Chapter XIX: Section XXXVI: 2. 3 (7)

When great pain exists without causing any fibrous motions, I conjecture that it contributes to exhaust or expend the general quantity of sensorial power; because people are fatigued by enduring pain, till at length they sleep. Which is contrary to what I had perhaps erroneously supposed in Sect. XXXV. 2. 3. If it causes fibrous motions, it then takes the name of sensation, according to the definition of sensation in Sect. II. 2. 9.; and increased fibrous action or inflammation is the consequence. This circumstance of the general exhaustion of sensorial power by the existence of pain will assist in explaining many of the diseases of this genus.

Many of the canals of the body, as the urethra, the bile-duct, the throat, have the motions of their two extremities associated by having been accustomed to feel pleasurable or painful sensations at the same time or in succession. This is termed sensitive association, though those painful or pleasurable sensations do not cause the motions, but only attend them; and are thus perhaps, strictly speaking, only catenated with them.

SPECIES.

1. _Torpor genae a dolore dentis._ In tooth-ach there is generally a coldness of the cheek, which is sensible to the hand, and is attended in some degree with the pain of cold. The cheek and tooth have frequently been engaged in pleasurable action at the same time during the masticating of our food; whence they have acquired sensitive associations. The torpor of the cheek may have for its cause the too great expenditure of sensorial power by the painful sensation of the membranes of the diseased tooth; whence the membranes of the cheek associated with those of the alveolar process are deprived of their natural share of it, and become torpid; thus they produce less secretions, and less heat, and the pain of cold is the consequence. This torpor of the vessels of the cheek cannot be produced by the activity of the sensorial power of sensation; for then they would act more violently than natural, or become inflamed. And though the pain by exhausting so much sensorial power may be a remote cause, it is the defeat of the power of association, which is the immediate cause of the torpor of the cheek.

After some hours this pain occasioned by the torpor of the vessels of the cheek either gradually ceases along with the pain of the diseased tooth; or, by the accumulation of sensorial power during their state of torpor, the capillaries of the cheek act with greater violence, and produce more secretions, and heat, and consequent tumour, and inflammation. In this state the pain of the diseased tooth ceases; as the sensorial power of sensation is now expended on the inflamed vessels of the cheek. It is probable that most other internal membranous inflammations begin in a similar manner; whence there may seem to be a double kind of sensitive association; first, with decreased action of the associated organ, and then with increased action of it; but the latter is in this case simply the consequence of the former; that is, the tumor or inflammation of the cheek is in consequence of its previous quiescence or torpor.

2. _Stranguria a dolore vesicae._ The strangury, which has its origin from pain at the neck of the bladder, consists of a pain in the external extremity of the urethra or of the glans penis of men, and probably in the external termination of the urethra or of the clitoris of women; and is owing to the sympathy of these with some distant parts, generally with the other end of the urethra; an endeavour and difficulty of making water attends this pain.

Its remote cause is from the internal or external use of cantharides, which stimulate the neck of the bladder; or from a stone, which whenever it is pushed into the neck of the bladder, gives this pain of strangury, but not at other times; and hence it is felt most severely in this case after having made water.

The sensations or sensitive motions of the glans penis, and of the sphincter of the bladder, have been accustomed to exist together during the discharge of the urine; and hence the two ends of the urethra sympathize by association. When there is a stone at the neck of the bladder, which is not so large or rough as to inflame the part, the sphincter of the bladder becomes stimulated into pain; but as the glans penis is for the purposes of copulation more sensitive than the sphincter of the bladder, as soon as it becomes affected with pain by the association above mentioned, the sensation at the neck of the bladder ceases; and then the pain of the glans penis would seem to be associated with the irritative motions only of the sphincter of the bladder, and not with the sensitive ones of it. But a circumstance similar to this occurs in epileptic fits, which at first are induced by disagreeable sensation, and afterwards seem to occur without previous pain, from the suddenness in which they follow and relieve the pain, which occasioned them. From this analogy I imagine the pain of the glans penis is associated with the pain of the sphincter of the bladder; but that _as soon as the greater pain in a more sensible part is produced; the lesser one, which occasioned it, ceases_; and that this is one of the laws of sensitive association. See Sect. XXXV. 2. 1.

A young man had by an accident swallowed a large spoonful or more of tincture of cantharides; as soon as he began to feel the pain of strangury, he was advised to drink large quantities of warmish water; to which, as soon as it could be got, some gum arabic was added. In an hour or two he drank by intervals of a few minutes about two gallons of water, and discharged his urine every four or five minutes. A little blood was voided towards the end, but he suffered no ill consequence.

M. M. Warm water internally. Clysters of warm water. Fomentation. Opium. Solution of fixed alkali supersaturated with carbonic acid. A bougie may be used to push back a stone into the bladder. See Class I. 1. 3. 10.

3. _Stranguria convulsiva._ The convulsive strangury, like that before described, is probably occasioned by the torpor or defective action of the painful part in consequence of the too great expenditure of sensorial power on the primary link of the associated motions, as no heat or inflammation attends this violent pain. This kind of strangury recurs by stated periods, and sometimes arises to so great a degree, that convulsion or temporary madness terminates each period of it. It affects women oftener than men, is attended with cold extremities without fever, and is distinguished from the stone of the bladder by the regularity of its periods, and by the pain being not increased after making water.

On introducing the catheter sometimes part of the urine will come away and not the whole, which is difficult to explain; but may arise from the weakness of the muscular fibres of the bladder; which are not liable suddenly to contract themselves so far as to exclude the whole of the urine. In some old people, who have experienced a long retention of urine, the bladder never regains the power of completely emptying itself; and many who are beginning to be weak from age can make water a second time, a few minutes after they supposed they had emptied the bladder.

I have believed this pain to originate from sympathy with some distant part, as from ascarides in the rectum, or from piles in women; or from caruncles in the urethra about the caput gallinaginis in men; and that the pain has been in the glans or clitoris by reverse sympathy of these more sensible parts with those above mentioned.

M. M. Venesection. Opium in large quantities. Warm bath. Balsams. Bark. Tincture of cantharides. Bougie, and the treatment for haemorrhoids. Leeches applied to the sphincter ani. Aerated alcaline water. Soap and sal soda. Opium in clysters given an hour before the expected return. Smoke of tobacco in clysters. Arsenic?

4. _Dolor termini intestinalis ductus choledochi._ Pain at the intestinal end of the gall-duct. When a gall-stone is protruded from the gall-bladder a little way into the end of the gall-duct, the pain is felt at the other end of the gall-duct, which terminates in the duodenum. For the actions of the two terminations of this canal are associated together from the same streams of bile passing through them in succession, exactly as the two terminations of the urethra have their actions associated, as described in Species 2 and 3 of this genus. But as the intestinal termination of the bile-duct is made more sensible for the purpose of bringing down more bile, when it is stimulated by new supplies of food from the stomach, it falls into violent pain from association; and then the pain on the region of the gall-bladder ceases, exactly as above explained in the account of the pain of the glans penis from a stone in the sphincter of the bladder.

The common bile-duct opens into the intestine exactly at what is called the pit of the stomach; and hence it has sometimes happened, that this pain from association with the sensation of a gall-stone at the other end of the bile-duct has been mistaken for a pain of the stomach.

For the method of cure see Class I. 1. 3. 8. to which should be added the use of strong electric shocks passed through the bile-duct from the pit of the stomach to the back, and from one side to the other. A case of the good effect of electricity in the jaundice is related in Sect. XXX. 2. And another case, where it promoted the passage of a painful gall-stone, is described by Dr. Hall, experienced on himself. Trans. of the College at Philadelphia, Vol. I. p. 192.

Half a pint of warm water two or three times a day is much recommended to dilute the inspissated bile.

5. _Dolor pharyngis ab acido gastrico._ The two ends of the throat sympathize by sensitive association in the same manner as the other canals above mentioned, namely, the urethra and the bile-duct; hence when too great acidity of undigested aliment, or the carbonic acid air, which escapes in fermentation, stimulates the cardia ventriculi, or lower end of the gula, into pain; the pharinx, or upper end of it, is affected with greater pain, or a disagreeable sensation of heat.

6. _Pruritus narium a vermibus._ The itching of the nose from worms in the intestines is another curious instance of the sensitive associations of the motions of membranes; especially of those which constitute the canals of the body. Previous to the deglutition of agreeable food, as milk in our earliest infancy, an agreeable odour affects the membrane, which lines the nostrils; and hence an association seems to take place between the agreeable sensations produced by food in the stomach and bowels, and the agreeable sensations of the nostrils. The existence of ascarides in the rectum I believe produces this itching of the nostrils more than the worms in other parts of the intestines; as we have already seen, that the terminations of canals sympathize more than their other parts, as in the urethra and gall-ducts. See Class I. 1. 5. 9. IV. 1. 2. 9.

7. _Cephalaea._ Head-ach. In cold fits of the ague, the head-ach arises from consent with some torpid viscus, like the pain of the loins. After drunkenness the head-ach is very common, owing to direct sympathy of the membranes of the head with those of the stomach; which is become torpid after the too violent stimulus of the preceding intoxication; and is hence removeable by spirit of wine, or opium, exhibited in smaller quantities. In some constitutions these head-achs are induced, when the feet are exposed to much external cold; in this case the feet should be covered with oiled silk, which prevents the evaporation of the perspirable matter, and thence diminishes one cause of external cold.

M. M. Valerian in powder two drams three or four times a day is recommended. The bark. Chalybeates. A grain of opium twice a day for a long time. From five to ten drops of the saturated solution of arsenic two or three times a day. See Class I. 2. 4. 11. A lady once assured me, that when her head-ach was coming on, she drank three pints (pounds) of hot water, as hastily as she could; which prevented the progress of the disease. A solution of arsenic is recommended by Dr. Fowler of York. Very strong errhines are said sometimes to cure head-achs taken at the times the pain recurs, till a few drops of blood issue from the nostrils. As one grain of turpeth mineral (vitriolic calx of mercury) mixed with ten grains of fine sugar. Euphorbium or cayan pepper mixed with sugar, and used with caution as an errhine. See the M. M. of the next Species.

8. _Hemicrania._ Pain on one side of the head. This disease is attended with cold skin, and hence whatever may be the remote cause, the immediate one seems to be want of stimulus, either of heat or distention, or of some other unknown stimulus in the painful part; or in those, with which it is associated. The membranes in their natural state are only irritable by distention; in their diseased state, they are sensible like muscular fibres. Hence a diseased tooth may render the neighbouring membranes sensible, and is frequently the cause of this disease.

Sometimes the stomach is torpid along with the pained membrane of the head; and then sickness and inappetency attends either as a cause or consequence. The natural cure of hemicrania is the accumulation of sensorial power during the rest or sickness of the patient. Mrs. ---- is frequently liable to hemicrania with sickness, which is probably owing to a diseased tooth; the paroxysm occurs irregularly, but always after some previous fatigue, or other cause of debility. She lies in bed, sick, and without taking any solid food, and very little of fluids, and those of the aqueous kind, and, after about 48 or 50 hours, rises free from complaint. Similar to this is the recovery from cold paroxysms of fever, from the torpor occasioned by fear, and from syncope; which are all owing to the accumulation of sensorial power during the inactivity of the system. Hence it appears, that, though when the sensorial power of volition is much exhausted by fatigue, it can be restored by eight or ten hours of sleep; yet, when the sensorial power of irritation is exhausted by fatigue, that it requires two whole solar or lunar days of rest, before it can be restored.

The late Dr. Monro asserted in his lectures, that he cured the hemicrania, or megrim, by a strong vomit, and a brisk purge immediately after it. This method succeeds best if opium and the bark are given in due quantity after the operation of the cathartic; and with still more certainty, if bleeding in small quantity is premised, where the pulse will admit of it. See Sect. XXXV. 2. 1.

The pain generally affects one eye, and spreads a little way on that side of the nose, and may sometimes be relieved by pressing or cutting the nerve, where it passes into the bone of the orbit above the eye. When it affects a small defined part on the parietal bone on one side, it is generally termed Clavus hystericus, and is always I believe owing to a diseased dens molaris. The tendons of the muscles, which serve the office of mastication, have been extended into pain at the same time, that the membranous coverings of the roots of the teeth have been compressed into pain, during the biting or mastication of hard bodies. Hence when the membranes, which cover the roots of the teeth, become affected with pain by a beginning decay, or perhaps by the torpor or coldness of the dying part of the tooth, the tendons and membranous fascia of the muscles about the same side of the head become affected with violent pain by their sensitive associations: and as soon as this associated pain takes place, the pain of the tooth entirely ceases, as explained in the second species of this genus.

A remarkable circumstance attends this kind of hemicrania, viz. that it recurs by periods like those of intermittent fevers, as explained in the Section on Catenation of Motions; these periods sometimes correspond with alternate lunar or solar days like tertian agues, and that even when a decaying tooth is evidently the cause; which has been evinced by the cure of the disease by extracting the tooth. At other times they observe the monthly lunations, and seem to be induced by the debility, which attends menstruation.

The dens sapientiae, or last tooth of the upper jaw, frequently decays first, and gives hemicrania over the eye on the same side. The first or second grinder in the under-jaw is liable to give violent pain about the middle of the parietal bone, or side of the head, on the same side, which is generally called the Clavus hystericus, of which an instructive case is related in Sect. XXXV. 2. 1.

M. M. Detect and extract the diseased tooth. Cut the affected nerve, or stimulate the diseased membrane by acu-puncture. Venesection to six ounces by the lancet or by leeches. A strong emetic and a subsequent cathartic; and then an opiate and the bark. Pass small electric shocks through the pained membrane, and through the teeth on the same side. Apply vitriolic ether externally, and a grain of opium with camphor internally, to the cheek on the affected side, where a diseased tooth may be suspected. Foment the head with warm vinegar. Drink two large spoonfuls of vinegar. Stimulate the gums of the suspected teeth by oil of cloves, by opium. See Class I. 1. 4. 4. Snuff volatile spirit of vinegar up the nostrils. Lastly, in permanent head-achs, as in permanent vertigo, I have seen good effect by the use of mercurial ointment rubbed on the shaved head or about the throat, till a mild salivation commences, which by inflaming the membranes of the teeth may prevent their irritative sympathy with those of the cranium. Thus by inflaming the tendon, which is the cause of locked jaw, and probably by inflaming the wound, which is the cause of hydrophobia, those diseases may be cured, by disuniting the irritative sympathy between those parts, which may not possess any sensitive sympathy. This idea is well worth our attention.

_Otalgia._ Ear-ach is another disease occasioned by the sympathy of the membranes of the ear with those which invest or surround a decaying tooth, as I have had frequent reason to believe; and is frequently relieved by filling the ear with tincture of opium. See Class I. 2. 4.

9. _Dolor humeri in hepatitide._ In the efforts of excluding the faeces and urine the muscles of the shoulders are exerted to compress the air in the lungs, that the diaphragm may be pressed down. Hence the distention of the tendons or fibres of these muscles is associated with the distention of the tendons or fibres of the diaphragm; and when the latter are pained by the enlargement or heat of the inflamed liver, the former sympathize with them. Sometimes but one shoulder is affected, sometimes both; it is probable that many other pains, which are termed rheumatic, have a similar origin, viz. from sensitive associations.

As no inflammation is produced in consequence of this pain of the shoulder, it seems to be owing to inaction of the membranous part from defect of the sensorial power of association, of which the primary link is the inflamed membrane of the liver; which now expends so much of the sensorial power in general by its increased action, that the membranes about the shoulder, which are links of association with it, become deprived of their usual share, and consequently fall into torpor.

10. _Torpor pedum in eruptione variolarum._ At the commencement of the eruption of the small-pox, when the face and breast of children are very hot, their extremities are frequently cold. This I ascribe to sensitive association between the different parts of the skin; whence when a part acts too violently, the other part is liable to act too weakly; and the skin of the face being affected first in the eruption of the small-pox, the skin of the feet becomes cold in consequence by reverse sympathy.

M. M. Cover the feet with flannel, and expose the face and bosom to cool air, which in a very short time both warms the feet and cools the face; and hence what is erroneously called a rash, but which is probably a too hasty eruption of the small-pox, disappears; and afterwards fewer and more distinct eruptions of the small-pox supervene.

11. _Testium dolor nephriticus._ The pain and retraction of the testicle on the same side, when there is a stone in the ureter, is to be ascribed to sensitive association; whether the connecting cause be a branch of the same nerve, or from membranes, which have been frequently affected at the same time.

12. _Dolor digiti minimi sympatheticus._ When any one accidentally strikes his elbow against any hard body, a tingling pain runs down to the little finger end. This is owing to sensitive association of motions by means of the same branch of a nerve, as in hemicrania from a decaying tooth the pain is owing to the sensitive association of tendons or membranes.

13. _Dolor brachii in hydrope pectoris._ The pain in the left arm which attends some dropsies of the chest, is explained in Sect. XXIX. 5. 2. 10. which resembles the pain of the little finger from a percussion of the nerve at the elbow in the preceding article. A numbness of this kind is produced over the whole leg, when the crural nerve is much compressed by sitting for a time with one leg crossed over the other.

Mr. ----, about sixty, had for two years been affected with difficulty of respiration on any exertion, with pain about the sternum, and of his left arm; which last was more considerable than is usual in dropsy of the chest; some months ago the pain of his arm, after walking a mile or two, became excessive, with coldness and numbness; and on the next day the back of the hand, and a part of the arm swelled, and became inflamed, which relieved the pain; and was taken for the gout, and continued several days. He after some months became dropsical both in respect to his chest and limbs, and was six or seven times perfectly relieved by one dram of saturated tincture of digitalis, taken two or three times a day for a few days in a glass of peppermint water. He afterwards breathed oxygen gas undiluted, in the quantity of six or eight gallons a day for three or four weeks without any effect, and sunk at length from general debility.

In this instructive case I imagine the pressure or stimulus of one part of the nerve within the chest caused the other part, which serves the arm, to become torpid, and consequently cold by sympathy; and that the inflammation was the consequence of the previous torpor and coldness of the arm, in the same manner as the swelling and inflammation of the cheek in tooth-ach, in the first species of this genus; and that many rheumatic inflammations are thus produced by sympathy with some distant part.

14. _Diarrhoea a dentitione._ The diarrhoea, which frequently attends dentition, is the consequence of indigestion; the aliment acquires chemical changes, and by its acidity acts as a cathartic; and changes the yellow bile into green, which is evacuated along with indigested parts of the coagulum of milk. The indigestion is owing to the torpor of the stomach and intestines caused by their association with the membranes of the gums, which are now stimulated into great exertion with pain; both which contribute to expend the general quantity of sensorial power, which belongs to this membranous association; and thus the stomach and intestines act with less than their natural energy. This is generally esteemed a favourable symptom in difficult dentition, as the pain of the alveolar membranes exhausts the sensorial power without producing convulsions for its relief. See Class I. 1. 4. 5. And the diarrhoea ceases, as the tooth advances.

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ORDO II.

_Decreased Associate Motions._

GENUS III.

_Catenated with Voluntary Motions._

SPECIES.

1. _Titubatio linguae._ Impediment of speech is owing to the associations of the motions of the organs of speech being interrupted or dissevered by ill-employed sensation or sensitive motions, as by awe, bashfulness, ambition of shining, or fear of not succeeding, and the person uses voluntary efforts in vain to regain the broken associations, as explained in Sect. XVII. 1. 10. and XVII. 2. 10.

The broken association is generally between the first consonant and the succeeding vowel; as in endeavouring to pronounce the word parable, the p is voluntarily repeated again and again, but the remainder of the word does not follow, because the association between it and the next vowel is dissevered.

M. M. The art of curing this defect is to cause the stammerer to repeat the word, which he finds difficult to speak, eight or ten times without the initial letter, in a strong voice, or with an aspirate before it, as arable, or harable; and at length to speak it very softly with the initial letter p, parable. This should be practised for weeks or months upon every word, which the stammerer hesitates in pronouncing. To this should be added much commerce with mankind, in order to acquire a carelessness about the opinions of others.

2. _Chorea St. Viti._ In the St. Vitus's dance the patient can at any time lie still in bed, which shews the motions not to be convulsive; and he can at different times voluntarily exert every muscle of his body; which evinces, that they are not paralytic. In this disease the principal muscle in any designed motion obeys the will; but those muscles, whose motions were associated with the principal one, do not act; as their association is dissevered, and thus the arm or leg is drawn outward, or inward, or backward, instead of upward or forward, with various gesticulations exactly resembling the impediment of speech.

This disease is frequently left after the itch has been too hastily cured. See Convulsio dolorifica, Class III. 1. 1. 6. A girl about eighteen, after wearing a mercurial girdle to cure the itch, acquired the Chorea St. Viti in so universal a manner, that her speech became affected as well as her limbs; and there was evidently a disunion of the common trains of ideas; as the itch was still among the younger children of the family, she was advised to take her sister as a bedfellow, and thus received the itch again; and the dance of St. Vitus gradually ceased. See Class II. 1. 5. 6.

M. M. Give the patient the itch again. Calomel a grain every night, or sublimate a quarter of a grain twice a day for a fortnight. Steel. Bark. Warm-bath. Cold-bath. Opium. Venesection once at the beginning of the disease. Electricity. Perpetual slow and repeated efforts to move each limb in the designed direction, as in the titubatio linguae above described.

3. _Risus._ Laughter is a perpetual interruption of voluntary exertion by the interposition of pleasurable sensation; which not being checked by any important consequences rises into pain, and requires to be relieved or moderated by the frequent repetition of voluntary exertion. See Sect. XXXIV. 1. 4. and Class III. 1. 1. 4. and IV. 1. 3. 3.

4. _Tremor ex ira._ The trembling of the limbs from anger. The interruption of the voluntary associations of motions by anger, originates from too great a part of the sensorial power being exerted on the organs of sense; whence the muscles, which ought to support the body upright, are deprived of their due quantity, and tremble from debility. See Class III. 2. 1. 1.

5. _Rubor ex ira._ Redness from anger. Anger is an excess of aversion, that is of voluntarity not yet employed. It is excited by the pain of offended pride; when it is employed it becomes outrage, cruelty, insanity. The cutaneous capillaries, especially those of the face, are more mobile, that is, more easily excited into increased action, or more easily become torpid, from less variation of sensorial power, than any other parts of the system, which is owing to their being perpetually subject to the vicissitudes of heat and cold, and of extension and corrugation. Hence, when an excess of voluntarity exists without being immediately expended in the actions of the large muscles, the capillary arteries and glands acquire more energetic action, and a flushed skin is produced, with increased secretion of perspirable matter, and consequent heat, owing to the pause or interruption of voluntary action; and thus the actions of these cutaneous vessels become associated between the irascent ideas and irascent muscular actions, which are thus for a time interrupted.

6. _Rubor criminati._ The blushing of accused people, whether guilty or not, appears to be owing to circumstances similar to that of anger; for in these situations there is always a sudden voluntarity, or wish, of clearing their characters arises in the mind of the accused person; which, before an opportunity is given for it to be expended on the large muscles, influences the capillary arteries and glands, as in the preceding article. Whence the increased actions of the capillaries, and the consequent redness and heat, become exerted between the voluntary ideas of self-defence, and the muscular actions necessary for that purpose; which last are thus for a time interrupted or delayed.

Even in the blush of modesty or bashfulness there is a self-condemnation for some supposed defect or indecorum, and a sudden voluntarity, or wish, of self-defence; which not being expended in actions of the larger muscles excites the capillaries into action; which in these subjects are more mobile than in others.

The blush of young girls on coming into an assembly room, where they expect their dress, and steps, and manner to be examined, as in dancing a minuet, may have another origin; and may be considered as a hot fit of returning confidence, after a previous cold fit of fear.

7. _Tarditas paralytica._ By a stroke of the palsy or apoplexy it frequently happens, that those ideas, which were associated in trains, whose first link was a voluntary idea, have their connection dissevered; and the patient is under the necessity by repeated efforts slowly to renew their associations. In this situation those words, which have the fewest other words associated with them, as the proper names of persons or places, are the most difficult to recollect. And in those efforts of recollection the word opposite to the word required is often produced, as hot for cold, winter for summer, which is owing to our associating our ideas of things by their opposites as well as by their similitudes, and in some instances perhaps more frequently, or more forcibly. Other paralytic patients are liable to give wrong names to external objects, as using the word pigs for sheep, or cows for horses; in this case the association between the idea of the animal and the name of it is dissevered; but the idea of the class or genus of the thing remains; and he takes a name from the first of the species, which presents itself, and sometimes can correct himself, till he finds the true one.

8. _Tarditas senilis._ Slowness of age. The difficulty of associating ideas increases with our age; as may be observed from old people forgetting the business of the last hour, unless they impress it strongly, or by frequent repetition, though they can well recollect the transactions of their youth. I saw an elderly man, who could reason with great clearness and precision and in accurate language on subjects, which he had been accustomed to think upon; and yet did not know, that he had rang the bell by his fire-side in one minute afterwards; nor could then recollect the object he had wanted, when his servant came.

Similar to this is the difficulty which old people experience in learning new bodily movements, that is, in associating new muscular actions, as in learning a new trade or manufactury. The trains of movements, which obey volition, are the last which we acquire; and the first, which are disassociated.

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ORDO II.

_Decreased Associate Motions._

GENUS IV.

_Catenated with External Influences._

As the diseases, which obey solar or lunar periods, commence with torpor or inactivity, such as the cold paroxysms of fevers, the torpor and consequent pain of hemicrania, and the pains which precede the fits of epilepsy and convulsion, it would seem, that these diseases are more generally owing to the diminution than to the excess of solar or lunar gravitation; as the diseases, which originate from the influence of the matter of heat, are much more generally in this country produced by the defect than by the excess of that fluid.

The periodic returns of so many diseases coincide with the diurnal, monthly, and annual rounds of time; that any one, who would deny the influence of the sun and moon on the periods of quotidian, tertian, and quartan fevers, must deny their effect on the tides, and on the seasons. It has generally been believed, that solar and lunar effect was exerted on the blood; which was thus rendered more or less stimulant to the system, as described in Sect. XXXII. 6. But as the fluid matter of gravitation permeates and covers all things, like the fluid matter of heat; I am induced to believe, that gravitation acts in its medium state rather as a causa sine qua non of animal motion, like heat; which may disorder the system chemically or mechanically, when it is diminished; but may nevertheless stimulate it, when increased, into animal exertion.

Without heat and motion, which some philosophers still believe to be the same thing, as they so perpetually appear together, the particles of matter would attract and move towards each other, and the whole universe freeze or coalesce into one solid mass. These therefore counteract the gravitation of bodies to one center; and not only prevent the planets from falling into the sun, but become either the efficient causes of vegetable and animal life, or the causes without which life cannot exist; as by their means the component particles of matter are enabled to slide over each other with all the various degrees of fluidity and repulsion.

As the attraction of the moon countervails or diminishes the terrene gravitation of bodies on the surface of the earth; a tide rises on that side of the earth, which is turned towards the moon; and follows it, as the earth revolves. Another tide is raised at the same time on the opposite side of the revolving earth; which is owing to the greater centrifugal motion of that side of the earth, which counteracts the gravitation of bodies near its surface. For the earth and moon may be considered as two cannon balls of different sizes held together by a chain, and revolving once a month round a common center of gravity between them, near the earth's surface; at the same time that they perform their annual orbits round the sun. Whence the centrifugal force of that side of the earth, which is farthest from this center of motion, round which the earth and moon monthly revolve, is considerably greater, than the centrifugal force of that side of the earth, which is nearest it; to which should be added, that this centrifugal force not only contributes to diminish the terrene gravitation of bodies on the earth's surface on that side furthest from this center of motion, but also to increase it on that side, which is nearest it.

Another circumstance, which tends to raise the tide on the part of the earth's surface, which is most distant from the moon, is, that the attraction of the moon is less on that part of the ocean, than it is on the other parts of the earth. Thus the moon may be supposed to attract the water on the side of the earth nearest it with a power equal to three; and to attract the central parts of the earth with a power equal to two; and the water on the part of the earth most distant from the moon with a power only equal to one. Hence on the side of the earth most distant from the moon, the moon's attraction is less, and the centrifugal force round their common center of motion is greater; both which contribute to raise the tides on that side of the earth. On the side of the earth nearest the moon, the moon's attraction is so much greater as to raise the tides; though the centrifugal force of the surface of the earth round their common center of motion in some degree opposes this effect.

On these accounts, when the moon is in the zenith or nadir, the gravitation of bodies on the earth's surface will be greatest at the two opposite quadratures; that is, the greatest gravitation of bodies on the earth's surface towards her center during the lunar day is about six hours and an half after the southing, or after the northing of the moon.

Circumstances similar to these, but in a less degree, must occur in respect to the solar influence on terrestrial bodies; that is, there must be a diminution of the gravity of bodies, near the earth's surface at noon, when the sun is over them; and also at midnight from the greater centrifugal force of that side of the earth, which is most distant from the center, round which the earth moves in her annual orbit, than on the side nearest that center. Whence it likewise follows, that the gravitation of bodies towards the earth is greatest about six hours after noon, and after midnight.

Now when the sun and moon have their united gravitation on the same side of the earth, as at the new moon; or when the solar attraction coincides with the greater centrifugal motion of that side of the earth, which is furthest distant from the moon, as at the full moon; and when this happens about noon or midnight, the gravitation of terrene bodies towards the earth will be greater about six hours after noon, and after midnight, than at any other part of the lunar period; because the attraction of both these luminaries is then exerted on those sides of the earth over which they hang, which at other times of the month are more or less exerted on other parts of it.

Lastly, as heat and motion counteract the gravitation of the particles of bodies to each other, and hence become either the efficient causes of vegetable and animal life, or the causes without which life cannot exist, it seems to follow, that when our gravitation towards the earth's center is greatest, the powers of life should be the least; and hence that those diseases, which begin with torpor, should occur about six hours after the solar or lunar noon, or about six hours after the solar or lunar midnight; and this most frequently about six hours after or before the new or full moon; and especially when these happen at noon or at midnight; or lastly, according to the combination of these powers in diminishing or increasing the earth's attraction to bodies on its surface.

The returns or exacerbations of many fevers, both irritative and inflammatory, about six in the evening, and of the periodic cough described in Sect. XXXVI. 3. 9. countenance this theory. Tables might be made out to shew the combined powers of the sun and moon in diminishing the gravitation of bodies on the earth's surface, at every part of their diurnal, monthly, and annual periods; and which might facilitate the elucidation of this subject. But I am well aware of the difficulty of its application to diseases, and hope these conjectures may induce others to publish more numerous observations, and more conclusive reasonings.

SPECIES.

1. _Somni periodus._ The periods of sleeping and of waking are shortened or prolonged by so many other circumstances in animal life, besides the minute difference between diurnal and nocturnal solar gravitation, that it can scarcely be ascribed to this influence. At the same time it is curious to observe, that vegetables in respect to their times of sleeping more regularly observe the hour of the day, than the presence or absence of light, or of heat, as may be seen by consulting the calendar of Flora. Botanic Garden, Part II. Canto 2. l. 165. note.

Some diseases, which at first sight might be supposed to be influenced by solar periods, seem to be induced by the increasing sensibility of the system to pain during our sleeping hours; as explained in Sect. XVIII. 15. Of these are the fits of asthma, of some epilepsies, and of some haemoptoes; all which disturb the patient after some hours sleep, and are therefore to be ascribed to the increase of our dormant sensibility. There may likewise be some doubt, whether the commencement of the pain of gout in the foot, as it generally makes its attack after sleep, should be ascribed to the increased sensibility in sleep, or to solar influence?

M. M. When asthmatic or epileptic fits or haemoptoe occur after a certain number of hours of sleep, the patient should be forcibly awakened before the expected time by an alarm clock, and drink a cup of chocolate or lemonade.--Or a grain of opium should be given at going to bed.--In one case to prevent the too great increase of sensibility by shortening the time of sleep; and in the other by increasing the irritative motions, and expending by that means a part of the sensorial power.

2. _Studii inanis periodus._ Class III. 1. 2. 2. The cataleptic spasm which preceded the reverie and somnambulation in the patient, whose case is related in Sect. XIX. 2. occurred at exactly the same hour, which was about eleven in the morning for many weeks; till those periods were disturbed by large doses of opium; and must therefore be referred to some effect of solar gravitation. In the case of Master A. Sect. XXXIV. 3. as the reverie began early in the morning during sleep, there may be a doubt, whether this commenced with torpor of some organ catenated with solar gravitation; or was caused by the existence of a previous torpid part, which only became so painful as to excite the exertions of reverie by the perpetual increase of sensibility during the continuance of sleep, as in some fits of epilepsy, asthma, and haemoptoe mentioned in the preceding article.

3. _Hemicraniae periodus._ Periods of hemicrania. Class IV. 2. 2. 8. The torpor and consequent pain of some membranes on one side of the head, as over one eye, is frequently occasioned by a decaying tooth, and is liable to return every day, or on alternate days at solar or lunar periods. In this case large quantities of the bark will frequently cure the disease, and especially if preceded by venesection and a brisk cathartic; but if the offending tooth can be detected, the most certain cure is its extraction. These partial head-achs are also liable to return at the greater lunar periods, as about once a month. Five drops from a two-ounce phial of a saturated solution of arsenic twice a day for a week or two have been said to prevent the returns of this disease. See a Treatise on Arsenic by Dr. Fowler, of York. Strong errhines have also been recommended.

4. _Epilepsiae dolorificae periodus._ Class III. 1. 1. 8. The pain which induces after about an hour the violent convulsions or insanity, which constitute the painful epilepsy, generally observe solar diurnal periods for four or five weeks, and are probably governed by solar and lunar times in respect to their greater periods; for I have observed that the daily paroxysms, unless disturbed by large doses of opium, recur at very nearly the same hour, and after a few weeks the patients have recovered to relapse again at the interval of a few months. But more observations are wanted upon this subject, which might be of great advantage in preventing the attacks of this disease; as much less opium given an hour before its expected daily return will prevent the paroxysm, than is necessary to cure it, after it has commenced.

5. _Convulsionis dolorificae periodus._ Class III. 1. 1. 6. The pains, which produce these convulsions, are generally left after rheumatism, and come on when the patients are become warm in bed, or have been for a short time asleep, and are therefore perhaps rather to be ascribed to the increasing sensibility of the system during sleep, than to solar diurnal periods, as in Species first and second of this Genus.

6. _Tussis periodicae periodus._ Periodic cough, Class IV. 2. 1. 9. returns at exact solar periods; that described in Sect. XXXVI. 3. 9. recurred about seven in the afternoon for several weeks, till its periods were disturbed by opium, and then it recurred at eleven at night for about a week, and was then totally destroyed by opium given in very large quantities, after having been previously for a few days omitted.

7. _Catameniae periodus._ Periods of menstruation. The correspondence of the periods of the catamenia with those of the moon was treated of in Sect. XXXII. 6. and can admit of no more doubt, than that the returns of the tides are governed by lunar influence. But the manner in which this is produced, is less evident; it has commonly been ascribed to some effect of the lunar gravitation on the circulating blood, as mentioned in Sect. XXXII. 6. But it is more analogous to other animal phenomena to suppose that the lunar gravitation immediately affects the solids by its influx or stimulus. Which we believe of the fluid element of heat, in which we are equally immersed; and of the electric fluid, which also surrounds and pervades us. See Sect. XXXVI. 2. 3.

If the torpor of the uterine veins, which induces the monthly periods of the catamenia, be governed by the increase of terrene gravitation; that is, by the deficiency of the counter-influence of solar and lunar gravitation; why does not it occur most frequently when the terrene gravitation is the greatest, as about six hours after the new moon, and next to that at about six hours after the full moon? This question has its difficulty; first, if the terrene gravitation be greatest about six hours after the new moon, it must become less and less about the same time every lunar day, till the end of the first quarter, when it will be the least; it must then increase daily till the full. After the full the terrene gravitation must again decrease till the end of the third quarter, when it will again be the least, and must increase again till the new moon; that is, the solar and lunar counter-gravitation is greatest, when those luminaries are vertical, at the new moon, and full moon, and least about six hours afterwards. If it was known, whether more menstruations occur about six hours after the moon is in the zenith or nadir; and in the second and fourth quarters of the moon, than in the first and third; some light would be thrown on this subject; which must in that respect wait for future observations.

Secondly, if the lunar influence produces a very small degree of quiescence, suppose of the uterine veins, at first; and if that recurs at certain periods, as of lunar days, or about 25 hours, even with less power to produce quiescence than at first; yet the quiescence will daily increase by the acquired habit acting at the same time, as explained in Sect. XII. 3. 3. till at length so great a degree of quiescence will be induced as to cause the inaction of the veins of the uterus, and consequent venous haemorrhage. See Sect. XXXII. 6. Class I. 2. 1. 11. IV. 1. 4. 4. See the introduction to this Genus.

8. _Haemorrhoidis periodus._ The periods of the piles depend on the torpor of the veins of the rectum, and are believed to recur nearly at monthly intervals. See Sect. XXVII. 2. and Class I. 2. 1. 6.

9. _Podagrae periodus._ The periods of gout in some patients recur at annual intervals, as in the case related above in Class IV. 1. 2. 15. in which the gouty paroxysm returned for three successive years on nearly the same day of the month. The commencement of the pain of each paroxysm is generally a few hours after midnight, and may thence either be induced by diurnal solar periods, or by the increasing sensibility during sleep, as mentioned in the first species of this genus.

10. _Erysipelatis periodus._ Some kinds of erysipelas which probably originate from the association of the cutaneous vessels with a diseased liver, occur at monthly periods, like the haemorrhois or piles; and others at annual periods like the gout; as a torpor of some part I suppose always precedes the erysipelatous inflammation, the periods should accord with the increasing influence of terrene gravitation, as described in the introduction to this Genus, and in Species the seventh of it. Other periods of diseases referable to solar and lunar influence are mentioned in Sect XXXVI. and many others will probably be discovered by future observation.

11. _Febrium periodus._ Periods of fevers. The commencement of the cold fits of intermittent fevers, and the daily exacerbations of other fevers, so regularly recur at diurnal solar or lunar periods, that it is impossible to deny their connection with gravitation; as explained in Sect. XXXVI. 3. Not only these exacerbations of fever, and their remissions, obey the diurnal solar and lunar periods; but the preparatory circumstances, which introduce fevers, or which determine their crisises, appear to be governed by the parts of monthly lunar periods, and of solar annual ones. Thus the variolous fever in the natural small-pox commences on the 14th day, and in the inoculated small-pox on the seventh day. The fever and eruption in the distinct kind take up another quarter of a lunation, and the maturation another quarter.

The fever, which is termed canine madness, or hydrophobia, is believed to commence near the new or full moon; and, if the cause is not then great enough to bring on the disease, it seems to acquire some strength, or to lie dormant, till another, or perhaps more powerful lunation calls it into action. In the spring, about three or four years ago, a mad dog very much worried one swine confined in a sty, and bit another in the same sty in a less degree; the former became mad, refused his meat, was much convulsed, and died in about four days; this disease commenced about a month after the bite. The other swine began to be ill about a month after the first, and died in the same manner.

* * * * *

ORDO III.

_Retrograde Associate Motions._

GENUS I.

_Catenated with Irritative Motions._

Those retrograde associate motions, the first links of which are catenated with irritative motions, belong to this genus. All the retrograde motions are consequent to debility, or inactivity, of the organ; and therefore properly belong to the genera of decreased actions both in this and the former classes.

SPECIES.

1. _Diabaetes irritata._ When the absorbents of the intestines are stimulated too strongly by spirit of wine, as in the beginning of drunkenness, the urinary absorbents invert their motions. The same happens from worms in the intestines. In other kinds of diabetes may not the remote cause be the too strong action of the cutaneous absorbents, or of the pulmonary ones? May not in such cases oil externally or internally be of service? or warm bathing for an hour at a time? In hysteric inversions of motion is some other part too much stimulated? or pained from the want of stimulus?

2. _Sudor frigidus in asthmate._ The cause of the paroxysms of humoral asthma is not well understood; I suppose it to be owing to a torpidity or inaction of the absorbents belonging to the pulmonary vessels, as happens probably to other viscera at the commencement of intermittent fevers, and to a consequent accumulation of fluids in them; which at length producing great irritation or uneasy sensation causes the violent efforts to produce the absorption of it. The motions of the cutaneous absorbent vessels by their association with those of the pulmonary ones become retrograde, and effuse upon the skin a fluid, which is said to be viscid, and which adheres in drops.