"MY DEAR SIR,--Having, by the vapour of prussic acid, been nearly cured by yourself of an opacity of the cornea, which, for twenty years past, had rendered the sight of my left eye of little worth more than to distinguish light from darkness; and firmly believing that, when I shall be able to replace myself under your care, my sight will be perfectly restored; and having also, during my attendance at your house, witnessed the beneficial effects of this remedy on many other persons, the subjects of cataract, amaurosis, staphyloma, &c., I earnestly beg you will accept this testimony of my high opinion of its efficacy in these cases. "I am yours gratefully, "WILLIAM H. NEWNHAM, Surgeon, &c. "Late of Alton, Hants." "To A. Turnbull Esq., 48, Russell Square." Extract from a letter of Professor Forbes, of King's College, Aberdeen, Jan. 23rd, 1843:-- "I seized the first hour which I could command after receiving your note to call on Milne, that I might see in what state he was, as I had not heard of him for some time. I was also desirous of having the particulars of his case accurately from himself. "John Milne was a cooper, and in that capacity had gone with the whale-ships to Davis's Straits and Greenland for sixteen years. "In July, 1836, he was seized with a violent inflammation in one of his eyes, which soon extended to the other. After two years he became so blind that he could not walk with safety in the streets, and after meeting with a severe accident from his want of sight, he gave up attempting to walk out alone. "He continued for more than two years in this state, always becoming worse and worse in his sight. His eye-balls were covered with ulcers; he suffered extreme pain, except when lying in bed with the room quite darkened; and was at various times confined for six weeks without being able to bear the admission of light into his room. During the whole of this long period he was under medical treatment by different surgeons without deriving any benefit, but, on the contrary, his case seemed to become daily more hopeless. The only relief, indeed, which he experienced was, he says, from the division of the blood-vessels, from time to time, with which the eye-ball was covered. "In these circumstances he was brought to you by a surgeon who had attended him, and began, under your direction, the application of the prussic acid vapour. This gave him immediate relief, and in six weeks the whole ulcers had disappeared, light was no longer troublesome to him, and he saw quite well to go about his business and to read.