KEYSER, Peter Direk, surgeon, born in Philadelphia, Pennsylvania, 8 February, 1835. He studied at Delaware college until 1851, when he entered the chemical laboratory of Professor Frederick A. Genth, and there made analyses of minerals, the results of which were published in the " American Journal of Science," and were afterward incorporated in Dana's " Mineralogy." In 1856 he went to Get-many and pursued professional studies for two years. Soon after the beginning of the civil war he became captain in the 91st Pennsylvania regiment, and served with the Army of the Potomac until after the battle of Fair Oak's. Failing health then led to his resignation, and he returned to Germany, where he studied at the University of Munich, and then at that of Jena, receiving there the degree of M. D. in 1864. On his return he was appointed acting assistant surgeon in the United States army, and was detailed to the Cuyler hospital in Germantown, Pennsylvania In 1865 he resigned from the service to enter on his private practice, and was called to the charge of the Philadelphia eye and ear infirmary. In 1868 he delivered a course of lectures to physicians upon the accommodation and refraction of the eye, and in 1870 he delivered the first regular course of clinical lectures on ophthalmology that ever was given in Philadelphia, repeating the course in 1871-'2. Dr. Keyser was elected ophthalmic surgeon to the medical department of the Philadelphia German society in 1870, and one of the surgeons to the Wills ophthalmic hospital in 1872. Dr. Kevser is a member of medical societies and of the P'ennsylvania historical society, and he has been a contributor of medical papers to the journals of his profession both in the United States and Europe.