"This was his state in autumn, 1841, at which time I first saw him, and he continues equally well down to the present date. A slight opacity in the cornea of both eyes still remains, and he cannot expose himself to the blaze of a very bright day or to violent winds for a length of time without experiencing a return of uneasiness. He is, however, quite positive, that had he continued under your care for a sufficient period, he would have quite recovered; and he has been planning a voyage to London to have your additional advice. I discovered, however, from him, that he has never got _the prussic acid of sufficient strength_ since you left this; for it has never had the power of bringing on the state of the eye which the strong acid did, and which he found to be attended with so good effects. I have taken means to get the acid prepared for him of the right strength, and hope that its application will be as efficacious as he so confidently expects. "N.B.--The patient Milne was brought to me by George Rainy, Esq., Surgeon to the Aberdeen Ophthalmic Institution." Extracted from the _Lancet_ of December 31st, 1842:-- "PRUSSIC ACID VAPOUR.--Mr. J. C. Atkinson, of Romney Terrace, Westminster, in a letter to the Editor, dated December 26th, after a few prefatory remarks, writes on this subject as follows:--A patient, aged 28, who had rather a severe attack of variola last May, became, after the recovery, subjected to staphyloma, one of the sequelæ of that formidable complaint. In this he was treated according to the approved methods, both at two public institutions and by private practitioners, for some months, without any apparent advantage, when I was applied to; I instantly determined on a trial of the prussic acid vapour, having read in your able journal an account of this new remedy some time before. After fourteen applications the opaqueness and prominence abated considerably, and the eye is now very serviceable, and nearly as useful as the sound one, no inflammation or appearance of irritation being observable. The plan adopted by me was most simple: the affected eye, open, was placed over a two-ounce phial, containing about half an ounce of the acid, while the patient's hand, properly directed, was to retain it in the position that was thought necessary. The time occupied in this operation was from five minutes to a quarter of an hour. The eye became in a short time inflamed, the conjunctiva exhibiting the appearance of deep injection, which gradually disappeared in a few hours, but which was not accompanied by any pain. No paralysis of any of the appendages of the eye has resulted from the application. Such is the outline of the case. I feel assured that this remedy will prove a powerful auxiliary in the hands of a surgeon-oculist." Extract from the _Lancet_, of January 7th, 1842. Cases in which the vapour of prussic acid was employed for the cure of Ophthalmic disease, by Donald J. Maclean, M.D., Lic. Roy. Col. Surg. in Edinburgh.