The curious tradition among the dairy folk of Gloucestershire, that persons who had suffered from Cowpox were thereby rendered insusceptible of Smallpox, was made known to Edward Jenner when a doctor’s apprentice, and was never afterwards absent from his mind. Thirty years elapsed before the fruit was borne to the public; but incessantly he thought, and watched, and experimented on the subject, and the work in which at length he recorded the incomparable results of his labour may well have commanded the confidence of reflecting persons.
Little would ever be heard of objections to Vaccination, if all who undertake the responsibility of its performance, and all who feel disposed to resist its adoption, would but thoroughly study that masterpiece of medical induction, and imitate the patience and caution and modesty with which Jenner laid the foundations of every statement he advanced.
In the first Inquiry into the Causes and Effects of the Variolæ Vaccinæ, Jenner set on a scientific basis the popular belief to which I have referred; and the close of the 18th Century, which had much to darken it, will be remembered till the end of human history for the greatest physical good ever yet given by science to the world.—Papers relating to the History and Practice of Vaccination. Pp. xi. and xii. London, 1857.
These are the words of Mr. John Simon, and in them we have the Jennerian legend with the morsel of fact to the mass of fable which characterises legendary matter, ancient and modern. The recommendation to “study thoroughly that master-piece of medical induction,” Jenner’s Inquiry, is a mere flourish of panegyric; for, as Mr. Simon was well aware, the book had been out of print for half a century, and was practically inaccessible; whilst its reproduction has usually been considered undesirable in the interests of Vaccination, inasmuch as it reveals more than is expedient for common knowledge. An idol that is good to swear by is always fortified by a convenient obscurity.
The Inquiry is a quarto of less than seventy pages in large type, set in broad margins in the grand style of the period, and illustrated with four coloured plates. There are eight pages of Introductory Matter, followed by thirty-four pages of Cases, concluding with twenty-six pages of General Observations.
It is to the Cases as the ground of the argument, that I would first direct attention. They are twenty-three, and may be thus assorted—
13 of Cowpox communicated by accident.
4 of Horsegrease communicated by accident and inoculated by design.
6 of Cowpox inoculated by design or transferred from arm-to-arm.
It may be tedious, but I should like to go with the reader over these Cases, for they are highly instructive. Let us take the first twelve of Cowpox communicated by accident.
I.—Joseph Merret, Gardener.
In 1770 attended to Horses, milked Cows, and caught Cowpox. Afterwards his family had Smallpox, but he escaped. In 1795 Jenner repeatedly inoculated him with Smallpox without effect.
II.—Sarah Portlock, Farm Servant.
In 1771 had Cowpox. In 1792 nursed her child in Smallpox “conceiving herself secure,” and was at the same time inoculated with Smallpox in both arms without effect.
III.—John Phillips, Tradesman.
Had Cowpox when nine years old. Was inoculated with Smallpox by Jenner at the age of 62 without effect.
IV.—Mary Barge, Farm Servant.
In 1767 had Cowpox. In 1791 was inoculated with Smallpox without effect. Had also acted as nurse to Smallpox patients without catching the disease.
V.—Mrs. H——, Gentlewoman.
Had Cowpox when very young, contracted by handling dairy utensils. Was subsequently exposed to Smallpox, “where it was scarcely possible for her to have escaped;” and in 1778 was inoculated with Smallpox by Jenner without effect.
At this point, I would draw attention to the ages of the persons set forth in these Cases: they were past middle life when the susceptibility to Smallpox was either low or extinct. The reason given by Jenner for their production was that he “wished to show that the change produced in the constitution by Cowpox is not affected by time”—a claim which vaccinators at this day surrender, insisting on the necessity of re-vaccination to maintain “the benign influence;” but apart from that consideration, there was nothing extraordinary in resistance to inoculated Smallpox. Without the intervention of Cowpox, inoculators were constantly meeting patients who would not “take,” even with repeated attempts, and especially among elderly people; and some who obstinately resisted inoculated Smallpox, subsequently contracted the disease in the ordinary way. So much Jenner himself allowed, saying—
There are many who from some peculiarity in habit resist the common effects of variolous matter inserted into the skin, and in consequence are haunted through life with the distressing idea of being insecure from subsequent infection. (P. 60.)
Yet he was pleased to refer this well recognised resistance to variolation in those who had had Cowpox to Cowpox, allowing nothing for habit of body!
VI.—Sarah Wynne, Dairymaid.
In 1796 had Cowpox in May, and “in so violent a degree, that she was confined to her bed, and rendered incapable for several days of pursuing her ordinary vocation.” On 28th March, 1797, she was inoculated with Smallpox by Jenner without effect.
Under this Case Jenner observes, that “among our dairy farmers those who have had Smallpox either escape Cowpox, or are disposed to have it slightly; and as soon as the complaint shows itself among cattle, assistants are procured, if possible, who are thus rendered less susceptible of it, otherwise the business of the farm could scarcely go forward.” At the farm where Sarah Wynne was employed, all had had Smallpox except Sarah, and all save Sarah, escaped.
VII.—William Rodway, Dairyman.
In 1796 had Cowpox. In 1797 was inoculated with Smallpox by Jenner without effect.
Under Rodway’s Case Jenner showed that the farmers were at fault in supposing that Smallpox kept off Cowpox. In the dairy where Rodway was employed, all the milkers had passed through Smallpox, except Rodway, and all contracted Cowpox; “but there was no comparison in the severity of the disease as it was felt by them and by Rodway. While he was confined to bed, they were able, without much inconvenience, to follow their ordinary business.” Thus Jenner argued that though Smallpox might not keep off Cowpox, it made Cowpox milder.
VIII.—Elizabeth Wynne, Dairymaid.
In 1759 had Cowpox slightly when 19 years of age. “As the malady had shown itself in so slight a manner,” observed Jenner, “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” without effect. Nevertheless in the following year, 1798, she again caught Cowpox, having a “large pustulous sore” accompanied with “general lassitude, shiverings, alternating with heat, coldness of extremities, and a quick and irregular pulse.”
IX.—William Smith, Farm Servant.
Although [wrote Jenner as preface to this Case] the Cowpox shields the constitution from the Smallpox, and the Smallpox proves a protection against its own poison, yet it appears that the human body is again and again susceptible of the infectious matter of the Cowpox.
In 1780, when attending to Horses with sore heels, Smith conveyed the equine infection to Cows, “and from the Cows it was communicated to Smith. In 1791, the Cowpox broke out at another farm where he then lived as a servant, and he became affected with it a second time; and in 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.” He was twice inoculated with Smallpox in 1795, and exposed to Smallpox without effect.
X.—Simon Nichols, Farm Servant.
In 1782 was employed in dressing the sore heels of Horses, and at the same time assisted in milking Cows, thereby infecting them and generating Smallpox. Changing his situation, he communicated the disease to other Cows, and was himself severely affected. Some years afterwards, he was inoculated with Smallpox by Jenner without effect.
XI.—William Stinchcomb, Farm Servant.
In 1782 had Cowpox severely on the same farm with Nichols. In 1792 he was inoculated with Smallpox along with a large party, but in his case without result. “During the sickening of some of his companions, their symptoms so strongly recalled to his mind his own state when sickening with the Cowpox, that he very pertinently remarked their striking similarity.”
XII.—Hester Walkley, Farm Servant.
In 1782 had Cowpox when she was attended by Jenner. In 1795 she, and seven other pauper women of Tortsworth, who also had had Cowpox, were inoculated with Smallpox by Henry Jenner without effect. “This state of security proved a fortunate circumstance,” observed Jenner, “as many of the poor women were at the same time in a state of pregnancy.” Why then, it might have been asked, did Henry Jenner try to variolate them?
These Twelve Cases illustrate Jenner’s procedure; and those familiar with scientific methods, and the scrutiny and caution requisite to arrive at trustworthy physiological data, will view with some astonishment his free and easy induction. In the majority of the Cases he was without proof that his subjects had suffered Cowpox; and the absence of this certainty was the more remarkable as he knew that the dairy-folk described as Cowpox several varieties of eruption. The same rural observers who held that Cowpox averted Smallpox, also held that Smallpox averted Cowpox; and yet Jenner had to show in Rodway’s Case No. vii., that they were mistaken; although, granting the thesis that Smallpox and Cowpox were equivalents and mutually preventive, the rural faith ought to have stood justified, and Smallpox shown to be good against Cowpox. Again Jenner allowed that an attack of Cowpox did not prevent a subsequent attack of Cowpox, saying—
It is singular to observe that the Cowpox virus, although it renders the constitution insusceptible of the variolous, should nevertheless leave it unchanged with respect to its own action.
Singular indeed! The observation in presence of the principle to be established was nothing short of imbecile. If Smallpox prevented Smallpox, and Cowpox was one with Smallpox, and Cowpox did not avert Cowpox, how was Cowpox to avert Smallpox? The insusceptibility of Jenner’s subjects to variolous inoculation was, as observed, of little account. Resistance to inoculated Smallpox was of common occurrence, and inoculators practised various dodges to overcome it. To have made such experiments approximately conclusive would have required the inoculation with Smallpox of subjects of corresponding ages and temperaments who had not passed through Cowpox; and the probability is that the results would not have been dissimilar.
We must not, however, proceed farther until Cowpox is described; and for that purpose I cannot do better than cite Jenner verbatim.
Cowpox appears on the nipples of the Cows in the form of irregular pustules. At their first appearance they are commonly a palish blue, or rather of a colour somewhat approaching to livid, and are surrounded by an inflammation. These pustules, unless a timely remedy be applied,[98] frequently degenerate into phagedenic [spreading] ulcers, which prove extremely troublesome. 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 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 centres, and of a colour distantly approaching to blue. Absorption takes place, and tumours appear in each axilla [arm-pit].
The system becomes affected, the pulse is quickened; shiverings, succeeded by heat, 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. (P. 3.)
And Jenner might have added, with convulsions.
Having drawn this alarming picture of the effects of Cowpox, he interposes—
These symptoms arise principally from the irritation of the sores, and not from the primary action of the vaccine virus upon the constitution. (P. 5.)
If Cowpox meant all this, some might prefer, at least, the risk of Smallpox; hence the judicious explanation—the irritation of the sores, and not the poison in the blood, was the cause of the distressing symptoms. Jenner went on—
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 sprang. During the progress of the disease, the lips, nostrils, eyelids, and other parts of the body, are sometimes affected with sores; but these evidently arise [How evidently?] from their being heedlessly rubbed or scratched with the patient’s infected fingers. (P. 5.)
It was this serious disease, this communicated Cowpox, which the subjects of the foregoing Cases were assumed to have passed through; and Jenner, in conformity with the opinion of the dairies, held that they were thereby rendered proof against Smallpox. Whilst his Twelve Cases make a show of inquiry, they bear no trace of extensive or critical research. In the general inoculations then prevalent, those who had undergone Cowpox were not treated as protected (as were those who had had Smallpox) but were “cut” with their neighbours—as, in Case xii., were the eight cowpoxed paupers of Tortworth. Yet Jenner was at no pains to collect and set forth the evidence of other Gloucestershire practitioners, who, in the course of duty, must have known as much of Cowpox as himself, and might have set scores of Cases alongside his perfunctory dozen.
Having perused Jenner’s description of Cowpox, let us now turn to his account of its origin.
There is a disease to which the Horse, from his state of domestication, is frequently subject. The Farriers have termed it The Grease. It is an inflammation and swelling in the heel, accompanied in its commencement with small cracks or fissures, from which issues a limpid fluid, possessing properties of a peculiar kind. This fluid seems capable of generating a disease in the human body (after it has undergone the modification 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 that 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 malady I have mentioned, 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 frequently happens that a disease is communicated to the Cows, and from the Cows to the Dairy-maids, which spreads through the farm until most of the cattle and domestics feel its unpleasant consequences. This disease has obtained the name of The Cowpox.
Thus the disease makes its progress from the Horse (as I conceive) to the nipples of the Cow, and from the Cow to the Human Subject. (Pp. 2 and 6.)
This conception of the origin and progress of the disease was not Jenner’s specially: he shared it with the farmers to whom it was a novelty—
The rise of Cowpox 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. Indeed a knowledge of the source of infection is new in the minds of most of the farmers in this neighbourhood, but has at length produced good consequences; and it seems probable from the precautions they are disposed to adopt, that the appearance of the Cowpox here may either be entirely extinguished or become extremely rare. (P. 56.)
Thus Cowpox was to be extinguished by forbidding milkers to handle Horses’ greasy heels. Jenner himself tried to produce Cowpox in the manner described, but without success—
It is very easy [he wrote] 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 inflammation. (P. 45.)
What was requisite for success, he concluded, was the limpid fluid from the Horse’s heel at an early stage of the disease, and that it should be applied to the Cow’s nipples at a certain season—
The virus from the Horses’ heels 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, 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. (P. 45.)
Whilst thus explicit as to what was requisite for the infection of the Cow by the Horse, Jenner did not succeed in producing Cowpox from Horsegrease. He had to write—
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. No Cowpox appeared in the neighbourhood; for it most frequently happens that while the farmers’ Horses are exposed to the cold rains of spring their heels become diseased. (P. 44.)
Yet without proof, he argued as if he had proof, saying—
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. (P. 43.)
Evidence adduced! Of evidence there was none. The farmers might be right in their opinion that Cowpox sprang from Horsegrease, but opinion was not evidence, nor even such assurance as this of Jenner’s—
I feel no room for hesitation respecting the common origin of the disease, being well convinced that it never appears among the Cows unless they have been milked by some who at the same time has the care of a Horse affected with diseased heels. (P. 44.)
But not even to this conviction did he adhere. “It was highly probable,” he thought, “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 Cowpox”—
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, 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 24, and the whole of them had the Cowpox. The milkers, consisting of the farmer’s wife, a man and a maid-servant, were infected by the Cows. The man servant had previously gone through the Smallpox, and felt but little of the Cowpox. The servant maid had some years before been infected with the Cowpox; and she also felt it now in a slight degree. But the farmer’s wife, who had never gone through either Smallpox or Cowpox 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 Cowpox, there can be scarcely any room for suspicion; yet it would have been more completely satisfactory had the effects of variolous matter [Inoculation with Smallpox] been ascertained on the farmer’s wife; but there was a peculiarity in her situation which prevented my making the experiment. (P. 62.)
Spurious Cowpox! What was Spurious Cowpox? Here is Jenner’s answer—
Pustulous sores frequently appear spontaneously on the nipples of the 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 are of a much milder nature than those which arise from that contagion which constitutes the True Cowpox. They are always free from the bluish or livid tint so conspicuous in the pustules of that disease. No erysipelas attends them, nor do they show 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 upon 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. (Pp. 7 and 8.)
Nothing could be more explicit. Cowpox was of two kinds—True and Spurious. The Spurious consisted of pustular sores which appeared spontaneously on the nipples of Cows, and was of no avail against Smallpox: the True Cowpox, on the other hand, was not a disease of the Cow, but of the Horse transmitted to the Cow.
It is of prime importance to bear this distinction in mind; for if it is not borne in mind, much that remains to be told must appear confused or unintelligible. As we have seen, it was the belief of the dairymaids that if they caught Cowpox they would never afterwards catch Smallpox. Medical men in practice in Gloucestershire ridiculed the dairymaids’ belief. They said—
“We know that such is the dairymaids’ faith, but it is mistaken; for we know dairymaids who have had Cowpox and afterwards had Smallpox in spite of their Cowpox.”
At this point Jenner intervened, saying—
“Let us distinguish. Eruptions contracted in milking are indiscriminately described as Cowpox by dairy-folk; but there is an eruption attended with erysipelas and fever which has all the virtue they claim for it. This variety of eruption does not originate on the Cow, but is communicated to the Cow from the Horse. Thus the dairymaids are right and they are wrong. They are right when the pox they catch is derived from the Horse through the Cow: they are wrong when the pox they catch originates on the Cow without the Horse. In short Cowpox proper is of no avail against Smallpox. It is Horsegrease Cowpox that is of sovereign and infallible virtue. Any maid who receives Horsegrease Cowpox into her veins is, as she believes, for ever after secure from the infection of Smallpox.”
Let us therefore bear in mind that Jenner’s prescription was not Cowpox but Horsegrease Cowpox. It is a point to be insisted upon; for, as we shall see, it was lost from sight, and kept out of sight, to the utter confusion of the question.
We now come to Jenner’s Cases of Horsegrease—for not only were farm-folk reputed secure from Smallpox by reason of Cowpox, but farriers likewise in consequence of infection with Horsegrease.
XIII.—Thomas Pearce, son of a Farrier.
In consequence of dressing Horses with sore heels at his father’s when a lad, had sores on his fingers which suppurated, and occasioned pretty severe indisposition. Six years afterwards, Jenner inoculated him repeatedly with Smallpox, but only produced slight inflammation, and exposed him to the contagion of Smallpox without effect.
On this Case Jenner observed—
It is a remarkable fact, and well-known to many, that we are frequently foiled in our endeavours to communicate 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 now to account for this on a rational principle?
XIV.—James Cole, Farmer.
Was infected with Horsegrease in the same way as Pearce. Some years afterwards was inoculated with Smallpox, but only a few eruptions appeared on his forehead, which passed away without maturation.
XV.—Abraham Riddiford, Farmer.
Was affected with very painful sores in both hands, tumours in each arm-pit, and severe and general indisposition, in consequence of dressing a Mare that had sore heels. He was attended by a surgeon, who recognising a similarity of the sores upon his hands with those of Cowpox, and knowing the effect of Cowpox on the human constitution, assured him that he never need fear Smallpox; but, twenty years afterwards, he caught the disease, which ran its regular course.
From these Cases Jenner drew this conclusion—
Although the absorption of matter from sores on the heels of Horses, secures, or nearly secures, the system from variolous infection, yet it is possible that this cannot be entirely relied upon, until a disease has been generated by morbid matter from the Horse on the nipple of the Cow, and passed through that medium to the human subject.
Which conclusion he repeated thus—
The active quality of the virus from the Horse’s 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 infection when she milks infected Cows. (P. 45.)
From this conclusion, Jenner at a subsequent period withdrew. The virus from the Horse was employed for inoculation without transmission through the Cow, and with results equally satisfactory. As we shall find, Jenner used and distributed Equine Virus neat, which he certified as “the true and genuine life-preserving fluid.”
So far the Cases set forth described no more than ordinary Gloucestershire experience; but we now come upon ground regarded as peculiarly Jennerian.
XVI.—Sarah Nelmes, Dairymaid.
In 1796 was infected with Cowpox, receiving the virus on a part of her hand scratched by a thorn. From the large pustulous sore on Sarah’s hand Jenner, on the 14th May, inoculated—
XVII.—James Phipps, eight years old.
Said Jenner, “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 Cowpox.” The matter was inserted into his arm by two incisions, barely penetrating the cutis, each about half an inch long. The inoculation “took,” and was followed by a chill, loss of appetite, headache, and restless sleep. On the 1st of July, the poor lad was inoculated with Smallpox, and again several months afterwards, it is said, without effect.
Here [wrote Jenner] 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 were affected with sore heels, in consequence of which Cowpox broke out among several of our dairies, which afforded me an opportunity of making further observations upon the curious disease.
About the latter end of February, 1798, William Haynes and Thomas Virgoe, having to wash a Mare with sore heels, were infected with Grease, and described their sensations as much the same as when they were inoculated with Smallpox. Their infection proved that if Grease was good against Smallpox, Smallpox was not good against Grease. Haynes was employed as a milker, and Pox broke out among his master’s Cows about ten days after he had first assisted in washing the Mare’s heels.
XVIII.—John Baker, five years old.
Inoculated, 16th March, 1798, with matter taken from a pustule on the hand of the aforesaid Thomas Virgoe poisoned with Grease from the Mare’s heels. “He became ill on the sixth day with symptoms similar to those excited by Cowpox, and on the eighth was free from indisposition.”
On this case of Horsegrease inoculation, Jenner observed—
We have seen that the virus from the Horse is not to be relied upon as rendering the system secure from variolous infection, but that the matter produced by it on the nipple of the Cow is perfectly so. Whether the virus passing from the Horse through the human constitution, as in the present instance, will produce a similar effect remains to be decided. This would have been effected, but the boy was rendered unfit for Smallpox Inoculation from having felt the effects of a contagious fever in a work-house soon after this experiment was made.
Mark the assumption, “The virus from the Horse is not to be relied upon as rendering the system secure from variolous infection, but the matter produced by it on the nipples of the Cow is perfectly so!” Such was Jenner’s method of induction! How could he leave the question undecided? Why not have waited until little Baker recovered from his fever? or why not have inoculated another work-house child with Horsegrease? The true sons of science do not rush into print in such shameless deshabille.
XIX.—William Summers, aged five and a half.
Inoculated 16th March, 1798, from the nipple of one of the Cows infected with Horsegrease by Haynes. Subsequently inoculated with Smallpox without effect.
XX.—William Pead, aged eight.
Inoculated, 28th March, from Summers. Subsequently inoculated with Smallpox without effect.
XXI.—Hannah Excell, aged seven.
And several children and adults were inoculated from the arm of Pead on 5th April. “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. 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.”
Excell was inoculated in three places on her arm. “This,” said Jenner, “was not done intentionally, but from the accidental touch of the lancet, one puncture being always sufficient.” The resulting pustules so much resembled those arising from inoculation with Smallpox, “that an experienced inoculator would scarcely have discovered a shade of difference.”
XXII.—Four Children.
On 12th April virus was taken from Hannah Excell and inserted in the arms of—
| Robert F. Jenner, | aged 11 months, |
| John Marklove, | ” 18 ” |
| Mary Pead, | ” 5 years, |
| Mary James, | ” 6 ” |
R. F. Jenner did not “take.” The arms of the others inflamed, and Jenner fearing erysipelas, as in the preceding cases, applied a caustic of soap and quick-lime to Marklove and James, “which,” he says, “effectually answered my intention in preventing erysipelas.” The disease was suffered to take its course in Pead, and no erysipelas appeared.
XXIII.—John Barge, aged seven.
Inoculated from Mary Pead, and successfully. Was subsequently inoculated with Smallpox without effect.
“These experiments,” said Jenner, “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, John Barge being the fifth who received the infection successively from Wm. Summers, the boy to whom it was communicated from the Cow.”
These are Jenner’s Cases. In them we have his “Masterpiece of Medical Induction”—the fruit of thirty years of incessant thought, of watching, and of experiment! Let us carefully observe the dates. Until 1796, when he operated on Phipps, he never made an experiment in Horsegrease Cowpox Inoculation; and not until the middle of March, 1798, a few weeks before going to press with the Inquiry, did he repeat the experiment; and though his later cases were complicated with erysipelas, he did not stay to dispose of the difficulty and alarm thereby excited. He got together his scratch lot of Cases, as if under some over-mastering compulsion, and consigned the concern, crude and incomplete, to the public. By-and-by the hasty performance came to be spoken of as the result of thirty years of incessant thought, of patient research, and of unwearied labour. It is unnecessary to argue the matter. Whilst there is nothing too great for the credulity of those who are in the disposition of belief, yet facts are facts, and there is the stone-wall of the Inquiry with its authentic details whereon to crack the skulls of romancers. In Jenner’s story as recited to the vulgar, we have the advantage of witnessing the development of myth in the light of our own age under our own eyes.
Taking Jenner’s Inquiry at the utmost, What was it? A suggestion to substitute Horsegrease Cowpox for Smallpox in inoculation. That was all. Beyond this there was no point of novelty. Some have credited Jenner with originating the transfer of virus from arm to arm; but in this respect he followed the example of many variolators. There was a mild form of Smallpox occasionally prevalent in London called “pearly pox,” and Dr. Adams and others kept it going from patient to patient; and the virus from the body of a healthy variolated child was in constant request by timid folk, who fancied the virulence of the original infection might thereby be abated in transmission.
So much for Jenner’s data. Now for a word or two as to the speculation that invested his prescription.
He considered that some of the diseases which afflict men are derived from their domestication of animals, and that thus several diseases might have a common origin. “For example,” he asked, “Is it difficult to imagine that measles, scarlet fever, and ulcerous sore throat with a spotted skin, have all sprung from the same source?”
About the imagination, there might be little difficulty: the difficulty lay in the production of proof that any disease in man was derived from disease in animals, and that disease so derived was variously manifested. Jenner wished to have it believed that a variety of Cowpox was generated from Horsegrease, which Cowpox was the source of Smallpox. He adduced no evidence, however, to connect outbreaks of Smallpox with Cowpox; nor did he ever suggest that dairymaids caught Smallpox from Cows, or farriers from Horses. His identification of Horsegrease Cowpox with Smallpox was the resemblance of their pustules, and on the ground of this resemblance he affirmed the equivalence of the diseases. Thus in describing his first inoculation of Cowpox, that of Phipps from the hand of Sarah Nelmes on the 14th of May, 1796, he wrote—
The appearance of the incisions in their progress to a state of maturation was much the same as when produced in a similar manner by variolous matter. This appearance was in a great measure new to me, and I ever shall recollect the pleasing sensations it excited; as, from its similarity to the pustule produced by variolous inoculation, it incontestably pointed out the close connection between the two diseases, and almost anticipated the result of my future experiments. (P. 30.)
The similarity of the Cowpox and Smallpox pustules incontestably pointed out the close connection between the two diseases! The observation and the conclusion are worth notice, being characteristic of Jenner’s loose and illogical mind. He was familiar with Tartar Emetic, and he might have observed that it produced pustules on the skin exactly like those of Cowpox and Smallpox; wherefore would it have been fair to argue that the pustules being alike, their causes were incontestably identical? Dr. Hamernik of Prague observes—
Some years ago the theory was brought forward, under the auspices of the great alchemistical artist, Hufeland, that Vaccination from Tartar Emetic pustules was a perfect substitute for Vaccination with Cowpox, and had the same beneficent effect. With this I fully agree; and I remark further, that if Tartar Emetic pustulation is produced in Cows and Calves, and vaccine matter is then taken from them, such Vaccination is also perfectly harmless. The most convincing proof of the beneficent and identical action of such Vaccination with that of Cowpox, is furnished by the fact that it presents pustules similar in size and form, therefore, necessarily of identical value.[99]
Having identified Horsegrease Cowpox with Smallpox, by reason of similarity of pustules, he went on to assert that such Horsegrease Cowpox was equivalent to Smallpox for inoculation, and was attended with the like prophylaxy, saying—
What renders the Cowpox virus so extremely singular is, that the person affected with it 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. (P. 7.)
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 insusceptible of the variolous contagion. (P. 48.)
And so on. The assurance was absolute, and the warrant for the assurance was the Cases adduced, and the similarity of Horsegrease Cowpox pustules and Cowpox pustules! But if the pustules were similar, the effects were not similar. Inoculation with Smallpox produced Smallpox, mild or otherwise, with pustules few or many; but inoculation with Horsegrease Cowpox was attended with no eruption beyond the points of incision—
It is an excess in the number of pustules which we chiefly dread in the Smallpox; but in the Cowpox no pustules appear, nor does it seem possible for the contagious matter to produce the disease from effluvia; 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. (P. 58.)
Very good; but where are we? If similarity of pustule proved the identity of Smallpox and Horsegrease Cowpox, what did those graver dissimilarities between the diseases prove? That an objection so obvious should never have occurred to Jenner indicates the extent of his logical capacity.
Jenner’s expectation from the issue of the Inquiry had nothing of the prophetic character described by his enthusiastic biographers. It is only necessary to peruse its pages and note the dates in order to perceive the impossibility of the vision of 1780 described by Baron when Jenner exhibited to Gardner his future glory, and how he was destined to stand like Aaron between the living and the dead until the plague was stayed. Alas! how many similar fables may we entertain because the means of detection are not, as in Jenner’s case, available.
When Jenner was writing, the English people were committed to Smallpox Inoculation, or more accurately Smallpox culture, and it was in competition with Smallpox that he advanced Cowpox. “If asked,” he said, “whether his investigation be matter of mere curiosity, or whether it tend to any beneficial purpose,” he replied by setting forth the draw-backs to the existing practice, and contrasting them with the advantages of his own.