medicines must be governed by the habit.

Another effect of

custom on the moving powers, resembles the operation of ideas. If two muscles, or even the different parts of one muscle, have been used to act together, exciting the action of one will produce that of the other. If, however, this kind of association be prevented by a strong effort of volition, and strengthened by a different habit, they are induced to act separately, with the greatest precision. This power is attained by musicians.

A singular effect has been attributed to custom, which may perhaps be more satisfactorily explained on other principles. As we usually feel only in the sentient extremities of nerves, it has been supposed that from custom we refer every affection of the nerve in its course to the extremities; and thus to the man who has lost a leg, even many years, a pain in the stump appears to be seated in the toe; and I have known a gentleman who had lost both legs above the knee, affected with gouty inflammation at the ends of the stumps, which appeared to him to be in the feet, and exactly similar to the paroxysms he had experienced before he lost his legs; and to quiet his mind, the clothes of the bed below his stumps were suspended by a strong cord, in the usual manner. This sensation, however, does not depend on custom; for a disease at the origin, or in the course of a nerve, is at once referred to its extremity, though the sensation was never before experienced. In cases of epilepsy dependent on diseased structure in the brain, it is common for the convulsive disturbance of the system to commence in a foot, with the sensation of something (termed the electric aura) ascending to the brains; and a pain in a foot, with a sense of numbness, is a common precursor of palsy of the same side from mischief in the brain.

Custom regulates the degree of tension necessary for sensation. The soldier or sailor, accustomed to the sound of a cannon, can hear a person speak in a common tone during the loudest roar; and a person, whose hearing is bad, will hear well while a drum is beating, or when travelling in a carriage. A person who sleeps near a mill during the time that it is at work, producing a noise that may be heard at a considerable distance, is sensible of the slightest noise occasioned by any other means, or which is in any way different. A person who has been accustomed for some time to be awoke at a certain hour, will continue to awake at that time; and this does not depend on the quantity of sleep: for whether he adjourns to his bed at an early or a late hour, he will awake at the same time. Custom equally regulates the degree of tension necessary to the muscular action, as the musician experiences by the degree of pressure suitable to the production of a given sound from a piano-forte or an organ: and it associates motions with

sensations not otherwise connected. For instance, there is no necessary connection between a particular figure of a countrydance and a given tune, since many different figures may be given to it; but when the music begins, the accustomed movements, without any sensible exertion of volition, follow. Custom also associates different motions, though not necessarily or naturally connected; and from the habit established, they cannot be performed separately. It determines the degree of force and velocity with which motions can be performed, and which, after the habit is established, cannot be violated. A blacksmith, unless peculiarly favoured, cannot become a watchmaker. Custom also establishes the order in which certain sensations and motions return. An infant may soon be brought to feed at regular hours; and those who retire to the garden immediately after breakfast, will feel little or no inconvenience should their breakfast be delayed an hour or two. The same call will also regularly return with almost every change of the constitution, in other respects. These motions, established and associated by custom, are sometimes broken with difficulty, and occasionally with injury to the constitution. If the supplies of food, or the discharge of the excretions, be not obeyed, the call will often not again recur till the next period, and the feelings in the interval will be uncomfortable. Indeed, the deprivation of the most trifling accustomed gratification frequently injures the health, while the most discordant noise, the most offensive smell, or the most disgusting object, lose every unpleasing effect from habit. It was this circumstance that occasioned the ancient sage to remark, "Choose the best occupation, for custom will make it the pleasantest." On the other hand, these accustomed associated motions render many diseases very obstinate, as ague, epilepsy, &c., when the periodical return is established. In such circumstances, we cannot often succeed without stopping, as it were, all motion, to commence a new and more salutary series. Mr. Abernethy, in his Lectures on Surgery, mentions a case of epilepsy in an opulent gentleman, which uniformly occurred on entering his carriage. Mr. Abernethy, supposing that interruption of the ideas, which were concatenated with his effort to enter the carriage, would prevent the paroxysm, directed a person to surprise him by some remark, or action, at the time he was about to put his foot on the step. This interruption had the desired effect, and the gentleman afterwards entered the carriage without any dread of experiencing a return of his malady. I knew an epileptic patient in Chepstow (a ship carpenter), who, when at work in the most perilous situations, always felt perfectly secure from a recurrence of a fit; but on being in a situation which did not engage the mind, generally experienced a fit.

I may here notice the impressions made on the mind before reason has scarcely dawned on it, and which frequently continue after reason has arrived to maturity, and the mind has been enlightened by education and observation. The mind of a Jew, even of a liberal education, is so prejudiced against the flesh of the swine (which, to a Christian, is often a great luxury), that nothing will induce him to eat it. An Englishman has, from early impressions, as great an aversion to the flesh of the horse, although a cleanfeeding animal, as the Jew has to that of a swine. I have known a British officer make a very hearty dinner of a steak of a young horse that had been killed in battle, which was introduced as a beef-steak; who, on being told two hours after the meal, that it was the flesh of horse, vomited violently, and for some years experienced nausea on seeing a beef-steak. A Hindoo, again, has an unconquerable objection to the flesh of the cow and of the pea-fowl, which, with Europeans, are great favourites. A Frenchman considers the hind quarter of a frog a great dainty, to which, from prejudice of education, an Englishman has an invincible dislike. Religious prejudices and opinions, impressed on the mind before reason has taken full possession of her throne, generally exist for life, and have an influence on disease, and on the operation of medicines.

QUESTIONS TO PATIENTS, &c. - Having noticed the passions of the mind, the various temperaments, customs, and habits which, more or less, modify all diseases, I shall introduce a series of questions to be put to patients, the answers to which are likely to afford the necessary information relative to temperament, customs, and habits, and the real nature of the malady, with such practical remarks which I conceive likely to afford a guide in its medical and dietetic treatment.

Q. What is your age? Did you, prior to your present illness, enjoy good health? Have you impaired your constitution by any irregularity?

In acute diseases as inflammation of the lungs, pleurisy, inflammatory fever, &c. - the propriety of blood-letting, its extent or repetition, as well as the use of aperient and diaphoretic medicines, must in a great measure depend on the age, natural constitution, and habits of the patient.

Q. How long have you been ill? In what manner were you attacked? Is your complaint stationary, or is it declining or advancing?

In fevers of all kinds the practitioner should be acquainted with the stage of the disease, and whether the complaint be advancing or otherwise.

Diseases are divided into two kinds, named acute and chronic. The period of an acute disease has been limited to within forty

days; if it extend beyond that time, it is regarded as chronic. The general symptoms of acute disease are a quick pulse, heat of skin, thirst, furred tongue, pain in the loins or limbs, an incapacity of attention or exertion of mind. These distinctions are not sanctioned by practice; for some diseases continue in an active state much longer, and it is common for some chronic diseases to exhibit symptoms of an acute nature.

Q. Have you been affected with slight shiverings (rigours)? Are you feverish or thirsty? Have you any pain in the head or chest?

In rheumatism or cough, it is of great consequence to be acquainted with the state of the system; for in case of fever, or a feverish disposition (indicated by rigours, increased heat, pains in the head or chest, and quickness of pulse), the guaiac gum, and other stimulating medicines, would be injurious in the former disease, and the paregoric elixir in the latter.

Rigours attendant on cough, indicate some serious mischief to be going on in the lungs. When rigours attend acute pains in the bowels, the disease may be suspected to be of an inflammatory nature, and not common colic. In cases of deep-seated pain, particularly in the loins, rigours denote the pain to arise from inflammation; and if the rigours continue to recur for a week or ten days after the first attack of pain, the disease is not to be considered rheumatic, but inflammatory, and that suppuration will probably take place if very active means be not employed to prevent it.

Q. Are you restless? Have you been accustomed to take laudanum? And in what quantity?

In irritative diseases the quantity or propriety of administering an anodyne, is to be determined by the habit of the patient; i. e. whether it be leucophlegmatic or sanguineous. (See SEDATIVES, p. 41.)

Q. Are you affected with heat or shiverings?

In cases of rheumatism, cough, pains in the head or bowels, these questions, answered in the affirmative, prove that the discase is of an inflammatory nature, and that whatever tends to stimulate the system should be avoided, both in medicine and diet.

Q. Have you pain in any part of the body?

In all fevers it is of great importance to attend to local pains; for inflammatory fever often terminates fatally, by producing inflammation either of the brain, lungs, or bowels, which, by early attention, may be in general obviated by the application of leeches, blisters, &c. If local inflammation should appear, during fever, in any part of the body not of vital importance, and in which suppuration is not likely to be attended with any se

rious consequence, it should be encouraged by warm poultices, rather than dispersed by any cold application. When dispersion is deemed necessary, it should be attempted by extracting blood from the part, or by scarification: and, if the joints be attacked, also by blistering.

Q. Have you been affected with shivering fits? Are they succeeded by heat and perspiration?

All inflammatory diseases are generally ushered in by the slight shiverings termed rigours, which are succeeded by an increased heat of the body, and sometimes by perspiration. These symptoms occurring during inflammatory fever, or local inflammation, often so far deceive an inexperienced practioner, as to induce him to consider the disease a species of ague, and thus lead to the improper exhibition of the Peruvian bark. In doubtful cases, it will be necessary to enquire how often the shiverings occur; and if only once a day, at what period, how long they last, and also the degree of heat and perspiration, and particularly if there be an evident intermission after the termination of the perspiration till the re-occurrence of the shivering; and also if any local mischief be going on in the system, of which the shivering may be symptomatic. The Peruvian bark, or stimulants of any kind, should not be administered in cases of shivering, until it be clear ague, as a considerable aggravation of the inflammatory affection might be thereby produced. An emetic and the saline mixture are proper in ambiguous cases, till its real nature be ascertained, which a few days will decide.

Q. Is your tongue furred, and of what colour? Have you a disagreeable taste in the mouth, nausea in the stomach, or is your appetite bad?

The answers to these questions will determine the propriety of exhibiting an emetic, particularly in cases of indigestion, and the commencement of fevers. The colour of the tongue, in ambiguous fevers, with a declining state of the strength of the patient, will often decide its nature. In almost every disease, particularly in fevers, it is proper to examine the state of the tongue, for by it the condition of the stomach may often be ascertained; and likewise the occasion the patient has for drink, when, on account of delirium or stupor, he neither feels his thirst, nor is capable of calling for drink:- from an inspection of the tongue, a judgment may be formed concerning the nature, increase, and remission of fever. When the tongue is dry, and covered with a dark scurf, attended with wandering of the mind and dejected countenance, there will be reason to suspect the fever to be Typhus, or strongly disposed to it. When the tongue becomes moist, and the edges clean and red, the disease may be considered on the decline, or near its termination.