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 genuine Cowpox? Until experience has determined which is the _true_ Cowpock, and which is _spurious_, we view our object through a mist. (P. 73.) Consider this declaration after thirty years of incessant thought, observation and experiment! The Masterpiece of Medical Induction with the essential fact undetermined! The discovery undiscovered! And the reputed discoverer sitting ready to appropriate any praise or profit from the execution by others of his proper business! Was there ever such an exhibition of self-satisfied futility? Among the gossip adduced to show that the country folk called eruptions Cowpox that were not Cowpox, we learn that the affection induced by Horsegrease was thus designated-- From the similarity of symptoms, both constitutional and local, between the Cowpox and the disease received from the morbid matter generated by a Horse, the common people in this neighbourhood, by a strange perversion of terms, frequently call it the Cowpox. (P. 95.) Wherefore, he argued, many thus affected may fancy themselves secure from Smallpox, supposing they have suffered Cowpox, when they have undergone nothing but Horsegrease; and in the event of incurring Smallpox, would bring discredit on the virtue of true Cowpox. How easy it was to confound the two diseases, he illustrated from the case of William Morris, a servant, aged 32, who applied to him on 2nd April, 1798-- His symptoms and the sores on his hands were so exactly like the Cowpox, that I pronounced he had taken the distemper from milking Cows. He assured me he had not milked a Cow for more than half a year, and that his master’s Cows had nothing the matter with them. I then asked him if his master had a Greasy Horse, which he answered in the affirmative; and further said, that he had constantly dressed him twice a day for the last three weeks or more, and remarked that the smell of his hands was much like that of the Horse’s heels. (P. 97.)