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.
GENERATION OF COWPOX IN HORSEGREASE.
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.