerted; and intuitive analogy, when used without our attention to it, and which always preserves our hourly trains of ideas consistent with truth and nature. See Sect. XVII. 3. 7.

3. Credulitas. Credulity. Life is short, opportunities of knowledge rare; our senses are fallacious, our reasonings uncertain, mankind therefore struggles with perpetual error from the cradle to the coffin. He is necessitated to correct experiment by analogy, and analogy by experiment; and not always to rest satisfied in the belief of facts even with this two-fold testimony, till future opportunities, or the observations of others, concur in their support.

Ignorance and credulity have ever been companions, and have misled and enslaved mankind; philosophy has in all ages endeavoured to oppose their progress, and to loosen the shackles they had imposed; philosophers have on this account been called unbelievers: unbelievers of what? of the fictions of fancy, of witchcraft, hobgobblins, apparitions, vampires, fairies; of the influence of stars on human actions, miracles wrought by the bones of saints, the flights of ominous birds, the predictions from the bowels of dying animals, expounders of dreams, fortune-tellers, conjurors, modern prophets, necromancy, cheiromancy, animal magnetism, with endless variety of folly? These they have disbelieved and despised, but have ever bowed their hoary heads to Truth and Nature.

Mankind may be divided in respect to the facility of their belief or conviction into two classes; those, who are ready to assent to single facts from the evidence of their senses, or from the serious assertions of others; and those, who require analogy to corroborate or authenticate them.

Our first knowledge is acquired by our senses; but these are liable to deceive us, and we learn to detect these deceptions by comparing the ideas presented to us by one sense with those presented by another. Thus when we first view a cylinder, it appears to the eye as a flat surface with different shades on it, till we correct this idea by the sense of touch, and find its surface to be circular; that is, having some parts gradually receding further from the eye than others. So when a child, or a cat, or a bird, first sees its own image in a looking-glass, it believes that another animal exists before it, and detects this fallacy by going behind the glass to examine, if another tangible animal really exists there.

Another exuberant source of error consists in the false notions, which we receive in our early years from the design or ignorance of our instructors, which affect all our future reasoning by their perpetual intrusions; as those habits of muscular actions of the face or limbs, which are called tricks, when contracted in infancy continue to the end of our lives.

A third great source of error is the vivacity of our ideas of imagination, which perpetually intrude themselves by various associations, and compose the farrago of our dreams; in which, by the suspension of volition, we are precluded from comparing the ideas of one sense with those of another, or the incongruity of their successions with the usual course of nature, and thus to detect their fallacy. Which we do in our waking hours by a perpetual voluntary exertion, a process of the mind above mentioned, which we have termed intuitive analogy. Sect. XVII. 3. 7.

This analogy presupposes an acquired knowledge of things, hence children and ignorant people are the most credulous, as not possessing much knowledge of the usual course of nature; and secondly, those are most credulous, whose faculty of comparing ideas, or the voluntary exertion of it, is slow or imperfect. Thus if the power of the magnetic needle of turning towards the north, or the shock given by touching both sides of an electrized coated jar, was related for the first time to a philosopher, and to an ignorant person; the former would be less ready to believe them, than the latter; as he would find nothing similar in nature to compare them to, he would again and again repeat the experiment, before he would give it his entire credence; till by these repetitions it would cease to be a single fact, and would therefore gain the evidence of analogy. But the latter, as having less knowledge of nature, and less facility of voluntary exertion, would more readily believe the assertions of others, or a single fact, as presented to his own observation. Of this kind are the bulk of mankind; they continue throughout their lives in a state of childhood, and have thus been the dupes of priests and politicians in all countries and in all ages of the world.

In regard to religious matters, there is an intellectual cowardice instilled into the minds of the people from their infancy; which prevents their inquiry: credulity is made an indispensable virtue; to inquire or exert their reason in religious matters is denounced as sinful; and in the catholic church is punished with more severe penances than moral crimes. But in respect to our belief of the supposed medical facts, which are published by variety of authors; many of whom are ignorant, and therefore credulous; the golden rule of David Hume may be applied with great advantage. "When two miraculous assertions oppose each other, believe the less miraculous." Thus if a person is said to have received the small-pox a second time, and to have gone through all the stages of it, one may thus reason: twenty thousand people have been exposed to the variolous contagion a second time without receiving the variolous fever, to every one who has been said to have thus received it; it appears therefore less miraculous, that the assertor of this supposed fact has been deceived, or wishes to deceive, than that it has so happened contrary to the long experienced order of nature.

M. M. The method of cure is to increase our knowledge of the laws of nature, and our habit of comparing whatever ideas are presented to us with those known laws, and thus to counteract the fallacies of our senses, to emancipate ourselves from the false impressions which we have imbibed in our infancy, and to set the faculty of reason above that of imagination.

The Orders and Genera of the Fourth Class of Diseases.

CLASS IV.

DISEASES OF ASSOCIATION.

ORDO I.

Increased Associate Motions.

GENERA.

ORDO II.

Decreased Associate Motions.

GENERA.

ORDO III.

Retrograde Associate Motions.

GENERA.

The Orders, Genera, and Species, of the Fourth Class of Diseases.

CLASS IV.

DISEASES OF ASSOCIATION.

ORDO I.

Increased Associate Motions.

GENUS I.

Catenated with Irritative Motions.

SPECIES.

1. Rubor vultûs pransorum.Flushing of the face after dinner.

2. Sudor stragulis immersorum.Sweat from covering the face in bed.

3. Cessatio ægritudinis cute excitata. Cure of sickness by stimulating the skin.

4. Digestio aucta frigore cutaneo.Digestion increased by coldness of the skin.

5. Catarrhus a frigore cutaneo.Catarrh from cold skin.

6. Absorptio cellularis aucta vomitu.Cellular absorption increased by vomiting.

7. Syngultus nephriticus.Nephritic hiccough.

8. Febris irritativa.Irritative fever.

GENUS II.

Catenated with Sensitive Motions.

SPECIES.

1. Lacrymarum fluxus sympatheticus. Sympathetic tears.

2. Sternutatio a lumine.Sneezing from light.

3. Dolor dentium a Stridore.Tooth-edge from grating sounds.

4. Risus sardonicus.Sardonic smile.

5. Salivæ fluxus cibo viso.Flux of saliva at sight of food.

6. Tensio mamularum viso puerulo.Tension of the nipples of lactescent women at sight of the child.

7. Tensio penis in hydrophobia.Tension of the penis in hydrophobia.

8. Tenesmus calculosus.Tenesmus from stone.

9. Polypus narium ex ascaride.Polypus of the nose from ascarides.

10. Crampus surarum in diarrhœa.Cramp from diarrhœa.

11. Zona ignea nephritica.Nephritic shingles.

12. Eruptio variolarum.Eruption of small-pox.

13. Gutta rosea stomatica.Stomatic rosy drop.

14. —— hepatica.Hepatic rosy drop.

15. Podagra.Gout.

16. Rheumatismus.Rheumatism.

17. Erysipelas.Erysipelas.

18. Testium tumor in gonorrhœa.Swelled testis in gonorrhœa.

19. —— in parotitide.—— in mumps.

GENUS III.

Catenated with Voluntary Motions.

SPECIES.

1. Deglutitio invita.Involuntary deglutition.

2. Nictitatio invita.—— nictitation.

3. Risus invitus.—— laughter.

4. Lusus digitorum invitus.—— actions with the fingers.

5. Unguium morsiuncula invita. —— biting the nails.

6. Vigilia invita.—— watchfulness.

GENUS IV.

Catenated with External Influences.

SPECIES.

1. Vita ovi.Life of an egg.

2. Vita hiemi-dormientium.Life of winter-sleepers.

3. Pullulatio arborum.Budding of trees.

4. Orgasmatis venerei periodus. Periods of venereal desire.

5. Brachii concussio electrica.Electric shock through the arm.

6. Oxygenatio sanguinis.Oxygenation of the blood.

7. Humectatio corporis.Humectation of the body.

ORDO II.

Decreased Associate Motions.

GENUS I.

Catenated with Irritative Motions.

SPECIES.

1. Cutis frigida pransorum.Chillness after dinner.

2. Pallor urinæ pransorum.Pale urine after dinner.

3. —— a frigore cutaneo.—— from cold skin.

4. Pallor ex ægritudine.Paleness from sickness.

5. Dyspnœa a balneo frigido.Shortness of breath from cold bathing.

6. Dyspepsia a pedibus frigidis.Indigestion from cold feet.

7. Tussis a pedibus frigidis.Cough from cold feet.

8. —— hepatica.Liver-cough.

9. —— arthritica.Gout-cough.

10. Vertigo rotatoria.Vertigo rotatory.

11. —— visualis.—— visual.

12. —— ebriosa.—— inebriate.

13. —— febriculosa.—— feverish.

14. —— cerebrosa.—— from the brain.

15. Murmur aurium vertiginosum.Noise in the ears.

16. Tactus, gustus, olfactus vertiginosi. Vertiginous touch, taste, smell.

17. Pulsus mollis a vomitione.Soft pulse in vomiting.

18. —— intermittens a ventriculo.Intermittent pulse from the stomach.

19. Febris inirritativa.Inirritative fever.

GENUS II.

Catenated with Sensitive Motions.

SPECIES.

1. Torpor genæ a dolore dentis.Coldness of the cheek from tooth-ach.

2. Stranguria a dolore vesicæ.Strangury from pain of the bladder.

3. —— convulsiva.Convulsive strangury.

4. Dolor termini ductûs choledochi.Pain of the end of the bile-duct.

5. Dolor pharyngis ab acido gastrico.Pain of the throat from gastric acid.

6. Pruritus narium a vermibus.Itching of the nose from worms.

7. Cephalæa.Head-ach.

8. Hemicrania et otalgia.Partial head-ach, and ear-ach.

9. Dolor humeri in hepatitide.Pain of shoulder in hepatitis.

10. Torpor pedum variolâ erumpente.Cold feet in eruption of small-pox.

11. Testium dolor nephriticus.Nephritic pain of testis.

12. Dolor digiti minimi sympatheticus. Pain of little finger from sympathy.

13. Dolor brachii in hydrope pectoris.Pain of the arm in dropsy of the chest.

14. Diarrhœa a dentitione.Diarrhœa from toothing.

GENUS III.

Catenated with Voluntary Motions.

SPECIES.

1. Titubatio linguæ.Impediment of speech.

2. Chorea sancti viti.St. Vitus' dance.

3. Risus.Laughter.

4. Tremor ex irâ.Trembling from anger.

5. Rubor ex irâ.Redness from anger.

6. —— criminati.Blush of guilt.

7. Tarditas paralytica. Slowness from palsy.

8. —— senilis.—— of age.

GENUS IV.

Catenated with External Influences.

SPECIES.

1. Somni periodus.Periods of sleep.

2. Studii inanis periodus.—— of reverie.

3. Hemicraniæ periodus.—— of head-ach.

4. Epilepsiæ dolorificæ periodus.—— of painful epilepsy.

5. Convulsionis dolorificæ periodus. —— of painful convulsion.

6. Tussis periodicæ periodus.—— of periodic cough.

7. Catameniæ periodus.—— of catamenia.

8. Hæmorrhoidis periodus.—— of the piles.

9. Podagræ periodus.—— of the gout.

10. Erysipelatis periodus.—— of erysipelas.

11. Febrium periodus.—— of fevers.

ORDO III.

Retrograde Associate Motions.

GENUS I.

Catenated with Irritative Motions.

SPECIES.

1. Diabætes irritata.Diabetes from irritation.

2. Sudor frigidus in asthmate. Cold sweat in asthma.

3. Diabætes a timore.Diabetes from fear.

4. Diarrhœa a timore.Diarrhœa from fear.

5. Pallor et tremor a timore.Paleness and trembling from fear.

6. Palpitatio cordis a timore.Palpitation of the heart from fear.

7. Abortio a timore.Abortion from fear.

8. Hysteria a timore.Hysterics from fear.

GENUS II.

Catenated with Sensitive Motions.

SPECIES.

1. Nausea idealis.Nausea from ideas.

2. —— a conceptu.Nausea from conception.

3. Vomitio vertiginosa.Vomiting from vertigo.

4. —— a calculo in uretere.—— from stone in the ureter.

5. —— ab insultu paralytico.—— from stroke of palsy.

6. —— titilatione faucium. —— from tickling the throat.

7. —— cute sympathetica.—— from sympathy with the skin.

GENUS III.

Catenated with Voluntary Motions.

SPECIES.

1. Ruminatio.Rumination.

2. Vomitio voluntaria.Voluntary vomiting.

3. Eructatio voluntaria. —— eructation.

GENUS IV.

Catenated with External Influences.

SPECIES.

1. Catarrhus periodicus. Periodical catarrh.

2. Tussis periodica.Periodic cough.

3. Histeria a frigore.Hysterics from cold.

4. Nausea pluvialis.Sickness against rain.

CLASS IV.

DISEASES OF ASSOCIATION.

ORDO I.

Increased Associate Motions.

GENUS I.

Catenated with Irritative Motion.

The importance of the subsequent class not only consists in its elucidating all the sympathetic diseases, but in its opening a road to the knowledge of fever. The difficulty and novelty of the subject must plead in excuse for the present imperfect state of it. The reader is entreated previously to attend to the following circumstances for the greater facility of investigating their intricate connections; which I shall enumerate under the following heads.

A. Associate Motions distinguished from Catenations.

Associate motions properly mean only those, which are caused by the sensorial power of association. Whence it appears, that those fibrous motions, which constitute the introductory link of an associate train of motions, are excluded from this definition, as not being themselves caused by the sensorial power of association, but by irritation, or sensation, or volition. I shall give for example the flushing of the face after dinner; the capillary vessels of the face increase their actions in consequence of their catenation, not their association, with those of the stomach; which latter are caused to act with greater energy by the irritation excited by the stimulus of food. These capillaries of the face are associated with each other reciprocally, as being all of them excited by the sensorial power of association; but they are only catenated with those of the stomach, which are not in this case associate motions but irritative ones. The common use of the word association for almost every kind of connection has rendered this subject difficult; from which inaccuracy I fear some parts of this work are not exempt.

B. Associate Motions of three Kinds.

Those trains or tribes of associate motions, whose introductory link consists of an irritative motion, are termed irritative associations; as when the muscles of the eyelids close the eye in common nictitation. Those, whose introductory link consists of a sensitive motion, are termed sensitive associations; as when the pectoral and intercostal muscles act in sneezing. And lastly, those, whose introductory link consists of a voluntary motion, are termed voluntary associations; as when the muscles of the lower limbs act in concert with those of the arm in fencing.

C. Associations affected by external Influences.

Circles of associate motions, as well as trains and tribes of them, are liable to be affected by external influences, which consist of etherial fluids, and which, by penetrating the system, act upon it perhaps rather as a causa sine quâ non of its movements, than directly as a stimulus; except when they are accumulated in unusual quantity. We have a sense adapted to the perception of the excess or defect of one of these fluids; I mean that of elementary heat; in which all things are immersed. See Class IV. 1. 4. 7. But there are others of them, which as we have no power to evade their influence, so we have no sense to perceive it; these are the solar, and lunar, and terrestrial gravitation, in which also all things are immersed; the electric aura, which pervades us, and is perpetually varying, See Class IV. 1. 4. 5; the magnetic fluid, Class IV. 1. 4. 5; and lastly, the great life-preserver oxygen gas, and the aqueous vapour of the atmosphere, see Class IV. 1. 4. 6. and 7. and 2.

Of these external influences those of heat, and of gravity, have diurnal periods of increase and decrease; besides their greater periods of monthly or annual variation. The manner in which they act by periodical increments on the system, till some effect is produced, is spoken of in Sect. XXXII. 3. and 6.

D. Associations affected by other Sensorial Motions.

Circles and trains of associate motions are also liable to be affected by their catenations with other sensorial powers, as of irritation, or sensation, or volition; which other sensorial powers either thus simply form some of the links of the catenation, or add to the energy of the associated motions. Thus when vomiting is caused by the stimulus of a stone in the ureter, the sensation of pain seems to be a link of the catenation rather than an efficient cause of the vomiting. But when the capillary vessels of the skin increase their action from the influence of external heat, they are excited both by the stimulus of unusual heat, as well as by the stimulus of the blood, and by their accustomed association with the actions of the heart and arteries. And lastly, in the blush of anger the sensorial power of volition is added to that of association, and irritation, to excite the capillaries of the face with increased action. See Class IV. 2. 3. 5.

E. Associations catenated with Sensation.

Pain frequently accompanies associate trains or circles of motion without its being a cause, or a link, of them, but simply an attendant symptom; though it frequently gives name to the disease, as head-ach. Thus in the cramp of the calves of the legs in diarrhœa, the increased sensorial power of association is the proximate cause; the preceding increased action of the bowels is the remote cause; and the proximate effect is the violent contractions of the musculi gastrocnemii; but the pain of these muscles is only an attendant symptom, or a remote effect. See Sect. XVIII. 15. Other sensitive associations are mentioned in Class IV. 1. 2. and IV. 1. 2. 15.

Thus, if the flushing of the face above mentioned after dinner be called a disease, the immediate or proximate cause is the increased power of association, the remote cause is the increased irritative motions of the stomach in consequence of the stimulus of food and wine. The disease or proximate effect consists in the increased actions of the cutaneous vessels of the face; and the sensation of heat, the existence of heat, and the red colour, are attendants or symptoms, or remote effects, of the increased actions of these cutaneous vessels.

F. Direct and reverse Sympathy.

The increased actions of the primary part of the trains of associated motions are sometimes succeeded by increased actions of the secondary part of the train; and sometimes by decreased actions of it. So likewise the decreased actions of the primary part of a train of associate motions are sometimes succeeded by decreased actions of the secondary part, and sometimes by increased actions of it. The former of these situations is called direct sympathy, and the latter reverse sympathy. In general I believe, where the primary part of the train of associated motions is exerted more than natural, it produces direct sympathy in strong people, and reverse sympathy in weak ones, as a full meal makes some people hot, and others chill. And where the primary part of the train is exerted less than natural, it produces direct sympathy in weak people, and reverse sympathy in strong ones, as on being exposed for a certain length of time on horseback in a cold day gives indigestion and consequent heart-burn to weak people, and strengthens the digestion, and induces consequent hunger in strong ones. See Sect. XXXV. 1.

This may perhaps be more easily understood, by considering strength and weakness, when applied to animal bodies, as consisting in the quantity of sensorial power residing in the contracting fibres, and the quantity of stimulus applied, as shewn in Sect. XII. 2. 1. Now when defective stimulus, within certain limits, is partially applied to parts subject to perpetual motion, the expenditure of sensorial power is for a while lessened, but not its general production in the brain, nor its derivation into the weakly-stimulated part. Hence in strong people, or such whose fibres abound with sensorial power, if the first tribe of an associate train of motions be deprived in part of its accustomed stimulus, its action becomes diminished; and the sensorial power becomes accumulated, and by its superabundance, or overflowing as it were, increases the action of the second tribe of the associate actions by reverse sympathy. As exposing the warm skin for a moderate time to cold air increases the action of the stomach, and thus strengthens the power of digestion.

On the reverse, when additional stimulus within certain limits is partially applied to parts, which are deficient in respect to the natural quantity of sensorial power, the expenditure of sensorial power is increased, but in a less degree than the increased production of it in the brain, or its increased derivation into the strongly-stimulated organ. Hence in weak people, or such whose fibres are deficient of sensorial power, if the first tribe of an associate train of motions be subjected for a while to greater stimulus than usual, a greater production of sensorial power, or a greater derivation of it into the stimulated parts occurs; which by its excess, or overflowing as it were, increases the actions of the second tribe of the associate motions by direct sympathy. Thus when vomiting occurs with cold extremities, a blister on the back in a few hours occasions universal warmth of the skin, and stops the vomiting. And when a diarrhœa occurs with pale skin and cold extremities, the pricking of the points of a flannel shirt, worn next the skin, occasions universal warmth of it, and checks or cures the diarrhœa.

In some associate trains of action nevertheless reverse sympathies more frequently occur than direct ones, and in others direct ones more frequently than reverse ones. Thus in continued fever with debility there appears to be a reverse sympathy between the capillary vessels of the stomach and those of the skin; because there exists a total aversion to solid food, and constant heat on the surface of the body. Yet these two systems of vessels are at other times actuated by direct sympathy, as when paleness attends sickness, or cold feet induces indigestion. This subject requires to be further investigated, as it probably depends not only on the present or previous plus or minus of the sensorial power of association, but also on the introduction of other kinds of sensorial power, as in Class IV. 1. 1. D; or the increased production of it in the brain, or the greater mobility of one part of a train of actions than another.

Thus when much food or wine is taken into the stomach, if there be no superfluity of sensorial power in the system, that is, none to be spared from the continual actions of it, a paleness and chillness succeeds for a time; because now the expenditure of it by the increased actions of the stomach is greater than the present production of it. In a little time however the stimulus of the food and wine increases the production of sensorial power in the brain, and this produces a superfluity of it in the system; in consequence of which the skin now becomes warm and florid, which was at first cold and pale; and thus the reverse sympathy is shortly converted into a direct one; which is probably owing to the introduction of a second sensorial power, that of pleasurable sensation.

On the contrary, when an emetic drug produces sickness, the skin is at first pale for a time by direct sympathy with the capillaries of the stomach; but in a few minutes, by the accumulation of sensorial power in the stomach during its less active state in sickness, the capillaries of the skin, which are associated with those of the stomach, act with greater energy by reverse sympathy, and a florid colour returns. Where the quantity of action is diminished in the first part of a train of motions, whether by previous diminution of sensorial power, or present diminution of stimulus, the second part of the train becomes torpid by direct sympathy. And when the quantity of action of the first part becomes increased by the accumulation of sensorial power during its previous torpor, or by increase of stimulus, the actions of the second part of it likewise become increased by direct sympathy.

In moderate hunger the skin is pale, as before dinner, and in moderate sickness, as no great accumulation of sensorial power has commenced; but in violent hunger, and in greater torpor of the stomach, as from contagious matter, the accumulation of sensorial power becomes so great as to affect the arterial and capillary system, and fever is produced in both cases.

In contagious fevers with arterial debilities commencing with torpor of the stomach, why is the action of the heart weakened, and that of the capillaries increased? Is it because the mobility of the heart is less than that of the stomach, and the mobility of the capillaries greater? Or is it because the association between the muscular fibres of the stomach and those of the heart have been uniformly associated by direct sympathy; and the capillaries of the stomach and those of the skin have been more frequently associated by reverse sympathy?

Where the actions of the stomach have been previously exhausted by long stimulus, as on the day after intoxication, little or no accumulation of sensorial power occurs, during the torpor of the organ, beyond what is required to replace the deficiency of it, and hence fever seldom follows intoxication. And a repetition of the stimulus sometimes becomes necessary even to induce its natural action, as in dram-drinkers.

Where there has been no previous exhaustion of sensorial power, and the primary link of associate motions is violently actuated by the sensorial power of sensation, the secondary link is also violently actuated by direct sympathy, as in inflammatory fevers. Where however the sensorial power of the system is less than natural, the secondary link of associated motions becomes torpid by reverse sympathy, as in the inoculated small-pox during the eruption on the face the feet are frequently cold.

G. Associations affected four Ways.

Hence associated trains or circles of motions may be affected four different ways. 1. By the greater or less energy of action of the first link with which they are catenated, and from which they take their names; as irritative, sensitive, or voluntary associations. 2. By being excited by two or more sensorial powers at the same time, as by irritation and association, as in the instance of the application of the stimulus of increased external heat to the cutaneous capillaries. 3. By catenation with other sensorial powers, as with pain or pleasure, which are in this case not the proximate cause of motion, but which, by becoming a link of catenation, excites the sensorial power of association into action; as the pain at the neck of the gall-bladder occasioned by a gall-stone is transferred to the other end of that canal, and becomes a link of catenation between the action of the two extremities of it. 4. The influence of ethereal fluids, as of heat and gravitation. To which last perhaps might be added moisture and oxygen gas as constituting necessary parts of the system, rather than stimuli to excite it into action.

H. The Origin of Associations.

Some trains or circles of associate motions must have been formed before our nativity, as those of the heart, arteries, and capillaries; others have been associated, as occasion required them, as the muscles of the diaphragm and abdomen in vomiting; and others by perpetual habit, as those of the stomach with the heart and arteries directly, as in weak pulse during sickness; with the capillaries directly, as in the flushed skin after dinner; and lastly, with the cellular absorbents reversely, as in the increased absorption in anasarca during sickness; and with the irritative motions of the organs of sense reversely, as in vertigo, or sea-sickness. Some of these associations shall be here shortly described to facilitate the investigation of others.

First, other congeries of glands occupy but a particular part of the system, or constitute a particular organ, as the liver, or kidneys; but those glands, which secrete the mucus, and perspirable matter, which are called capillaries, are of very great extent; they receive the blood from the arteries, separate from it the mucus, which lines every cell, and covers every cavity of body; and the perspirable matter, which softens and lubricates the whole surface of the skin, and the more extensive surface of the air-vessels, which compose the lungs. These are supplied with blood by the perpetual action of the heart and arteries, and have therefore their motions associated with the former, and with each other, by sympathy, which is sometimes direct, and sometimes reverse.

One branch of this association, the capillaries of the skin, are very irritable by the increased quantities of cold and heat, another branch, that of the lungs, has not the perception of cold and heat, but is liable by direct sympathy to act in concert with the former, as in going into the cold bath. And it is probable the capillaries of the internal membranes are likewise directly affected by their sympathy with those of the skin, as appears from the defect of secretion in ulcers during the cold fits of agues.

The motions of this extensive system of capillaries, thus associated by direct sympathy, are also associated with those of the heart and arteries, sometimes by reverse and sometimes by direct sympathy; and thus constitute simple fever. The cold paroxysm of which consists in their torpor, and the hot one in their orgasm, or increased activity.

I. Of the Action of Vomiting.

The manner, in which the stomach and the diaphragm and abdominal muscles acquire their associate action in vomiting, requires some attention. It is not probable, that this action of vomiting occurs before nativity; as the uniform application of the nutritive liquor amnii to the mouth of the fœtus, and the uniform expenditure of its nourishment, would not seem to give occasion to too great temporary repletion of the stomach; and would preclude the deglutition of any improper material. After nativity the stomach of the child may be occasionally too much distended with milk; as previous hunger may induce it to overgorge itself; and by repeated efforts the act of vomiting is learned, as a means of getting free from a disagreeable sensation. Thus when any disgustful material, as a bitter drug, is taken into the mouth; certain retrograde motions of the tongue and lips are produced, for the purpose of putting the disagreeable material out of the mouth again.

When the stomach is disagreeably stimulated by the distention or acrimony of the aliment, a similar effort to regurgitate it must occur; and by repeated trials the action of the diaphragm and abdominal muscles by squeezing the stomach assists its retrograde exertion to disgorge its contents. In the same manner when a piece of gravel is pushed into the urethra, or a piece of indurated bile into the neck of the gall-bladder, after they have been in vain pressed forward by the usual motions of those ducts, they return into the bladders of gall and urine by the retrograde motions of them.

That this is one mode, in which vomiting is induced, appears from the instantaneous rejection from the stomach occasioned by some nauseous drug, or from some nauseous idea; and lastly, from the voluntary power, which some people have been said to have acquired, of emptying their stomachs, much in the same manner as ruminating animals bring up the grass from their first stomach.