I Did not at all wonder at your earnestness (the other day) in reading the first Pages of a little Book, entituled, A Discovery of the admirable En­glish Remedy, &c. upon which [...]ou desired I should communi­cate [Page 2] my Sentiments to you; as also concerntng Febrifuges, a­bout which there is now so much discourse. And this I thought I might better do by Letter, than by a verbal Discourse.

This Book of Monsieur de Ble­gny's (to which we are indebted for the new Discoveries in Phy­sick) was no sooner brought hi­ther, but I had the curiosity to run it over, to see whether the Remedy and the Method of ad­ministring it were the same I had practised with good success in Tertians, double Tertians, Quar­tans, and also in continual and Malignant Fevers, for five or six Months last past. In the last of which Fevers, it is not so in­fallible as in the Intermittents, which it cures in few days. I read, or rather devoured, the [Page 3] Book in a short time, in hopes to find what I sought after: but I found nothing of it but onely the manner of his Discovery, with an engagement to dispense it to such as shall have occasi­on.

I was at first a little offended at his manner of proceeding, and I doubt not but other Readers of that Book have been so too. But after some Reflections made upon it, I found that the Author had done as became a wise and prudent man. For the making this Remedy common, were in effect to render it contemptible, and to expose it to the abuses of Apothecaries, to whose interest the longest Fevers are most a­greeable; or to the calumny of those old Physicians who have long since taken the Oaths of Al­legiance [Page 4] to Hippocrates and Galen; these Gentlemen are unwilling to use any Medicines but those left them by their Ancestors, lest their present Practice should prove a convincing Argument of their past Ignorance. Nay, every little Barber would pre­tend to know as much of it as the most learned of Physicians, who have for several years made it their study: and would have abused a Remedy which ought no more to be trusted in the hands of the unskilful, than Fire-Arms in the hands of a Child.

Methinks it were not just that the pains and study of a Curious and Ingenious man should be exposed as a prey to every ignorant fellow: And that the Honey of an industrious [Page 5] Bee should be a prize for a lazy and idle Drone. The desire and emulation of discovering what is by others kept as a se­cret, is an admirable way to find out many other secrets, though perhaps we find not that we search for. Many Physicians (I suppose) in France have, as well as my self, applied themselves to the study of Experiments about Febrifuges, ever since they have been so much spoken of. In­deed there are Medicines which seem too loathsome to be taken, their Composition being known, but go down without difficulty when they are kept as Se­crets.

The saying of St. Augustine may possibly be objected to me, That being Christians, we ought not to conceal that, which made known, [Page 6] would conduce to the utility and good of Mankind. To which may be added what Dr. Sidenham, a learned English Physician, saith, That whoever hath any Specifick Remedy, or any certain Method of curing intermitting Fevers, merits not the name of a good Citizen, or of a prudent man, if he communi­cate not a thing so necessary for the good of Mankind: For it is not the part of a good Citizen to turn to his own particular profit that which may bring so great an ad­vantage to Humane Society; nor of a prudent man, to deprive him­self of the Divine Benediction, which we may expect, when we ap­ply our selves to procure the pub­lick good, and when we prefer Virtue and Wisdom before Riches and vain Reputation.

To this may be answered, [Page 7] That if one were assured of the benefit the Publick would re­ceive by communicating the Composition of this Remedy, an honest man could not conceal it without a crime.

But on the contrary, if it be more advantageous not to di­vulge it, then 'tis the part of a good Citizen and a prudent man to keep the mystery of it secret, procuring means whereby all such as desire to have it prepared may be furnished with it. I have already given my reasons in a few words; and Dr. Sidenham himself may serve for an instance, that the publishing of a Reme­dy does not gain it a general ac­ceptation. He printed (about four or five years since) his Ob­servations upon Acute Diseases, wherein there are excellent me­thods [Page 8] for the cure of many Di­seases; and of Fevers also, which he cures so perfectly, that at Lon­don he is called the Fever-Doctor; and yet for all this, we do not see that his method is much u­sed.

There have come out Books very learned about the cure of Fevers, and other Subjects, which have been considered rather as subtile Idea's, than as Discourses grounded upon Experience; and yet these Books have been very well received.

But the English Doctor had no sooner signalized himself by the great Cures he did, but every one strove to imitate his method. And some particular persons, who thought they had his Secret, have sold it by the name of the English Doctors Remedy at Paris, [Page 9] and all over France. So much did the very name of Secret pro­mote its reputation. And now, seeing that nothing will take but what has the name of a Secret, it is fit that we speak no more of our Remedy but as of a Secret, to justifie the saying, Populus vult decipi, decipiatur.

I'm so far from being of their opinion who treat the English Doctor as a Mountebank, that I do ingenuously acknowledge that Physick is much indebted unto him; and though he were but an Apothecary in his own Country, yet his Merit should make him be considered as a fa­mous Physician of Fevers (or Ague-Doctor). And those who slight and scorn his Method, without knowing it, deserve much less than he to be called true Physicians.

[Page 10] Not that I approve either of the great mystery which he made of his Remedy, or of his exorbitant Price: for this shew'd too much of Covetousness, and too little Charity. And if this be not the hiding ones Talent, it is at least a too reserved em­ploying it.

I should think, that to keep the Scales even, and to preserve as well the quality of a good Christian as of a good Citizen, these Rules might be prescribed, as well for the satisfaction of those who would have it made publick, as of those who would have it still kept secret.

1. Endeavour, with Monsieur de Blegny, to give the Remedy, or one very like it, to the Poor, gratis.

2. Not to impose upon ones [Page 11] self a necessity of administring every Dose to the Patient; nor to endeavour to hinder such Phy­sicians as are curious in the search of it from finding it, they ha­ving taken the pains to examine it: for after that, being satisfied with the trouble they have been at, they'l hardly go and disco­ver it to those who have not al­so taken pains for the discovery of the same.

3. Not to fear to communi­cate it to those of our Professi­on and our Friends, especially if they live far remote from us, whither it would be difficult to send the Remedy; yet with this Proviso, that they do not make it common.

4. To assure our selves for two or three years of its operation and effects, by reiterated experi­ences, [Page 12] before we communicate it to any: And if after this we give some light of it in Writing, in such manner that the Learned may (near the truth) conje­cture what it is, and form to themselves Idea's of it, which may come very near the truth, without letting the common sort penetrate into it.

5. Not to maintain too eager­ly that it is not such or such a Drug; but let those that will, be­lieve that it is a simple Infusion of Kinkina, or of Centaury, or if they please, of Nut-shells, provided the Patient be quickly, safely, and agreeably cured, as far as is pos­sible for a Physician who has ne're a Loop-hole to see through into the body of his Patient.

Thus I believe that Monsieur de Blegny, whose aim is the pub­lick [Page 13] good, and the good of the Poor, would not be sorry that a­nother should find out his Reme­dy, after examination of the taste, colour, sediment, and its effects; since he himself had the ingenuity to find out that of the English Doctor, who made it so great a mystery.

In the Chapter of the utility of this Discovery, we find a very good description of certain Phy­sicians, who in the cure of Fe­vers use nothing but Bleeding, Cassia, Sena, Clysters, and a great number of hard words; which are to little purpose, unless to deceive the curiosity of the Pa­tient, of the Nurse, or of those people who will needs know e­very thing. 'Tis not good so to tie ones self up to the authority of the Ancients, as not to consi­der [Page 14] what additions to the Art of Physick have been made by the Moderns, as well in the Oeco­nomy of the Body, as in the cau­ses of Diseases and their Reme­dies. For there are a sort of Physicians who derive every thing from Hippocrates: Nay, one of these days, you shall see, now that Febrifuges have gotten a general esteem, they'l be rea­dy to say, the Moderns borrow­ed them out of that Author.

The Chapter about Mounte­banks is very well done; for he plainly sets forth who they are that deserve that name, whether those who with great swelling words of Greek and Latine pro­mise the cure of the Sick, but rarely perform it; or those who not being very well skill'd in those Tongues, yet cure their [Page 15] Patients in few days. But me­thinks he puts too great an e­steem upon some people who have indeed made a great noise in France, as one that was called the Medecin de Boeufs, or Ox-Do­ctor, and one Father Ange, who did no Miracles but such, where­of either hazard, or an imagina­tion prepossessed by their Admi­mirers, were the greatest promo­ters. And then on the other side, for a man that is an Enemy to Satyr, he treats the ordinary Physicians with too little re­spect.

The preference which ought to be given to the English Reme­dy is sufficiently authorized by its success, and from that it does not tire out the Patient. If this of Monsieur de Blegny produce the same effect, one would be glad [Page 16] to save forty Pistols by taking his Remedy; for the English Doctor seldom took under Fif­ty: And people will be very cautious how they trust them­selves with him that was his Foot-man, who pretends he has the secret of the Remedy; how­ever, he not having the least knowledge in Physick, may ea­sily mistake one Disease for ano­ther.

As for the Country-people they will apparently be more reserved in sending for it; for besides that it may corrupt i [...] carrying, they will sooner trus [...] themselves to a skilful Physician than to the hazard of a Medi­cine blindly given, whereof th [...] Composition is not known. Be­sides, there are every where me [...] that are curious, which make n [...] [Page 17] bustle in the world, and yet un­derstand very well how to cure a Fever.

The design of advancing our progress in the matter of Febri­fuges beyond that of the English Doctor, which we believe we have found, obliged Monsieur de Ville and my self to stay a Ger­man Chymical Physician here, in his return from America, where he had practised Physick for a­bout Ten years: But the poor man, after he had told us very strange things of the practice of Physick among the Americans, fell unfortunately down a pair of Stairs, and remained dead up­on the place. He had been a­bout a Month with us, during which time he had begun to dis­course unto us of the manner of curing several very conside­rable [Page 18] Diseases, as of Intermitting Fevers, and particularly of Quar­tans; of the ulcerated Cancer; of the Gout; of the Ulcer of the Lungs; of the Epilepsie, and some others which puzzle the most expert Physicians. He had also prepared (for us) cer­tain Medicines in our presence, which we have found answera­ble to the relation he had gi­ven of them; of the goodness of which every days experience convinces us.

The Digression I am going to make, touching the practice of Physick among the Americans of Virginia, where he had sojourned, will not, I hope, be unpleasant to the Reader, nor quite from our purpose, to shew the little care had here of searching into the nature and virtues of Plants.

[Page 19] He told us that they had ad­mirable Remedies (for all Di­seases) drawn from Simples; and that he had seen very extra­ordinary Cures done there: That they pierce the Skin with points of Cane, which served them in­stead of Lancets; and suck out the Bloud without swallowing it, which is instead of Phlebotomy and Cupping-glasses. That they cure the Dropsie after an extra­ordinary manner, of which man­ner of curing he has been an eye­witness: They take Flint-stones and make them red-hot, and put them into a hole made for that purpose in the Earth, and make the Patient lay his Belly over them, whilst they sprinkle a cer­tain Decoction of three sorts of Herbs; one whereof is a kind of Essula or Spurge: that after [Page 20] the Patient has received the Smoak very hot against his Bel­ly, his Navel opens, and the Physician lets out a certain quan­tity of Water, according to the strength of the Sick; after which, to close up the aperture, he applies a certain Moss to it; and this he repeats as often as he thinks necessary, to draw out all the Water. He related to us the manner how they cured the hardness of the Spleen, with a Pultis made of a Root, which produces the effect of a Vesica­tory in drawing to it abundance of Water. This has some affi­nity to the practice of the An­cients, who were wont to apply actual Cauteries to the region of the Spleen. He was also to have discoursed to us of their ingeni­ous method of curing Venerial [Page 21] Distempers, and the Lethargie, [...]n a Description of Virginia, which at my request he was ma­king. An American named Rao­comoco, one of their Physicians, (for a little money) shew'd him a certain Root, which if chewed in the Mouth, and the hands rubbed therewith, one might handle all sorts of Serpents without danger. He said that none besides himself understood the vertues of that Plant, which he called Kibaschkonko, that is, in their Language, the Death of Ser­pents; or Serpents-bane: Its ver­tues are much like those of the Plant called Dictamnus Virginius, which is found in Virginia. The Philosophical Transactions of the Royal Society of London, Anno 1665, relate, that with this Plant [...]ounded and put upon the end [Page 22] of a Staff, they kill that kind of Serpent by them called Rattle-Snakes if they but smell it, its very smell making them dye within the space of half an hour. That in all places where this Plant grows, none of those Ser­pents are found.

In the same Transactions we find, that the Virginians have a Root called Vichacan, wherewith they cure Wounds. Raocomoco passed for so able a Magician, that he could (by the Invoca­tion of one of their Gods called Heiamsough) cause Slaves that were run away to return to their Masters; and could handle bur­ning Coals without receiving any harm. He foretold that he should die a violent death; for which cause he preserved a friend­ship, and conversed much with [Page 23] the English, from whom he ap­prehended less danger than from those of his own Nation: as indeed he had good reason; for he was assassinated by order of one of their petty Kings, he ha­ving rendred himself suspected for having sojourned too long among the English of Carolina. The knowledge of the qualities of so many Plants is admirable in those ignorant people. There may be some reason to believe, that those Daemons which instruct their Priests, or Sacrifisers, in the art of Physick, cure Diseases only by the knowledge of cer­tain Plants and Minerals whose vertues they understand, and not without such external means as may naturally produce the effect.

A Fragment of the Oracles [Page 24] of Aesculapius may be seen in Gruter, where the Remedies which this God, or rather this Daemon, prescribes to the Sick which come to consult him, are natural and proper for the Di­sease. Here follow three which I have translated.

LƲCIƲS BEING SICK of a pain in his side, and being given over by all, the God Aesculapius pro­nounced this Oracle: That he should come and take off from the Altar Ashes which he should mix with Wine, and apply the mixture to his side: Which he did, and was presently cured, and came publickly to give thanks unto the God; and the people congratulated his reco­very.

Here's the Remedy which [Page 25] Women use for the pain in their Sides; for they are wont upon this occasion to apply to their side a little bag fill'd with hot Ashes. The Wine augments the vertue of the Ashes, in dissi­pating the Wind, which is some­times the cause of this pain. But as it must be a Physician who can discern whether this pain pro­ceed from Wind or from some other cause; it happens often­times that people do more harm than good with their Applica­tions; and instead of discussing a Wind, augment an Inflamma­tion which was but beginning.

JƲLIANƲ'S SPITTING Bloud, being given over by every body, the God being asked, com­manded him to come and take off the Altar Kernels of Pine-apples, [Page 26] and eat them with Honey for three days; wherewith he was cured; and came to give thanks to the God in the presence of all the peo­ple.

Kernels of Pine-apples are good for the Breast; they swee­ten the Humours, and serve for a Balm to shut up the Vessels▪ so that they are excellent in Pti­sick and Spitting of Bloud; and every one knows that Honey is [...] great Pectoral. Hippocrates, wh [...] is by some accused to have co­pied his Remedies from those i [...] the Temple of Aesculapius, pre­scribes these Kernels with Myrrh [...] to compose a Remedy for th [...] Breast.

VALERIƲS APER BEIN [...] Blind, the God ordered him [...] [Page 27] his Oracle, that he should come and take of the bloud of a white Cock, and mix it with Honey, and make thereof a Collyrium to be put upon his Eyes for three days; and he re­covered his Sight, and came to give thanks publickly to this God.

The bloud of a Cock is very proper by its heat to dissipate the spots that are beginning in the Eyes, and Honey clears the sight; so that there is nothing strange in it, if Medicines composed of these two ingredients recover the sight of a man that began to be blind. 'Tis true indeed, that upon the same Marble may be read the Cure of another blind man, whom the God comman­ded to put his five fingers upon the Altar, and then put them upon his Eyes; which has in it [Page 28] no natural cause which might produce such an effect.

But to return to our Febrifu­ges; we may hope that the re­serches which shall be made here­in, may discover unto us many things which now lie hid. And to this purpose I think it would be necessary for us to disengage our selves from the Sentiments of the Antients wherewith we are prepossessed; for these tell us of nothing but Choler, Flegm, Melancholy, Remedies cooling and evacuating, and such-like: For upon their Principles, there is no way for any new discove­ries, but we are confin'd, and hindered from penetrating fur­ther into the nature of things. I shall now give you some Idea's, the clearest I can, of the nature [Page 29] and causes of a Fever, which are not much different from the Sentiments of the most learned of the Moderns; upon which it will be easie to explain its Sym­ptoms and cure.

A Fever is an extraordinary a­gitation of the mass of Bloud, which disturbs the Oeconomy of the body of man.

This Agitation is produced by many external causes; as immo­derate Exercises, heat of the Sun, Falls, all those Objects which may stir up our Anger, Fear, or Sadness, and by other causes, which move the Bloud with too much violence. But the most ordinary cause of Fevers, and which doth not onely produce Ephemera's, and those of a few [...]ays, but also intermitting and [...]ontinual Fevers with their re­turns [Page 30] at certain periods, and also malignant Fevers, is a Ferment or Chyle become too sharp; which being introduced into the Bloud, does there produce an ex­traordinary Emotion, which cau­ses different Symptoms.

And this may be proved from this, that all sharp Liquors, or A­cids, mixed with other Liquors of an opposite nature, which we call Alkalies, do cause an Effer­vescence. So if you mix Oyl of Vitriol with Oyl of Tartar, they make a considerable ebullition, and become sensibly hot. The same may be said of many other Liquors, of which I shall say no­thing in this place, since it may be seen at large in a book of Dr. Grews, of the mixture of Liquors, translated into French by Mon­sieur Mesmin, a Physician of Pa­ris.

[Page 31] Another proof, which to me seems convincing, is, that the Chyle mixing it self with the Bloud, causes every day natural­ly, even in the most healthy, a certain shadow as it were of a Fever; which differs not from a real Fever, but as more and less. For half an hour or an hour after Meals, as soon as the most subtile part of the Chyle, or but the va­pour, which by its fermentation it drives before it, doth insinuate it self into the Bloud, it causes a coldness in the hands and feet, which is taken for a signe of Health. In some it produces Yawnings, and a desire of Sleep; with a Pulse less, and more fre­quent than ordinary. Here you have the beginning of the Fever. This cold being past, there suc­ceeds a heat all over the Body, [Page 32] which is very great in the palms of the hands, and soals of the feet of such as are of a Cholerick temperament; and at the same time the Pulse rises and beats stronger. Here you have the state and vigour of the Fever.

Four or five hours after Meals, when all the Chyle is mixed with the Bloud, and has receiv'd a part of its perfection from the circulation, the Heat diminishes, the Pulse comes to his natural state, and Appetite returns. Here you have the declination of the Fever.

If after this one stay twelve hours, or more, without eating any thing, the Pulse becomes ex­treamly slow, and the vigour one had diminishes. Here you have the state of a man when the Fe­ver is almost past. But as the [Page 33] Aliments wherewith we are nou­rished are not all alike, and our Temperaments different; which is the reason why some have lit­tle or no Cold, that others feel a great heat after Meat, and are lighter or heavier; all which has relation to the different accidents or symptoms which accompany the Fever.

If the Chyle find the Bloud too much subtilized or exalted, it produces a lingring Fever; which may be particularly perceived after Meals. This causes lean­ness, and a considerable falling away in the Patient.

By this may be understood the reason why Coffee and Thea, taken after Meals, hinders those from sleeping who are subject to sleep, unless a common custome of drinking one or other of them [Page 34] render them ineffectual, because by their bitterness and moderate heat, they dissipate the over­thick fumes of the Chyle. This also conduces to the understand­ing what the Naturalists say of Lions and Goats, that they have every day a Fever: for as they are of a Temperament hot and dry, their Chyle has the greater disproportion to their Bloud, and in mixing it self with it, it pro­cures a greater Combat than in other Animals.

Pliny makes mention of one Caius Maesenas, who had all his life long a Fever, and never slept a moment during the three last years of his life. On the other side, Deer that are of a cold and dry Temperament, and by con­sequence their Bloud less apt to ferment, never have any Fever, [Page 35] as the same Author says. He adds, that certain Ladies having accustomed themselves to eat Deers flesh every morning, lived very long free from Fevers.

This Ferment, in intermitting Fevers, has its seat in the Glan­dules of the Velvet-coat of the Stomach and Intestines, descri­bed by Monsieur Payer. These Glandules have each their little Channels of Excretion, through which they discharge a very lym­pid Serosity, which is of the same nature of the Lympha which circulates through the whole Body; and this subtile Liquor joyned to that which is constant­ly furnished by the ductus Sali­vales, and to the Pancreatick juice, serves for a ferment and dissolvent for the Chyle.

This Dissolvent being too a­cid, [Page 36] communicates to the Chyle its Aciditie, even as Acids cause a Coagulation in Milk; so that the Chyle entering into the Veins and Arteries, and not being capa­ble of being perfectioned by the ordinary circulation, when a quan­titie thereof great enough to pro­duce a Fermentation, remains in the Bloud more violent than that which happens after Meals; the fit of the Fever begins and con­tinues until this sharp Chyle be dissipated and driven out by Sweat or insensible Transpira­tion.

Now according as this Fer­ment is in greater or less quan­titie, or the Bloud more or less susceptible of an Effervescence, Fevers become Tertians, double Tertians, or Quotidians, Quar­tains, or double Quartains. So [Page 37] the Cholerick having their Bloud more boyling and subtile, fall commonly into Tertian, or dou­ble Tertian Fevers.

Hence it is that the Antients have said, and 'tis in some mea­sure true, That Choler is the cause of Tertian Fevers, both in­termitting and continual: for there is reason to believe, that that which causes an Intermit­tent, causes also a continual Fe­ver of the same kind, seeing that every fit of an Intermitting Fe­ver is as it were alittle Continual Fever, and a Continual as a long fit of an Intermittent; the fit of this, beginning, continuing, and ending almost as a Continual Fe­ver. The continuity proceeds from this, that the Chyle intro­duced into the Bloud, could not be perfected, and by consequence [Page 38] the mass of Bloud could not fur­nish a Ferment fit to make the digestion of the Aliments per­fect. 'Tis also to be observed, that the mass of Bloud acquiring a more acre and inflamable dis­position; the Chyle, although na­tural, produces also a Continual Fever; which is a thing to be noted in the practice of Physick: for then bleeding and cooling A­liments, and Medicines, will be more convenient; and above all, such Acids as calm the agitation of the Bloud, by thickning and cooling it, and by precipitating the sulphurous parts which main­tain the Tumult.

This being thus laid down, it will not be difficult for me to answer many Questions that may be made about Fevers and Febrifuges. And,

[Page 39] First, Whence come the Shiver­ings in Fevers, and why are the Shakings greatest in Quartains?

The Acid Liquors thickning the Bloud among which they be­ging to mix themselves, hinder it from communicating its heat to the parts; and the Bloud the more distant it is from the Heart, the less hot it is: This is the reason why the Shiverings begin at the Extremities of the Body, and continue until, by the efforts of the Heart and Arteries to purifie the Bloud by their re­doubted pulsation, all that fume be dissipated, the heat of the Bloud violently agitated succee­ding the cold fit. The Ferment of Quartains is more acid and glutinous, and the Bloud more [Page 40] gross; which causes most com­monly the Cold to be more vio­lent. And as these Vapours often have much acrimony in them, they sometimes affect the membranous parts by which they pass, in such manner, that the Patient suffers pains as if one stuck Pins in his Body. Those who have their Bloud subtile, and the Chyle more gross, have their Fits without any conside­rable Cold.

2. Whence proceeds the heat of Fevers which succeeds the cold fit, whence the thirst, pains of the Reins, and Head-ach?

The heat proceeds from the irregular motion of the Particles of the Bloud, which is composed (according to the Observations [Page 41] of the English by the Microscope) of an infinite number of little red Globules swimming in a clear wa­ter: for the heat of all Bodies proceeds but from the motion of their several Particles. The thirst proceeds from the heat, which consumes the serosity of the Chyle. The pains of the Reins which accompany some­times the cold fit, sometimes the hot, are caused by the ebullition of the mass of Bloud, in the great Vessels lying along the Reins. The Head-ach is the effect of the violent beating of the Arteries of the Brain against the Membranes that encompass it: so those whose Bloud rises higher, or beats stronger, or who have their Membranes more sensible, have also more of the Head-ach than others.

[Page 42] 3. Why are melancholy People, which abound with acid humours, less subject to Feavours than o­thers?

Because the mass of Bloud be­ing infected with this Acidity, and unapt to ferment, and the Chyle, though it often contract an acidity in the Stomach, yet produces it no Fever, as being of the same nature with the Bloud: for two Liquors that are not con­trary one to the other, do not ferment together, no more than two Friends whose Sentiments are agreeable, do quarrel and fight. So that you need not wonder if in cold Countries they be less subject to Fevers, than in hot Climates; and if those whose Bloud is more gross and melan­choly, [Page 43] are less attacked by Fe­vers than others. This made Hippocrates say, That those who have sharp Winds, are not very subject to the Pleurisie; because their Bloud is more gross, and so less apt to precipitate it self with violence upon the side, to cause Inflammation. I remember I saw at Monpellier a Dane, who in a Fit of Melancholy had cast him­self out of a Window two stories high into the street, and had with the fall broken his legs and arms: This man during his whole Cure had no Fever at all.

4. Whence is it that Fevers are more frequent and more obstinate in Autumn, than in the other Sea­sons of the year?

[Page 44] 'Tis because the preceding Summer has rendred the Bloud too inflamable, and more suscep­tible of a Fever; besides that the inequality of the Season helps much to corrupt the Chyle▪ Further, Fruit coming in now in abundance, produces in those that eat much of it, a Ferment that causes long and obstinate Fevers, particularly Quartains; which sometimes continue from one year to another, according to the Sentence of Hippocrates, and the old method of curing them. Pliny says, that Quartains begin not in Winter; and indeed it is but very rarely that they do: But the temperature of the Sea­sons is uncertain; for sometimes we see in the middle of Winter, days like those in the Spring or Autumn.

[Page 45] 5. How is it that Tertians change into double Tertians and Quartains, and Quartains into Tertians?

Tertians change into double Tertians, and Quartains into double Quartains, when the Chyle becomes more dispropor­tionate to the Bloud; and these two Liquors not agreeing toge­ther, do justle one another the oftener. Tertians become Quar­tains, when by a too cooling Diet or cooling Medicines, unseasona­bly given, the Ferment becomes sharper or sowerer, and the Bloud thicker.

On the other side, Quartains change into Tertians, when by a too hot Diet or Medicines, the Ferment and the mass of Bloud [Page 46] become more subtile and more inflamable. And generally, In­termittents may be changed into Continuals, by an ill Regimen, and over-hot Medicines; which makes all the Ferment pass into the Veins, and renders the Bloud too susceptible of an Agitation of long continuance. And Con­tinuals become Intermittents, when Nature strives to disengage her self from this Ferment, in precipitating it into its first pas­sages; as after the ebullition of Oyl of Vitriol and Oyl of Tar­tar, there is precipitated to the bottom of the Glass a white mat­ter, which we call Tartar Vi­triolat.

6. What is the cause of the re­gular Return of Fevers?

[Page 47] Though there be something inexplicable in the return of Fe­vers, which is sometimes as cer­tain as the flux and reflux of the Sea, I say, that it seems probable that it proceeds from the equal portion of Aliments which is ta­ken, and of the Chyle which is made: For those who eat too much, cause the Fit to come sooner, though indeed it might come sooner for other reasons, as when the Bloud, heated by the preceding Fits, becomes more susceptible of Fermentation. On the other side, it comes later, when less nourishment is taken, or when the Ferment begins to grow milder. In fine, there are some Fevers that are both un­certain and unequal as to their Returns; which is a mark of [Page 48] disorder either in the Orgains, or in the mass of Bloud, which ren­ders the cure of such Fevers more difficult, and more subject to Re­lapses; and this may be called a Symptomatick Fever, as is that which proceeds from Obstructi­ons.

7. Why comes not the Fever up­on the sick soon after Meal?

The reason will easily appear, if you do but consider that the last Fit of the Fever has dissipa­ted and driven out, by a conside­rable Transpiration, and some­times by a copious Sweat, a great part of the Acidity of the Lympha that produced these dis­orders: So that immediately af­ter a Fit, it is not strong enough, nor in quantity great enough, to [Page 49] give to the Chyle a certain de­gree of Acidity; which may produce (when it is mixed with the mass of Bloud) that Fer­mentation, and Emotion, which we call a Fever. But this Fer­ment having recruited its forces, and being augmented both by time, and the Aliments taken, will not fail to give battel to the Bloud, as formerly. Those who have any knowledge in Chymi­stry, and have made Observations on the Opperations of Nature, will easily be of my Opinion: for they will have observed that a long Fermentation is required to make a Liquor that is sweet, be­come acid; and that there must be a certain quantity of Liquors one contrary to another, to produce a Fermentation that is conside­rable. By this one may give [Page 50] a reason why those who observe no Regimen, and forbear nothing that they imagine will gratifie their Appetites, cause the Fit to come sooner, and to continue longer. On the contrary, those who govern themselves regular­ly, are sooner delivered from that domestick Enemy. At the same time may be seen the rea­son why the Fever ceases, if the Ferment be changed by a Medi­cament contrary to its nature; and which may reduce it to its first state, and that without any considerable evacuation. Had I been minded to make a Book ra­ther than a kind of Letter, I should here have made some Ob­servations upon the Nature and Origine of Acids, and upon the difference of Fermentations; but since these things are so lear­nedly [Page 51] treated of by D'Willis and Monsieur Maiow; I should have done no great service to the Pub­lick, by explaining in French what they have written in La­tine.

8. Whence is it that the hands and feet, and sometimes the faces of those who have Fevers, swell?

Because the aqueous parts of the corrupted Chyle being driven to the extremities of the Body, the heat of the hands and feet, in comparison of the other parts of the Body, being so small that it cannot dissipate it, and the hardness and density of the skins does not easily admit of Trans­piration. This may be consi­dered in the hands and feet, where working and walking ren­der [Page 52] the skin of those parts harder than that of the rest of the Bo­dy. And our Practice shews us that these Swellings happen most commonly in those who void the least Urine and sweat not, and in feeble and aged persons. So that these Swellings are not so much to be feared, provided they depend not on some Disease of the Viscera, and the Fever di­minish: for they will afterwards be dissipated by Purgatives and Cordials.

9. Why do Quartains, when they continue long, introduce a Dropsie, hardness of the Liver, or Spleen, or a Jaundice?

A Dropsie succeeds a Quartain by the same means that cause the swellings of the extreme parts of [Page 53] the Body. When this Serosity, instead of discharging it self up­on the hands and feet, falls into the Belly, or when those parts are already puft up, then the Swelling rises up to the legs, then to the thighs, and so to the belly; or what is yet worse, when by the long continuance of the Disease, the Viscera are so dried and hardened, that they cannot purifie the Bloud, nor se­parate the Serosity from it. This hardening and schircus of the Liver and Spleen, are the effects of the continual dissipation which the febrifick heat makes of the nutritive moisture. And the Jaundice is an effect of these hardenings and obstructions of the lower Belly, caused by the acid Ferment, which makes the Choler flow back into the Veins, [Page 54] stopping the passages which should convey it to the bladder of the Gall. Now it is certain, that Acids obstruct and coagu­late in those parts where they predominate. So that what Hippocrates saith, That a Quar­tain is not onely not dangerous, but exempts those that have it from other great Diseases, may be true in Greece, which lying under a hotter Climate than ours, produces not Quartains so obstinate and incommode, as are those which reign in this Coun­try: as well because their Bloud is not so gross, as because there is a better Transpiration. In ef­fect, Climates do strangely di­versifie Diseases; for we are not acquainted with those Quintains, Septain, and Nonain Fevers, which have their Fits every fifth, every [Page 55] 7th and every 9th day, whereof the same Hippocrates speaks. A Collegue of mine told me that he had seen, not long since, a Septain Fever, the Patient having had five or six Fits, which hap­pened regularly every seventh day. And I saw one lately who had three Fits every seventh day, which might perhaps be the ef­fect of hazard, rather than of a regular motion.

10. Whether a great Abstinence can cure a Fever?

That which gives occasion for this Question, is, what I have al­ready said, That it was the cor­rupted and sharp Chyle that was the most ordinary cause of Fe­vers; whence it might be infer­red, that eating nothing from [Page 56] one Fit to another, would cure the Patient. To which I answer, That it is the ordinary Remedy of the Greeks, who have few Physicians among them, they re­main four or five days together without eating any thing, or ta­king Broths, drinking no­thing but Water wherein are a few pounded Almonds; and most commonly in this time they are cured of the Fever, whether it be Continual or Intermitting, especially of Tertians and double Tertians. But this Example is not to be imitated in our Coun­try: For the Greeks keeping Fast two third parts of the year, and oftentimes fasting whole days without taking any thing at all, 'tis no wonder if they can sup­port so long an Abstinence. But in our Climate where we eat [Page 57] much, and that of very nourish­ing Aliments, it were no less than the hazard of ones life, to under­take such an Abstinence: And we have seen here a Person of Quality die with fasting from one Fit of a Quartain to another. It may be objected, that they ought to be cured after the se­cond or third day; but you must consider that their Drink, which has in it somewhat of nourish­ment, makes a little Chyle, which may cause some Fits, though less than if the Patient had taken more solid Aliments. And yet the heat being at liber­ty from the digestion of the Ali­ments, doth more easily dissipate the rest of the Ferment. The method of the most part of Ita­lian Physicians is yet more cruel, and less reasonable: for they [Page 58] forbid their Patients to drink du­ring the whole Fit; which doth grievously heat them, and for the most part nothing advance their Cure.

11. Whether is Phlebotomy a Febrifuge?

As the word Febrifuge signi­fies every thing that may drive away the Fever, there is no doubt but that bloud-letting is oftentimes a Febrifuge, especially when the Fever proceeds onely from some exteriour cause, which has excited an emotion in the Bloud, as Exercise, heat of the Sun, Wine, Anger: for in these cases bleeding has almost the same effect that giving air to a Tun when the Wine boils, lest it should burst. If bleeding [Page 59] were not used, the Bloud which then possesses more room than at other times, might open the vessels of the Lungs, and of the Brain, and so cause spitting of Bloud, a Phrensie, or some other grievous Symptoms. But in In­termitting Fevers, where an acid Ferment is the principal cause, bleeding is no Febrifuge; not but that we must often begin with it, especially in double Tertians, which are next to Continuals, and that with designe to render the Bloud less susceptible of A­gitation, or to diminish its ple­nitude; but I take it to be for the most part dangerous in Quar­tains, and onely apt to make the Disease of longer continuance; unless there be some other Indi­cation which require it, the knowledge whereof belongs on­ly to the Physician.

[Page 60] 12. Whether Laxatives, Pli­sanes, and other Purgatives, be Febrifuges?

When the Ferment of the Fe­ver is supported by Crudities of the Stomach, then purging may be a Febrifuge, and prevent the Fit which would have followed by delivering the Organs from that burthen which loaded them, leaving them the liberty to con­tract themselves, and to drive out the rest of the Ferment. But if this Levain or Ferment have its source in the posts we have assigned it, or if the Sto­mach have any disease which may make it corrupt the Ali­ments that are taken, then pur­ging cannot be a Febrifuge, un­less by accident: For Example, [Page 61] by exciting a Diarrhea, which often cures the Patient. Purga­tives are for the most part neces­sary to clear the way for Febri­fuges, otherwise Catharticks do not cure the Fever; whether it be that the Ferment being not yet qualified and tamed, is there­by rendered more fierce and wild, or that they pass but onely into the Veins and Arteries. Nay, it often happens that the Agitation which they make in the several parts of the Body, pervert their Action, and do ex­tremely weaken the Patient, and carry off too much Bile; which is the balm of the Chyle and Bloud, when it is not irrita­ted.

13. Whether Vomitives be Fe­brifuges?

[Page 62] Vomitives are sometimes ne­cessary for the sick of Fevers, but especially when the sick person finds in himself a disposition to vomit, because they discharge the Stomach of those impurities which hinder it from doing its office, and evacuate the matter which would augment the Fer­ment; so that they are not Fe­brifuges but by accident: Nay, they are very often dangerous, because they do much fatigate the Patient, weaken the Stomach, and sometimes open the vessels of the Lungs. In a Quartain particularly you must make no use of them, when it hath con­tinued too long, because the Fer­ment being glutinous and infil­terated into the first Region, cannot be dislodged without vio­lent [Page 63] efforts: if they are mild, they do but cause an emotion or disturbance; and if they are violent, they put the Patient in danger of his life, unless he be of a very robust Constitution. And herein I think my self obliged to give the Publick this Advertise­ment, That they be very cau­tious how they commit them­selves to those Barbers, Empe­ricks, and Mountebanks, who promise to cure all Diseases with a little Powder, or a little clear insipid Water; because these Me­dicines are for the most part An­timonial, and of the most violent, which are put up in a little room, or Water wherein they have boiled Vitriol or Arsenic, or Rea­gale; which never operate with­out causing a furious Irritation or Convulsion of the Stomach. [Page 64] And if they do carry off the Fe­ver, yet do they leave behind them impressions of heat in the Visera, pains in the Stomach, and spitting of Bloud. It were but just that the Judges of the Court established for the punish­ment of Poysoners, should take cognizance of such as kill the sick by these Poysons. Though they may say that a small quan­tity of these Drugs is not capable of poysoning, yet I will main­tain, that when they give them to persons of delicate Constitu­tions who die of it, one may just­ly say that they have given them Poyson. Besides that, under pretence of these dangerous Re­medies, it would be easie for a Poysoner to augment the quan­tity of his Dose, and then say he gave it onely for a Vomit.

[Page 65] 14. Whether the making ones self drunk with Wine or Aquâ Vitae, will cure a Fever?

Wine drank to an excess, cau­ses a great ebullition in the Bloud, and often drives out (by different ways) the cause of the Fever; and some have been so cured: but this is not an Exam­ple to be imitated; for one ought to be very well assured of his own strength, and the resi­stance which a body, already grown feeble with the effects of the Disease, can make against the effects of Drunkenness, as it may be either a Lethargie, Pleurisie, or Death it self: so that he must neither have common Sense, nor any the least tincture of Chri­stianity, that would preserve the [Page 66] health of his Body by a dange­rous Remedy, to the prejudice of that of his Soul. I leave it to others to think whether a man dying drunk, die in a good condition. As for Brandy, we shall leave it to the Hollanders, who have accustomed themselves to drink it, and so can better sup­port the effects; they drink it commonly before the cold Fit, which it may possibly lessen; but must needs render the suc­ceeding hot Fit more intense and violent. And when they would quite rid themselves of it, they drink whole pints; which has sometimes good success upon Sea­men and other robust bodies.

15. Whether are Mineral Wa­ters Febrifuges?

[Page 67] 'Tis certain that Mineral Wa­ters are a great help towards the cure of Intermitting Chronical Fevers: but you must observe, that 'tis those Waters particular­ly which are hot and impregna­ted with a niterous salt like that of the Antients, and with some sulphur, as those of Bourbon l'Ar­chambaud, and Vichy. This I ob­served in them, in the Journey I made last Spring with Monsieur Garnier the Son, and Monsieur de Ville my Collegue. In this Jour­ney, I say, we throughly infor­med our selves of all that ought to be believed of these great Pis­cines; from which indeed many sick people return very much relieved: but we found that they were not universal Remedies, as several Historians have written, [Page 68] who have rather applied them­selves to the making a descripti­on of the magnificence of the Bathes, Vases, and Buildings that belong to them, than to per­swade us by repeated Experi­ments, of the Salt, and of the Mineral wherewith they are im­pregnated. And when they un­dertake this, whether it be that they understand not how to make the Analysis, or that they believed that one single Salt could not be capable of produ­cing so many effects; one while they tell us that they are im­pregnated with Niter, Sulphur, and Vitriol altogether; another while they tell us, that 'tis with Sulphur, Vitriol, and Alum: After all this, they tell us that they are impregnated with Iron, Niter, and Vitriol; whereof they [Page 69] are pleased to give us no other proofs than the pretended Cures done by those Waters. But if (happily for us) they had set a­bout it, as did the learned Mon­sieur du Clos, and after him Mon­sieur Fouet, a Physician of Vichy, they had spared us the trouble of a Journey of six or seven weeks, to examine the Waters of about thirty Mineral Springs arising thereabouts; of which one can­not rightly make use, without first having taken the pains to visit them, and anatomize them by several Experiments. Here­by may one avoid the confusion of seeing his Patients return from the Waters in a worse condition than they went thither. And had not the most part of our Physicians been herein so often deceived, the wittiest Comedian [Page 70] of our Age would never have made it the subject of his publick Raillery. But to return, I say that the Waters of Bourbon l' Archam­baud, and those of Vichy, provi­ded one know how to use them, and that great care be taken of the state and condition of the sick, are often Febrifuges, by rea­son of their niterous Salt where­with they are impregnated, and the sulphurous and balsamick parts wherewith they are inrich­ed. By this Composition, I say, the Acidity of the Lympha is ve­ry much sweetned, the nutritive parts are fortified, and the natu­ral heat restored to its former state, the obstructions of the first Region opened, and in fine, what remains of surcharge and sedi­ment in the whole mass of Bloud, is thrust out from the centre to [Page 71] the circumference, by Transpira­tion, Sweats, and Urine. Yet nevertheless, if before the use of these Waters the sick be not du­ly prepared, or be subject to a defluxion of sharp Serosities up­on his Breast, or to Obstructions of the Hypochondres, then the Waters which abound in Niter, meeting with a mass of Bloud very sulphurous and inflamed, will not fail to raise very impe­tuous motions, and to change an Intermitting Fever into a most acute Continual; and so reduce the Patient to the last extremity; as may be seen every day in those who neglect the Advice of an a­ble Physician.

16. Whether Theriaca, Orvie­tan, and such-like, cure Fevers?

[Page 72] It may happen that Bodies that have been well prepared by bleeding, purging, and other means, wanting strength and vigour, have been holpen by a dose of Theriaca, or other hot Compositions which subtilize the humours: But as People give these Remedies without in­dication or method, it happens oftentimes that the Bloud is thereby rendred more apt to ser­ment; which increases Thirst, Head-ach, and the Fever it self. There are some who cure a Quartain when it is inveterate, by rubling the back-bone with Theriaca and Aquâ Vitae; which subtilizes the Bloud, and helps to dissipate the Ferment by Trans­spiration: But for the most part stronger Machines are required [Page 73] to subdue an Enemy so pertina­tious.

17. How can Fear cure a Quar­tain?

Some have been known to be cured of a Quartain by a sudden fear, even when they were shi­vering in their cold Fit. 'Tis re­ported that Henry the Fourth cured one on this manner: He had taken a Castle wherein he found a Gentleman in a Fit of a Quartain Ague; the King made as if he had been in great anger, and looking upon him, told him he'd dispatch his Fever presently; and call'd for a Paper, and wrote thus:

The poor Gentleman, who thought the King was writing the Sentence of his Death, was seized with so great a fear, that the Fe­ver left him. 'Tis the effect of the extraordinary agitation of the Spirits, which subtilizes the gross bloud of Quartains. Ne­vertheless, this is a Remedy not to be used: for if the Fear be but ordinary, it is not capable of pro­ducing the desired effects; and if it be great, it may cause Death: for there are many that die of Fear, either suddenly, or some small time after, by the disorder which it raises in the whole Oe­conomy of the Body.

18. Why are Fenny, Morish, [Page 75] and Moist places most subject to Fevers?

Because out of these places there is a perpetual Exhalation of acid Corpuscules, which by respiration mix themselves with the Bloud, and so communicate their Acidity to the Lympha; which produces different sorts of Fevers, according to the disposi­tion of the Body. This may be seen in Iron, which in all moist places contracts Rust in a very short time; and every body knows that Rust is caused by all Acids. And further, if in moist grounds there be vaults which may stop those Atomes, they become considerably furnished therewith, and afford us Saltpe­ter, which is so acid, that out of it they make Aqua Fortis. Hence [Page 76] it is that going by Water, espe­cially fresh water, is not good for those People who have Agues; as for the Sea-water, so far is it from being prejudicial to them, that many lose their Agues after their going to Sea, because the Marine Air abounds with Saline Particles, contrary to the acid ones. There are notwithstan­ding some Sea-ports which are very subject to Agues, by reason of the standing Waters about them, and the Vapours which a­rises from thence, mixed with those that arise out of the Earth, infect the Neighbouring Air. So there is no place more subject to Agues than Alexandretta, where almost all that arrive catch A­gues; and no wonder: for the place being very Morish by rea­son of the breaking down the [Page 77] Harbour, and a very high Moun­tain on the Eeast, which hinders the Sun from shining upon it be­fore the day be far spent. The most certain and ready Remedy, and that which is most practised there, is to depart quickly from thence, that they may breathe a better Air. So likewise Smyrna; which is seated at the bottom of an Arm of the Archipelago, ha­ving the unwholsome neighbour­hood of Marshes, is subject to A­gues in the Autumn. And so the Inhabitants of Lyons seldom fail to catch Agues when they go into the Dombe, which is a Country full of Ponds and stan­ding Waters. From all this may be drawn practical consequences▪ which may be of good use: As for Example, it may be good for the sick of Fevers or Agues to be [Page 78] removed out of Ground-rooms, and Apartments which stand upon or adjoyn to Rivers, and to cause those who by an ill Air have taken an Ague, to change the Air.

19. Whether the skin within the shell of an Egg tyed to the end of the Finger, or a live Tench ap­plied to the Back-bone, or to the soal of the Feet, can cure an A­gue?

These are the Remedies of the Country-people, which having perhaps cured one of a hundred, are ever after employed as if they had some specifick quality; yet how often do we see their inuti­lity? If they have cured any, 'twas either by the force of the imagination of the Sick, or by [Page 79] the pain which their coldness and binding them upon the heated nervous parts, caused. The pain causing an extraordinary agita­tion of the Bloud, even to that degree, that we have seen a per­son die here of the violent Sym­ptoms caused by the application of a live Tench to the soals of his feet: the Tench becomes some­times black, and then the People straight imagine that it is the malignity of the Disease, which passes out of the body of the Sick into that of the Fish; though it be no more than an effect of the heat and moisture which corrupt the Fish. The Antients (according to the report of Pli­ny) had some Febrifuges a great deal more ridiculous and super­stitious, which he himself laughs at; as the paring of Nails, which [Page 80] they were to seek for before the rising of the Sun, and apply them with Wax to another mans door, and into this mans body the A­gue was to transmigrate. For Quartains they took three drops of Bloud out of the vein of an Asses Ear, which they drank in about a gallon of Water; the Liver of a Cat kill'd in the wane of the Moon, and salted and drank with Wine before the Fit. For all Intermitting Fevers they took the Eye-tooth of a Croco­dile and filled it with Incense, and tyed it to the right arm of the Sick. Diascorides saith also, that three Spiders pounded and put in a linnen cloath, being ap­plied to the Forehead and the Temples, cure the Tertian A­gue.

[Page 81] 20. How do Vesicatories cure Fevers, and particularly malignant Fevers?

In Holland they apply Vesi­catories to the arms, thighs, and legs, not onely in malignant Fe­vers, but also in simple Tertians. The French, who are more de­licate, will scarcely suffer them to be applied, unless it be in case of a Delirium, Lethargy, or Con­vulsions. 'Tis true, the Remedy is somewhat cruel, but yet it produces great effects. And Na­ture teaches us this way in ma­lignant Fevers, in making depo­sition of sharp humours, where the Gangrene takes hold, particu­larly among the Muscles of the Os Sacrum, to which the heat of the Bed (which heats▪ that part) [Page 82] contributes much. And some­times this which at first seem'd a thing of ill presage, is the Cure of the Sick, by the suppuration and expulsion of the malignant humours which Nature hath pro­duced, and that Art durst not have attempted. So it is by the drawing out these sharp Serosi­ties that Vesicatories promote the Cure of Fevers.

21. Whether are Medecines applied to the Wrists (with de­signe to put away the Fever) Fe­brifuges?

These sorts of Medicaments, to which the People give so great credit, are for the most part a kind of Vesicatories, as being compounded of Salt, Vinegar, Gunpowder, Nettles, Soot, the [Page 83] Root of Ranunculus, or Crowfoot, Garlick, and other such-like In­gredients. They are some­times more troublesome than Vesicatories, because they are applied to the Wrists, which are rather membranous and nervous, than fleshy. Some are made of Drugs that have not this quality to ulcerate the skin, yet may communicate to the Bloud a hea­ling and precipitating quality; as those made of Camphire and Aqua Vitae, or of fixing in some sort the Bloud; or those made of Spiders Webs with Snails, or Shepherds Purse, which is an A­stringent Plant. However, we see no great success of this kind of Medicines, unless the Imagina­tion of the Patient be strongly moved by those which apply them, promising a quick and in­fallible [Page 84] Cure. And it may be also that they have not recourse to these, but when they are weary of other Medicines which have half cured the Patient. The Fever perhaps ceases two or three days after the application of these Medicines; which it would ac­cordingly have done, had they never applied them. These may indeed be of some use for Children who refuse to take any internal Medicines, and whose Bloud is more susceptible of the impressions of an external Re­medy.

22. Whether Centaury or Ger­mander be Febrifuges?

These Plants are extremely bitter; yet one is willing to do any thing to be rid of so trouble­some [Page 85] a Companion. The Coun­try-People use the Decoction of them to drive away their Agues. Many Authors make great e­steem of the less Centaury, to which they have given the name of Febrifuge. And Diascorides doth very much commend Ger­mander in Tertians: so that we need not doubt but that they are good when methodically and duely administred; yet does it not seldom fail of producing the effects expected from it, ei­ther because it is unseasonably given, or else given to People of too delicate Constitutions, where­in it stirs up Heat and Thirst. Further, they have not all the qualities of a true Febrifuge, which ought to be at the same time Diuretick, Diaphoretick; or Sudorifick, to drive out the Fer­ment; [Page 86] Balsomick, to repair lost Strength; Styptick or Astrin­gent, to fortifie the Fibres of the parts; sometimes Narcotick, to calm the too great Agitations of the Bloud; and also a true Alkaly, to dull and break the points of the Acids. Hippocrates gives the Root of Pentaphillam or Cinquefoil, in Tertians: but un­less that Plant had greater Ver­tues in Greece than in France, it could not effect the Cure, al­though it be somewhat Astrin­gent. He also adds, that if the Fever cease not, the Patient must take the juice of Trefoil, with that of Silphium, in equal parts of Wine and Water mixed. 'Tis pity that we have lost the know­ledge of that famous Plant called Silphium or Laserpitium, which the Antients cried up for a Re­medy [Page 87] against so many Diseases. Pliny writes a whole Chapter of its Vertues. It grew in Lybia, and the figure of it may be seen yet upon a Medal of the Cyre­neans, where it has some resem­blance to Apium or Seleri, as The­ophrastus and Diascorides have ob­serv'd in their Works of Plants. Hippocrates would have the juice of these Plants given in pure Wine, in Quartains; from which it may be observed that he did not so much fear to give Wine in Fevers, as do most part of the Physicians of our times, though they boast themselves to be his Disciples. He also prescribes in this Fever Garlick pounded and mixed with Honey, which should heat much more than Wine. Diascorides and Serenus Sammoni­cus, add to it Punaises, to render [Page 88] the ragoust more excellent. The Medicaments which the Anti­ents called [...] or Febrifuges, were generally composed of hot Ingredients, as may be seen in Galen, Marcellus, and Trallian.

23. Why does the breaking out of the Lips shew that the Fever is past?

Because it is a signe that Na­ture or Medicines have made a considerable Effort to drive out the sharp and acid Ferment of the Fever, which in passing has made impressions upon these parts, being delicate and spongy. And for the same reason, the Itch breaking out in a Quartain, makes it cease; and striking in again, makes it return. This ought not to hinder from pur­ging [Page 89] the Patient after the Fever, to evacuate the Relicks which neither Sweat nor simple Tran­spiration were able to carry off, and which might cause a Re­lapse.

24. Whence come Loathings and bitterness of the Mouth after Fevers?

Loathings proceed from the disorders of the Stomach, which has not of a long time rightly done its office; or from the Fer­ment of the Stomach, which the heat of the Fever, and frequent drinking, have dissipated and washed away. Bitterness of the Mouth is caused by the fumes which the boiling of the bloud in the Veins, and of the Chyle in the Stomach, has left, and which [Page 90] have insinuated themselves into the Tongue, being a very spon­geous part; for no body but knows that Smoak and Soot are bitter. So that there is no ne­cessity of attributing this bitter­ness to Choler, which is often unjustly accused.

25. Why do Milk-meats, raw Fruits, and new Wines, often cause a Relapse of Fevers?

Milk-meats, new Wines, and raw Fruits, abound much with acid Particles, which in a weak Stomach separate themselves, and renew again the former dis­orders of the Fever. So that it was well said of Pliny, That fresh Grapes are naught for the sick of the Fever; yet it falls out some­times by accident that they cure [Page 91] a Fever, being eaten in a great quantity at the time of the Vin­tage, because they commonly cause a Diarrhea, which carries off all the ill humours, and the Leven or Ferment of the Fe­ver. The same things may be said of low Wines as of new Wines, because its Tartar or else its Lye, being remixed with the Wine, hath made it sharp, and by consequence hath rendered it proper to renew the Ferment: And for the same cause the Pa­tient should, for some time after he is cured, forbear Pastry Meats, salt Meats, and Ragousts, or compounded Dishes, which are commonly made up of sharp, bi­ting, and fiery parts. These raise a tumult in a weak Sto­mach, without being perfectly digested; they fatigate the parts [Page 92] destined for the digestion, and heat the mass of Bloud: so that 'tis no wonder if we see many Relapses, because there are a sort of Patients who will rather go­vern their Physicians, than be governed by them, and who will deny nothing to their Appe­tites. Others there are who no sooner cured, but they straight conclude that they have no more need of the Physician; and that he prescribes now onely for the benefit of the Apothecary, to make his [...] [...]he longer: And probably this may be the reason why after the English Remedy so few have been subject to Re­lapses; for the great sum they paid for it, made those that gave it not to spare it. Indeed there is no appearance that this Re­medy should put the Patient out [Page 93] of all danger of a Relapse, or that it should have power enough to hinder a new Fermentation; which an excess in eating or drinking may cause in a Conva­lescent, a fortnight or a month after he has left taking it. But Fevers that have continued long, and much weakened the Organs, are much more subject to return, than when they are cured after a few Fits.

26. Whether there be any univer­sal specifick Febrifuges which put a­way Fevers by an occult quality?

These occult qualities are a very commodious subterfuge for the ordinary ignorance of man, who does not penetrate into the essence of the Works of Nature: And it cannot be denied but that [Page 94] what is unknown unto us, may justly be called occult; and that there are some things in Nature which it will be always more easie, or if you will, more honest, to admire than to explain. However, we ought to have as little recourse as we can to this Asyle; and methinks according to the Principles I have laid down, it will not be so hard a matter to give an account of all those pretended Specificks. I have not spoken of Kinkina, be­cause a famous Physician of Paris, whom I do infinitely honour, hath written a Book of it, with­out putting his name to it; 'tis the same Book which Monsieur de Blegny thought to have been written by one of Lyons, because it was first printed there.

I say further, that there may [Page 95] be found every-where, in Plants and Animals, whereof to com­pose Febrifuges; and we cannot imagine that Nature has been so illiberal to our Climate, that it should not produce Aliments and Medicines necessary for the pre­servation of Life. We have of­tentimes a preoccupated opinion in favour of Drugs which come out of the Indies and other re­mote Countries, which makes us put an esteem upon them; and on the contrary, slight and despise those that grow in our own Gardens. If we have not Rheuburb, Sena, and Cassia, we have instead thereof Peach-flow­ers and leaves, Roses, Berbery, and many other Purgatives, which may be used with good success; provided that either one Plant alone, or many Drugs [Page 96] mixed or united in a Composi­tion by Chymistry, or a simple Galenical Preparation, have all the qualities which we have said to be necessary for a true Febri­fuge; we need not doubt but that they will have their effect, without putting us to the ne­cessity of attributing it to an oc­cult quality. But what is yet considerable, and serves to esta­blish our Hypothesis of the cause of Fevers, is, that all the Plants and other Drugs which have hi­therto gained a Reputation for the Cure of Fevers, are so far from having an Acidity which might sympathize with the acid Ferment, that they have a bitter­ness, an astriction, heat, volatile salt, and Alkalies; the Enemies of all Acids, and cure Fevers by their manifest qualities: So that [Page 97] one may with good hopes of success, taking such Precautions, and using such Preparations as are necessary, make use of the Powder of Vipers, Salt of Vi­pers, Pepper, Nutmegs, Sulphur, Wormwood, bark of Ash, roots of Centrayerva, Mullein, Gen­tian, wild Valerian, Mustard­seed, Salt Armoniac, salt of Tar­tar, Salts of Centaury and Speed­well, Panax or Clowns-all-heal, Carduus Benedictus, Angelica, Chamemile, Juniper, Sage, Rue, St. Johns wort, Galengal, Ver­vain, Centaury, Germander, Nettle, Asarum, Celendine, Be­tony, Thea, Coffee, Opium, An­timony, Sassafras, Guyacum, nay and Mercury it self.

I cannot imagine how one and the same Medicament can cure [Page 98] all Fevers, they being diversified by a thousand circumstances; yet I cannot deny but that there may be found some, which either naturally or by Art have almost all the qualities of the true Fe­brifuge. And as an ill Cook with the best Ingredients, can­not make a good dish of Meat, and on the contrary a good Cook with a few Ingredients will make a very good one; so a man un­learned in Physick, and little versed in the work of Nature, cannot succeed, unless by chance: whereas he that a serious Study, or at least a frequent Experience hath enabled, will cure his Pa­tients happily, and with a few Medicines. In fine, I cannot but perswade my self that all Physi­cians may invent Febrifuges, and administer them seasonably, pro­vided [Page 99] they understand well the nature of the Fever in general, and the state of their Patient in particular. The famous Sir The­odore de Mayerne Physician to the King of England, whose par­ticular Talent lay in the under­standing the Materia Medica, which he did admirably well; he, I say, had Waters and other lexipuretick Compositions, which were made onely of Plants grow­ing in our Climate, as I find by some Manuscripts now in my hands.

Methinks for this effect, it were expedient not to neglect a­ny thing, and to try those Me­dicaments which may seem ex­travagant, provided they be not such as may endanger the Pa­tient. The Liver of a Hare or [Page 100] of a Cat, dried in an Oven, pou­dered, and drank in Wine, may to many seem ridiculous; and yet these have been commended by learned Writers; and there may be some reason to believe them to be Febrifuges, because these parts abound in alkalious and volatile Salts, as doth the bloud whereof they are compo­sed. Authors are full of this kind of Medicines, where in truth a good Judgment is very neces­sary; that the Physician be not exposed to the confusion of see­ing his Patient become worse than when he first began with him.

For conclusion of this Dis­course, we ought to rejoyce that we live in an Age so fertile in new Inventions, and under the Reign [Page 101] of so great a Monarch, who does no less make the liberal Arts than the Art of War to flourish; which may rationably make us hope to see the study of Physick arrive every day at a higher point of perfection, we on our parts con­tributing thereto (as 'tis but just we should) by our Reflections and Experiments, whatsoever may serve for its Ornament.

Thus, Sir, you see how far the Complaisance I have for you, has engaged me; I must confess, that desiring to inform you of those things you desired, I have in­structed my self, in examining a matter which multiplied it self under my hands: And thinking to write you onely a Letter, I have almost made a just Trea­tise, which I may perhaps here­after [Page 102] enlarge. However, I ought to content my self with these Idea's, how unpolite soever they are, since they have given me oc­casion of testifying unto you the passion I have to be all my life,