Of all diseases of the eye and its appendages, none are more perplexing to us as regards etiology and prognosis than are those of the optic nerve. Inflammations and atrophies of said nerve are easily diagnosticated, but when asked the question, what caused this or that inflammation or atrophy? or, what will be the result? then do we often find ourselves unable to answer. Some of them may be read as easily as an open book while others upon the contrary baffle us at every turn, and though every opportunity may be offered by the patient objectively and subjectively, still sphinx-like the cause forever remains to us a sealed scroll.
Take for example the two cases which follow:
Case 1.—J. D., aged 38, occupation baggage master, a fine looking man the picture of health, who came to see me about his failing sight which was found at that time to