From this discovery it appears, that, whatever may be the cause of

the frequency and violence of epidemics in warm climates, it _is not_

the want of oxygen. Nay, we should rather be tempted to think that

they were produced by too great an abundance of it; and this the

more especially when we know that animals confined in oxygen air are

supposed to die of a burning fever; and it is likewise known that this

kind of air is prejudicial to consumptive people, and even brings on

the disease on those who had it not before. From the experiments

mentioned in the note, it seems probable that there are but few even of

swampy places in hot climates, where oxygen does not predominate; and

in these the heat thrown into the blood must still be augmented by that

produced from the quantity of vapour decomposed or condensed in the

lungs, which, as the condensation depends upon unknown circumstances,

can never be foreseen, or ever prevented, but by a removal from the

place.

With regard to other kinds of air, such as inflammable, phlogisticated

air, &c. experiments are yet wanting to determine their effects upon

people who breathe them habitually. The proportion in which they

occasionally exist in the atmosphere on particular occasions has not

been ascertained, and from the experiment made by Dr. Priestley with

offensive air taken from a manufactory, as well as from Dr. Chisholm

just mentioned, the probability is, that, even in the most offensive

places, the proportion of azote is by no means so great to the oxygen

that we could suppose the excess capable of producing a disorder of any

consequence, much less a violent epidemic. Fixed air is always produced

in the putrefactive process, and from its quality above mentioned of

rarefying and heating the blood, might reasonably be supposed to have

some share in producing epidemics, were it not that this kind of air is

so readily absorbed by water, as well as a number of other substances,

that, except at the very moment of emission, we can scarce suppose it

to have any considerable effect.

Mr. Watt in a letter to Dr. Beddoes gives an account of a kind of air,

seemingly more noxious than any yet discovered, which he produced by

distillation from flesh and from wool. The effects upon himself were so

disagreeable that he determined to make no more such experiments, lest

he should to his own hurt discover a mode of producing some grievous

disease. But we cannot, from an artificial air of this kind, argue to

a natural one; as the one produced by Mr. Watt was totally different

from any species of air naturally known. All that we can say is, that,

as far as we can trace the connexion between our bodies and the

different kinds of air which may be breathed, the latter act chiefly

by the heat they contain, and which they impart to the body in various

proportions; by which means the latent or sensible heat of the blood,

and consequently of the whole body, may be occasionally augmented

or diminished. Thus the body may be considerably altered in its

constitution, and rendered more liable to diseases than it was before;

but still it is found that diseases continue to appear at uncertain

intervals, though all the causes we are able to discover, or at least

all that are constantly evident to our senses, continue to operate

without intermission. Though the obvious qualities of air and climate

therefore may _predispose_ to an epidemic, we cannot affirm any thing

farther: the direct _cause_ is always different, and hath hitherto so

much eluded our researches, that we can have little hope of discovering

it, except by reasoning from facts less obscure.

8. In all the operations of nature which we have access to investigate,

the action of electricity is so much concerned, that we can scarce

suppose it to be wanting in any of them. That it is concerned in

preserving the health of the human body is likewise certain, if it

be the fluid which acts in the nerves, as most probably it is. But

whatever preserves health will also bring on disease, if it be applied

to that purpose; and we have already seen that this fluid is capable

of bringing on the most dreadful symptoms, viz. mortification in its

highest stage, fever, convulsions, bilious discharges, lethargy, &c.

If it be capable of producing all these, can we say that it is not

capable of producing those of an inferior kind, or of varying diseases

and symptoms without end, according to the immense diversity of its

action? It may be said that this disease was occasioned by a violent

stroke of electricity, similar to lightning; but how many people have

declared, that, in the beginning of some violent epidemics, they have

felt a sudden stroke at the time of seizure! Dr. Hodges mentions this

in the plague of 1665 at London, but treats the accounts as effects of

a distempered imagination. Procopius relates the same of the plague in

his time, viz. that many of the diseased felt a stroke. It is true that

they said such strokes were given by spirits in human shape, in which

we know they must have been deceived; but, though they were mistaken

in supposing that they had been struck by a spirit, it does not from

thence follow that they felt no stroke at all. The people mentioned

by Dr. Hodges did not say that they were struck by a _spirit_, yet he

treats their accounts with as great contempt as though they had. Where

people have no interest in deceiving, we ought certainly to look with

a favourable eye upon their testimony; for, even although some part of

it should be incredible, we have still reason to believe that there

is some foundation for what they say. Thus, the poor sailor, so much

frightened at the sight of a large bat in New Holland, was certainly

mistaken in saying that he had seen the devil; he was even mistaken in

saying that he had _horns_;[92] but from all this it would have been

doing him great injustice to say that he had seen nothing. In like

manner, when numbers of people in Procopius’s time said that they were

struck by spirits, when we find others in Dr. Hodges’s time saying that

they were struck by some invisible agent, when we know that electricity

_can_ strike in an invisible manner, it certainly is more reasonable

to conclude that violent diseases sometimes do begin by an electric

stroke, than that _all_ who said they were struck in this manner were

madmen or liars.

[92] In the account of this sailor’s speech a most essential part of

the devil’s character was omitted. The speech, according to Capt.

Cook, was, that the devil “was about the size of a one gallon keg,

and very like it. He had horns and wings; and he was so near, that,

if I had not been _afear’d_, I might have touched him.” (See p. 105,

n.)

It may now again be asked, if the plague, or violent epidemics, be

produced by electric strokes, why are they not much more frequently

felt, or by what are those milder diseases produced which are not

accompanied by any sensible stroke? Here we can be at no loss to say,

that whatever produces the highest disease, may also produce the

lowest. But, besides this argument, we have positive evidence that

commotions in the electric fluid will not only produce sickness, but

very extraordinary and seemingly miraculous effects upon inanimate

bodies. It has frequently been remarked that people are sick during the

time of earthquakes, when the electric matter is in violent agitation.

This has been accounted for from the motion of the earth, as the motion

of a ship produces sea-sickness. But Dr. Hillary mentions a slight

earthquake in Barbadoes where people were affected with sickness and

vomiting for _some hours_ after the phenomenon had ceased altogether;

which undoubtedly shows, that a certain state of this fluid will

disorder the human body, independent of every other circumstance,

either of the heat or cold of the atmosphere, or the oxygen, hydrogen

or azote contained in it. Again, we find that a certain state of the

electric matter is not only capable of producing very extraordinary

effects by itself, but also of communicating a power to the human

body to do the same. A good number of years ago, a powder-mill near

London was blown up. The explosion, as might be expected, was violent

and tremendous; but the most remarkable circumstance was, that the

electric matter, for a great way round, was thrown into unusual, though

invisible, commotions, which discovered themselves by the rattling and

breaking of china dishes though sitting apparently undisturbed upon

their shelves. This phenomenon did not suddenly cease, and, during

the time of it, some people appeared to be infected by an electric

_contagion_; the power of breaking china seemed to reside in their

bodies, so that if they approached or touched this kind of ware,

it would instantly fly to pieces. Accounts of this extraordinary

circumstance were published in many of the periodical works of the

time, particularly in Dodsley’s Annual Register; and the fact seems

to be established beyond controversy. It proves that what has been

advanced by Dr. Priestley concerning electrical operations, on a small

scale, holds good also on a large one, viz. that the fluid, when

once set in motion, is not easily quieted. It establishes the fact,

also, that by great explosions of gun-powder the electric matter is

violently agitated; and the consequence of these agitations we cannot

know. It may be said, indeed, that in the operations of nature the

electric matter is often violently moved without any sickness taking

place; neither in fact did any ensue at the time the powder-mill in

question was blown up. But it must be remembered, that, in the ordinary

course of nature, if the electric matter is moved, a receptacle is

also provided for it. In a thunder-storm, where immense discharges

of electricity are made from one cloud, there is another cloud of an

electricity opposite to the former ready to receive them, or if not,

the earth itself is frequently struck. In eruptions of volcanoes, the

smoke receives the electricity discharged, and becomes charged with

lightning of a more dangerous kind than that of ordinary thunderstorms;

and Sir William Hamilton relates, that in the great eruption of

Vesuvius, in 1794, lightning of this kind proceeded from the smoke for

no less a space than _seventeen_ days. But in artificial commotions

of this fluid, where nature has not provided any receptacle, the

phenomena must be quite different; and though we may with safety to

ourselves interfere with the operations of fire and electricity to

a certain degree, yet we may at last rouse these terrible elements

into such action as will prove fatal to great numbers. Hence possibly

may arise in part some of those sicknesses which take place after

battles, in violent sieges, &c. An instance of this is said to have

happened at Valenciennes, when last besieged by the Duke of York. A

disease prevailed chiefly among women, children, and persons of a weak

constitution; great numbers of whom died so suddenly that it was at

first thought to be a plague, until it was found not to be infectious.

The blood was found greatly dissolved, and the physicians ascribed it

to the monstrous bombardment and cannonading which took place during

the siege. Such was the account published in some of the newspapers

of the time, and from the subsequent considerations it will not seem

improbable that such things may take place.

From the experiments of Mr. Bennet (an English gentleman who has made

several discoveries in electricity) it appears, that we can neither

brush a piece of chalk, open or shut a book, or do several of the most

trifling actions, without agitating this subtile fluid in a perceptible

manner. It is well known that in some cases we cannot stroke a cat’s

back without making the electric matter visible, and in some positions,

by putting our fingers near the ears of the animal, very pungent sparks

will be received. If then we can neither open or shut a book, if we

cannot stroke a cat’s back, or approach a finger to her ear, without

agitating the electric fluid, is it reasonably to think we could burn

a book, or kill a cat, without doing the same? Certainly it is not.

If we cannot burn a book or kill a cat without affecting this fluid,

it cannot be supposed that we can burn a house or kill a man without

producing a still greater commotion; and in proportion to the extent

of our devastations, and the multitude of our massacres, the invisible

agitation of this element must become still greater and greater. In

all these transactions it must be remembered that the fluid is forced

out of its natural mode of action; for electric matter is made for the

preservation, not the destruction, of life: but if, by long continued

and extensive application of its power to a contrary purpose, we in

some measure pervert its action, no wonder that we then feel the

consequences of our own proceedings by its partly turning its power

against the human race altogether.

Again, the human body is not made for the habitation of an infernal

spirit, but for one of a quite different character. The boisterous

passions of fury, discord and hatred ought never to disturb the

mind, which is made for the habitation of endless peace and joy. The

tumultuous passions are enemies to health; and this is so well known

to physicians that they are very careful to prevent their patients

from being any way ruffled or disturbed by violent passions. It is

true these passions act upon the rational soul, which we may suppose

to be distinct from that merely animal spirit, probably no other

than the electric fluid, which runs along the nerves; but experience

shows that each of these can act upon the other; a disorder in the

body, particularly in the nervous system, will sometimes disturb the

rational soul in such a manner as almost entirely to deprive it of

all its faculties; while on the other hand a violent commotion in the

rational soul may at once extinguish all the powers of life, as has

already been shown from Zimmerman. Now, let any one consider what

must be the sensations of those who engage in war. Whatever pity or

humanity may be pretended, it is evident that in the day of battle all

these sensations must give way to horror and fury on the part of the

conquerors, and terror and dismay on that of the vanquished. That these

passions never do entirely subside, is evident from the treatment of

conquered countries and conquered people. When Jenghiz Khan beheaded

his prisoners by hundreds of thousands, when Tamerlane pounded them in

mortars, when Khouli Khan caused those who offended him to be carried

from place to place, and a piece of flesh to be cut from their bodies

at each stage, what must have been the sensations of these miscreants,

and those whom they employed in such horrid scenes? On the other hand,

what must be the sensations of those who see their dearest relations

torn from them and slaughtered or treated even worse than if they were;

themselves driven from their peaceable abodes to wander like beasts,

while their cruel enemies exult in the miseries they have brought upon

them, and glory in doing all the mischief they can, and spreading

devastation as wide as possible? Thus, every passion, inimical to

health, must, on both sides, be carried to its utmost height; and if

these horrid scenes overspread a great part of the earth, for hundreds

of years together, is it any wonder that plagues should ensue? If man,

forgetting the dignity of his nature, converts the habitation assigned

him by his Maker into a kind of hell, and himself into a devil, can

we wonder that, in such circumstances, the spirit of life, originally

appointed for his use, should become to such a being the spirit of

death? Dr. Moseley seems to speak slightly of Helmont for assigning

_moral_ causes to fever; but if we consider the matter attentively it

will certainly be found that the moral conduct of the human race in

general has more connexion with the diseases which befal them, than we

are perhaps willing to believe.

Most authors speak of some hidden, unknown and unsearchable power in

the atmosphere as the occasion of plagues and other epidemics; and,

from what has been already laid down, it seems by no means improbable

that this hidden power resides in the electric part of it. But we

know that electricity proceeds from the earth, as well as from the

air; so that in some countries the evaporation of electric matter

from the earth may affect the health of the inhabitants, as well as

the constitution of the atmosphere. Hence some spots may be naturally

unhealthy, and incurably so, independent of either the perceptible or

imperceptible properties of the air; their healthiness may occasionally

increase or decrease by means entirely beyond the reach of our

investigation. Here then our inquiries must stop. We may indeed make a

general conjecture that such differences are produced by the action of

the electric matter; but, unless this action be pointed out, and some

connexion traced between the situation of the country and a particular

mode of action of the fluid, we may as well own our ignorance at once.

9. From all that has been said, then, we may conclude, that none of the

obvious properties of the atmosphere, or of any constituent part of

it, or of any variation in the proportion of its ingredients, can be

accounted the cause of epidemic diseases; that the hidden constitution

of the atmosphere may with probability be attributed to the agency of

the electric fluid, and that by the action of this secret cause, along

with the other more obvious properties of the air, such as heat or

cold, moisture or dryness, &c. the human body may be so predisposed to

diseases, that they will readily break forth; and that the conduct of

mankind themselves may greatly contribute to this predisposition; the

question then is, supposing every thing to be thus laid, like a train

of gun-powder, what is the spark which first sets it on fire. Does the

disease arise spontaneously in the first person affected by it, or does

it come from without?

In answer to this we must in the first place observe, that the accounts

of all plagues mentioned in profane history trace their progress from

one place to another; whence the probability is, that at its origin the

disease was confined to a few, perhaps to a single person. In very few

cases, however, has it been possible to trace it to an individual; and,

even when this has been done, the unfortunate individual is always said

to come from some other place. The instance quoted from Dr. Moore is

perhaps the only one upon record where the plague arose spontaneously

in any person separated from society; and from a single instance little

can be inferred. In those terrible examples we have given of people

being burned to death without any accident from terrestrial fuel, the

agent seems almost certainly to have been electricity. In the plague of

Procopius, said not to have been infectious, the strokes complained of

by many patients seem to indicate an action of the same fluid. The same

in the plague at London, which was infectious, and likewise of others.

But, in cases of plagues which are not infectious, another question

arises--By what means do such diseases spread from place to place?

for even this dreadful pestilence of Procopius did not overspread the

earth at once, but is said to have begun at Pelusium in Egypt. To this

no answer can be given. To suppose an omnipresent contagion in the

atmosphere, proceeding either from contagion or any thing else, cannot

be admitted; for upon this supposition the whole world must have been

infected at once. The cause, whatever it was, plainly moved from one

place to another, or was successively generated in different places.

Recourse may be had to the precipitation of the contagious matter

of former plagues from the atmosphere; but to account for this in

succession will be found very difficult; and the same difficulty will

attend every other solution which may be attempted. Mr. Gibbon indeed

censures Procopius for supposing it not to have been infectious; and

perhaps the spreading of the disease by infection is the only way by

which we can account, in a satisfactory manner, for the way in which

it diffused itself over the world, which was, by first infecting the

maritime places, and afterwards those which were more inland; always

visiting the second year those whom it had spared the first.

10. Lastly, to form some idea of the nature of contagion, or infection,

as it is more properly called, we must consider, that as the ethereal

fluid, acting as heat, pervades the human body, so doth it likewise

under that particular modification which we call electricity. Some

kinds of air, indeed most of those with which we are acquainted, seem

to act by augmenting or diminishing the latent or the sensible heat of

the body. Such, when taken in moderate quantity, may produce slight

diseases, as head-ach, &c. and, when taken very largely, may even put

an end to life at once, either by rarefaction of the blood and rupture

of the small vessels, as is the case with fixed air, or by oppressing

the lungs entirely with their basis, which cannot be thrown out by the

breath as in ordinary respiration. Others may affect the electricity

of it, or what in this treatise has been called the _vital spirit_,

as well as the latent or sensible heat. The consequence of this will

be diseases of a more serious nature; for upon this principle in all

probability depend not only the secretion and proper regulation of

the nervous fluid, but what has been called the _crafts_, or proper

consistence of the blood and other fluids. Hence it is possible that

such an instantaneous shock may be given to the body, as will not only

injure the organization in an irreparable manner, but may be felt

throughout the whole body like an electric stroke, even though there be

no visible fire, or sensation of burning, as in the case of the Italian

priest and others, who perished in such a miserable manner.

Formerly all acute diseases were supposed to depend on morbific matter

taken into the body, and absorbed by the blood: the cure was thought

to be accomplished by the expulsion of this morbific matter from the

body by sweat, or some of the other natural evacuations. The doctrine

was attended by many difficulties, and in many cases did not admit

of a satisfactory explanation. It was therefore laid aside, and the

debility or excitement of the nervous system arose in its place. But

this new system admitting of _miasmata_ and _contagion_, it was plain

that morbific matter still kept its ground. With a view, it would seem,

to render the nervous theory more complete, it has been found necessary

to deny the doctrine of contagion and infection entirely. This has

been done, wherever there was a possibility; but the phenomena of the

small-pox and measles, as well as those arising from poisons, still

militated strongly in favour of morbific matter. To avoid the force

of arguments drawn from these sources, the doctrine of absorption was

denied, and contagions of all kinds were said to act immediately upon

the nervous system without affecting the blood or other fluids. At last

the matter seemed to be decided by the experiments of the Abbe Fontana

on poisons. He found that some proved fatal by being mixed with the

blood, others by being applied to the nerves, and others by being taken

into the stomach. Even this did not give satisfaction. It was contended

that the effects of poisonous bites were too quick to be accounted for

on the principle of absorption; that, after the most violent symptoms

had commenced, they might be removed by cutting out the part affected;

and consequently that, instead of any absorption by the blood, we were

only to believe that the nervous system was irritated.

“Poisons, (says Dr. Girtanner) remedies, and, in general, all

surrounding bodies, acting only on the irritable fibre, it follows that

they act upon the system in a similar manner, and that every substance

capable of producing the greatest possible effect upon the fibre, that

is to say, every substance capable of exhausting all the irritability

both of the fibre itself and of the system, in an instant, as for

instance, laurel water, or white arsenic, is also capable of producing

all the inferior degrees of action, either by acting on a fibre less

irritable, or by acting upon the same fibre, but in a less quantity.

Laurel water, opium, white arsenic, ammoniac, are of course both

medicines and poisons capable of _healing_, as well as of _producing_,

_all maladies whatsoever, without exception_.[93] And this is

confirmed by a number of experiments which I have made upon different

animals. This _truth_ seems to me _of the utmost importance_; and the

Abbe Fontana, who made more than six hundred experiments to prove that

ammoniac is no remedy against the bite of a viper, would have saved

himself the trouble, had he known it. If, instead of applying the venom

of the viper to so many animals, and afterwards applying ammoniac to

the wound, he had made a single comparative experiment, and applied

ammoniac to a wound made by a lancet that was not poisoned, he would

have found that ammoniac itself, applied in this manner, would have

produced a disease exactly analogous to that caused by the venom of

the viper; and, consequently, so far from removing the malady, must

necessarily increase it, by exhausting the irritability of the fibre in

a much less time than the venom of the viper by itself was capable of

doing. Mr. Fontana has made more than six thousand experiments upon the

poison of the viper; he employed more than three thousand vipers, and

caused to be bit more than four thousand animals; and the conclusion

he drew after this truly enormous number of observations was, that

the poison of the viper kills all animals, and produces the disease

by its action on the blood. But why did Mr. Fontana neglect to make

the decisive experiment, the _experimentum crucis_ of Bacon? It is

well known that frogs, and many animals with cold blood, live a long

time without the heart, and entirely deprived of blood. If therefore

the poison of the viper kills animals by its action on the blood, it

will not destroy frogs without blood. But experiment contradicts this

reasoning. The poison of the viper will kill frogs without blood in

as short a time as it kills those animals who have not lost their

blood. It is not therefore by its action upon the blood that the

venom of the viper destroys animals; and thus does it happen that a

single experiment frequently overturns all that _six thousand_ other

experiments have apparently established. According to my experiments,

poisons operate upon the blood just as they do upon the muscular fibre,

by depriving it of its principle of irritability, or of its oxygen.

After having made this observation upon the experiments of Mr. Fontana,

I must do him the justice to add, that I have found all his experiments

very accurate, and that in all those which I have repeated, the result

has been exactly conformable to the account given by him; it is in his

conclusion only that he appears to be deceived.”

[93] This is an assertion so extravagant, that is difficult to

imagine what could induce any one to make it. Did our author ever

hear that laurel water, &c. produced the venereal disease, the

plague, yellow fever, gout, stone, small-pox, &c. &c. or to what

patients and in what diseases did he ever administer this remedy

with success? I mean not to deny that these substances will cure

_some_ diseases as well as produce others; but such an unqualified

expression that they can not only produce but cure all diseases

without exception, never can be admitted.

On this I must in the first place observe, that since _philosophers_

and _truth_ seem to be so far distant from each other that even _six

thousand_ experiments cannot bring them together, it were greatly to

be wished that in their researches they would pay a little more regard

to humanity. If the Author of Nature has set man at the head of the

creation, if inferior animals must patiently resign their lives to

preserve ours, are we therefore authorised to torment and put them

to death by thousands for every idle whim that comes into our heads?

After Spallanzani, Fontana, Girtanner and a multitude of other learned

_barbarians_ had cut in pieces, boiled alive, poisoned and tortured

thousands of inoffensive animals, new massacres it seems must be made,

and new tortures inflicted, because an _experimentum crucis_ is still

wanted! If knowledge is to be obtained only by such means as these, it

certainly must be derived from a very polluted source.

2. The experiment on which Dr. Girtanner builds so much is far from

being above suspicion. Though we may cut the heart out of an animal,

and let it bleed as freely as possible, yet we certainly overrate our

abilities if we say that _all_ the blood is taken out of it. The more

perfectly an animal is bled, the less irritability it has; which gives

a reasonable suspicion, that, if _all_ the blood could be taken away,

the irritability would cease entirely. In frogs, and all other cold

blooded animals, the blood contains fewer red globules than in such as

are warmer; the circulation is more languid than in such as have warm

blood, and, of consequence, the blood will retain its irritability

for a longer time, and it will likewise be more difficult to deprive

the body of all its blood. In making this experiment, therefore, Dr.

Girtanner ought to have brought unexceptionable proofs that he had

deprived the frog of _all_ the blood it contained. But, as this was

not done, we shall be ready to suspect that some was left; in which

case we should be still as uncertain as before whether the poison acted

on the irritable fibre, or on the blood. But the decisive experiment,

or _experimentum crucis_, seems to have been made by Fontana himself,

by injecting a little of the diluted poison of the ticunas into the

jugular vein of a rabbit. Here the poison was applied to the blood

itself. It could get at no other part of the fibre but the inside of

the vein, which is not accounted very irritable; and the quantity

injected was so small, that the Abbe thought his experiment had

failed; yet the animal died as if by lightning. The moment he turned

his eyes towards it, it was absolutely dead, without discovering the

least convulsive agony, or other sign of some little life remaining,

generally observable for some time in animals killed by the common

methods. On applying the same poison to a large nerve of another animal

of the same species, no injury followed.

3. The dispute is of no consequence, and the experiment will prove the

same thing whether we suppose the poison to act upon the irritable

fibre (the nerves and muscles) or upon the blood. The only important

point to be ascertained is, whether there be in nature any substance

which, applied to the internal parts of the body, or to a wound, will

instantly disorder the whole in such a manner as to bring on a violent

disease which may prove mortal in a short time. If any such there is,

that substance, whether solid or fluid, visible or invisible, may with

propriety be called _contagion_; and if any such proceeds from the

body of a diseased person to one in health, the vapour so proceeding is

_infection_. As to the _mode_ of its operation we are little concerned;

the sudden manner in which people are affected shows that poisons

kill by suppressing in a very short time the principle of life, which

seems to be analogous to electricity, or rather the very same with

it; neither is it more incredible that the poison of a serpent should

kill by disturbing the natural electricity of the body, than that the

stroke of a torpedo, or electrical eel, should kill by the same means.

The only difference is, that, in the case of poisons, the pernicious

substance is introduced into the body itself; in the torpedo, it comes

with violence from without. The former we may compare to the silent

discharge of an electrified jar by a point, the latter to its discharge

with a violent flash by a knob. But that in poisonous bites the blood

is greatly affected, and that in a very short time, we certainly know.

There are some kinds of serpents whose bites are so suddenly fatal,

that no cure can be applied: one of these, called the small _laharra_,

is mentioned by Mr. Bancroft in his Natural History of Guiana. Mr.

D’Opsonville, in his Philosophic Essays, takes notice of one in the

East-Indies, which he calls the _poison serpent_ or _serpent poison_,

which seems to be as bad as the _laharra_ mentioned by Bancroft. This

too is but small, viz. two feet long, and very slender. Its skin is

freckled with “little traits of brown, or a pale red, and contrasted

with a ground of dirty yellow: it is mostly found in dry and rocky

places, and its bite proves mortal in less than one or two minutes. In

the year 1759, and in the province of Cadapet, I saw several instances

of it; and, among others, one very singular, in the midst of a corps of

troops, commanded by M. de Bussy. An Indian Gentoo merchant perceived

a Mahometan soldier of his acquaintance going to kill one of these

reptiles, which he had found sleeping under his packet. The Gentoo flew

to beg its life, protesting that it would do no hurt if it was not

first provoked; passing at the same time his hand under its belly, to

carry it out of the camp; when suddenly it twisted round, and bit his

little finger; upon which this unfortunate martyr of a fanatic charity

gave a shriek, took a few steps, and fell down insensible. They flew to

his assistance, applied the serpent-stone, fire, and scarifications,

but they were all ineffectual; his blood was already _coagulated_.[94]

About an hour after I saw the body as they were going to burn it, and I

thought I perceived some indications of a _complete dissolution of the

blood_.”

[94] There must certainly be some error here; for as he mentions a

_dissolution_ of the blood so soon afterwards, we should think it

impossible that any coagulation would have taken place. Perhaps the

word only imports that the circulation was completely stopped.

The bite of the _brulan_ or _burning serpent_, according to the same

author, is almost as terrible. “This is nearly of the same form with

the last, its skin is not quite so deep a brown, and is speckled with

dark green spots: its poison is almost as dangerous, but it is less

active, and its effects are very different. In some persons it is a

devouring fire, which, as it circulates through the veins, presently

occasions death; the blood dissolves into a lymphatic liquor resembling

thin broth, without apparently having passed through the intermediate

state of _coagulation_,[95] and runs from eyes, nose and ears, and even

through the pores. In other subjects the poison seems to have changed

the very nature of the humours in dissolving them; the skin is chapped

and becomes scaly, the hair falls off, the members are tumefied, the

patient feels all over his body the most racking pains, then numbness,

and is not long in perishing.”

[95] The blood certainly does not coagulate in the vessels, in any

case whatever, unless by injecting something into them.

From these accounts it is plain that poisons do operate very powerfully

on the blood; and if they do so in one case it is reasonable to think

that they do so in all. According to the degree of strength of the

poison, however, we are sure that the effects will be more or less

visible to us; but, though we should not be able to perceive any

alteration whatever in the consistence or colour of the vital fluid, we

cannot positively say that it has not undergone any change; for the

spirit which operates in it is too subtile for our observation. In the

beginning of almost all diseases, perhaps, blood drawn from a vein will

not be perceptibly different from that of a person in health; and Dr.

Fordyce particularly takes notice of this in fevers; but as the disease

goes on, an alteration becomes very perceptible, which gives just

ground for suspicion, that there had been some alteration from the very

first, though invisible to us.

After all our disputes, however, we shall find that the controversy,

though ultimately important, begins more about words and trifles than

any thing else. Dr. Brown used the word _excitability_, Dr. Girtanner

uses _irritability_, and the author of this treatise, the words _vital

spirit_ and _electricity_, to express something equally unknown to

them all. The only difference is, that Drs. Brown and Girtanner speak

of their excitability and irritability as a kind of power essentially

inherent in living bodies, acted upon indeed by certain substances,

but incapable of deriving any supply from without; the author of this

treatise considers it only as a modification in the human body, or an

_organization_, if we please to call it so, of that fluid which he

believes to be universally diffused, under the names of heat, light

and electricity. Hence that portion modified or organized in the human

body must be under an entire and absolute dependence upon the immense

mass of surrounding fluid, and, by any alteration in the motions of it,

must be often very perceptibly affected; nevertheless as this fluid was

originally created to preserve and not to destroy human life, there is

much less danger from a _natural_ than from an _artificial_ commotion

in it. In some visible bodies, such as poisons, the fluid acts in such

a manner as to counteract the operation of that part which is organized

in the blood or nerves, or both. Hence on the introduction of such into

the body the disorder flies like lightning through all parts of it,

and in a very short time brings on death. In those vapours properly

called _contagions_, the opposite action is less violent, and therefore

the disorders they produce are in proportion. Hence such diseases may

either be promoted or retarded by the perceptible properties of the

atmosphere, which in poisons have little or no effect. There is indeed

a remarkable difference in the strength of the poison secreted in the

bodies of serpents at certain seasons of the year, or according to

their food. M. D’Opsonville observes that the poison of serpents is

in general more powerful, the more they live in hot and dry places,

where they feed upon insects that are full of saline, volatile and

acrimonious particles. But, notwithstanding this difference in the

strength of poisons according to the circumstances of time and place,

there is not the least reason to suppose that poison of a given

strength would not produce the very same effects, let the state of the

atmosphere be what it would.

If therefore we certainly know that there are some kinds of aerial

vapours which when applied to the human body do exert a power directly

opposite to the vital principle, there is no reason to doubt that

such vapours may be confined among certain soft substances, such as

cotton, wool, &c. and remain there for an unknown length of time,

again exerting their malignant powers, when a fresh object comes in

their way. Besides, as all kinds of air with which we are acquainted

consist of a basis united with the ethereal fluid and volatilised by

it, there is reason to suppose that contagions themselves are formed

in the same manner. Some kinds of air also are very easily decomposed,

in which case the basis attaches itself to some terrestrial substance,

the ethereal fluid which volatilised it diffusing itself around in an

invisible manner, but generally with a perceptible heat. Fixed air

affords a notable example of this; for, by exposing it to lime-water,

or even dry lime, alkaline salt, volatile alkali, or common water, a

decomposition of the air very readily takes place, and its basis is

found to be attached to those substances. What happens to fixed air

may also happen to _contagion_. The basis of it may have a tendency

to unite itself to cotton, or such like substances, and thus may

not only infect them, but concentrate itself to such a degree as to

produce a disease much more violent than that of the person who gave

the infection; and something of this kind has even been observed with

regard to infected cotton. But now another question occurs: As fixed

air, by being attached to terrestrial substances, loses its aerial

property, why should the basis of contagious effluvia still retain its

malignant quality though in a state of decomposition? Here we are again

helped out by analogy. Fixed air is known to be capable of resuming

its aerial properties occasionally, from causes unknown to us, though

we cannot suppose them to be any thing else than the invisible action

of the ethereal fluid so often mentioned; which, being guided by laws

unknown to us, we cannot possibly comprehend. The fact, however,

is certain, that the basis of fixed air does very often quit the

substances to which it is attached, and assume an aerial state in great

quantity, and with very mischievous effects. Thus the old lavas of

volcanoes, if chemically tried will be found at _all_ times to contain

great quantities of the basis of fixed air, but it is only at _some_

times that the mofetes which are supposed to be the air itself, break

forth.[96] In like manner the strata under ground always contain great

quantities of the aerial basis, but the _damps_ in mines, which are

certainly known to consist mostly of fixed air, do not always appear;

neither do they gradually accumulate, but come suddenly, spreading

unexpected destruction among those who unfortunately come in their way.

The same may take place with contagion. After remaining some time in a

state of decomposition it may have a tendency to become volatile again,

or it may lie dormant entirely; and this last will explain what is

quoted from Dr. Russel, p. 178, that sometimes commerce may be carried

on with infected places without danger.

[96] See p. 128, note.

Thus we see that the dispute, originally begun about a word, involves

at last a matter of the utmost importance; for, if it be found

unreasonable to believe that any such thing as contagion exists or can

exist, it follows of course that it is also unreasonable to take any

precautions against it. Mr. McLean even goes a step beyond those who

deny the existence of contagion; for we find him also denying that

putrid effluvia can produce epidemics; according to which doctrine, it

seems, we may not only safely visit places accounted the most dangerous

on account of infection, but live in all manner of filth and nastiness

with impunity. It is plain that no person can ever prove that it is

impossible for contagion or any thing else to _have an existence_.

Indeed if nothing had ever induced people to believe that it did exist,

it would have been superfluous to say any thing about it. But when we

have innumerable testimonies to the contrary; when the opinions of the

greatest physicians, as Dr. Lind, Dr. Clarke, Dr. Mead, Dr. Sydenham,

Dr. Fordyce, Dr. Russel, &c. agree that not only the plague, but every

kind of fever, is infectious; when we know from the analogy of nature

that contagion _may_ exist; when we know that there certainly _are_

powers in nature able to produce it; is all this to be thrown aside

merely on the strength of a theory, and a theory too which can never

be proved? for it is impossible to prove the _non-existence_ of any

thing, much less the _impossibility_ of its existence. The lives of

mankind are too precious to be sported with on philosophical theories;

and prudence will always suggest, that wherever danger may at any time

arise, there it is proper to be on our guard.

Dismissing at length the subject of contagion in general, we now enter

upon the question, Whether doth it appear from fair investigation of

testimony, that the plague has, at any time, been communicated by

contagion or not? And here I shall confine myself to what has been

adduced by Dr. P. Russel on the subject; for, if we find that the

disease has only _once_ been introduced by contagion, it signifies

nothing though we were able to prove, which we never can do, that it

had been _an hundred_ times bred in some other way. The matter is of

too great importance to allow even a _chance_ of its importation by the

neglect of the precautions necessary to prevent it.

Our author begins with observing, that though the infectious nature

of the plague had been a question much agitated in the schools, “it

was less to be expected that physicians who had been engaged in

practice among the infected should have persisted in the opinion that

the disease was never communicated by contagion.” Such, however, has

been the case. In 1720 some French physicians laboured exceedingly to

prove that the plague which then raged at Marseilles and throughout

Provence arose from corrupt humours bred in the body in consequence

of irregularity in the seasons, and bad aliment; that it was spread

by the same means, in concurrence with terror, grief, despondence,

or other debilitating affections of the mind; but was neither bred

nor disseminated contagion. Dr. Russel mentions in a note, seemingly

with surprise, that “_so late_ as the year 1778, Dr. Stoll of Vienna

should have written expressly against the doctrine of pestilential

contagion.” To this professor he thinks it a sufficient answer to quote

the following passage from Mr. Howard on Lazarettos, “It must appear

very strange, that he should go back to Livy’s Roman History for proofs

to establish his point, totally neglecting all the facts concerning the

numerous visitations of the plague recorded in modern medical books,

or which had happened during his own time. I suppose professional men

will lay very little stress upon all that can be said on pestilential

diseases, in general, which happened in wars and sieges two thousand

years ago, as applied to the plague properly so called, a disease

then confounded with various others from which the accuracy of latter

observations have sufficiently distinguished it.”

Dr. Russel complains of the French physicians at Marseilles having

made unfair representations; particularly that while they produce as

irrefragable arguments against contagion their own escape unhurt, amid

circumstances of supposed danger, they pass slightly over, or omit

all mention of numbers of the medical assistants whom they saw perish

in the exercise of their profession. M. Dedier, however, who at first

opposed the doctrine of infection, at last renounced his opinions so

far as to allow that the disease might be communicated to dogs by

injecting pestiferous bile into their veins; and he likewise admitted

that it might be communicated from one human creature to another, by

drawing in for a considerable time the breath of a diseased person,

putting on his shirt, lying in the same bed-clothes, and touching the

wounded parts of one’s own body with hands embrued with the sweat or

blood of one infected. He affirms, however, that the atmosphere of a

person in the plague is no more to be dreaded than that of a venereal

patient; and that the touching or dressing of buboes or carbuncles

is not attended with any danger. He restricts the infectious quality

of the humours to the bile; but the _inoculation_ of a person by the

matter of a pestilential ulcer[97] undoubtedly decides this point

against him.

[97] See p. 196.

On the subject of contagion Dr. Russel observes, that the vague manner

in which the word has been used has given rise to much confusion. Some,

taking advantage of the inaccurate mode of expression on this subject

used by Dr. Mead, attacked him with sophistical nonsense. The following

may serve as a specimen, from a pamphlet entitled “Distinct Notions

of the Plague, &c. by the _Explainer_.” This _explainer_ observes,

that, according to Dr. Mead, “air and his other causes propagate and

spread contagion, not the plague; and therefore either contagion and

the plague are the same, or else the plague is not considered; if the

first, then his causes propagate the plague; and the plague accompanies

the plague; an excellent defence! But, if the plague is out of the

play, then contagion accompanies nothing.”--From writers like this we

certainly can expect nothing.

The opinion of Dr. Cullen concerning contagion has been already

noticed, p. 179; but though he supposes it to be a matter floating in

the atmosphere, he observes that contagions are never “found to act

but when they are near to the sources from whence they arise; that is,

either near to the bodies of men, from which they immediately issue,

or near to some substances which, as having been near to the bodies of

men, are embued with their effluvia, and in which substances these

effluvia are sometimes retained in an active state for a very long

time. The substances thus embued with an active matter may be called

_fomites_; and it appears to me probable, that contagions as they arise

from fomites, are more powerful than as they arise immediately from

the human body.” This opinion concerning the great power of contagion

imbibed by certain substances is conformable to what was above laid

down by reasoning _a priori_ on the nature of contagion.[98] It is

doubted by Dr. Russel, but Dr. Lind adopts it, and Van Swieten gives

his opinion to the same purpose. “I am convinced, that the body of the

diseased, kept exactly neat and clean, is not so liable to impress the

taint, as his late wearing apparel, dirty linen, and uncleanliness of

any sort about him long retained in that impure state. I say, these

last contain a more concentrated and contagious poison than the newly

emitted effluvia or excretions of the sick.”

[98] See p. 226.

With regard to the original cause, our author observes, “that the

plague is bred or produced originally from vitiated human effluvia, is

a matter which has by no means been established on proper authority.”

Setting aside therefore inquiries of this kind, he thinks it sufficient

to inquire whether the infection be not communicated from a sick to a

sound person by immediate contact; whether it be not also communicated

at some distance through the medium of the air; and whether substances

of various kinds do not imbibe the infectious effluvia, and retain them

for a considerable time. So far as these points admit of proof from

the experience of times past, the question concerning pestilential

contagion will admit of a solution, independent of all theoretic

reasoning whatever.

2. On the subject of contagion people have been embarrassed by

confounding the true plague with other malignant diseases. This

has been done, not only by the ancients, but by some moderns; and

our author quotes Dr. Pye, saying “that any epidemic sickness,

which rages with more than ordinary violence, and which occasions

extraordinary mortality amongst mankind, may be, and is, properly

termed a pestilence, or the plague.” By not attending to the proper

distinctions, in these cases, circumstances belonging to what are

commonly termed malignant or pestilential fevers will often come to be

very improperly applied to the true plague.

3. “It may be remarked, that those who contend in favour of contagion,

from zeal for accumulating proofs, have collected a number of

facts from historical records of very unequal authority, and often

with little critical skill in discrimination. Of this error their

antagonists availing themselves, have selected from the mass the

instances most liable to doubt or objection, and have endeavoured, by

their manner of arranging them, to place the whole in a ridiculous

light; while more important instances are either evasively past over,

misstated in the representation, or invalidated by general declamation

on the little credit due to historians in matters of physic, or

the prejudices prevalent in ancient times of ignorance, and on

contradictions to be found in the arguments of those who support the

system of contagion.”

To this the Doctor adds the great quantity of hypothetical reasoning

which has been introduced into the controversy, and above all the

unfair dealing of the parties in carrying on the dispute, which has

reduced the matter from “a calm inquiry in pursuit of truth, to a

wrangling contest for victory.” Lastly he insists, that, had it not

been for the misrepresentations and sinister dealings of those who

have written against contagion, “the question seems to have been

properly resolved in the affirmative;” and he complains greatly of the

conduct of the Montpelier physicians in this respect, insomuch that

“their misstating of circumstances, and the partiality so evidently

discoverable in their narrative of cases, will serve more effectually

to remove doubts on the subject, than any arguments that could be used

against their hypothesis.”

On the subject of contagion our author observes, that some difficulties

still remain; but these, though proper subjects of future inquiry,

“do not appear to be of force sufficient to invalidate facts already

established. It is well known, that the same person who has been

inoculated two or three times for the small-pox without effect, even

in an epidemic season, has afterwards received the infection upon

repeating the operation at a distance of time when the disease was

hardly sporadic. The cause of this remains unknown; but ignorance of

it was never produced as an argument against the reality of variolous

contagion.... If, of one hundred persons exposed to the infection

of the plague by a near aproach to the sick, ninety should fall sick,

shall human inability to assign satisfactory reasons for the escape of

the other ten be converted into a positive proof against the disease

having been caught by contagion? If persons retired from all commerce

with the infected and their attendants, breathing the same air with

the rest of the inhabitants, and nourished by the same aliment, remain

untouched during the ravage of the plague, as long as they continue

secluded, but, upon unguarded communication, are taken ill like others;

can any rational doubt be entertained about the cause of their former

security? Or if through stealth, or neglect of requisite precautions,

substances tainted by the sick should be conveyed into these secluded

retreats, and persons living temperately as before, ignorant of what

had happened, and consequently in the midst of imaginary security,

happen to be seized with the distemper; can it with any show of

reason be ascribed, not to contagion, but to terror, or to colluvies

in the stomach and bowels, produced by intemperance and bad aliment?

The instances here alluded to are not the _creation of fancy_, but

_strictly consonant to repeated experience_ in Turky; to say nothing at

present of what has been observed at Marseilles and in various cities

in Europe.”

“But a greater difficulty than that of all persons not being equally

susceptible of the infection arises from the cessation of the plague,

at a period when the supposed contagious effluvia, preserved in

apparel, furniture, and other fomites, at the end of a pestilential

season, must be allowed to exist, not only in a much greater quantity

than can be supposed to be at once accidentally imported by commerce,

but in a state also of universal dispersion over the city: the fact,

however unaccountable, is unquestionably certain; the distemper seems

to be extinguished by some cause or causes equally unknown as those

which concurred to render it more or less epidemical in its advance

and at its height. In Europe something may be ascribed to the means

employed for the cleansing of houses and goods supposed liable to

retain the latent seeds of infection; but, at Aleppo, where the

distemper is left to take its natural course, and few or no means of

purification are employed, it pursues nearly the same progress in

different years: it declines and revives in certain seasons, and, at

length, without the intervention of human aid, ceases entirely.”

On this we shall remark in general, that the failure of contagion

in some cases to produce the usual effects may proceed from some

constitution of the body, disposing it not to allow the cause to

produce its usual effects at one time, though at another, the

constitution may be so far changed as very readily to admit it.

This opinion has been very generally received among medical people,

who have, to this singularity of constitution given the name of

_idiosyncrasy_. It is, however laughed at by Mr. McLean. “As the

fact (says he) cannot be denied, that a great majority have escaped

after contact with persons ill of diseases supposed to be contagious,

attempts may perhaps be made to account for it by supposing a certain

peculiarity of constitution, which exempts from, or disposes to,

disease. Is it the many who escape that have this happy peculiarity

of constitution; or the few who are seized that are so unfortunate as

to possesses it? The former are evidently too numerous to admit such

an hypothesis. The property must therefore, I conclude, be given to

the latter. But a child here and there is exempted from small-pox,

although exposed to its contagion. In order to preserve a consistency,

this fact must be accounted for by the same or another peculiarity

of constitution. Peculiarities of constitution, then, exempt from

contagion in one case, and dispose to it in another; and thus a

term, which in reality means nothing, may be made to account for any

thing. For my own part I confess my inability to comprehend any other

_peculiarities_ of _constitution_, or _idiosyncrasies of habit_, than

what are constituted by the different degrees of health and disease;

the different states of the excitability.”

In the same manner that Mr. McLean argues with regard to disease,

let us argue concerning bodily strength. Some men are able to lift

a weight of 6 or 700 pounds, but a great majority cannot lift above

300. Whence proceeds the difference? Is it the few who lift the great

weight that _by nature_ have _more_ strength, or is it the many who can

lift only the smaller that _by nature_ have _less_? This is precisely

his argument, and there needs no other refutation than stating it in

this manner. What he calls the states of excitability are as much

_idiosyncrasies_ at the time as any thing else. Mr. McLean will not

deny that a person debilitated by certain causes is more liable to be

seized with typhus fever than one who is not. What does this proceed

from, but that the body of the one is prepared for the disease, is

_constitutionally_ disposed to receive it, or has an _idiosyncrasy_ of

habit disposing to it, which the other has not? It is true, that unless

we point out the circumstances which constitute this idiosyncracy we

do nothing; but Mr. McLean’s scheme, of resolving every thing into

_excitability_, would forever prevent us from doing so. This is the

great deficiency of the Brunonian system altogether; for, by attending

only to the animal life of the body, he seems to have absolutely

forgot that we had any thing in common with vegetables. The bones,

for instance, or indeed any part of the body, cannot be formed by the

power which governs it after it was formed. The growth of the human

body is as strict vegetation as that of a tree; and therefore we find

that after the excitability is entirely gone, after death has taken

place for a considerable time, the body still retains its form, and

would do so forever, did not other powers interfere with it. Human life

therefore is a compound of the vegetable and animal life, the former

being the basis of the latter; and it is the vegetable life which is

much more commonly the subject of disease than the animal life. In

vegetables we observe an _idiosyncracy_ of habit, as well as among

animals. Some, even of the same species, are much more vigorous than

others, and, among some, diseases are much more common than others. In

like manner among the human race some are strong, others weak; in some

the blood is much more confident, and coagulates on exposure to the

air much more firmly than in others. Excitability, or excitement, is

common to all, and the degrees of it (though enumerated by Yates and

McLean in a kind of thermometrical scale) must be merely imaginary,

because excitability is not the object of our senses. The obvious

properties of the body itself, independent of any excitement whatever,

are principally to be considered in medicine. These constitute the

peculiar constitution, or the _idiosyncracy_ of habit, belonging to

each individual. Yet, in defiance of every confederation of these

obvious properties, which all have access to observe, the new system

leads us only to consider an invisible and unknown being called

_excitability_. Hence diseases peculiar to certain constitutions more

than others are said to be occasioned only by certain degrees of

excitability common to all, or perhaps to consist in these very degrees

themselves. Thus a peculiar mode of practice has been introduced, in

which almost the whole materia medica is rejected. We have already

quoted Dr. Girtanner, saying that _all diseases whatever_ may be

_cured_, as well as _produced_, by only _four_ articles; but in the

following quotation he goes still farther. “The art of pharmacy and

the science of prescription will become useless; a phial of alcohol or

laudanum will supply the place of that enormous quantity of drugs which

crowd the shops of apothecaries. The trade of the druggist----but hold;

if I continue this prophetic language, I shall only expose myself to

ridicule,” &c. Reveries of this kind certainly deserve the most severe

reproof. People may no doubt amuse themselves with _theories_ as well

as any thing else, while these theories continue inoffensive; but when

the belief of them leads to a rejection of what has been established by

the _experience_ of many ages, they begin to assume a consequence which

they originally had not. We have already seen that a disbelief of the

doctrine of contagion leads people into a practice accounted dangerous

by many, and which cannot be proved to be safe. A total rejection of

medicines, the efficacy of which have been attested by thousands, and

which never can be proved to have _no_ efficacy, must be attended with

still worse consequences, as thus we should be deprived of the means

of curing those diseases which our imprudence in rejecting the former

doctrine might have brought on. But, to return to the subject of the

plague.

The disappearance of the disease, while all the causes that we suppose

capable of producing it remain in full force, is a demonstration that

it depends on something entirely distinct from the human body, and from

all those powers which perceptibly act upon it. It proves that this

unknown power has only a temporary existence, coming to perfection

at one season, and dying away in another; sometimes capable of being

revived, and sometimes not. This corresponds entirely with what has

been laid down concerning contagion itself, viz. that like other

aerial vapours it is capable of decomposition, and remaining for an

uncertain length of time in a dormant state; but that occasionally it

may revive, and appear unexpectedly, as _mofetes_ arise from lavas,

or damps in mines. After a city has been thoroughly infected with a

pestilential disorder, therefore, there can be no security against its

re-appearance; it being impossible to know whether the contagion may

not be still existing and capable of being revived by some unknown

cause, though it has been dormant ever so long. In such cases it may

with propriety be said to have arisen _spontaneously_, though, had it

not been there at a former period, there could be no reason to think

that it would have appeared at that time.

Dr. Russel next takes into consideration the plague at Marseilles in

1720, of which he says the accounts “are more full, and circumstances

better authenticated, than most of the accounts of anterior plagues

to be met with in books.” From the opposition to the doctrine of

contagion at the time, he also supposes that the facts relative to its

introduction would be severely scrutinized, and falsehoods detected:

“but (says he) if, instead of such detection, the most material

have been passed over in silence, and little more than hypothetical

reasoning opposed to others, the main facts may be considered as

established, if possible, more firmly than they were before.” These

facts are stated as follows: “1. That the plague did not exist in

France before the 25th of May, 1720. 2. That it was imported in goods

from the Levant, by a ship which left the coast of Syria the beginning

of February, and arrived at Marseilles the 25th of May. Two days after

her arrival one of the sailors died; an officer of quarantine who had

been put on board died on the 12th of June, and a cabin boy on the 23d.

Some porters employed in opening the merchandise at the lazaretto also

died about this time. Three others were taken ill in the beginning of

July, with buboes in the groin and axilla. This alarmed the surgeon of

the lazaretto; a consultation was held with two other surgeons on the

28th; the disease was unanimously declared to be the plague, and the

three patients died next day: the surgeon of the lazaretto, with part

of his family, and the priest who attended the sick, were also taken

ill and died.”

From the lazaretto the disease made its way into the city, and began to

appear about the 20th of June. By what means it was introduced is not

directly said; but it seems to have been by smuggling infected goods.

In the beginning of July it began to spread; but a kind of pause having

taken place between the 12th and 23d, the physicians were reproached

with having mistaken the distemper. During this supposed interval,

however, it was discovered on the 18th of July that the disease had

spread in a certain part of the city. A surgeon, employed to examine

into the matter, declared the distemper to be the worm-fever; and

about the 23d the council of health were informed of the death of

fourteen persons in that quarter, and of several others falling sick.

The surgeon still adhered to his opinion, but a physician declared it

to be the true plague. About the end of the month it had got into the

suburbs; four physicians declared it to be the true plague, but their

report was not believed; they were insulted in the streets, and it was

not until some of the inhabitants of better rank were taken ill, that

the true state of the matter gained credit.

“Such (says Dr. Russel) was the rise of the plague at first, and

its progress afterwards in the months of June and July; whence it

appears, that persons on board the suspected ship, those employed in

airing the goods, a surgeon and a priest, who attended the sick, were

among the first infected; that the passengers from the several ships,

all of which ships, the first excepted, brought foul patents, were,

together with their baggage, admitted into the city, after preforming a

quarentine of little more than eighteen days; that the distemper from

the 20th of June till towards the end of July advanced very slowly,

and sometimes seemed to pause; that it attacked chiefly the poorer

sort of people, and was found in distinct quarters of the city; and

lastly, that, _during the first forty days, few or none of the infected

recovered_; a circumstance entirely consonant to what was observed in

the beginning of the plague at Aleppo.”

Three other facts are mentioned by our author, viz. that the disease

was evidently communicated by infection; that those who were careful

to seclude themselves from all communication with the sick and with

infected goods, were not infected; and lastly, that the disease, which

began to rage violently in August, continued to do so through that and

the following month, but declined fast in the months of October and

November, and seemed to cease in the middle of winter. Some accidents

happened in 1721, between the months of February and July, which gave

occasional alarm; but the distemper did not spread, and ceased entirely

after the summer solstice of that year.

To all this, however, objections have been made. 1. That the irregular

seasons of the former year, a bad crop, and unwholesome aliment,

had produced a malignant epidemic, all which, joined to the popular

dread of contagion, were sufficient to produce the plague without any

imported infection. To this Dr. Russel replies, that these positions,

assumed as facts, had no existence; for which he refers to the

publications of the times. 2. It was objected that there were instances

of the plague in Marseilles before the 25th of May. These instances are

only five in number, produced by M. Deidier, “who saw not the cases

himself, yet (says Dr. Russel) from the very imperfect accounts he had

been able to glean, he thought himself justified in declaring they bore

all the marks of the true plague. Nothing (adds the Doctor) but extreme

partiality to an hypothesis could have led any one practised in the

plague, into such a declaration; the cases bearing every internal mark

of belonging to a different class from the plague. I shall endeavour to

show this in a few words.

“Of the five supposed infected patients, three recovered, two died, and

all had eruptions. One who died had a parotis (the most ambiguous of

all pestilential tumours) without any concurrence, so far as appears,

of pestilential symptoms. The tumour had appeared six days before the

woman’s death, but how long she had been sick remains unknown. The

other died the 16th or 17th day, a very unusual period in the plague.

She also had a parotis, which did not make its appearance till the

10th or 11th day of the disease. No pestilential symptoms whatever

are mentioned. Of the three who recovered, one was very ill with a

fever and carbuncle; but neither the invasion nor the duration of the

disease are mentioned. Another had a carbuncle and a small tumour

on the thigh; and the third (which bears the nearest resemblance

to a very slight infection) had also a bubo in the thigh; but the

tumours in neither of these patients are described in such a manner

as distinguishes them from ordinary tumours; and the apothecary, who

gives the account from memory, had in all likelihood never seen a

pestilential bubo before.”

“Of the persons infected for some time after the arrival of the ships

from the Levant, none had eruptions, and all perished after a few

days illness; which agrees entirely with what was observed at Aleppo

in the beginning of the plague: hardly any of the sick recovered, and

the major part died in three or four days, without any appearance of

buboes. Upon the whole, therefore, I think it very clearly established,

that the plague did not exist in France before the month of May, 1720.

Prior to M. Deidier, however, I find a M. Pons had endeavoured to prove

that the plague was in Marseilles, not only before the month of May

1720, but even in the preceding year. I have not had an opportunity of

examining that gentleman’s book.”

3. It is objected that the disease was not brought from the Levant by

infected goods. “Captain Chataud’s vessel, supposed to have brought

the infected goods, arrived with a clean patent, or bill of health,

having left the coast of Syria before the plague broke out there; she

consequently cannot reasonably be thought to have transported the

plague, which was not in the ports from whence she came.”

To this Dr. Russel answers, that on commercial accounts the Turks

carefully conceal the appearance of the plague from the Europeans.

Should reports of accidents get abroad, they are variously and

contradictorily represented, and pestilential marks and tumours

fraudulently concealed. Though Chataud obtained a clean patent, the

plague broke out soon after his departure, and three vessels with foul

patents arrived at Marseilles a few days after Chataud. “To this (says

Dr. Russel) it may be further added, that, notwithstanding his clean

patent, persons acquainted with the Levant will think it far from

improbable, that the plague might actually have been in Sidon when

he sailed, though unknown to the magistrate, by whom the patents are

granted.... A clean bill of health imports that the place has been free

from plague, and all suspicion of plague, for a certain space of time;

but the clean patents of the two first arriving from the Levant, after

the cessation of the plague, are, according to Mr. Howard, deemed foul

at Marseilles, and the passengers are obliged to perform a quarantine

of thirty-one days. The French consuls lying under an obligation to

insert in their patents a detail of circumstances, it must appear

strange, when the condition of Syria at that time is considered, how

Captain Chataud should have obtained a clean patent.”

Though this must certainly be deemed a sufficient answer to the

objection, Dr. Russel goes on to give an account of what had happened

the preceding year, when the plague had raged violently at Aleppo; and

shows that, from the condition of the whole coast of Syria, a return

of the plague was certainly to be expected; that the French consuls

could not be ignorant of this, neither could the council of health

at Marseilles be unacquainted with what had happened at Aleppo the

preceding year. “The facility with which the patents seem to have been

issued in Turky, and the partial indulgence of the council to Chataud’s

ship, notwithstanding the very extraordinary mortality which had

avowedly happened on the voyage, together with their easy confidence

afterwards in the reports of the surgeon of the lazaretto, can only

be accounted for from the prevailing influence of private commercial

interest over a sense of official duty.”

Our author next proceeds to take notice of what happened during this

ship’s voyage to Marseilles. On the 31st of January he left the coast

of Syria with a clean patent, before the plague broke out. On the

25th of May he arrived at Marseilles, from Sidon, Tripoli and Cyprus.

On the voyage, or at Leghorn, he lost six of the crew; but, by the

certificates of the physicians of health at Leghorn, these died only

_of malignant fevers caused by unwholesome provisions_. These last

words in the Traite de la Peste are said to have been interpolated at

Marseilles. At any rate, as Dr. Russel observes, they could relate only

to those who died at Leghorn, not to the others, whom the physicians

had not seen.

The other account is much less favourable. According to it, Chataud

“left Sidon the 31st of January with a clean patent. The plague

discovered itself there a few days after his departure. Having

sustained some damage by bad weather, he put into Tripoli, where he

embarked some merchandise; he took in also some Turks, passengers

for Cyprus, together with their luggage. Soon after the ship had

left Tripoli, one of these passengers fell sick and died. Two of the

sailors employed to throw the corpse overboard desisted at the desire

of the pilot, and the rest of the ceremony was performed by the other

Mahommedan passengers; the ropes with which the body was lowered down,

being by way of precaution thrown into the sea. Within a few days the

two sailors who had handled the corpse were taken sick and died. At

Cyprus the ship put her remaining passengers on shore, and made a very

short stay. Soon after her departure from that island, a third sailor

and the surgeon died of an illness of a few days duration. The captain,

justly alarmed by these accidents, ordered the bedding and other things

used by the deceased to be thrown into the sea; and kept himself

carefully separate from the crew during the remainder of his voyage.

Some time after this three more sailors fell sick, and, there being no

surgeon on board, the vessel put into Leghorn, where the three sick

men died, and the physician and surgeon of the lazaretto declared the

disease to be a malignant pestilential fever.”

Our author considers the above account as a full proof of the plague

being imported by Chataud’s vessel: he declines entering into the

question about the _possibility_ of importing contagion in merchandise.

How this _might_ take place has already been explained; and the

present instance of its having been imported is as clearly proved as

can be expected. A collateral proof, with regard to the contagion of

the small-pox, we have from Dr. Huxham. A beggar, ill of that disease,

approached a certain town in England, but was not suffered to enter,

for fear of infection. The beggar died, and the infected clothes were

burnt at some distance from the town; but the smoke being blown upon

it by the wind, the small-pox in a short time made its appearance,

beginning in that part upon which the smoke was blown. This clearly

proves that _one_ species of contagion may adhere to clothes, and is a

very strong presumption that any other may do the same. It also shows

that contagion, when once produced, is by no means easily destroyed;

and consequently that all kinds of purification, even when used with

the utmost care and diligence, are scarce sufficient to ensure safety.

It would now be superfluous to enter farther into the subject of the

plague being communicated by infected goods, did not our author quote a

work of Dr. Pye of London, in which the latter from the very _Journal_

(which has been used as containing arguments in favour of contagion)

makes inferences directly opposite. “The facts related in this journal

(says Dr. Pye) seemed to me to make so clearly against the modern

doctrine of contagion, that if this writer had not mentioned them as

undeniable instances in his favour, I should not have thought there had

been any persons here in England so dull of understanding, or so much

blinded with prejudice, as to stand in need of having these facts put

into a more obvious light: but, having this occasion, I shall consider

them more largely than otherwise I would have done, and show that the

porters, who died in the lazaretto at Marseilles, received no hurt or

infection from the goods.

“To leave no room for objection, I shall take notice, that a guard

of quarantine died on board Chataud’s ship the 12th of June; but, as

this officer was no ways concerned either in unloading or opening the

goods, he could receive no hurt from them; and besides, this must have

been fourteen or fifteen days after the goods had been carried out of

the ship into the lazaretto. Further, six of their men are said to die

at Leghorn; but the town of Leghorn was not infected from thence, which

would have been more likely if there had been any infection in the

case, than that Marseilles should be afterwards infected.

“If any infection or infectious _aura_ can be supposed to be packed

up, and brought in goods, such infection or infectious aura must

necessarily issue forth from them in greatest abundance, and with the

greatest force, at the first opening or unpacking of them; and, as

it must continue to fly off every moment, and be thereby continually

diminishing, it is likewise certain, that in a very few days the goods

must be in a great measure, if not entirely, cleared of it. Wherefore,

if the porters could have been infected from the goods at all, it must

have been at the first opening of them: but, even according to this

journal, the porters that first fell sick were not taken ill before the

23d of June, whereas Chataud’s ship arrived the 25th of May preceding;

so that the goods of that ship, in purifying which the porter first

mentioned was employed, had been airing and purifying for twenty-six

or twenty-eight days before this accident happened; and it cannot be

conceived that after so long a time they should not have been entirely

purged of all infection or infectious aura, if any could have been

brought with them. Or if it can be supposed, which I think impossible,

that any part might still be left, it must withal be supposed so much

less than at first, as not to be capable of doing, those porters

especially, the least hurt: to suppose otherwise would be to argue

that the same man who some days before had received and borne a very

great quantity and force without any injury, could then be killed by a

quantity and force infinitely less.

According to the report of merchants, _Frenchmen are not subject to the

plague in Turky_; and it cannot be conceived that so small a quantity

of infectious air as can be packed up and brought in a bale of goods,

should destroy them in France, or in an air and climate distant and

different; when the whole atmosphere of the same infectious air is

found not to injure them in very infected places, and wherein it is

allowed to be bred and generated.”

Thus far Dr Pye.--Let us now hear Dr. Russel in answer.

“The death of the quarantine officer was mentioned in order to leave

no room for objection; but still it may be objected that he has

omitted the death of the sailor on the 27th of May, and asserted, in

contradiction to the journal, that the former six sailors died at

Leghorn. That Leghorn was more likely to be infected than Marseilles,

is a strange notion. The ship had landed no goods there, nor had any

intercourse with the shore; for the physician who visits the sick on

board, remains at a distance from the ship, in a boat, and the dead

bodies are sunk in the sea. As to the circumstance of the goods of

Chataud’s vessel being all in the lazaretto before the 12th of June,

it is a supposition to be attributed to Dr. Pye’s unacquaintance with

matters of that kind; for it is impossible a ship which arrived the

25th of May should discharge the whole of her cargo in two or three

days. The dispatch would have been miraculous, considering the ship

lay near two leagues from the lazaretto, and was unloaded, and the

boats navigated, by her own crew. It did not occur to Dr. Pye, that

some time, previous to the vessels beginning to unload, is taken up in

examination and other forms at _Pomegue_, and the council of health.

The loss of six men on the voyage was an extraordinary circumstance,

that required deliberation; and it appears that on the 29th, after the

death of the sailor on board Chataud’s vessel, the council determined

the quarantine of his cargo to be forty days, commencing from the

landing of the last bale; which was double the time usually allowed for

a ship with a clean patent. It is very probable, therefore, that the

ship did not begin to unload till after the 29th of May, and possibly

had not finished when the quarantine officer died, the 12th of June,

who must have been taken ill two or three days before.

“In regard to the time requisite for the complete evaporation of the

infectious aura, in what proportionate gradation its activity is

impaired by ventilation, and the specific quantity required to produce

effect on the human body, they are matters which I apprehend will

not readily be admitted to be clearly and certainly known. That the

first porters were not taken ill before the 23d of June, is very true;

but that the goods had been airing and purifying for twenty-six or

twenty-eight days, has been shown above to be an error. The Doctor also

makes two other suppositions equally erroneous. The first, that the

whole of the cotton contained in a number of bales is equally imbued

with infectious aura; the second, that all the bales of a ship’s cargo

are opened nearly about the same time. But, as the cotton contained in

these bales may not only have been collected from different villages at

different times, but packed up under various circumstances relative to

the materials used for embalage, and the persons employed in embaling

or steeving them; it may easily be conceived how the cargo of a ship,

coming even from a place where the plague actually rages, may be only

partially infected, or not infected at all. The warmest advocate for

contagion never contended for every bale of a ship’s cargo being

equally infectious. As to the airing of the bales, it is a laborious

and a tedious process. Where there is a considerable number, it takes

up several days to open and arrange them, goods of different kinds

must be disposed separately, accounts taken, and the cordage, &c.

laid up with care where it may be found again. The laborious part of

these operations is performed by the porters, who also transport the

goods from the water side to the enclosure where they are to be aired:

and, as the days of quarantine do not begin to be reckoned till all

the goods are landed, the porters for some days at the beginning are

sufficiently employed in receiving and arranging the cargo, that being

the business requiring the first dispatch. When these circumstances

are considered, it will appear no extravagant supposition, that some

of the last opened bales of Chataud’s cargo might still retain enough

of infectious aura to infect the porter on the 23d of June. To set

this retardment, almost unavoidable in the opening of bales, in a

still clearer light, it should be observed, that, by the regulations

at Marseilles, all suspected goods are subject to what is termed

_sereines_; that is, a certain number of bales are taken out of the

hold, and, being opened at both ends, are exposed to the air for

two, three, or six days, by way of trial, in order to see if any

signs of infection should appear among those employed in handling the

merchandise. When these have been aired, more or less, according to

circumstances, another parcel is opened and exposed to ventilation in

like manner: so that, according to the burden of the ship, there may

be several of these sereines, each of several days duration. In this

manner, independent of accidental impediments from wind and weather,

in sending the goods from the ship, it maybe supposed, were it at all

necessary to make the supposition, that the porters, not only on the

23d of June, but on the 7th and 8th of July, were infected upon opening

some new bales. As to the porter being infected by goods from another

ship, Dr. Pye thinks it impossible, because the ship had been twelve

days in port, and the goods must have been eight or nine days in airing

and purifying: had he been acquainted with the practice of the sereines

in quarantine, he would have been at no loss to make the accident agree

exactly with his notion of the infectious aura.... The plain matter of

fact, as it stands in the journal, is this, that six porters, employed

in purifying suspected merchandise from the Levant, died of the plague;

and their death was followed by that of the surgeon who attended them,

and part of his family.”

From this the reader will be able to judge how far the question

is decided in favour of the fact that the plague at Marseilles

was actually produced by imported contagion. It seems needless to

follow our author through his investigation of those facts which

his adversaries have misrepresented; for these must of course be in

his favour; every misrepresentation by a disputant being plainly an

abandonment of his cause. Indeed the argument against contagion at that

time was properly but one, and is set forth in no stronger language

now than formerly. Even as long ago as 1665 Dr. Russel quotes one

Gadbury an astrologer stating the difficulty as strongly, and giving a

solution of it as clearly, upon _his_ principles, as the best modern

theorists can do upon _theirs_. “If the pestilence, (says Mr. Gadbury)

be infectious, and really catching in itself, it must be so equally to

all persons that approach it, or that it approacheth; or else it must

be infectious to some particular persons only. If it be infectious to

all persons, or catching to all alike, then all persons, that come

into the sight or within the scent of it, must necessarily be subject

unto it. If not infectious unto all, but unto some particular persons

only, I say then it ought not to be deemed or esteemed infectious at

all, at least not any more infectious than are all other diseases,

viz. small-pox, scurvy, pleurisy, ague, gout, &c. since (though the

notion of infection be laid aside) there is not a person born into the

world that hath not at some time of his life (as his _nativity_ shall

truly show) some one disease or other. Never was any person subject to

violent diseases, as plague, &c. but had a violent _nativity_ to show

it, and _e contra_.”

The answer to this has been already given.--Let any other cause than

contagion or infection be supposed, and the difficulty remains equally

great. The probability is in favour of contagion, rather than a general

disposition of the atmosphere, because in the latter case the disease

would, contrary to experience, begin in a great many places at once;

but the plague begins in such a secret manner that we scarce know

whence it comes. Like fire, or a ferment in liquors, it diffuses itself

far and wide, and lastly, like an immense inundation, the source of

which is dried up, it seems to lose its power by extending too far,

and dies away altogether. We cannot penetrate into the causes of those

things, but, without any speculation at all, we can observe that the

disease falls upon people of a certain constitution more than others,

and this may be of use in preserving ourselves from it, as shall be

explained in the next section.

It is still necessary to say something of the infection spreading

from one person to another, and being kept off by refraining from

communication with the diseased. This indeed naturally follows from

its proceeding originally from the cotton: for as all the infected did

not touch this cotton, there can be no other cause assigned from its

spreading than by communication from one to another; and, therefore,

if such communication was cut off, we should naturally think that the

disease would not spread. But, in opposition to this, we have already

quoted Dr. Moseley giving a long list of convents infected, though

they kept themselves strictly shut up. Dr. Russel cites, in favour

of prevention by shutting up, two certificates, one by the bishop of

Marseilles, the other by the sheriff of the same place. To these he

adds the testimony of M. Langeron, who was actively employed throughout

the whole time that the plague continued, first as a commodore of the

gallies, and afterwards as governor of the town and its dependencies.

In opposition to these, however, he takes notice of two passages “in

books of acknowledged authority,” which he is at pains to answer;

the one is from the Journal already quoted, which says, “and what is

unaccountable, those who have shut themselves up most securely in their

own houses, and are the most careful to take in nothing without the

most exact precautions, are attacked there by the plague, which creeps

in no one knows how.” The other passage is taken from the _Relation

Historique_, “that, in the height of the pestilence, the infection

penetrated into places which had till then remained inaccessible; that

monasteries and houses shut up in the most exact manner were no longer

places of security.”

To the former of these our author answers, that “from the manner of

stating the case, one would think that all these religious had been

close shut up, without any communication with persons without doors;

and this was certainly intended by an author who has made remarks

upon it; but it will be found, upon looking into the beginning of the

very paragraph cited, that the greatest part of them are represented

as martyrs who had meritoriously exposed themselves. Of the twelve

different orders mentioned on this occasion, the Grand Augustines only

are said to have kept in their convent. But, supposing the Augustin

convent to have been actually shut up, and in that state infected; it

would by no means invalidate the instances brought of the preservation

of the convents, the certificates concerning which were granted

deliberately, after all was over; whereas the journal, written from day

to day, marking circumstances rapidly as they occurred, the author,

amongst various other affairs, had not always leisure or opportunity to

examine minutely into circumstances. It is in this light I am inclined

to consider the houses being infected which took in nothing without

the most exact precautions; and the rather, because I met with several

instances of the like kind at Aleppo, in the houses of the Christian

and Jewish nations: but in the sequel it generally appeared there had

been some improper communication carried on by the domestics, unknown

to the family at the time.”

“That the atmosphere, in a city so dreadfully circumstanced as

Marseilles, may become so highly tainted as to convey the plague into

houses shut up, cannot confidently be affirmed to be impossible, by

those who hold mediate contagion; and the concurrence of circumstances

at that period in Marseilles, renders it highly probable that such

accidents happened. But, in general, the pestiferous effluvia once

emitted into the air, do not appear to operate at any great distance

from their source; and M. Deidier asserts, that two monasteries

(from their situation, one near a burial ground, the other near a

pest-house) very dangerously situated, remained nevertheless untouched,

which he thinks an argument against infection being conveyed by the

air.”

From this long and contested account of the manner in which the plague

was received into Marseilles, we see how very difficult it must be to

come at a true state of facts, when a number of people think it their

interest to misrepresent or conceal them. The limits of this treatise

will not allow us to follow our author through the numerous details

of misrepresentations and unfair methods which the adversaries of the

doctrine of contagion have made use of to establish their opinion:

neither shall we enter into any discussion concerning the origin of

other plagues, as we should in them find the same opposite kinds of

evidence without such documents for distinguishing the true from the

false as Dr. Russel has produced in the case of Marseilles. A single

fact only, mentioned by Mr. Howard in his Treatise on Lazarettos, shall

be related, and which, if allowed to be _fact_, decides the question as

effectually as a thousand.

“When the plague raged at London in 1665, it was conveyed to the

remote village of Eyam near Tideswell in Derbyshire. In this place it

broke out in September 1665, and continued its ravages upwards of a

year, when two hundred and fifty of the inhabitants had died of it.

The worthy rector, Mr. Mompesson, whose name may rank with those of

Cardinal Borromeo of Milan, and the good bishop of Marseilles, at its

breaking out, resolved not to quit his parishioners, but used every

argument with his wife to quit the infected spot. She, however, refused

to forsake her husband, and is supposed to have died of the plague.

They sent away their children. Mr. Mompesson constantly employed

himself, during the dreadful visitation, in his pastoral office, and

preached to his flock in a field, where nature had formed a sort of

alcove in a rock, which place still retains the appellation of a

church. He survived, and the entries in the parish register relative to

this calamity are in his own hand writing, viz.

In 1665, Sept. Died 6

Oct. 22

Nov. 5

Dec. 7

1666 Jan. 3

Feb. 5

March 2

April 12

May 5

June 20

July 53

Aug. 78

Sept. 14

Oct. 17

Nov. 1

This plague is said to have arisen from a box of clothes sent from

London while the distemper was at its height in that city. But whether

this be admitted or not, it cannot well be supposed that in a small

village there could either be a peculiar constitution of the air,

collections of filth, immoderate heat, cold, or in short any general

cause from which a plague could be supposed to arise, that would not

have affected the country for a great way round. How then came this

insulated spot to be so violently affected, except by contagion? No

matter whether by clothes or any thing else. The very particular manner

in which the numbers who died are recorded, leaves no doubt as to the

fact of the distemper having been there; neither is it possible to

account for its rise on any other principle than contagion.

Mr. Howard, previous to his going abroad, had been furnished, by Dr.

Aikin and Dr. Jebb, with a set of queries relative to the plague, to

be put to the physicians in the different countries through which

he travelled. This commission he executed with great fidelity and

exactness. The physicians to whom he proposed them were, _Raymond_

of Marseilles, physician; _Demollins_ of do. surgeon; _Giovanelli_,

physician to the lazaretto at Leghorn; _They_, to do. at Malta;

_Morandi_, physician at Venice; _Verdoni_, at Trieste; _Jew_ physician

at Smyrna; _Fra. Luigi di Pavia_, prior to the hospital of San Antonio

at Smyrna. The questions proposed were as follow:

1. Is the infection of the plague frequently received by the French?

Though this was not asking in direct terms whether the plague is

infectious or not, all to whom it was proposed seem to have viewed

it in this light, Raymond of Marseilles only excepted, who answered

directly, “Sometimes it is.” All the rest, except Giovanelli, agreed

that it might be communicated by the touch, or by the breath. Verdoni

gave an instance of its being communicated by a flower which three

persons smelt at; two remained free, but the third sickened and died in

twenty-four hours.

2. Does the plague ever rise spontaneously?

In this Verdoni alone answered positively in favour of the spontaneous

rise of the plague. _They_ spoke ambiguously.

3. To what distance is the air infected? How far does actual contact,

wearing infected clothes, or touching other things, produce the disease?

To this question Verdoni answered in a manner seemingly inconsistent

with his former answer; allowing not only that the plague was

infectious, but that infected things might communicate the disease

after an interval of many years. All agreed that the strength of the

infection was greater or less according to circumstances; the distance

at which it could act was likewise uncertain. Raymond said that the

sick might be safely conversed with, across a barrier, at a few paces

distance; the Jew said at _two ells_ distance, provided the chamber

windows be not all shut. Giovanelli said it had been proved that the

infection did not extend beyond five geometrical paces. The touch of

infected clothes, or drawing in the breath of the sick, was looked upon

by him and Fra. Luigi to be very dangerous.

4. What are the seasons in which the plague chiefly appears; and what

is the interval between the infection and the disease?

To this it was answered by Raymond, that the two solstices are the

times in which it has least power. The others agreed that hot and

moist weather was favourable to its ravages; the spring, summer and

first month of autumn are dreaded. These circumstances, however,

must be variable in different countries. As to the time in which the

infection shows itself, the answer was various. According to _They_,

it “sometimes acts slowly, sometimes like a _stroke of lightning_.”

According to Verdoni, “the disease generally shows itself at the

instant of touch, _like an electrical shock_.” Sometimes the infection

will be communicated from a sick person to a sound one, who without any

disease may communicate it to a second, and that second to a third, in

whom alone it would become active.

The other questions, relative to the symptoms, prevention and cure of

the distemper, will be taken notice of in the course of the treatise.

In the mean time having discussed, with a prolixity almost exceeding

our bounds, such preliminaries as seemed most likely to throw some

light on the nature of the distemper, we shall now proceed to the

medical history of the plague, as we find it laid down in different

authors.

Though this distemper has most frequently been accounted a _fever_ in

the highest degree, yet, as we have already noticed, it seems to be

essentially different.[99] The testimonies there quoted are sufficient

to establish the fact; and, were it needful, many others might be

brought from authors both ancient and modern. In the plague said to

have taken place in the days of Romulus,[100] Plutarch relates, that

the people died without any sickness. To this very ancient testimony

we shall add that of Dr. Patrick Russel, who closes the account of

his first class of patients with the following paragraph: “That the

plague, under a form of all others the most destructive, exists

without its characteristic eruptions, or other external marks reckoned

pestilential, can admit of no doubt; and it is to be regretted that

mankind have so often, from the absence of these, been betrayed into

errors of fatal consequence on its first invasion; at which early

period human prudence can only be exerted in the way of defence with

any probability of success.”

[99] See p. 102 _et seq._

[100] P. 19, note.