The following Letter will explain it self, and needs no Apology.
'I am one of that sickly Tribe who are commonly known by the Name of Valetudinarians, and do confess to you, that I first contracted this ill Habit of Body, or rather of Mind, by the Study of Physick. I no sooner began to peruse Books of this Nature, but I found my Pulse was irregular, and scarce ever read the Account of any Disease that I did not fancy my self afflicted with. Dr. Sydenham's learned Treatise of Fevers  threw me into a lingring Hectick, which hung upon me all the while I was reading that excellent Piece. I then applied my self to the Study of several Authors, who have written upon Phthisical Distempers, and by that means fell into a Consumption, till at length, growing very fat, I was in a manner shamed out of that Imagination. Not long after this I found in my self all the Symptoms of the Gout, except Pain, but was cured of it by a Treatise upon the Gravel, written by a very Ingenious Author, who (as it is usual for Physicians to convert one Distemper into another) eased me of the Gout by giving me the Stone. I at length studied my self into a Complication of Distempers; but accidentally taking into my Hand that Ingenious Discourse written by Sanctorius,  I was resolved to direct my self by a Scheme of Rules, which I had collected from his Observations. The Learned World are very well acquainted with that Gentleman's Invention; who, for the better carrying on of his Experiments, contrived a certain Mathematical Chair, which was so Artifically hung upon Springs, that it would weigh any thing as well as a Pair of Scales. By this means he discovered how many Ounces of his Food pass'd by Perspiration, what quantity of it was turned into Nourishment, and how much went away by the other Channels and Distributions of Nature.
Having provided myself with this Chair, I used to Study, Eat, Drink, and Sleep in it; insomuch that I may be said, for these three last Years, to have lived in a Pair of Scales. I compute my self, when I am in full Health, to be precisely Two Hundred Weight, falling short of it about a Pound after a Day's Fast, and exceeding it as much after a very full Meal; so that it is my continual Employment, to trim the Ballance between these two Volatile Pounds in my Constitution. In my ordinary Meals I fetch my self up to two Hundred Weight and [a half pound ]; and if after having dined I find my self fall short of it, I drink just so much Small Beer, or eat such a quantity of Bread, as is sufficient to make me weight. In my greatest Excesses I do not transgress more than the other half Pound; which, for my Healths sake, I do the first Monday in every Month. As soon as I find my self duly poised after Dinner, I walk till I have perspired five Ounces and four Scruples; and when I discover, by my Chair, that I am so far reduced, I fall to my Books, and Study away three Ounces more. As for the remaining Parts of the Pound, I keep no account of them. I do not dine and sup by the Clock, but by my Chair, for when that informs me my Pound of Food is exhausted I conclude my self to be hungry, and lay in another with all Diligence. In my Days of Abstinence I lose a Pound and an half, and on solemn Fasts am two Pound lighter than on other Days in the Year.
I allow my self, one Night with another, a Quarter of a Pound of Sleep within a few Grains more or less; and if upon my rising I find that I have not consumed my whole quantity, I take out the rest in my Chair. Upon an exact Calculation of what I expended and received the last Year, which I always register in a Book, I find the Medium to be two hundred weight, so that I cannot discover that I am impaired one Ounce in my Health during a whole Twelvemonth. And yet, Sir, notwithstanding this my great care to ballast my self equally every Day, and to keep my Body in its proper Poise, so it is that I find my self in a sick and languishing Condition. My Complexion is grown very sallow, my Pulse low, and my Body Hydropical. Let me therefore beg you, Sir, to consider me as your Patient, and to give me more certain Rules to walk by than those I have already observed, and you will very much oblige
Your Humble Servant.'
This Letter puts me in mind of an Italian Epitaph written on the Monument of a Valetudinarian; 'Stavo ben, ma per star Meglio, sto qui': Which it is impossible to translate.  The Fear of Death often proves mortal, and sets People on Methods to save their Lives, which infallibly destroy them. This is a Reflection made by some Historians, upon observing that there are many more thousands killed in a Flight than in a Battel, and may be applied to those Multitudes of Imaginary Sick Persons that break their Constitutions by Physick, and throw themselves into the Arms of Death, by endeavouring to escape it. This Method is not only dangerous, but below the Practice of a Reasonable Creature. To consult the Preservation of Life, as the only End of it, To make our Health our Business, To engage in no Action that is not part of a Regimen, or course of Physick, are Purposes so abject, so mean, so unworthy human Nature, that a generous Soul would rather die than submit to them. Besides that a continual Anxiety for Life vitiates all the Relishes of it, and casts a Gloom over the whole Face of Nature; as it is impossible we should take Delight in any thing that we are every Moment afraid of losing.
I do not mean, by what I have here said, that I think any one to blame for taking due Care of their Health. On the contrary, as Cheerfulness of Mind, and Capacity for Business, are in a great measure the Effects of a well-tempered Constitution, a Man cannot be at too much Pains to cultivate and preserve it. But this Care, which we are prompted to, not only by common Sense, but by Duty and Instinct, should never engage us in groundless Fears, melancholly Apprehensions and imaginary Distempers, which are natural to every Man who is more anxious to live than how to live. In short, the Preservation of Life should be only a secondary Concern, and the Direction of it our Principal. If we have this Frame of Mind, we shall take the best Means to preserve Life, without being over-sollicitous about the Event; and shall arrive at that Point of Felicity which Martial has mentioned as the Perfection of Happiness, of neither fearing nor wishing for Death.
In answer to the Gentleman, who tempers his Health by Ounces and by Scruples, and instead of complying with those natural Sollicitations of Hunger and Thirst, Drowsiness or Love of Exercise, governs himself by the Prescriptions of his Chair, I shall tell him a short Fable.
Jupiter, says the Mythologist, to reward the Piety of a certain Country-man, promised to give him whatever he would ask. The Country-man desired that he might have the Management of the Weather in his own Estate: He obtained his Request, and immediately distributed Rain, Snow, and Sunshine, among his several Fields, as he thought the Nature of the Soil required. At the end of the Year, when he expected to see a more than ordinary Crop, his Harvest fell infinitely short of that of his Neighbours: Upon which (says the fable) he desired Jupiter to take the Weather again into his own Hands, or that otherwise he should utterly ruin himself.
[Footnote 1: Dr. Thomas Sydenham died in 1689, aged 65. He was the friend of Boyle and Locke, and has sometimes been called the English Hippocrates; though brethren of an older school endeavoured, but in vain, to banish him as a heretic out of the College of Physicians. His 'Methodus Curandi Febres' was first published in 1666.]
[Footnote 2: Sanctorius, a Professor of Medicine at Padua, who died in 1636, aged 75, was the first to discover the insensible perspiration, and he discriminated the amount of loss by it in experiments upon himself by means of his Statical Chair. His observations were published at Venice in 1614, in his 'Ars de Static Medicind', and led to the increased use of Sudorifics. A translation of Sanctorius by Dr. John Quincy appeared in 1712, the year after the publication of this essay. The 'Art of Static Medicine' was also translated into French by M. Le Breton, in 1722. Dr. John Quincy became well known as the author of a 'Complete Dispensatory' (1719, &c.).]
[Footnote 3: an half]
[Footnote 4: The old English reading is:
'I was well; I would be better; and here I am.']Translation of motto: