Hume has remarked, how mankind are constantly deceived, by the very same tricks played over and over again. Human credulity, indeed, seems wholly incurable; and, in spite of all warning, we see one generation after another, with their eyes wide open, walk into the same gulf of fraud, quackery, and imposture. This observation is confirmed, by the following memorandum from the notebook of a gentleman, many years a distinguished physician in London :-
"Sep. 1, 1795. I went in a Bath coach to Reading with an Irish gentleman from near Wexford, who had been consulting Myersback for one of his friends, an hypochondriacal man, and on being told by the Doctor, that he could do nothing without a sight of the patient's water, had carried a little of his own in a phial, and called it his friend's. Myersback, who had at the said interview, remarked the healthy look of the gentleman, now spoke of many complaints of the owner of the water, alluded to the good living of his early days, and hinted at ulcers in the kidney, &c. My fellow traveller said, that, in consequence, he had fancied a pain in his back all day; he had got the Doctor's medicines with him, (a bottle of drops and some pills), for which he had paid eight shillings, in addition to ten shillings and six-pence to the Doctor. He proposed at Bath to throw them away, as they might be active medicines, and do his friend harm, whom he supposed to be merely hypochondriacal, and he meant to get something very harmless made up in their stead. Notwithstanding the experience this gentleman had thus had of Myersback's imposition and ignorance, he continued to have great faith in him, and spoke of a wonderful cure he had performed on an Irish friend of his, after he had been given over by Dr. Falconer, of Bath, and others, on account of a supposed ulcer of the bladder; and when I observed to him, that Myersback had been a groom, "It matter'd not," said he, "what he had been, or where or how he had got his knowledge; - and knowledge he has to a wonderful degree!"
Dr. Lettsom had the credit of ridding society of this impostor, but not till he had done considerable mischief. "In every unhappy case," says the Doctor, "in which I have followed Myersback, my heart has bled over the follies of my fellow-creatures." And yet Myersback returned to Germany with a splendid fortune.
Source: Mems. Maxims, and Memoirs by William Wadd, Surgeon Extraordinary to the King, Page 296, Published 1827