CHAPTER XVII

THE MOTION AND CIRCULATION OF THE BLOOD ARE CONFIRMED FROM THE

PARTICULARS APPARENT IN THE STRUCTURE OF THE HEART, AND FROM

THOSE THINGS WHICH DISSECTION UNFOLDS

I do not find the heart as a distinct and separate part in all

animals; some, indeed, such as the zoophytes, have no heart; this

is because these animals are coldest, of one great bulk, of soft

texture, or of a certain uniform sameness or simplicity of

structure; among the number I may instance grubs and earth-worms,

and those that are engendered of putrefaction and do not preserve

their species. These have no heart, as not requiring any impeller

of nourishment into the extreme parts; for they have bodies which

are connate and homogeneous and without limbs; so that by the

contraction and relaxation of the whole body they assume and

expel, move and remove, the aliment. Oysters, mussels, sponges,

and the whole genus of zoophytes or plant-animals have no heart,

for the whole body is used as a heart, or the whole animal is a

heart. In a great number of animals,--almost the whole tribe of

insects--we cannot see distinctly by reason of the smallness of

the body; still in bees, flies, hornets, and the like we can

perceive something pulsating with the help of a magnifying-glass;

in pediculi, also, the same thing may be seen, and as the body is

transparent, the passage of the food through the intestines, like

a black spot or stain, may be perceived by the aid of the same

magnifying-glass.

But in some of the pale-blooded and colder animals, as in snails,

whelks, shrimps, and shell-fish, there is a part which pulsates,

--a kind of vesicle or auricle without a heart,--slowly, indeed,

and not to be perceived except in the warmer season of the year.

In these creatures this part is so contrived that it shall

pulsate, as there is here a necessity for some impulse to

distribute the nutritive fluid, by reason of the variety of

organic parts, or of the density of the substance; but the

pulsations occur unfrequently, and sometimes in consequence of

the cold not at all, an arrangement the best adapted to them as

being of a doubtful nature, so that sometimes they appear to

live, sometimes to die; sometimes they show the vitality of an

animal, sometimes of a vegetable. This seems also to be the case

with the insects which conceal themselves in winter, and lie, as

it were, defunct, or merely manifesting a kind of vegetative

existence. But whether the same thing happens in the case of

certain animals that have red blood, such as frogs, tortoises,

serpents, swallows, may be very properly doubted.

In all the larger and warmer animals which have red blood, there

was need of an impeller of the nutritive fluid, and that,

perchance, possessing a considerable amount of power. In fishes,

serpents, lizards, tortoises, frogs, and others of the same kind

there is a heart present, furnished with both an auricle and a

ventricle, whence it is perfectly true, as Aristotle has

observed, [Footnote: De Part. Animal., lib. iii.] that no

sanguineous animal is without a heart, by the impelling power of

which the nutritive fluid is forced, both with greater vigour and

rapidity, to a greater distance; and not merely agitated by an

auricle, as it Is in lower forms. And then in regard to animals

that are yet larger, warmer, and more perfect, as they abound in

blood, which is always hotter and more spirituous, and which

possess bodies of greater size and consistency, these require a

larger, stronger, and more fleshy heart, in order that the

nutritive fluid may be propelled with yet greater force and

celerity. And further, inasmuch as the more perfect animals

require a still more perfect nutrition, and a larger supply of

native heat, in order that the aliment may be thoroughly

concocted and acquire the last degree of perfection, they

required both lungs and a second ventricle, which should force

the nutritive fluid through them.

Every animal that has lungs has, therefore, two ventricles to its

heart--one right, the other left; and wherever there is a right,

there also is there a left ventricle; but the contrary of this

does not hold good: where there is a left there is not always a

right ventricle. The left ventricle I call that which is distinct

in office, not in place from the other, that one, namely, which

distributes the blood to the body at large, not to the lungs

only. Hence the left ventricle seems to form the principle part

of the heart; situated in the middle, more strongly marked, and

constructed with greater care, the heart seems formed for the

sake of the left ventricle, and the right but to minister to it.

The right neither reaches to the apex of the heart nor is it

nearly of such strength, being three times thinner in its walls,

and in some sort jointed on to the left (as Aristotle says),

though, indeed, it is of greater capacity, inasmuch as it has not

only to supply material to the left ventricle, but likewise to

furnish aliment to the lungs.

It is to be observed, however, that all this is otherwise in the

embryo, where there is not such a difference between the two

ventricles. There, as in a double nut, they are nearly equal in

all respects, the apex of the right reaching to the apex of the

left, so that the heart presents itself as a sort of double-

pointed cone. And this is so, because in the foetus, as already

said, whilst the blood is not passing through the lungs from the

right to the left cavities of the heart, it flows by the foramen

ovale and ductus arteriosus directly from the vena cava into the

aorta, whence it is distributed to the whole body. Both

ventricles have, therefore, the same office to perform, whence

their equality of constitution. It is only when the lungs come to

be used and it is requisite that the passages indicated should be

blocked up that the difference in point of strength and other

things between the two ventricles begins to be apparent. In the

altered circumstances the right has only to drive the blood

through the lungs, whilst the left has to propel it through the

whole body.

There are, moreover, within the heart numerous braces, in the

form of fleshy columns and fibrous bands, which Aristotle, in his

third book on "Respiration," and the "Parts of Animals," entitles

nerves. These are variously extended, and are either distinct or

contained in grooves in the walls and partition, where they

occasion numerous pits or depressions. They constitute a kind of

small muscles, which are superadded and supplementary to the

heart, assisting it to execute a more powerful and perfect

contraction, and so proving subservient to the complete expulsion

of the blood. They are, in some sort, like the elaborate and

artful arrangement of ropes in a ship, bracing the heart on every

side as it contracts, and so enabling it more effectually and

forcibly to expel the charge of blood from its ventricles. This

much is plain, at all events, that in some animals they are less

strongly marked than in others; and, in all that have them, they

are more numerous and stronger in the left than in the right

ventricle; and while some have them present in the left, yet they

are absent in the right ventricle. In man they are more numerous

in the left than in the right ventricle, more abundant in the

ventricles than in the auricles; and occasionally there appear to

be none present in the auricles. They are numerous in the large,

more muscular and hardier bodies of countrymen, but fewer in more

slender frames and in females.

In those animals in which the ventricles of the heart are smooth

within and entirely without fibres of muscular bands, or anything

like hollow pits, as in almost all the smaller birds, the

partridge and the common fowl, serpents, frogs, tortoises, and

most fishes, there are no chordae tendineae, nor bundles of

fibres, neither are there any tricuspid valves in the ventricles.

Some animals have the right ventricle smooth internally, but the

left provided with fibrous bands, such as the goose, swan, and

larger birds; and the reason is the same here as elsewhere. As

the lungs are spongy and loose and soft, no great amount of force

is required to force the blood through them; therefore the right

ventricle is either without the bundles in question, or they are

fewer and weaker, and not so fleshy or like muscles. Those of the

left ventricle, however, are both stronger and more numerous,

more fleshy and muscular, because the left ventricle requires to

be stronger, inasmuch as the blood which it propels has to be

driven through the whole body. And this, too, is the reason why

the left ventricle occupies the middle of the heart, and has

parietes three times thicker and stronger than those of the right

Hence all animals--and among men it is similar--that are endowed

with particularly strong frames, and with large and fleshy limbs

at a great distance from the heart, have this central organ of

greater thickness, strength, and muscularity. This is manifest

and necessary. Those, on the contrary, that are of softer and

more slender make have the heart more flaccid, softer, and

internally either less or not at all fibrous. Consider, farther,

the use of the several valves, which are all so arranged that the

blood, once received into the ventricles of the heart, shall

never regurgitate; once forced into the pulmonary artery and

aorta, shall not flow back upon the ventricles. When the valves

are raised and brought together, they form a three-cornered line,

such as is left by the bite of a leech; and the more they are

forced, the more firmly do they oppose the passage of the blood.

The tricuspid valves are placed, like gate-keepers, at the

entrance into the ventricles from the venae cavae and pulmonary

veins, lest the blood when most forcibly impelled should flow

back. It is for this reason that they are not found in all

animals, nor do they appear to have been constructed with equal

care, in all animals in which they are found. In some they are

more accurately fitted, in others more remissly or carelessly

contrived, and always with a view to their being closed under a

greater or a slighter force of the ventricle. In the left

ventricle, therefore, in order that the occlusion may be the more

perfect against the greater impulse, there are only two valves,

like a mitre, and produced into an elongated cone, so that they

come together and touch to their middle; a circumstance which

perhaps led Aristotle into the error of supposing this ventricle

to be double, the division taking place transversely. For the

same reason, and that the blood may not regurgitate upon the

pulmonary veins, and thus the force of the ventricle in

propelling the blood through the system at large come to be

neutralized, it is that these mitral valves excel those of the

right ventricle in size and strength and exactness of closing.

Hence it is essential that there can be no heart without a

ventricle, since this must be the source and store-house of the

blood. The same law does not hold good in reference to the brain.

For almost no genus of birds has a ventricle in the brain, as is

obvious in the goose and swan, the brains of which nearly equal

that of a rabbit in size; now rabbits have ventricles in the

brain, whilst the goose has none. In like manner, wherever the

heart has a single ventricle, there is an auricle appended,

flaccid, membranous, hollow, filled with blood; and where there

are two ventricles, there are likewise two auricles. On the other

hand, some animals have an auricle without any ventricle; or, at

all events, they have a sac analogous to an auricle; or the vein

itself, dilated at a particular part, performs pulsations, as is

seen in hornets, bees, and other insects, which certain

experiments of my own enable me to demonstrate, have not only a

pulse, but a respiration in that part which is called the tail,

whence it is that this part is elongated and contracted now more

rarely, now more frequently, as the creature appears to be blown

and to require a large quantity of air. But of these things, more

in our "Treatise On Respiration."

It is in like manner evident that the auricles pulsate, contract,

as I have said before, and throw the blood into the ventricles;

so that wherever there is a ventricle, an auricle is necessary,

not merely that it may serve, according to the general belief, as

a source and magazine for the blood: for what were the use of its

pulsations had it only to contain?

The auricles are prime movers of the blood, especially the right

auricle, which, as already said, is "the first to live, the last

to die"; whence they are subservient to sending the blood into

the ventricles, which, contracting continuously, more readily and

forcibly expel the blood already in motion; just as the ball-

player can strike the ball more forcibly and further if he takes

it on the rebound than if he simply threw it. Moreover, and

contrary to the general opinion, neither the heart nor anything

else can dilate or distend itself so as to draw anything into its

cavity during the diastole, unless, like a sponge, it has been

first compressed and is returning to its primary condition. But

in animals all local motion proceeds from, and has its origin in,

the contraction of some part; consequently it is by the

contraction of the auricles that the blood is thrown into the

ventricles, as I have already shown, and from there, by the

contraction of the ventricles, it is propelled and distributed.

Concerning local motions, it is true that the immediate moving

organ in every motion of an animal primarily endowed with a

motive spirit (as Aristotle has it [Footnote: In the book de

Spiritu, and elsewhere.]) is contractile; in which way the word

veopou is derived from veuw, nuto, contraho; and if I am

permitted to proceed in my purpose of making a particular

demonstration of the organs of motion in animals from

observations in my possession, I trust I shall be able to make

sufficiently plain how Aristotle was acquainted with the muscles,

and advisedly referred all motion in animals to the nerves, or to

the contractile element, and, therefore, called those little

bands in the heart nerves.

But that we may proceed with the subject which we have in hand,

viz., the use of the auricles in filling the ventricles, we

should expect that the more dense and compact the heart, the

thicker its parietes, the stronger and more muscular must be the

auricle to force and fill it, and vice versa. Now this is

actually so: in some the auricle presents itself as a

sanguinolent vesicle, as a thin membrane containing blood, as in

fishes, in which the sac that stands in lieu of the auricles is

of such delicacy and ample capacity that it seems to be suspended

or to float above the heart. In those fishes in which the sac is

somewhat more fleshy, as in the carp, barbel, tench, and others,

it bears a wonderful and strong resemblance to the lungs.

In some men of sturdier frame and stouter make the right auricle

is so strong, and so curiously constructed on its inner surface

of bands and variously interlacing fibres, that it seems to equal

in strength the ventricle of the heart in other subjects; and I

must say that I am astonished to find such diversity in this

particular in different individuals. It is to be observed,

however, that in the foetus the auricles are out of all

proportion large, which is because they are present before the

heart makes its appearance or suffices for its office even when

it has appeared, and they, therefore, have, as it were, the duty

of the whole heart committed to them, as has already been

demonstrated. But what I have observed in the formation of the

foetus, as before remarked (and Aristotle had already confirmed

all in studying the incubated egg), throws the greatest light and

likelihood upon the point. Whilst the foetus is yet in the form

of a soft worm, or, as is commonly said, in the milk, there is a

mere bloody point or pulsating vesicle, a portion apparently of

the umbilical vein, dilated at its commencement or base.

Afterwards, when the outline of the foetus is distinctly

indicated and it begins to have greater bodily consistence, the

vesicle in question becomes more fleshy and stronger, changes its

position, and passes into the auricles, above which the body of

the heart begins to sprout, though as yet it apparently performs

no office. When the foetus is farther advanced, when the bones

can be distinguished from the fleshy parts and movements take

place, then it also has a heart which pulsates, and, as I have

said, throws blood by either ventricle from the vena cava into

the arteries.

Thus nature, ever perfect and divine, doing nothing in vain, has

neither given a heart where it was not required, nor produced it

before its office had become necessary; but by the same stages in

the development of every animal, passing through the forms of

all, as I may say (ovum, worm, foetus), it acquires perfection in

each. These points will be found elsewhere confirmed by numerous

observations on the formation of the foetus.

Finally, it is not without good grounds that Hippocrates in his

book, "De Corde," entitles it a muscle; its action is the same;

so is its functions, viz., to contract and move something else--

in this case the charge of the blood.

Farther, we can infer the action and use of the heart from the

arrangement of its fibres and its general structures, as in

muscles generally. All anatomists admit with Galen that the body

of the heart is made up of various courses of fibres running

straight, obliquely, and transversely, with reference to one

another; but in a heart which has been boiled, the arrangement of

the fibres is seen to be different. All the fibres in the

parietes and septum are circular, as in the sphincters; those,

again, which are in the columns extend lengthwise, and are

oblique longitudinally; and so it comes to pass that when all the

fibres contract simultaneously, the apex of the cone is pulled

towards its base by the columns, the walls are drawn circularly

together into a globe--the whole heart, in short, is contracted

and the ventricles narrowed. It is, therefore, impossible not to

perceive that, as the action of the organ is so plainly

contraction, its function is to propel the blood into the

arteries.

Nor are we the less to agree with Aristotle in regard to the

importance of the heart, or to question if it receives sense and

motion from the brain, blood from the liver, or whether it be the

origin of the veins and of the blood, and such like. They who

affirm these propositions overlook, or do not rightly understand,

the principal argument, to the effect that the heart is the first

part which exists, and that it contains within itself blood,

life, sensation, and motion, before either the brain or the liver

were created or had appeared distinctly, or, at all events,

before they could perform any function. The heart, ready

furnished with its proper organs of motion, like a kind of

internal creature, existed before the body. The first to be

formed, nature willed that it should afterwards fashion, nourish,

preserve, complete the entire animal, as its work and dwelling-

place: and as the prince in a kingdom, in whose hands lie the

chief and highest authority, rules over all, the heart is the

source and foundation from which all power is derived, on which

all power depends in the animal body.

Many things having reference to the arteries farther illustrate

and confirm this truth. Why does not the pulmonary vein pulsate,

seeing that it is numbered among the arteries? Or wherefore is

there a pulse in the pulmonary artery? Because the pulse of the

arteries is derived from the impulse of the blood. Why does an

artery differ so much from a vein in the thickness and strength

of its coats? Because it sustains the shock of the impelling

heart and streaming blood. Hence, as perfect nature does nothing

in vain, and suffices under all circumstances, we find that the

nearer the arteries are to the heart, the more do they differ

from the veins in structure; here they are both stronger and more

ligamentous, whilst in extreme parts of the body, such as the

feet and hands, the brain, the mesentery, and the testicles, the

two orders of vessels are so much alike that it is impossible to

distinguish between them with the eye. Now this is for the

following very sufficient reasons: the more remote the vessels

are from the heart, with so much the less force are they

distended by the stroke of the heart, which is broken by the

great distance at which it is given. Add to this that the impulse

of the heart exerted upon the mass of blood, which must needs

fill the trunks and branches of the arteries, is diverted,

divided, as it were, and diminished at every subdivision, so that

the ultimate capillary divisions of the arteries look like veins,

and this not merely in constitution, but in function. They have

either no perceptible pulse, or they rarely exhibit one, and

never except where the heart beats more violently than usual, or

at a part where the minute vessel is more dilated or open than

elsewhere. It, therefore, happens that at times we are aware of a

pulse in the teeth, in inflammatory tumours, and in the fingers;

at another time we feel nothing of the sort. By this single

symptom I have ascertained for certain that young persons whose

pulses are naturally rapid were labouring under fever; and in

like manner, on compressing the fingers in youthful and delicate

subjects during a febrile paroxysm, I have readily perceived the

pulse there. On the other hand, when the heart pulsates more

languidly, it is often impossible to feel the pulse not merely in

the fingers, but the wrist, and even at the temple, as in persons

afflicted with lipothymiae asphyxia, or hysterical symptoms, and

in the debilitated and moribund.

Here surgeons are to be advised that, when the blood escapes with

force in the amputation of limbs, in the removal of tumours, and

in wounds, it constantly comes from an artery; not always indeed

per saltum, because the smaller arteries do not pulsate,

especially if a tourniquet has been applied.

For the same reason the pulmonary artery not only has the

structure of an artery, but it does not differ so widely from the

veins in the thickness of its walls as does the aorta. The aorta

sustains a more powerful shock from the left than the pulmonary

artery does from the right ventricle, and the walls of this last

vessel are thinner and softer than those of the aorta in the same

proportion as the walls of the right ventricle of the heart are

weaker and thinner than those of the left ventricle. In like

manner the lungs are softer and laxer in structure than the flesh

and other constituents of the body, and in a similar way the

walls of the branches of the pulmonary artery differ from those

of the vessels derived from the aorta. And the same proportion in

these particulars is universally preserved. The more muscular and

powerful men are, the firmer their flesh; the stronger, thicker,

denser, and more fibrous their hearts, the thicker, closer, and

stronger are the auricles and arteries. Again, in those animals

the ventricles of whose hearts are smooth on their inner surface,

without villi or valves, and the walls of which are thin, as in

fishes, serpents, birds, and very many genera of animals, the

arteries differ little or nothing in the thickness of their coats

from the veins.

Moreover, the reason why the lungs have such ample vessels, both

arteries and veins (for the capacity of the pulmonary veins

exceeds that of both crural and jugular vessels), and why they

contain so large a quantity of blood, as by experience and ocular

inspection we know they do, admonished of the fact indeed by

Aristotle, and not led into error by the appearances found in

animals which have been bled to death, is, because the blood has

its fountain, and storehouse, and the workshop of its last

perfection, in the heart and lungs. Why, in the same way, we find

in the course of our anatomical dissections the pulmonary vein

and left ventricle so full of blood, of the same black colour and

clotted character as that with which the right ventricle and

pulmonary artery are filled, is because the blood is incessantly

passing from one side of the heart to the other through the

lungs. Wherefore, in fine, the pulmonary artery has the structure

of an artery, and the pulmonary veins have the structure of

veins. In function and constitution and everything else the first

is an artery, the others are veins, contrary to what is commonly

believed; and the reason why the pulmonary artery has so large an

orifice is because it transports much more blood than is

requisite for the nutrition of the lungs.

All these appearances, and many others, to be noted in the course

of dissection, if rightly weighed, seem clearly to illustrate and

fully to confirm the truth contended for throughout these pages,

and at the same time to oppose the vulgar opinion; for it would

be very difficult to explain in any other way to what purpose all

is constructed and arranged as we have seen it to be.

THE THREE ORIGINAL PUBLICATIONS ON VACCINATION AGAINST SMALLPOX

BY EDWARD JENNER

INTRODUCTORY NOTE

Edward Jenner was born at his father's vicarage at Berkeley,

Gloucestershire, England, on May 17, 1749. After leaving school,

he was apprenticed to a local surgeon, and in 1770 he went to

London and became a resident pupil under the great surgeon and

anatomist, John Hunter, with whom he remained on intimate terms

for the rest of Hunter's life. In 1773 he took up practise at

Berkeley, where, except for numerous visits to London, he spent

the rest of his life. He died of apoplexy on January 26, 1823.

Jenner's scientific interests were varied, but the importance of

his work in vaccination has overshadowed his other results. Early

in his career he had begun to observe the phenomena of cowpox, a

disease common in the rural parts of the western counties of

England, and he was familiar with the belief, current among the

peasantry, that a person who had suffered from the cowpox could

not take smallpox. Finally, in 1796, he made his first experiment

in vaccination, inoculating a boy of eight with cowpox, and,

after his recovery, with smallpox; with the result that the boy

did not take the latter disease.

Jenner's first paper on his discovery was never printed; but in

1798 appeared the first of the following treatises. Its reception

by the medical profession was highly discouraging; but progress

began when Cline, the surgeon of St. Thomas's Hospital, used the

treatment with success. Jenner continued his investigations,

publishing his results from time to time, and gradually gaining

recognition; though opposition to his theory and practise was at

first vehement, and has never entirely disappeared. In 1802,

Parliament voted him 10,000 pounds, and in 1806, 20,000 pounds, in

recognition of the value of his services, and the sacrifices they

had entailed. As early as 1807, Bavaria made vaccination

compulsory; and since that date most of the European governments

have officially encouraged or compelled the practise; and

smallpox has ceased to be the almost universal scourge it was

before Jenner's discovery.

To C.H. PARRY, M.D. AT BATH

MY DEAR FRIEND:

In the present age of scientific investigation it is remarkable

that a disease of so peculiar a nature as the cow-pox, which has

appeared in this and some of the neighbouring counties for such a

series of years, should so long have escaped particular

attention. Finding the prevailing notions on the subject, both

among men of our profession and others, extremely vague and

indeterminate, and conceiving that facts might appear at once

both curious and useful, I have instituted as strict an inquiry

into the causes and effects of this singular malady as local

circumstances would admit.

The following pages are the result, which, from motives of the

most affectionate regard, are dedicated to you, by

Your sincere friend,

EDWARD JENNER.

BERKELEY, GLOUCESTERSHIRE, June 21st, 1798.

VACCINATION AGAINST SMALLPOX

I AN INQUIRY INTO THE CAUSES AND EFFECTS OF THE VARIOLE VACCINE,

OR COW-POX. 1798

The deviation of man from the stage in which he was originally

placed by nature seems to have proved to him a prolific source of

diseases. From the love of splendour, from the indulgences of

luxury, and from his fondness for amusement he has familiarised

himself with a great number of animals, which may not originally

have been intended for his associates.

The wolf, disarmed of ferocity, is now pillowed in the lady's

lap. [Footnote: The late Mr. John Hunter proved, by experiments,

that the dog is the wolf in a degenerate state.] The cat, the

little tiger of our island, whose natural home is the forest, is

equally domesticated and caressed. The cow, the hog, the sheep,

and the horse, are all, for a variety of purposes, brought under

his care and dominion.

There is a disease to which the horse, from his state of

domestication, is frequently subject. The farriers have called it

the grease. It is an inflammation and swelling in the heel, from

which issues matter possessing properties of a very peculiar

kind, which seems capable of generating a disease in the human

body (after it has undergone the modification which I shall

presently speak of), which bears so strong a resemblance to the

smallpox that I think it highly probable it may be the source of

the disease.

In this dairy country a great number of cows are kept, and the

office of milking is performed indiscriminately by men and maid

servants. One of the former having been appointed to apply

dressings to the heels of a horse affected with the grease, and

not paying due attention to cleanliness, incautiously bears his

part in milking the cows, with some particles of the infectious

matter adhering to his fingers. When this is the case, it

commonly happens that a disease is communicated to the cows, and

from the cows to the dairymaids, which spreads through the farm

until the most of the cattle and domestics feel its unpleasant

consequences. This disease has obtained the name of the cow-pox.

It appears on the nipples of the cows in the form of irregular

pustules. At their first appearance they are commonly of a palish

blue, or rather of a colour somewhat approaching to livid, and

are surrounded by an erysipelatous inflammation. These pustules,

unless a timely remedy be applied, frequently degenerate into

phagedenic ulcers, which prove extremely troublesome. [Footnote:

They who attend sick cattle in this country find a speedy remedy

for stopping the progress of this complaint in those applications

which act chemically upon the morbid matter, such as the

solutions of the vitriolum zinci and the vitriolum cupri, etc.]

The animals become indisposed, and the secretion of milk is much

lessened. Inflamed spots now begin to appear on different parts

of the hands of the domestics employed in milking, and sometimes

on the wrists, which quickly run on to suppuration, first

assuming the appearance of the small vesications produced by a

burn. Most commonly they appear about the joints of the fingers

and at their extremities; but whatever parts are affected, if the

situation will admit, these superficial suppurations put on a

circular form, with their edges more elevated than their centre,

and of a colour distantly approaching to blue. Absorption takes

place, and tumours appear in each axilla. The system becomes

affected--the pulse is quickened; and shiverings, succeeded by

heat, with general lassitude and pains about the loins and limbs,

with vomiting, come on. The head is painful, and the patient is

now and then even affected with delirium. These symptoms, varying

in their degrees of violence, generally continue from one day to

three or four, leaving ulcerated sores about the hands, which,

from the sensibility of the parts, are very troublesome, and

commonly heal slowly, frequently becoming phagedenic, like those

from whence they sprung. The lips, nostrils, eyelids, and other

parts of the body are sometimes affected with sores; but these

evidently arise from their being heedlessly rubbed or scratched

with the patient's infected fingers. No eruptions on the skin

have followed the decline of the feverish symptoms in any

instance that has come under my inspection, one only excepted,

and in this case a very few appeared on the arms: they were very

minute, of a vivid red colour, and soon died away without

advancing to maturation; so that I cannot determine whether they

had any connection with the preceding symptoms.

Thus the disease makes its progress from the horse [Footnote:

Jenner's conclusion that "grease" and cow-pox were the same

disease has since been proved erroneous; but this error has not

invalidated his main conclusion as to the relation of cow-pox and

smallpox.--EDITOR.] to the nipple of the cow, and from the cow to

the human subject

Morbid matter of various kinds, when absorbed into the system,

may produce effects in some degree similar; but what renders the

cow-pox virus so extremely singular is that the person who has

been thus affected is forever after secure from the infection of

the smallpox; neither exposure to the variolous effluvia, nor the

insertion of the matter into the skin, producing this distemper.

In support of so extraordinary a fact, I shall lay before my

reader a great number of instances. [Footnote: It is necessary to

observe that pustulous sores frequently appear spontaneously on

the nipples of cows, and instances have occurred, though very

rarely, of the hands of the servants employed in milking being

affected with sores in consequence, and even of their feeling an

indisposition from absorption. These pustules arc of a much

milder nature than those which arise from that contagion which

constitutes the true cow-pox. They are always free from the

bluish or livid tint so conspicuous in the pustules in that

disease. No erysipelas attends them, nor do they shew any

phagedenic disposition as in the other case, but quickly

terminate in a scab without creating any apparent disorder in the

cow. This complaint appears at various seasons of the year, but

most commonly in the spring, when the cows are first taken from

their winter food and fed with grass. It is very apt to appear

also when they are suckling their young. But this disease is not

to be considered as similar in any respect to that of which I am

treating, as it is incapable of producing any specific effects on

the human constitution. However, it is of the greatest

consequence to point it out here, lest the want of discrimination

should occasion an idea of security from the infection of the

smallpox, which might prove delusive.]

CASE I.--Joseph Merret, now an under gardener to the Earl of

Berkeley, lived as a servant with a farmer near this place in the

year 1770, and occasionally assisted in milking his master's

cows. Several horses belonging to the farm began to have sore

heels, which Merret frequently attended. The cows soon became

affected with the cow-pox, and soon after several sores appeared

on his hands. Swellings and stiffness in each axilla followed,

and he was so much indisposed for several days as to be incapable

of pursuing his ordinary employment. Previously to the appearance

of the distemper among the cows there was no fresh cow brought

into the farm, nor any servant employed who was affected with the

cow-pox.

In April, 1795, a general inoculation taking place here, Merret

was inoculated with his family; so that a period of twenty-five

years had elapsed from his having the cow-pox to this time.

However, though the variolous matter was repeatedly inserted into

his arm, I found it impracticable to infect him with it; an

efflorescence only, taking on an erysipelatous look about the

centre, appearing on the skin near the punctured parts. During

the whole time that his family had the smallpox, one of whom had

it very full, he remained in the house with them, but received no

injury from exposure to the contagion.

It is necessary to observe that the utmost care was taken to

ascertain, with the most scrupulous precision, that no one whose

case is here adduced had gone through the smallpox previous to

these attempts to produce that disease.

Had these experiments been conducted in a large city, or in a

populous neighbourhood, some doubts might have been entertained;

but here, where population is thin, and where such an event as a

person's having had the smallpox is always faithfully recorded,

as risk of inaccuracy in this particular can arise.

CASE II.--Sarah Portlock, of this place, was infected with the

cow-pox when a servant at a farmer's in the neighbourhood,

twenty-seven years ago. [Footnote: I have purposely selected

several cases in which the disease had appeared at a very distant

period previous to the experiments made with variolous matter, to

shew that the change produced in the constitution is not affected

by time.]

In the year 1792, conceiving herself, from this circumstance,

secure from the infection of the smallpox, she nursed one of her

own children who had accidentally caught the disease, but no

indisposition ensued. During the time she remained in the

infected room, variolous matter was inserted into both her arms,

but without any further effect than in the preceding case.

CASE III.--John Phillips, a tradesman of this town, had the cow-

pox at so early a period as nine years of age. At the age of

sixty-two I inoculated him, and was very careful in selecting

matter in its most active state. It was taken from the arm of a

boy just before the commencement of the eruptive fever, and

instantly inserted. It very speedily produced a sting-like feel

in the part. An efflorescence appeared, which on the fourth day

was rather extensive, and some degree of pain and stiffness were

felt about the shoulder; but on the fifth day these symptoms

began to disappear, and in a day or two after went entirely off,

without producing any effect on the system.

CASE IV.--Mary Barge, of Woodford, in this parish, was inoculated

with variolous matter in the year 1791. An efflorescence of a

palish red colour soon appeared about the parts where the matter

was inserted, and spread itself rather extensively, but died away

in a few days without producing any variolous symptoms.

[Footnote: It is remarkable that variolous matter, when the

system is disposed to reject it, should excite inflammation on

the part to which it is applied more speedily than when it

produces the smallpox. Indeed, it becomes almost a criterion by

which we can determine whether the infection will be received or

not. It seems as if a change, which endures through life, had

been produced in the action, or disposition to action, in the

vessels of the skin; and it is remarkable, too, that whether this

change has been effected by the smallpox or the cow-pox that the

disposition to sudden cuticular inflammation is the same on the

application of variolous matter.] She has since been repeatedly

employed as a nurse to smallpox patients, without experiencing

any ill consequences. This woman had the cow-pox when she lived

in the service of a farmer in this parish thirty-one years

before.

CASE V.--Mrs. H---, a respectable gentlewoman of this town, had

the cow-pox when very young. She received the infection in rather

an uncommon manner: it was given by means of her handling some of

the same utensils [Footnote: When the cow-pox has prevailed in

the dairy, it has often been communicated to those who have not

milked the cows, by the handle of the milk pail.] which were in

use among the servants of the family, who had the disease from

milking infected cows. Her hands had many of the cow-pox sores

upon them, and they were communicated to her nose, which became

inflamed and very much swollen. Soon after this event Mrs. H----

was exposed to the contagion of the smallpox, where it was

scarcely possible for her to have escaped, had she been

susceptible of it, as she regularly attended a relative who had

the disease in so violent a degree that it proved fatal to him.

In the year 1778 the smallpox prevailed very much at Berkeley,

and Mrs. H----, not feeling perfectly satisfied respecting her

safety (no indisposition having followed her exposure to the

smallpox), I inoculated her with active variolous matter. The

same appearance followed as in the preceding cases--an

efflorescence on the arm without any effect on the constitution.

CASE VI.--It is a fact so well known among our dairy farmers that

those who have had the smallpox either escape the cow-pox or are

disposed to have it slightly, that as soon as the complaint shews

itself among the cattle, assistants are procured, if possible,

who are thus rendered less susceptible of it, otherwise the

business of the farm could scarcely go forward.

In the month of May, 1796, the cow-pox broke out at Mr. Baker's,

a farmer who lives near this place. The disease was communicated

by means of a cow which was purchased in an infected state at a

neighbouring fair, and not one of the farmer's cows (consisting

of thirty) which were at that time milked escaped the contagion.

The family consisted of a man servant, two dairymaids, and a

servant boy, who, with the farmer himself, were twice a day

employed in milking the cattle. The whole of this family, except

Sarah Wynne, one of the dairymaids, had gone through the

smallpox. The consequence was that the farmer and the servant boy

escaped the infection of the cow-pox entirely, and the servant

man and one of the maid servants had each of them nothing more

then a sore on one of their fingers, which produced no disorder

in the system. But the other dairymaid, Sarah Wynne, who never

had the smallpox, did not escape in so easy a manner. She caught

the complaint from the cows, and was affected with the symptoms

described on page 154 in so violent a degree that she was

confined to her bed, and rendered incapable for several days of

pursuing her ordinary vocations in the farm.

March 28, 1797, I inoculated this girl and carefully rubbed the

variolous matter into two slight incisions made upon the left

arm. A little inflammation appeared in the usual manner around

the parts where the matter was inserted, but so early as the

fifth day it vanished entirely without producing any effect on

the system.

CASE VII.--Although the preceding history pretty clearly evinces

that the constitution is far less susceptible of the contagion of

the cow-pox after it has felt that of the smallpox, and although

in general, as I have observed, they who have had the smallpox,

and are employed in milking cows which are infected with the cow-

pox, either escape the disorder, or have sores on the hands

without feeling any general indisposition, yet the animal economy

is subject to some variation in this respect, which the following

relation will point out:

In the summer of the year 1796 the cow-pox appeared at the farm

of Mr. Andrews, a considerable dairy adjoining to the town of

Berkeley. It was communicated, as in the preceding instance, by

an infected cow purchased at a fair in the neighbourhood. The

family consisted of the farmer, his wife, two sons, a man and a

maid servant; all of whom, except the farmer (who was fearful of

the consequences), bore a part in milking the cows. The whole of

them, exclusive of the man servant, had regularly gone through

the smallpox; but in this case no one who milked the cows escaped

the contagion. All of them had sores upon their hands, and some

degree of general indisposition, preceded by pains and tumours in

the axillas: but there was no comparison in the severity of the

disease as it was felt by the servant man, who had escaped the

smallpox, and by those of the family who had not, for, while he

was confined to his bed, they were able, without much

inconvenience, to follow their ordinary business.

February the 13th, 1797, I availed myself of an opportunity of

inoculating William Rodway, the servant man above alluded to.

Variolous matter was inserted into both his arms: in the right,

by means of superficial incisions, and into the left by slight

punctures into the cutis. Both were perceptibly inflamed on the

third day. After this the inflammation about the punctures soon

died away, but a small appearance of erysipelas was manifest

about the edges of the incisions till the eighth day, when a

little uneasiness was felt for the space of half an hour in the

right axilla. The inflammation then hastily disappeared without

producing the most distant mark of affection of the system.

CASE VIII.--Elizabeth Wynne, aged fifty-seven, lived as a servant

with a neighbouring farmer thirty-eight years ago. She was then a

dairymaid, and the cow-pox broke out among the cows. She caught

the disease with the rest of the family, but, compared with them,

had it in a very slight degree, one very small sore only breaking

out on the little finger of her left hand, and scarcely any

perceptible indisposition, following it.

As the malady had shewn itself in so slight a manner, and as it

had taken place at so distant a period of her life, I was happy

with the opportunity of trying the effects of variolous matter

upon her constitution, and on the 28th of March, 1797, I

inoculated her by making two superficial incisions on the left

arm, on which the matter was cautiously rubbed. A little

efflorescence soon appeared, and a tingling sensation was felt

about the parts where the matter was inserted until the third

day, when both began to subside, and so early as the fifth day it

was evident that no indisposition would follow.

CASE IX.--Although the cow-pox shields the constitution from the

smallpox, and the smallpox proves a protection against its own

future poison, yet it appears that the human body is again and

again susceptible of the infectious matter of the cow-pox, as the

following history will demonstrate.

William Smith, of Pyrton in this parish, contracted this disease

when he lived with a neighbouring farmer in the year 1780. One of

the horses belonging to the farm had sore heels, and it fell to

his lot to attend him. By these means the infection was carried

to the cows, and from the cows it was communicated to Smith. On

one of his hands were several ulcerated sores, and he was

affected with such symptoms as have been before described.

In the year 1791 the cow-pox broke out at another farm where he

then lived as a servant, and he became affected with it a second

time; and in the year 1794 he was so unfortunate as to catch it

again. The disease was equally as severe the second and third

time as it was on the first. [Footnote: This is not the case in

general--a second attack is commonly very slight, and so, I am

informed, it is among the cows.]

In the spring of the year 1795 he was twice inoculated, but no

affection of the system could be produced from the variolous

matter; and he has since associated with those who had the

smallpox in its most contagious state without feeling any effect

from it.

CASE X.--Simon Nichols lived as a servant with Mr. Bromedge, a

gentleman who resides on his own farm in this parish, in the year

1782. He was employed in applying dressings to the sore heels of

one of his master's horses, and at the same time assisted in

milking the cows. The cows became affected in consequence, but

the disease did not shew itself on their nipples till several

weeks after he had begun to dress the horse. He quitted Mr.

Bromedge's service, and went to another farm without any sores

upon him; but here his hands soon began to be affected in the

common way, and he was much indisposed with the usual symptoms.

Concealing the nature of the malady from Mr. Cole, his new

master, and being there also employed in milking, the cowpox was

communicated to the cows.

Some years afterward Nichols was employed in a farm where the

smallpox broke out, when I inoculated him with several other

patients, with whom he continued during the whole time of their

confinement. His arm inflamed, but neither the inflammation nor

his associating with the inoculated family produced the least

effect upon his constitution.

CASE XI.--William Stinchcomb was a fellow servant with Nichols at

Mr. Bromedge's farm at the time the cattle had the cow-pox, and

he was, unfortunately, infected by them. His left hand was very

severely affected with several corroding ulcers, and a tumour of

considerable size appeared in the axilla of that side. His right

hand had only one small tumour upon it, and no sore discovered

itself in the corresponding axilla.

In the year 1792 Stinchcomb was inoculated with variolous matter,

but no consequences ensued beyond a little inflammation in the

arm for a few days. A large party were inoculated at the same

time, some of whom had the disease in a more violent degree than

is commonly seen from inoculation. He purposely associated with

them, but could not receive the smallpox.

During the sickening of some of his companions their symptoms so

strongly recalled to his mind his own state when sickening with

the cow--pox that he very pertinently remarked their striking

similarity.

CASE XII.--The paupers of the village of Tortworth, in this

county, were inoculated by Mr. Henry Jenner, Surgeon, of

Berkeley, in the year 1795. Among them, eight patients presented

themselves who had at different periods of their lives had the

cow-pox. One of them, Hester Walkley, I attended with that

disease when she lived in the service of a farmer in the same

village in the year 1782; but neither this woman, nor any other

of the patients who had gone through the cow-pox, received the

variolous infection either from the arm or from mixing in the

society of the other patients who were inoculated at the same

time. This state of security proved a fortunate circumstance, as

many of the poor women were at the same time in a state of

pregnancy.

CASE XIII.--One instance has occurred to me of the system being

affected from the matter issuing from the heels of horses, and of

its remaining afterwards unsusceptible of the variolous

contagion; another, where the smallpox appeared obscurely; and a

third, in which its complete existence was positively

ascertained.

First, Thomas Pearce is the son of a smith and farrier near to

this place. He never had the cow-pox; but, in consequence of

dressing horses with sore heels at his father's, when a lad, he

had sores on his fingers which suppurated, and which occasioned a

pretty severe indisposition. Six years afterwards I inserted

variolous matter into his arm repeatedly, without being able to

produce any thing more than slight inflammation, which appeared

very soon after the matter was applied, and afterwards I exposed

him to the contagion of the smallpox with as little effect.

[Footnote: It is a remarkable fact, and well known to many, that

we are frequently foiled in our endeavours to communicate the

smallpox by inoculation to blacksmiths, who in the country are

farriers. They often, as in the above instance, either resist the

contagion entirely, or have the disease anomalously. Shall we not

be able to account for this on a rational principle?]

CASE XIV.--Secondly, Mr. James Cole, a farmer in this parish, had

a disease from the same source as related in the preceding case,

and some years after was inoculated with variolous matter. He had

a little pain in the axilla and felt a slight indisposition for

three or four hours. A few eruptions shewed themselves on the

forehead, but they very soon disappeared without advancing to

maturation.

CASE XV.--Although in the former instances the system seemed to

be secured, or nearly so, from variolous infection, by the

absorption of matter from the sores produced by the diseased

heels of horses, yet the following case decisively proves that

this cannot be entirely relied upon until a disease has been

generated by the morbid matter from the horse on the nipple of

the cow, and passed through that medium to the human subject.

Mr. Abraham Riddiford, a farmer at Stone in this parish, in

consequence of dressing a mare that had sore heels, was affected

with very painful sores in both his hands, tumours in each

axilla, and severe and general indisposition. A surgeon in the

neighbourhood attended him, who knowing the similarity between

the appearance of the sores upon his hands and those produced by

the cow-pox, and being acquainted also with the effects of that

disease on the human constitution, assured him that he never need

to fear the infection of the smallpox; but this assertion proved

fallacious, for, on being exposed to the infection upwards of

twenty years afterwards, he caught the disease, which took its

regular course in a very mild way. There certainly was a

difference perceptible, although it is not easy to describe it,

in the general appearance of the pustules from that which we

commonly see. Other practitioners who visited the patient at my

request agreed with me in this point, though there was no room

left for suspicion as to the reality of the disease, as I

inoculated some of his family from the pustules, who had the

smallpox, with its usual appearances, in consequence.

CASE XVI.--Sarah Nelmes, a dairymaid at a farmer's near this

place, was infected with the cow-pox from her master's cows in

May, 1796. She received the infection on a part of her hand which

had been previously in a slight degree injured by a scratch from

a thorn. A large pustulous sore and the usual symptoms

accompanying the disease were produced in consequence. The

pustule was so expressive of the true character of the cow-pox,

as it commonly appears upon the hand, that I have given a

representation of it in the annexed plate. The two small pustules

on the wrists arose also from the application of the virus to

some minute abrasions of the cuticle, but the livid tint, if they

ever had any, was not conspicuous at the time I saw the patient.

The pustule on the forefinger shews the disease in an earlier

stage. It did not actually appear on the hand of this young

woman, but was taken from that of another, and is annexed for the

purpose of representing the malady after it has newly appeared.

CASE XVII.--The more accurately to observe the progress of the

infection I selected a healthy boy, about eight years old, for

the purpose of inoculation for the cow-pox. The matter was taken

from a sore on the hand of a dairymaid [Footnote: From the sore

on the hand of Sarah Nelmes. See the preceding case.], who was

infected by her master's cows, and it was inserted, on the 14th

of May, 1796, into the arm of the boy by means of two superficial

incisions, barely penetrating the cutis, each about half an inch

long.

On the seventh day he complained of uneasiness in the axilla, and

on the ninth he became a little chilly, lost his appetite, and

had a slight headache. During the whole of this day he was

perceptibly indisposed, and spent the night with some degree of

restlessness, but on the day following he was perfectly well.

The appearance of the incisions in their progress to a state of

maturation were much the same as when produced in a similar

manner by variolous matter. The only difference which I perceived

was in the state of the limpid fluid arising from the action of

the virus, which assumed rather a darker hue, and in that of the

efflorescence spreading round the incisions, which had more of an

erysipelatous look than we commonly perceive when variolous

matter has been made use of in the same manner; but the whole

died away (leaving on the inoculated parts scabs and subsequent

eschars) without giving me or my patient the least trouble.

In order to ascertain whether the boy, after feeling so slight an

affection of the system from the cow--pox virus, was secure from

the contagion of the smallpox, he was inoculated the 1st of July

following with variolous matter, immediately taken from a

pustule. Several slight punctures and incisions were made on both

his arms, and the matter was carefully inserted, but no disease

followed. The same appearances were observable on the arms as we

commonly see when a patient has had variolous matter applied,

after having either the cow--pox or smallpox. Several months

afterwards he was again inoculated with variolous matter, but no

sensible effect was produced on the constitution.

Here my researches were interrupted till the spring of the year

1798, when, from the wetness of the early part of the season,

many of the farmers' horses in this neighbourhood were affected

with sore heels, in consequence of which the cow--pox broke out

among several of our dairies, which afforded me an opportunity of

making further observations upon this curious disease.

A mare, the property of a person who keeps a dairy in a

neighbouring parish, began to have sore heels the latter end of

the month of February, 1798, which were occasionally washed by

the servant men of the farm, Thomas Virgoe, William Wherret, and

William Haynes, who in consequence became affected with sores in

their hands, followed by inflamed lymphatic glands in the arms

and axillae, shiverings succeeded by heat, lassitude, and general

pains in the limbs. A single paroxysm terminated the disease; for

within twenty--four hours they were free from general

indisposition, nothing remaining but the sores on their hands.

Haynes and Virgoe, who had gone through the smallpox from

inoculation, described their feelings as very similar to those

which affected them on sickening with that malady. Wherret never

had had the smallpox. Haynes was daily employed as one of the

milkers at the farm, and the disease began to shew itself among

the cows about ten days after he first assisted in washing the

mare's heels. Their nipples became sore in the usual way, with

bluish pustules; but as remedies were early applied, they did not

ulcerate to any extent.

CASE XVIII.--John Baker, a child of five years old, was

inoculated March 16, 1798, with matter taken from a pustule on

the hand of Thomas Virgoe, one of the servants who had been

infected from the mare's heels. He became ill on the sixth day

with symptoms similar to those excited by cow--pox matter. On the

eighth day he was free from indisposition.

There was some variation in the appearance of the pustule on the

arm. Although it somewhat resembled a smallpox pustule, yet its

similitude was not so conspicuous as when excited by matter from

the nipple of the cow, or when the matter has passed from thence

through the medium of the human subject.

This experiment was made to ascertain the progress and subsequent

effects of the disease when thus propagated. We have seen that

the virus from the horge, when it proves infectious to the human

subject, is not to be relied upon as rendering the system secure

from variolous infection, but that the matter produced by it upon

the nipple of the cow is perfectly so. Whether its passing from

the horse through the human constitution, as in the present

instance, will produce a similar effect, remains to be decided.

This would mow have been effected, but the boy was rendered unit

for inoculation from having felt the effects of a contagious

fever in a workhouse soon after this experiment was made.

CASE XIX.--William Summers, a child of five years and a half old,

was inoculated the same day with Baker, with matter taken from

the nipples of one of the infected cows, at the farm alluded to.

He became indisposed on the sixth day, vomited once, and felt the

usual slight symptoms till the eighth day, when he appeared

perfectly well. The progress of the pustule, formed by the

infection of the virus, was similar to that noticed in Case XVII,

with this exception, its being free from the livid tint observed

in that instance.

CASE XX.-From William Summers the disease was transferred to

William Pead, a boy of eight years old, who was inoculated March

28th. On the sixth day he complained of pain in the axilla, and

on the seventh was affected with the common symptoms of a patient

sickening with the smallpox from inoculation, which did not

terminate till the third day after the seizure. So perfect was

the similarity to the variolous fever that I was induced to

examine the skin, conceiving there might have been some

eruptions, but none appeared. The efflorescent blush around the

part punctured in the boy's arm was so truly characteristic of

that which appears on variolous inoculation that I have given a

representation of it. The drawing was made when the pustule was

beginning to die away and the areola retiring from the centre.

CASE XXI.-April 5th: Several children and adults were inoculated

from the arm of William Pead. The greater part of them sickened

on the sixth day, and were well on the seventh, but in three of

the number a secondary indisposition arose in consequence of an

extensive erysipelatous inflammation which appeared on the

inoculated arms. It seemed to arise from the state of the

pustule, which spread out, accompanied with some degree of pain,

to about half the diameter of a sixpence. One of these patients

was an infant of half a year old. By the application of mercurial

ointment to the inflamed parts (a treatment recommended under

similar circumstances in the inoculated smallpox) the complaint

subsided without giving much trouble.

Hannah Excell, an healthy girl of seven years old, and one of the

patients above mentioned, received the infection from the

insertion of the virus under the cuticle of the arm in three

distinct points. The pustules which arose in consequence so much

resembled, on the twelfth day, those appearing from the infection

of variolous matter, that an experienced inoculator would

scarcely have discovered a shade of difference at that period.

Experience now tells me that almost the only variation which

follows consists in the pustulous fluids remaining limpid nearly

to the time of its total disappearance; and not, as in the direct

smallpox, becoming purulent.

CASE XXII.--From the arm of this girl matter was taken and

inserted April 12th into the arms of John Macklove, one year and

a half old, Robert F. Jenner, eleven months old, Mary Pead, five

years old, and Mary James, six years old. [Footnote: Perhaps a

few touches with the lapis septicus would have proved equally

efficacious.] Among these, Robert F. Jenner did not receive the

infection. The arms of the other three inflamed properly and

began to affect the system in the usual manner; but being under

some apprehensions from the preceding cases that a troublesome

erysipelas might arise, I determined on making an experiment with

the view of cutting off its source. Accordingly, after the

patients had felt an indisposition of about twelve hours, I

applied in two of these cases out of the three, on the vesicle

formed by the virus, a little mild caustic, composed of equal

parts of quick--lime and soap, and suffered it to remain on the

part six hours. [Footnote: What effect would a similar treatment

produce in inoculation for the smallpox?] It seemed to give the

children but little uneasiness, and effectually answered my

intention in preventing the appearance of erysipelas. Indeed, it

seemed to do more, for in half an hour after its application the

indisposition of the children ceased. These precautions were

perhaps unnecessary, as the arm of the third child, Mary Pead,

which was suffered to take its common course, scabbed quickly,

without any erysipelas.

CASE XXIII.--From this child's arm matter was taken and

transferred to that of J. Barge, a boy of seven years old. He

sickened on the eighth day, went through the disease with the

usual slight symptoms, and without any inflammation on the arm

beyond the common efflorescence surrounding the pustule, an

appearance so often seen in inoculated smallpox.

After the many fruitless attempts to give the smallpox to those

who had had the cow-pox, it did not appear necessary, nor was it

convenient to me, to inoculate the whole of those who had been

the subjects of these late trials; yet I thought it right to see

the effects of variolous matter on some of them, particularly

William Summers, the first of these patients who had been

infected with matter taken from the cow. He was, therefore,

inoculated with variolous matter from a fresh pustule; but, as in

the preceding cases, the system did not feel the effects of it in

the smallest degree. I had an opportunity also of having this boy

and William Pead inoculated by my nephew, Mr. Henry Jenner, whose

report to me is as follows: "I have inoculated Pead and Barge,

two of the boys whom you lately infected with the cow-pox. On the

second day the incisions were inflamed and there was a pale

inflammatory stain around them. On the third day these

appearances were still increasing and their arms itched

considerably. On the fourth day the inflammation was evidently

subsiding, and on the sixth day it was scarcely perceptible. No

symptom of indisposition followed.

"To convince myself that the variolous matter made use of was in

a perfect state I at the same time inoculated a patient with some

of it who never had gone through the cow-pox, and it produced the

smallpox in the usual regular manner."

These experiments afforded me much satisfaction; they proved that

the matter, in passing from one human subject to another, through

five gradations, lost none of its original properties, J. Barge

being the fifth who received the infection successively from

William Summers, the boy to whom it was communicated from the

cow.

I shall now conclude this inquiry with some general observations

on the subject, and on some others which are interwoven with it.

Although I presume it may be unnecessary to produce further

testimony in support of my assertion "that the cow--pox protects

the human constitution from the infection of the smallpox," yet

it affords me considerable satisfaction to say that Lord

Somerville, the President of the Board of Agriculture, to whom

this paper was shewn by Sir Joseph Banks, has found upon inquiry

that the statements were confirmed by the concurring testimony of

Mr. Dolland, a surgeon, who resides in a dairy country remote

from this, in which these observations were made. With respect to

the opinion adduced "that the source of the infection is a

peculiar morbid matter arising in the horse," although I have not

been able to prove it from actual experiments conducted

immediately under my own eye, yet the evidence I have adduced

appears sufficient to establish it.

They who are not in the habit of conducting experiments may not

be aware of the coincidence of circumstances necessary for their

being managed so as to prove perfectly decisive; nor how often

men engaged in professional pursuits are liable to interruptions

which disappoint them almost at the instant of their being

accomplished: however, I feel no room for hesitation respecting

the common origin of the disease, being well convinced that it

never appears among the cows (except it can be traced to a cow

introduced among the general herd which has been previously

infected, or to an infected servant) unless they have been milked

by some one who, at the same time, has the care of a horse

affected with diseased heels.

The spring of the year 1797, which I intended particularly to

have devoted to the completion of this investigation, proved,

from its dryness, remarkably adverse to my wishes;-for it

frequently happens, while the farmers' horses are exposed to the

cold rains which fall at that season, that their heels become

diseased, and no cow-pox then appeared in the neighbourhood.

The active quality of the virus from the horses' heels is greatly

increased after it has acted on the nipples of the cow, as it

rarely happens that the horse affects his dresser with sores, and

as rarely that a milkmaid escapes the infection when she milks

infected cows. It is most active at the commencement of the

disease, even before it has acquired a pus-like appearance;

indeed, I am not confident whether this property in the matter

does not entirely cease as soon as it is secreted in the form of

pus. I am induced to think it does cease [Footnote: It is very

easy to procure pus from old sores on the heels of horses. This I

have often inserted into scratches made with a lancet, on the

sound nipples of cows, and have seen no other effects from it

than simple inflamation.], and that it is the thin, darkish-

looking fluid only, oozing from the newly-formed cracks in the

heels, similar to what sometimes appears from erysipelatous

blisters, which gives the disease. Nor am I certain that the

nipples of the cows are at all times in a state to receive the

infection. The appearance of the disease in the spring and the

early part of the summer, when they are disposed to be affected

with spontaneous eruptions so much more frequently than at other

seasons, induces me to think that the virus from the horse must

be received upon them when they are in this state, in order to

produce effects: experiments, however, must determine these

points. But it is clear that when the cow-pox virus is once

generated, that the cows cannot resist the contagion, in whatever

state their nipples may chance to be, if they are milked with an

infected hand.

Whether the matter, either from the cow or the horse, will affect

the sound skin of the human body, I cannot positively determine;

probably it will not, unless on those parts where the cuticle is

extremely thin, as on the lips, for example. I have known an

instance of a poor girl who produced an ulceration on her lip by

frequently holding her finger to her mouth to cool the raging of

a cow-pox sore by blowing upon it. The hands of the farmers'

servants here, from the nature of their employments, are

constantly exposed to those injuries which occasion abrasions of

the cuticle, to punctures from thorns, and such like accidents;

so that they are always in a state to feel the consequence of

exposure to infectious matter.

It is singular to observe that the cow--pox virus, although it

renders the constitution unsusceptible of the variolous, should

nevertheless, leave it unchanged with respect to its own action.

I have already produced an instance [Footnote: See Case IX.] to

point out this, and shall now corroborate it with another.

Elizabeth Wynne, who had the cow-pox in the year 1759, was

inoculated with variolous matter, without effect, in the year

1797, and again caught the cow-pox in the year 1798. When I saw

her, which was on the eighth day after she received the

infection, I found her affected with general lassitude,

shiverings, alternating with heat, coldness of the extremities,

and a quick and irregular pulse. These symptoms were preceded by

a pain in the axilla. On her hand was one large pustulous sore,

which resembled that delineated in Plate No. I. (Plate appears in

original.)

It is curious also to observe that the virus, which with respect

to its effects is undetermined and uncertain previously to its

passing from the horse through the medium of the cow, should then

not only become more active, but should invariably and completely

possess those specific properties which induce in the human

constitution symptoms similar to those of the variolous fever,

and effect in it that peculiar change which for ever renders it

unsusceptible of the variolous contagion.

May it not then be reasonably conjectured that the source of the

smallpox is morbid matter of a peculiar kind, generated by a

disease in the horse, and that accidental circumstances may have

again and again arisen, still working new changes upon it until

it has acquired the contagious and malignant form under which we

now commonly see it making its devastations amongst us? And, from

a consideration of the change which the infectious matter

undergoes from producing a disease on the cow, may we not

conceive that many contagious diseases, now prevalent among us,

may owe their present appearance not to a simple, but to a

compound, origin? For example, is it difficult to imagine that

the measles, the scarlet fever, and the ulcerous sore throat with

a spotted skin have all sprung from the same source, assuming

some variety in their forms according to the nature of their new

combinations? The same question will apply respecting the origin

of many other contagious diseases which bear a strong analogy to

each other.

There are certainly more forms than one, without considering the

common variation between the confluent and distinct, in which the

smallpox appears in what is called the natural way. About seven

years ago a species of smallpox spread through many of the towns

and villages of this part of Gloucestershire: it was of so mild a

nature that a fatal instance was scarcely ever Heard of, and

consequently so little dreaded by the lower orders of the

community that they scrupled not to hold the same intercourse

with each other as if no infectious disease had been present

among them. I never saw nor heard of an instance of its being

confluent. The most accurate manner, perhaps, in which I can

convey an idea of it is by saying that had fifty individuals been

taken promiscuously and infected by exposure to this contagion,

they would have had as mild and light a disease as if they had

been inoculated with variolous matter in the usual way. The

harmless manner in which it shewed itself could not arise from

any peculiarity either in the season or the weather, for I

watched its progress upwards of a year without perceiving any

variation in its general appearance. I consider it then as a

variety of the smallpox. [Footnote: My friend, Dr. Hicks, of

Bristol, who, during the prevalence of this distemper, was

resident at Gloucester, and physician of the hospital there

(where it was soon after its first appearance in this country),

had opportunities of making numerous observations upon it, which

it is his intention to communicate to the public.].

In some of the preceding cases I have noticed the attention that

was paid to the state of the variolous matter previous to the

experiment of inserting it into the arms of those who had gone

through the cow-pox. This I conceived to be of great importance

in conducting these experiments, and, were it always properly

attended to by those who inoculate for the smallpox, it might

prevent much subsequent mischief and confusion. With the view of

enforcing so necessary a precaution I shall take the liberty of

digressing so far as to point out some unpleasant facts relative

to mismanagement in this particular, which have fallen under my

own observation.

A medical gentleman (now no more), who for many years inoculated

in this neighbourhood, frequently preserved the variolous matter

intended for his use on a piece of lint or cotton, which, in its

fluid state, was put into a vial, corked, and conveyed into a

warm pocket; a situation certainly favourable for speedily

producing putrefaction in it. In this state (not unfrequently

after it had been taken several days from the pustules) it was

inserted into the arms of his patients, and brought on

inflammation of the incised parts, swellings of the axillary

glands, fever, and sometimes eruptions. But what was this

disease? Certainly not the smallpox; for the matter having from

putrefaction lost or suffered a derangement in its specific

properties, was no longer capable of producing that malady, those

who had been inoculated in this manner being as much subject to

the contagion of the smallpox as if they had never been under the

influence of this artificial disease; and many, unfortunately,

fell victims to it, who thought themselves in perfect security.

The same unfortunate circumstance of giving a disease, supposed

to be the smallpox, with inefficacious variolous matter, having

occurred under the direction of some other practitioners within

my knowledge, and probably from the same incautious method of

securing the variolous matter, I avail myself of this opportunity

of mentioning what I conceive to be of great importance; and, as

a further cautionary hint, I shall again digress so far as to add

another observation on the subject of inoculation.

Whether it be yet ascertained by experiment that the quantity of

variolous matter inserted into the skin makes any difference with

respect to the subsequent mildness or violence of the disease, I

know not; but I have the strongest reason for supposing that if

either the punctures or incisions be made so deep as to go

through it and wound the adipose membrane, that the risk of

bringing on a violent disease is greatly increased. I have known

an inoculator whose practice was "to cut deep enough (to use his

own expression) to see a bit of fat." and there to lodge the

matter. The great number of bad cases, independent of

inflammations and abscesses on the arms, and the fatality which

attended this practice, was almost inconceivable; and I cannot

account for it on any other principle than that of the matter

being placed in this situation instead of the skin.

It was the practice of another, whom I well remember, to pinch up

a small portion of the skin on the arms of his patients and to

pass through it a needle, with a thread attached to it previously

dipped in variolous matter. The thread was lodged in the

perforated part, and consequently left in contact with the

cellular membrane. This practice was attended with the same ill

success as the former. Although it is very improbable that any

one would now inoculate in this rude way by design, yet these

observations may tend to place a double guard over the lancet,

when infants, whose skins are comparatively so very thin, fall

under the care of the inoculator.

A very respectable friend of mine, Dr. Hardwicke, of Sodbury, in

this county, inoculated great numbers of patients previous to the

introduction of the more modern method by Sutton, and with such

success that a fatal instance occurred as rarely as since that

method has been adopted. It was the doctor's practice to make as

slight an incision as possible upon the skin, and there to lodge

a thread saturated with the variolous matter. When his patients

became indisposed, agreeably to the custom then prevailing, they

were directed to go to bed and were kept moderately warm. Is it

not probable then that the success of the modern practice may

depend more upon the method of invariably depositing the virus in

or upon the skin, than on the subsequent treatment of the

disease?

I do not mean to insinuate that exposure to cool air, and

suffering the patient to drink cold water when hot and thirsty,

may not moderate the eruptive symptoms and lessen the number of

pustules; yet, to repeat my former observation, I cannot account

for the uninterrupted success, or nearly so, of one practitioner,

and the wretched state of the patients under the care of another,

where, in both instances, the general treatment did not differ

essentially, without conceiving it to arise from the different

modes of inserting the matter for the purpose of producing the

disease. As it is not the identical matter inserted which is

absorbed into the constitution, but that which is, by some

peculiar process in the animal economy, generated by it, is it

not probable that different parts of the human body may prepare

or modify the virus differently? Although the skin, for example,

adipose membrane, or mucous membranes are all capable of

producing the variolous virus by the stimulus given by the

particles originally deposited upon them, yet I am induced to

conceive that each of these parts is capable of producing some

variation in the qualities of the matter previous to its

affecting the constitution. What else can constitute the

difference between the smallpox when communicated casually or in

what has been termed the natural way, or when brought on

artificially through the medium of the skin?

After all, are the variolous particles, possessing their true

specific and contagious principles, ever taken up and conveyed by

the lymphatics unchanged into the blood vessels? I imagine not.

Were this the case, should we not find the blood sufficiently

loaded with them in some stages of the smallpox to communicate

the disease by inserting it under the cuticle, or by spreading it

on the surface of an ulcer? Yet experiments have determined the

impracticability of its being given in this way; although it has

been proved that variolous matter, when much diluted with water

and applied to the skin in the usual manner, will produce the

disease. But it would be digressing beyond a proper boundary to

go minutely into this subject here.

At what period the cow-pox was first noticed here is not upon

record. Our oldest farmers were not unacquainted with it in their

earliest days, when it appeared among their farms without any

deviation from the phaenomena which it now exhibits. Its

connection with the smallpox seems to have been unknown to them.

Probably the general introduction of inoculation first occasioned

the discovery.

Its rise in this country may not have been of very remote date,

as the practice of milking cows might formerly have been in the

hands of women only; which I believe is the case now in some

other dairy countries, and, consequently, that the cows might not

in former times have been exposed to the contagious matter

brought by the men servants from the heels of horses. [Footnote:

I have been informed from respectable authority that in Ireland,

although dairies abound in many parts of the island, the disease

is entirely unknown. The reason seems obvious. The business of

the dairy is conducted by women only. Were the meanest vassal

among the men employed there as a milker at a dairy, he would

feel his situation unpleasant beyond all endurance.] Indeed, a

knowledge of the source of the infection is new in the minds of

most of the farmers in this neighbourhood, but it has at length

produced good consequences; and it seems probable, from the

precautions they are now disposed to adopt, that the appearance

of the cow-pox here may either be entirely extinguished or become

extremely rare.

Should it be asked whether this investigation is a matter of mere

curiosity, or whether it tends to any beneficial purpose, I

should answer that, notwithstanding the happy effects of

inoculation, with all the improvements which the practice has

received since its first introduction into this country, it not

very unfrequently produces deformity of the skin, and sometimes,

under the best management, proves fatal.

These circumstances must naturally create in every instance some

degree of painful solicitude for its consequences. But as I have

never known fatal effects arise from the cow-pox, even when

impressed in the most unfavourable manner, producing extensive

inflammations and suppurations on the hands; and as it clearly

appears that this disease leaves the constitution in a state of

perfect security from the infection of the smallpox, may we not

infer that a mode of inoculation may be introduced preferable to

that at present adopted, especially among those families which,

from previous circumstances, we may judge to be predisposed to

have the disease unfavourably? It is an excess in the number of

pustules which we chiefly dread in the smallpox; but in the cow-

pox no pustules appear, nor does it seem possible for the

contagious matter to produce the disease from effluvia, or by any

other means than contact, and that probably not simply between

the virus and the cuticle; so that a single individual in a

family might at any time receive it without the risk of infecting

the rest or of spreading a distemper that fills a country with

terror.

Several instances have come under my observation which justify

the assertion that the disease cannot be propagated by effluvia.

The first boy whom I inoculated with the matter of cow-pox slept

in a bed, while the experiment was going forward, with two

children who never had gone through either that disease or the

smallpox, without infecting either of them.

A young woman who had the cow-pox to a great extent, several

sores which maturated having appeared on the hands and wrists,

slept in the same bed with a fellow-dairymaid who never had been

infected with either the cow-pox or the smallpox, but no

indisposition followed.

Another instance has occurred of a young woman on whose hands

were several large suppurations from the cow-pox, who was at the

same time a daily nurse to an infant, but the complaint was not

communicated to the child.

In some other points of view the inoculation of this disease

appears preferable to the variolous inoculation.

In constitutions predisposed to scrophula, how frequently we see

the inoculated smallpox rouse into activity that distressful

malady! This circumstance does not seem to depend on the manner

in which the distemper has shewn itself, for it has as frequently

happened among those who have had it mildly as when it has

appeared in the contrary way.

There are many who, from some peculiarity in the habit, resist

the common effects of variolous matter inserted into the skin,

and who are in consequence haunted through life with the

distressing idea of being insecure from subsequent infection. A

ready mode of dissipating anxiety originating from such a cause

must now appear obvious. And, as we have seen that the

constitution may at any time be made to feel the febrile attack

of cow-pox, might it not, in many chronic diseases, be introduced

into the system, with the probability of affording relief, upon

well-known physiological principles?

Although I say the system may at any time be made to feel the

febrile attack of cow-pox, yet I have a single instance before me

where the virus acted locally only, but it is not in the least

probable that the same person would resist the action both of the

cow-pox virus and the variolous.

Elizabeth Sarfenet lived as a dairymaid at Newpark farm, in this

parish. All the cows and the servants employed in milking had the

cow-pox; but this woman, though she had several sores upon her

fingers, felt no tumours in the axillae, nor any general

indisposition. On being afterwards casually exposed to variolous

infection, she had the smallpox in a mild way. Hannah Pick,

another of the dairymaids who was a fellow-servant with Elizabeth

Sarfenet when the distemper broke out at the farm, was, at the

same time, infected; but this young woman had not only sores upon

her hands, but felt herself also much indisposed for a day or

two. After this, I made several attempts to give her the smallpox

by inoculation, but they all proved fruitless. From the former

case then we see that the animal economy is subject to the same

laws in one disease as the other.

The following case, which has very lately occurred, renders it

highly probable that not only the heels of the horse, but other

parts of the body of that animal, are capable of generating the

virus which produces the cow-pox.

An extensive inflammation of the erysipelatous kind appeared

without any apparent cause upon the upper part of the thigh of a

sucking colt, the property of Mr. Millet, a farmer at

Rockhampton, a village near Berkeley. The inflammation continued

several weeks, and at length terminated in the formation of three

or four small abscesses. The inflamed parts were fomented, and

dressings were applied by some of the same persons who were

employed in milking the cows. The number of cows milked was

twenty-four, and the whole of them had the cow-pox. The milkers,

consisting of the farmer's wife, a man and a maidservant, were

infected by the cows. The man-servant had previously gone through

the smallpox, and felt but little of the cow-pox. The servant

maid had some years before been infected with the cow-pox, and

she also felt it now in a slight degree; but the farmer's wife,

who never had gone through either of the diseases, felt its

effects very severely.

That the disease produced upon the cows by the colt and from

thence conveyed to those who milked them was the TRUE and not the

SPURIOUS cow-pox, there can be scarcely any room for suspicion;

yet it would have been more completely satisfactory had the

effects of variolous matter been ascertained on the farmer's

wife, but there was a peculiarity in her situation which

prevented my making the experiment.

Thus far have I proceeded in an inquiry founded, as it must

appear, on the basis of experiment; in which, however, conjecture

has been occasionally admitted in order to present to persons

well situated for such discussions objects for a more minute

investigation. In the mean time I shall myself continue to

prosecute this inquiry, encouraged by the hope of its becoming

essentially beneficial to mankind.

II

FURTHER OBSERVATIONS ON THE VARIOLA VACCINAE, OR COW-POX. 1799

Although it has not been in my power to extend the inquiry into

the causes and effects of the variolae vaccinae much beyond its

original limits, yet, perceiving that it is beginning to excite a

general spirit of investigation, I think it of importance,

without delay, to communicate such facts as have since occurred,

and to point out the fallacious sources from whence a disease

imitative of the true variolae vaccinae might arise, with the

view of preventing those who may inoculate from producing a

spurious disease; and, further, to enforce the precaution

suggested in the former treatise on the subject, of subduing the

inoculated pustule as soon as it has sufficiently produced its

influence on the constitution. From a want of due discrimination

of the real existence of the disease, either in the brute or in

the human subject, and also of that stage of it in which it is

capable of producing the change in the animal economy which

renders it unsusceptible of the contagion of the smallpox,

unpleasant consequences might ensue, the source of which,

perhaps, might not be suspected by one inexperienced in

conducting such experiments.

My late publication contains a relation of most of the facts

which had come under my own inspection at the time it was

written, interspersed with some conjectural observations. Since

then Dr. G. Pearson has established an inquiry into the validity

of my principal assertion, the result of which cannot but be

highly flattering to my feelings. It contains not a single case

which I think can be called an exception to the fact I was so

firmly impressed with--that the cow-pox protects the human body

from the smallpox. I have myself received some further

confirmations, which shall be subjoined. I have lately also been

favoured with a letter from a gentleman of great respectability

(Dr. Ingenhousz), informing me that, on making an inquiry into

the subject in the county of Wilts, he discovered that a farmer

near Calne had been infected with the smallpox after having had

the cow-pox, and that the disease in each instance was so

strongly characterized as to render the facts incontrovertible.

The cow-pox, it seems, from the doctor's information, was

communicated to the farmer from his cows at the time that they

gave out an offensive stench from their udders.

Some other instances have likewise been represented to me of the

appearance of the disease, apparently marked with its

characteristic symptoms, and yet that the patients have

afterwards had the smallpox. On these cases I shall, for the

present, suspend any particular remarks, but hope that the

general observations I have to offer in the sequel will prove of

sufficient weight to render the idea of their ever having had

existence, but as cases of spurious cow-pox, extremely doubtful.

Ere I proceed let me be permitted to observe that truth, in this

and every other physiological inquiry that has occupied my

attention, has ever been the object of my pursuit, and should it

appear in the present instance that I have been led into error,

fond as I may appear of the offspring of my labours, I had rather

see it perish at once than exist and do a public injury.

I shall proceed to enumerate the sources, or what appear to me as

such, of a spurious cow-pox.

First: That arising from pustules on the nipples or udder of the

cow; which pustules contain no specific virus.

Secondly: From matter (although originally possessing the

specific virus) which has suffered a decomposition, either from

putrefaction or from any other cause less obvious to the senses.

Thirdly: From matter taken from an ulcer in an advanced stage,

which ulcer arose from a true cow pock.

Fourthly: From matter produced on the human skin from contact

with some peculiar morbid matter generated by a horse.

On these subjects I shall offer some comments: First, to what

length pustulous diseases of the udder and nipples of the cow may

extend it is not in my power to determine; but certain it is that

these parts of the animal are subject to some variety of maladies

of this nature; and as many of these eruptions (probably all of

them) are capable of giving a disease to the human body, would it

not be discreet for those engaged in this investigation to

suspend controversy and cavil until they can ascertain with

precision what IS and what IS NOT the cow-pox?

For example: A farmer who is not conversant with any of these

maladies, but who may have heard of the cow-pox in general terms,

may acquaint a neighbouring surgeon that the distemper appears at

his farm. The surgeon, eager to make an experiment, takes away

matter, inoculates, produces a sore, uneasiness in the axilla,

and perhaps some affection of the system. This is one way in

which a fallacious idea of security both in the mind of the

inoculater and the patient may arise; for a disease may thus have

been propagated from a simple eruption only.

One of the first objects then of this pursuit, as I have

observed, should be, to learn how to distinguish with accuracy

between that peculiar pustule which is the true cow pock, and

that which is spurious. Until experience has determined this, we

view our object through a mist. Let us, for instance, suppose

that the smallpox and the chicken-pox were at the same time to

spread among the inhabitants of a country which had never been

visited by either of these distempers, and where they were quite

unknown before: what confusion would arise! The resemblance

between the symptoms of the eruptive fever and between the

pustules in either case would be so striking that a patient who

had gone through the chicken-pox to any extent would feel equally

easy with regard to his future security from the smallpox as the

person who had actually passed through that disease. Time and

future observation would draw the line of distinction.

So I presume it will be with the cow-pox until it is more

generally understood. All cavilling, therefore, on the mere

report of those who TELL US they have had this distemper, and are

afterwards found susceptible of the smallpox, should be

suspended. To illustrate this I beg leave to give the following

history:

Sarah Merlin, of the parish of Eastington in this county, when

about thirteen or fourteen years of age lived as a servant with

farmer Clarke, who kept a dairy consisting of about eighteen cows

at Stonehouse, a neighbouring village. The nipples and udders of

three of the cows were extensively affected with large white

blisters. These cows the girl milked daily, and at the time she

assisted, with two others, in milking the rest of the herd. It

soon appeared that the disease was communicated to the girl. The

rest of the cows escaped the infection, although they were milked

several days after the three above specified, had these eruptions

on the nipples and udders, and even after the girl's hand became

sore. The two others who were engaged in milking, although they

milked the cows indiscriminately, received no injury. On the

fingers of each of the girl's hands there appeared several large

white blisters--she supposes about three or four on each finger.

The hands and arms inflamed and swelled, but no constitutional

indisposition followed. The sores were anointed with some

domestic ointment and got well without ulcerating.

As this malady was called the cow-pox, and recorded as such in

the mind of the patient, she became regardless of the smallpox;

but, on being exposed to it some years afterwards she was

infected, and had a full burthen.

Now had any one conversant with the habits of the disease heard

this history, they would have had no hesitation in pronouncing it

a case of spurious cow-pox; considering its deviation in the

NUMEROUS blisters which appeared on the girl's hands; their

termination without ulceration; its not proving more generally

contagious at the farm, either among the cattle or those employed

in milking; and considering also that THE PATIENT FELT NO GENERAL

INDISPOSITION, ALTHOUGH THERE WAS SO GREAT A NUMBER OF VESICLES.

This is perhaps the most deceptious form in which an eruptive

disease can be communicated from the cow, and it certainly

requires some attention in discriminating it. The most perfect

criterion by which the judgment may be guided is perhaps that

adopted by those who attend infected cattle. These white blisters

on the nipples, they say, NEVER EAT INTO THE FLESHY PARTS like

those which are commonly of a bluish cast, and which constitute

the TRUE COW-POX, but that they affect the skin only, quickly end

in scabs, and are not nearly so infectious.

That which appeared to me as one cause of spurious eruptions, I

have already remarked in the former treatise, namely, the

transition that the cow makes in the spring from a poor to a

nutritious diet, and from the udder's becoming at this time more

vascular than usual for the supply of milk. But there is another

source of inflammation and pustules which I believe is not

uncommon in all the dairy counties in the west of England. A cow

intended to be exposed for sale, having naturally a small udder,

is previously for a day or two neither milked artificially nor is

her calf suffered to have access to her. Thus the milk is

preternaturally accumulated, and the udder and nipples become

greatly distended. The consequences frequently are inflammation

and eruptions which maturate.

Whether a disease generated in this way has the power of

affecting the constitution in any PECULIAR manner I cannot

presume positively to determine. It has been conjectured to have

been a cause of the true cow-pox, though my inquiries have not

led me to adopt this supposition in any one instance; on the

contrary, I have known the milkers affected by it, but always

found that an affection thus induced left the system as

susceptible of the smallpox as before.

What is advanced in my second position I consider also of very

great importance, and I could wish it to be strongly impressed on

the minds of all who may be disposed to conclude hastily on my

observations, whether engaged in their investigation by

experiments or not to place this in its clearest point of view

(as the similarity between the action of the smallpox and the

cow-pox matter is so obvious) it will be necessary to consider

what we sometimes observe to take place in inoculation for the

smallpox when imperfect variolous matter is made use of. The

concise history on this subject that was brought forward

respecting what I had observed in this neighbourhood [Footnote:

Inquiry into the Causes and Effects of the Variolae Vaccinae,

p.56 of the original article]. I perceive, by a reference since

made to the Memoirs of the Medical Society of London, may be

considered as no more than a corroboration of the facts very

clearly detailed by Mr. Kite [Footnote: See an account of some

anomalous appearances consequent to the inoculation of the

smallpox, by Charles Kite, Surgeon, of Gravesend, in the Memoirs

of the Medical Society of London, vol. iv, p. 114.]. To this

copious evidence I have to add still more in the following

communications from Mr. Earle, surgeon, of Frampton-upon-Severn,

in this county, which I deem the more valuable, as he has with

much candour permitted me to make them public:

"SIR:

"I have read with satisfaction your late publication on the

Variolae Vaccinae, and being, among many other curious

circumstances, particularly struck with that relating to the

inefficacy of smallpox matter in a particular state, I think it

proper to lay before you the following facts which came within my

own knowledge, and which certainly tend to strengthen the

opinions advanced in pages 56 and 57 of your treatise.

"In March, 1784, a general inoculation took place at Arlingham in

this county. I inoculated several patients with active variolous

matter, all of whom had the disease in a favourable way; but the

matter being all used, and not being able to procure any more in

the state I wished, I was under the necessity of taking it from a

pustule which, experience has since proved, was advanced too far

to answer the purpose I intended. Of five persons inoculated with

this last matter, four took the smallpox afterwards in the

natural way, one of whom died, three recovered, and the other,

being cautioned by me to avoid as much as possible the chance of

catching it, escaped from the disease through life. He died of

another disorder about two years ago.

"Although one of these cases ended unfortunate, yet I cannot

suppose that any medical man will think me careless or

inattentive in their management; for I conceive the appearances

were such as might have induced any one to suppose that the

persons were perfectly safe from future infection. Inflammation

in every case took place in the arm, and fever came on with a

considerable degree of pain in the axilla. In some of their arms

the inflammation and suppuration were more violent than is

commonly observed when perfect matter is made use of; in one

there was an ulcer which cast off several large sloughs. About

the ninth day eruptions appeared, which died away earlier than

common without maturation. From these circumstances I should

suppose that no medical practitioner would scarcely have

entertained a doubt but that these patients had been infected

with a true smallpox; yet I must confess that some small degree

of doubt presented itself to me at the speedy disappearance of

the eruptions; and in order, as far as I could, to ascertain

their safety, I sent one of them to a much older practitioner

than myself. This gentleman, on hearing the circumstances of the

case, pronounced the patient perfectly secure from future

infection.

"The following facts are also a striking proof of the truth of

your observations on this subject:

"In the year 1789 I inoculated three children of Mr. Coaley, of

Hurst farm in this county. The arms inflamed properly, fever and

pain in the axillae came on precisely the same as in the former

cases, and in ten days eruptions appeared, which disappeared in

the course of two days. I must observe that the matter here made

use of was procured for me by a friend; but no doubt it was in an

improper state; for, from the similarity of these cases to those

which happened at Arlingham five years before, I was somewhat

alarmed for their safety, and desired to inoculate them again:

which being permitted, I was particularly careful to procure

matter in its most perfect state. All the children took the

smallpox from this second inoculation, and all had a very full

burthen. These facts I conceive strikingly corroborate your

opinion relative to the different states of matter; for in both

instances that I have mentioned it was capable of producing

something strongly resembling the true smallpox, although it

afterwards proved not to be so.

"As I think the communication of these cases is a duty I owe to

the public, you are at liberty to make what use you please of

this letter. I remain, &c.,

"John Earle.

"FRAMPTON-UPON SEVERN, GLOUCESTERSHIRE, November 10, 1798.

"P. S. I think it necessary to observe that I can pronounce, with

the greatest certainty, that the matter with which the Arlingham

patients were inoculated was taken from a true smallpox pustule.

I took it myself from a subject that had a very full burthen."

Certain then it is that variolous matter may undergo such a

change from the putrefactive process, as well as from some of the

more obscure and latent processes of nature, as will render it

incapable of giving the smallpox in such a manner as to secure

the human constitution from future infection, although we see at

the same time it is capable of exciting a disease which bears so

strong a resemblance to it as to produce inflammation and matter

in the incised skin (frequently, indeed, more violent than when

it produces its effects perfectly), swelling of the axillary

glands, general indisposition, and eruptions. So strongly

persuaded was the gentleman, whose practice I have mentioned in

page 56 of the late treatise, that he could produce a mild

smallpox by his mode of managing the matter, that he spoke of it

as a useful discovery until convinced of his error by the fatal

consequence which ensued.

After this ought we to be in the smallest degree surprised to

find, among a great number of individuals who, by living in

dairies, have been casually exposed to the cow-pox virus when in

a state analogous to that of the smallpox above described, some

who may have had the disease so imperfectly as not to render them

secure from variolous attacks? For the matter, when burst from

the pustules on the nipples of the cow, by being exposed, from

its lodgment there, to the heat of an inflamed surface, and from

being at the same time in a situation to be occasionally

moistened with milk, is often likely to be in a state conducive

to putrefaction; and thus, under some modification of

decomposition, it must, of course, sometimes find access to the

hand of the milker in such a way as to infect him. What confusion

should we have were there no other mode of inoculating the

smallpox than such as would happen from handling the diseased

skin of a person labouring under that distemper in some of its

advanced and loathsome stages! It must be observed that every

case of cow-pox in the human species, whether communicated by

design or otherwise, is to be considered as a case of

inoculation. And here I may be allowed to make an observation on

the case of the farmer communicated to me by Dr. Ingenhousz. That

he was exposed to the matter when it had undergone the

putrefactive change is highly probable from the doctor's

observing that the sick cows at the farm gave out an OFFENSIVE

STENCH FROM THEIR UDDERS. However, I must remark that it is

unusual for cattle to suffer to such an extent, when disordered

with the cowpox, as to make a bystander sensible of any ill

smell. I have often stood among a herd which had the distemper

without being conscious of its presence from any particular

effluvia. Indeed, in this neighbourhood it commonly receives an

early check from escharotic applications of the COW LEECH. It has

been conceived to be contagious without contact; but this idea

cannot be well founded because the cattle in one meadow do not

infect those in another (although there may be no other partition

than a hedge) unless they be handled or milked by those who bring

the infectious matter with them; and of course, the smallest

particle imaginable, when applied to a part susceptible of its

influence, may produce the effect. Among the human species it

appears to be very clear that the disease is produced by contact

only. All my attempts, at least, to communicate it by effluvia

have hitherto proved ineffectual.