[Sir J. Risdon Bennett was a leading physician of London for
many years, holding the highest offices as an educator and
administrator. The article from which the following extracts
have been taken appeared in the _Leisure Hour_, 1882.]
No department of medical science has made greater advances in modern
times than that which is termed "Preventive Medicine." Nor is there any
in which the public at large is more deeply interested, and the
knowledge of which it is of more importance should be diffused as widely
as possible. The devoted and zealous service rendered by the medical
profession in all questions relating to the maintenance of health and
the prevention of disease is a sufficient answer, if any be needed, to
the ignorant and prejudiced statements that are sometimes made, that in
support of various scientific theories and proceedings medical men are
actuated by interested and selfish motives. No name stands, or will ever
stand, out more brilliant among the benefactors of mankind than that of
Edward Jenner, by whose genius and labours untold multitudes of human
lives have been saved, and an incalculable amount of human suffering and
misery prevented. At the present time various circumstances, both social
and scientific, have combined to recall attention to this illustrious
man and his remarkable scientific and beneficial labours. It is not,
however, our intention on the present occasion to give either a complete
sketch of his life, or a detailed account of his work. But in order to
show the connection between his discoveries and more recent advances in
the same field of scientific investigation, it will be necessary to give
a brief _resume_ of Jenner's life-work, and the benefits which he
conferred on the human race throughout the world.
He was born on the 17th May, 1749, at Berkeley, in Gloucestershire, of
which place his father was the vicar. On leaving Dr. Washbourn's school,
at Cirencester, he was apprenticed to Mr. Ludlow, a gentleman in
practice as a surgeon at Sudbury, near Bristol. On the completion of his
apprenticeship he came to London, and had the good fortune to be placed
under the care of the celebrated John Hunter, with whom he resided for
two years. The observing powers and taste for natural history which
Jenner had early shown, as a boy, were quickened and fostered by the
daily example and friendship of the illustrious man who, as surgeon and
lecturer at St. George's Hospital, was carrying on those laborious
scientific investigations, and building up that marvelous monument of
his genius, which have rendered his name and fame immortal. So much
skill and knowledge had been shown by Jenner in arranging the natural
history collection of Sir J. Banks, to whom he had been recommended by
Hunter, that he was offered the appointment of naturalist to Captain
Cook's second expedition. He, however, declined this and other
flattering proposals, in order to return to the rural scenes of his
boyhood, and be near an elder brother who had been the guide of his
orphanhood. He rapidly acquired an extensive business as a general
practitioner, while his polished manners, wide culture, and kind and
genial social qualifications, secured him welcome admission to the first
society of his neighbourhood. His conscientious devotion to his
professional duties did not, however, quell his enthusiastic love of
natural history, or preclude him from gaining a distinguished reputation
as a naturalist. A remarkable paper on the cuckoo, read before the Royal
Society and printed in the _Transactions_, gained him the fellowship of
that illustrious body. Jenner's paper established what has been properly
termed the "parasitic" character of the cuckoo, _i. e._, it deposits its
eggs in the nests of other birds, by whose warmth they are hatched, and
by whom the young are fed. His observations have received general
confirmation by subsequent observers, more especially the remarkable
facts that the parent cuckoo selects the nests of those birds whose eggs
require the same period of time for their incubation as its own (which
are much larger), and the food of whose young is the same, viz.,
insects, which the young cuckoo ultimately monopolizes by ousting the
young of the rightful owner of the nest.
By this and similar studies was Jenner preparing his acute powers of
investigation for the great purpose of his life. For this he secured
more time and more extended opportunities for inquiry by abandoning
general practice, and confining himself to medicine proper, having
obtained, in 1792, the degree of M.D. from the University of St.
Andrews. In conjunction with the "dear man," as he used to call his
great master, John Hunter, he carried on his experiments illustrative of
the structure and functions of animals. With great industry and
ingenuity he explained some of the unaccountable problems in
ornithology; he ascertained the laws which regulate the migration of
birds; made considerable advances in geology and in our knowledge of
organic remains; he amended various pharmaceutical processes; he was an
acute anatomist and pathologist, and investigated and explained one of
the most painful affections of the heart, and many of the diseases to
which animals are liable. By such labours he established a just claim to
distinction as a medical philosopher, apart from his claims to the
gratitude and admiration of mankind by his self-denying and devoted
labours in connection with his great discovery; but like other great men
absorbed in the establishing of important truths, he was regardless of
personal objects, and never ostentatiously promulgated his claims to
public distinction.
It was while still a youth, living with his master at Sudbury, that his
mind first became deeply impressed on the subject of the cow-pox. A
young country woman came to seek advice, when the subject of small-pox
was incidentally mentioned in her presence, and she immediately
observed, "I cannot take that disease, for I have had cow-pox." This was
a popular notion prevalent in the district, and not unknown to Jenner,
but from this time he never ceased to think on the subject. On coming to
London he mentioned it to several persons, and among others to Hunter;
but all thought his notion of getting rid of small-pox Utopian, and gave
him little or no encouragement. Hunter, however, who never liked to
daunt the enthusiasm of inquirers, said, in his characteristic way:
"Don't _think_, but _try_; be patient, be accurate." About the year
1775, some time after his return to the country, he first had the
opportunity of examining into the truth of the common traditions
regarding cow-pox, but it was not until 1780, after much study and
careful inquiry, that he was able to unravel the various obscurities and
contradictions with which the subject was involved, and in that year he
first disclosed his hopes and his fears to his friend, Edward Gardner.
His mind seems to have caught a glimpse of the reputation awaiting him,
and he felt that, in God's good providence, it "might be his lot to
stand between the living and the dead, and that through him a great
plague might be stayed."
It would be impossible in the brief space at our disposal to recount the
various difficulties and sources of error that Jenner encountered. It
may, however, be mentioned that he ascertained that there was more than
one form of local disease with which cows are afflicted, and which may
give rise to sores on the hands of milkmaids, but that one only of these
was the true cow-pox, giving origin to constitutional as well as local
disease, and which proves protective against small-pox. He also found
reason to believe that it was only in a particular stage of its
development that the true cow-pox vesicle was capable of being
transmitted so as to prove a prophylactic [preventive]. He was aware
that though, as a rule, persons did not have small-pox a second time,
yet there are instances where, from peculiarity of constitution or other
causes, small-pox occurs a second time in the same individual. Such
considerations as these cheered him to continue his inquiries when
apparent exceptions occurred to the protective influence of true
cow-pox.
Having at length satisfied his own mind, and, indeed, succeeded in
convincing others also, respecting the important protective influence
exerted on the constitutions of those who had received the true cow-pox
in the casual way, he sought to prove whether it was possible to
propagate the disease by inoculation from one human being to another. On
the 19th May, 1796, an opportunity occurred of making the experiment.
Matter was taken from the hand of Sarah Nelmes, who had been infected by
her master's cows, and inserted into the arm of James Phipps, a healthy
boy eight years of age. He went through the disease in a regular and
perfectly satisfactory way. But was he secure against the contagion of
small-pox? It is needless to say how full of anxiety Jenner was, when in
July following he put this to the test by inoculating the boy with
matter taken from the pustule of a small-pox patient. No disease
followed! This, his first crucial experiment, Jenner related to his
friend Gardner, and said: "I shall now pursue my experiments with
redoubled ardour." This ever-to-be-remembered day, 19th May, 1796, is
commemorated by an annual festival in Berlin, where, in 1819, little
more than twenty years after, it was officially reported that 307,596
persons had been vaccinated in the Prussian dominions alone. The account
which Jenner has given of his own feelings at this time is deeply
interesting. "While the vaccine discovery was progressing," he says,
"the joy I felt at the prospect before me of being the instrument
destined to take away from the world one of its greatest calamities,
blended with the fond hope of enjoying independence and domestic peace
and happiness, was often so excessive that in pursuing my favourite
subject among the meadows I have sometimes found myself in a kind of
reverie. It is pleasant to me to recollect that these reflections always
ended in devout acknowledgments to that Being from whom this and all
other mercies flow." Having obtained further corroboration of the truth
of his conclusions by the vaccination of his own son and several others,
he published in the form of a quarto pamphlet called "An Inquiry," a
brief and modest but complete account of his investigations and
discoveries. By this the attention of the whole medical world and
general public was called to the subject. His doctrines were put to the
test and abundantly confirmed, so that Mr. Clive, the celebrated surgeon
of the day, urged him to come to London, and promised him an income of
£10,000 a year. Jenner, however, declined the request, saying,
"Admitting as a certainty that I obtain both fortune and fame, what
stock should I add to my fund of little happiness? And as for fame, what
is it? A gilded butt forever pierced by the arrows of malignancy."
Jenner always maintained that small-pox and cow-pox were modifications
of the same disease, and that in employing vaccine lymph we only make
use of means to impregnate the system with the disease in its mildest
form, instead of propagating it in its virulent and contagious form, as
is done when small-pox is inoculated. He felt, also, that there was this
objection to the latter practice, which had obtained prevalence since
its introduction to this country by Lady Mary Wortley Montagu, that the
disease was thus spread among the community. He had, however, at that
time to contend against the prevalent notions that epidemic diseases
affecting the human race are peculiar to man and have no influence on
the lower animals, and that the diseases of other animals are not
communicable to man. But we have now abundant evidence that both these
notions are erroneous. Jenner himself, indeed, had shown what was well
known in various parts of the country, that the "grease" of the heel of
the horse was frequently communicated to those who had the care of
horses, whether or not it was the same disease as that which affected
the cow. It is sufficient only further to adduce another disease of
horses, called "farcy," which is not infrequently fatal to grooms and
others, not to mention the still more dreaded hydrophobia communicated
by dogs and animals of the feline species.
The rapid acceptance and spread of Jenner's doctrines speedily silenced
all cavillers except that small minority of incredulous and fanatical
opponents who are always to be found refusing to accept any truth that
does not coincide with their own ignorant and prejudiced views. The
frightful mortality and appalling effects of small-pox prior to the
introduction of vaccination were indeed such as to impel men to grasp at
any means that held out a probability of escape from the scourge. In the
present day the public can form but a faint idea of the ravages of
small-pox before Jenner's time. The records of historians, not only of
our own country, but throughout the world, teem with the most appalling
accounts. Dr. Lettsom calculated that 210,000 fell victims to it
annually in Europe. Bernouilli, an Italian, believed that not less than
15,000,000 of human victims were deprived of life by it every
twenty-five years, _i. e._, 600,000 annually. In Russia 2,000,000 were
cut off in one year. In Asia, Africa, and South America, whole cities
and districts were depopulated. Nor was it only the actual mortality
which rendered it so appalling. The records of the Institution for the
Indigent Blind in our own country showed that three-fourths of the
objects relieved had lost their sight by small-pox, while the number of
persons with pitted and scarred faces and deformed features that were
met with in the streets testified to the frightful ordeal that they had
passed through. Multitudes died of diseases set up by this plague, or
from ruined constitutions which it entailed. And what, of all this, it
may be asked, do we now see? Is it not a rare thing to meet a person
whose face is scarred and his features deformed by small-pox? How few
persons can cite instances among their acquaintance of those who have
died of small-pox after having been properly vaccinated? Is it necessary
to go into statistics and elaborate investigations of the bills of
mortality of the present day in order to be convinced that, as compared
with the records of anti-vaccine times, we have indeed cause to bless
the memory of Jenner?
We do not ignore the fact that small-pox, like other similar diseases
having an epidemic character, may be absent for a length of time from
certain districts and then break out again; nor that each epidemic has
its period of increment and decrement, and varies in its degree of
malignancy. But a full and careful review of the whole history of
small-pox since the introduction of vaccination, proves to every
unprejudiced mind that every recurring epidemic finds its victims, with
comparatively few exceptions, among the unvaccinated, that its spread is
arrested by renewed attention to vaccination and its vigorous
enforcement, and that, even taking into account the countries and
localities where from various causes it has been neglected, the
mortality from this foul and fatal disease, small-pox, has been
enormously reduced. Human lives have been saved, and human life
prolonged to such an extent that it is impossible to estimate the
benefits that mankind has derived from the genius and devoted patriotic
labours of one man.
That doubts and difficulties in connection with this subject, involving
the well-being of the whole human race, have lately arisen, must be
admitted. But there is good reason to believe that, by modern researches
on the subject of epidemic diseases and the germ theory of disease,
these doubts are already being dispelled, and that the difficulties will
be speedily obviated.
The grounds for this belief will be understood by the consideration of
those scientific investigations to a brief detail of which we now
proceed. The reader will then also be better able to judge of the
propriety, and necessity of certain measures which, to the uninformed,
must appear objectionable or even repulsive and arbitrary.
We now, then, turn to the remarkable experiments and discoveries of M.
Pasteur, which have gained for him a world-wide reputation, and the
bearing of which on the science of preventive medicine is commanding the
attention and admiration of the whole scientific world, and indeed we
may say of mankind at large. M. Pasteur is not a medical man, nor,
indeed, a physiologist. He is simply a French chemist, a modest,
retiring labourer in the field of science whose sole object has been the
discovery of truth, and whose chemico-physical researches gained for him
the Rumford Medal of the Royal Society in 1856. Having devoted himself
specially to the chemistry of organic substances, he was naturally
attracted by the discovery of Cagniard de la Tour, that yeast is really
a plant, a species of fungus, whose vegetative action in fermentable
liquids is the true cause of their fermentation. This was so opposed to
the theories of all the chemists of the day, among whom may particularly
be mentioned the celebrated Liebig, that it met with their warm
opposition. When, however, Helmholtz and others succeeded in showing
that by preventing the passage of the minute organisms constituting the
yeast plant into fermentable liquids, no fermentation took place, the
doctrine soon became established that the first step in the process of
alcoholic fermentation is due, not to ordinary chemical changes, but to
the presence of living organisms. In like manner the putrefaction and
decomposition of various liquids containing organic matter was found to
be due, not to the simple action of the oxygen of the atmosphere, but to
the introduction from without of microscopic germs which found material
for their development in such liquids. So that if by mechanical
filtration of the air the entrance of such germs can be prevented, or if
by heat or other means they can be destroyed, any fluid, however readily
it may undergo putrefaction in ordinary circumstances, will remain
perfectly sweet, though freely exposed to the air. And the same fluid
will undergo a different kind of fermentation according as it is
subjected to the action of different species of germs. These and other
facts of scarcely less importance, which cannot here be detailed,
induced Pasteur to test the application of the doctrines deduced from
them to the study of disease in living animals.
His attention was first directed to the disease affecting the silkworm,
and known as the _Pebrine_, which at one time seemed likely to destroy
the silk cultivation both in France and Italy. It had been ascertained
that the bodies of the silkworm, in all its stages of chrysalis, moth,
and worm, were in this disease infested by minute corpuscles which even
obtained entrance into the undeveloped eggs. After a prolonged and
difficult inquiry, Pasteur found that these minute corpuscles were
really independent, self-propagating organisms, introduced from without,
and were not merely a sign of the disease, but its real cause. As a
result of the application of these discoveries, the silkworm disease has
been extinguished, or so controlled as to have saved a most important
and valuable culture.
Between the years 1867 and 1870 above 56,000 deaths from a disease
variously designated as "anthrax," or "carbuncular disease," and
"splenic fever," and in France known by the terms "charbon," or "pustule
maligne," are stated to have occurred among horses, cattle, and sheep in
one district of Russia, Novgorod, occasioning also the deaths of 528
among the human population. It occurs in two forms, one more malignant
and rapid in its action than the other. In France the disease appears
to be scarcely ever absent, and is estimated to entail on the breeders
of cattle an annual loss of many millions of francs. As a milder
epidemic it has prevailed in this country, and the disease which has
lately broken out in Bradford and some other towns in the north among
wool-sorters, has now been shown to be a modification of the same
disease communicated by the wool of sheep that have been infected.
On examining the blood of animals, the subjects of "splenic fever," some
French pathologists had discovered the presence of certain minute
transparent filaments which, by the investigations of a German physician
named Koch, were proved to be a fungoid plant developed from germ
particles of microscopic minuteness. By gradual extension these minute
particles, termed "microbes," attain the form of small threads or rods,
to which the name of "bacilli" has been given, from the Latin
_bacillus_, a rod or staff. These rods were found to be in fact hollow
tubes, divided at intervals by partitions, which, on attaining full
growth, break up into fragments, the interiors of which are found to be
full of minute germs similar to those from which the rods were at first
developed. These germs were found by Koch and his collaborateurs to be
capable of cultivation by being immersed in some suitable organic liquid
kept at a proper temperature, and the supply could be kept up by
introducing even a few drops of such impregnated fluids into other
fluids, and repeating the process again and again. The next step to test
the potency of these germs to generate the disease in animals whence
they were originally obtained, was to vaccinate animals with a few drops
of the fluid thus artificially infected. Accordingly it was found that
the bodies of guinea-pigs, rabbits, and mice thus inoculated became
infected, and developed all the characteristic symptoms of splenic fever
or carbuncular disease.
Pasteur, whose enthusiasm in the pursuit of investigations which had
already been crowned with such signal success kept him awake to all that
was being done by other inquirers, and made him watchful of every event
that transpired relative to the epidemic diseases of cattle, was struck
with the fact that some of the most fatal outbreaks of "charbon" among
flocks of sheep occurred in the midst of apparently the most healthy
pastures. His sagacity led him to inquire what had been done with the
carcasses of animals that had died from previous outbreaks of the
disease in these localities, when he found that they had been buried in
the soil and often at great depths, of the same pastures. But how could
the disease germs make their way to the surface from a depth of eight or
ten feet? Earthworms, he guessed, might have conveyed them. And
notwithstanding the incredulity with which his explanation was received,
he forthwith proceeded to verify his supposition. Having collected a
number of worms from the ground of the pastures in question, he made an
extract of the contents of the alimentary canal of the worms, and with
this he inoculated rabbits and guinea-pigs, gave them the "charbon" in
its most fatal form, and proved the identity of the malady by
demonstrating that the blood of the victims swarmed with the deadly
"bacillus." And here we cannot but stop to notice the remarkable
confirmation that is thus given to the wonderful and beautiful
observations of Darwin as set forth in his last work on "The Formation
of Vegetable Mould Through the Action of Worms." Darwin has shown beyond
all dispute, as the result of his incomparable researches, that though
"the plough is one of the most ancient and most valuable of man's
inventions, long before he existed the land was in fact regularly
ploughed, and still continues to be ploughed, by earthworms." He has
shown us that the smoothness which we admire in a wide, turf-covered
expanse "is mainly due to all the inequalities having been slowly
leveled by worms," and that "the whole of the superficial mould over any
such expanse has passed, and will pass again, every few years, through
the bodies of worms!" It was left for Pasteur to show that these
innumerable and indefatigable plowmen, whilst rendering to man such
efficient service, may also be the carriers of the seeds of disease and
death.
In proceeding with our brief historical account of Pasteur's and allied
researches, we are arrived at the point where their analogy to Jenner's
becomes manifest, and where their direct bearing on the welfare of
mankind comes into view. So soon as it was known that these disease
germs were low forms of vegetation, and that, like other vegetables,
they could be cultivated, it was natural to ask whether, like other
vegetables, their characters and properties could not be so modified as
to render them at least less deleterious. Every one knows the difference
between the crab-apple and its cultivated variety, the sloe and the
plum, the wild and the cultivated celery. It is all the difference
between unwholesome and wholesome food.
Two methods of cultivation, with a view to obtaining the desired
modification of the power exercised by the bacilli and other similar
germs, presented themselves, the one analogous to that really pursued by
Jenner where small-pox, or the grease of the horse, was passed through
the system of the cow, and then from one human being to another; and the
second by carrying on the cultivation out of the living body. Both these
plans have been adopted, with the result of proving that the potency of
the germs can be so diminished as to render the disease produced by
their introduction so mild as to be of no importance. Pasteur cultivated
the bacillus in chicken broth or meat juice, and allowed a certain time
to elapse before he made use of the mixture. After allowing only two
months to elapse, the virulence of the germs seemed to be but little
impaired, but after three or four months animals inoculated with the
fluid, though they took the disease, had it in so mild a form that the
greater number recovered. After a long period of six or eight months the
engendered disease was so mild that all the animals speedily recovered
and regained health and strength.
And now the question will naturally arise, Did animals which had passed
through the mild disease thus induced acquire a protection against the
original disease, if brought in contact with it in subsequent epidemics,
in the same way that Jenner's vaccinated patients were protected against
small-pox?
An answer in the affirmative may now be given with the utmost
confidence. Experiments conducted, both in this country and abroad, by
both methods of procedure, have abundantly proved that animals may be
protected by inoculation so as to render them insusceptible of any form
of the destructive anthrax disease.
From a remarkable paper read by Pasteur before the International Medical
Congress we extract the concluding paragraph. After detailing the method
pursued to obtain the requisite attenuation of the virus, and stating
that by certain physiological artifices it may be made again to assume
its original virulence, he proceeds: "The method I have just explained,
of obtaining the vaccine of splenic fever, was no sooner made known
then it was very extensively employed to prevent the splenic affection.
In France we lose every year by splenic fever animals to the value of
20,000,000 francs, and even, according to one of the persons in the
office of the Minister of Agriculture, more than 30,000,000 francs, but
exact statistics are still wanting. I was asked to give a public
demonstration at Pouilly-le-Fort, near Melun, of the results already
mentioned. This experiment I may relate in a few words. Fifty sheep were
placed at my disposition, of which twenty-five were vaccinated, and the
remaining twenty-five underwent no treatment. A fortnight afterwards the
fifty sheep were inoculated with the most virulent anthracoid microbe
(or germ). The twenty-five vaccinated sheep resisted the infection, the
twenty-five unvaccinated died of splenic fever within fifty hours.
"Since that time the capabilities of my laboratory have been inadequate
to meet the demands of farmers for supplies of this vaccine. In the
space of fifteen days we have vaccinated in the departments surrounding
Paris, more than 20,000 sheep, and a large number of cattle and horses.
This experiment was repeated last month at the Ferme de Lambert, near
Chartres. It deserves special mention.
"The very virulent inoculation practiced at Pouilly-le-Fort, in order to
prove the immunity produced by vaccination, had been effected by the aid
of anthracoid germs deposited in a culture which had been preserved in
my laboratory more than four years, that is to say, from the 21st March,
1877. There was assuredly no doubt about its virulence, since in fifty
hours it killed twenty-five sheep out of twenty-five. Nevertheless, a
commission of doctors, surgeons, and veterinary-surgeons, of Chartres,
prejudiced with the idea that virus obtained from infectious blood must
have a virulence capable of defying the action of what I call cultures
of virus, instituted a comparison of the effects upon vaccinated sheep
and upon unvaccinated sheep of inoculation with the blood of an animal
which had died of splenic fever. The result was identical with that
obtained at Pouilly-le-Fort--absolute resistance of the vaccinated and
deaths of the unvaccinated. If I were not pressed for time I should
bring to your notice other kinds of virus attenuated by similar means.
These experiments will be communicated by-and-by to the public."
The bearing of these researches of Pasteur on vaccination with cow-pox,
and the whole of the Jennerian doctrines, will be evident. They throw a
flood of light both on the efficacy of vaccination and the many supposed
failures which have given a handle to the unscrupulous fanatical
detractors of Jenner and his doctrines. They go far toward establishing
the correctness of the view entertained by Jenner as to the identity of
small-pox and cow-pox, showing how great may be the modifications
effected in the original virus by repeated transmission, either through
the animal or the human system.
But apart from the question of identity or diversity of small-pox and
vaccinia, Pasteur's researches prove beyond all question that a disease
virus may be both diminished and augmented in power by physiological
devices, and that therefore the efficacy of the vaccine lymph may, in
various ways, be so diminished as to lose its protective power, without
shaking our faith in the principle of vaccination or detracting in the
least from the inestimable value of Jenner's discovery. The attention of
the scientific world will now be, and is, directed to the important
inquiry, How far has the original vaccinia of Jenner lost its protective
power? If so, how has this been brought about, and by what means can it
be restored? Must we again revert to the cow for a new supply? Need we
only be more scrupulous in the selection of the vesicles, and the
particular stage of their development, and in the mode in which the
operation of vaccination is performed? These and numerous other similar
questions are now being discussed and investigated, but none probably is
more important than the question how far the protective influence in
each individual is dissipated by time, and hence the principle of
re-vaccination is now being enforced. There can be no doubt that
different epidemics possess different degrees of virulence, and what
proves a sufficient protection in a mild epidemic of small-pox may not
be sufficient in a more virulent one. In certain seasons and in certain
conditions of the atmosphere, the human system is more prone to certain
disease than at other times. Pasteur's experiments on cultivated virus
or germs show that in the course of time, and in certain conditions of
exposure to the action of oxygen or other agents, the vitality, or
constitution, so to speak, of the germs may be so changed as materially
to alter their action on the animal system. We have, therefore,
scientific grounds for reverting from time to time to the heifer for a
new stock, rather than continuing to rely on the perpetual transmission
from one human body to another.
This is not the place to enter on the whole question of the germ theory
of disease, but who does not see how wide is the field for investigation
opened up by Pasteur and others? Already the application of the
principle of vaccination has been successfully applied by Pasteur to a
very fatal epidemic disease attacking fowls, and known by the name of
"chicken cholera." By inoculating chickens with the cultivated variety
of the particular "bacillus" he has afforded to them complete
protection. The economic value of this to France may in some measure be
estimated by the many millions of eggs which are exported from France to
this country alone. How many other diseases, such as scarlatina and
diphtheria, which now carry off annually thousands of children, may not
ere long be extinguished by like means who shall say? "I venture,"
states Mr. Simon, in his address to the Health Section of the
International Congress, "to say that in the records of human industry it
would be impossible to point to work of more promise to the world than
these various contributions to the knowledge of disease and of its cure
and prevention, and they are contributions which, from the nature of the
case, have come, and could only have come, from the performance of
experiments on living animals."
Compulsory vaccination is, no doubt, a strong measure, and one which
might, in this land of individual liberty, be expected to give rise both
to question and opposition. It can only be justified by proving that it
is to the interest of the individual as well as of the whole community
that it should be enforced. Of its propriety and necessity we believe it
needs only a calm and unprejudiced inquiry to be convinced. Most of the
objections raised against it are either baseless or admit of being
obviated. That some of the objections are of a character that command
our respect may be admitted, but mere sentiment or prejudiced and
ill-founded objections, must give place to sound arguments and
well-established evidence. In this, as in many similar cases, opposition
and discussion open up entrances for light by which the clouds of
ignorance and darkness are sure to be dispelled. But even as this whole
question of vaccination now stands, the responsibility of those who are
persistently misrepresenting facts and misleading the public is great,
nay, criminal, when we reflect how many lives are sacrificed by the
neglect of precautionary means within the reach of all.