1866 he organized a hospital for the treat- ment of cholera, and had charge of the Post Hospital.
After a brief stay on duty in Louisiana, he resigned in 1868 and was elected a fellow of the College of Physicians of Philadelphia in April, 1869.
While in Washington he was largely interested in the Army Medical Museum, — the creation of John H. Brinton — and was the largest contributor to the first published catalogue, for which he wrote valuable descriptions of osteomyelitis and wounds of joints.
With his friend, William Norris, he had utilized photography in the study of wounds, and had induced the surgeon- general to establish, in connection with the museum, a photographic bureau. Thomson and Norris were the first to make negatives by the wet process of the field of the microscope with high and low powers, and led the way to the splendid success obtained later through the resources of the surgeon-general's office. These studies in optics finally dominated the future of Thomson and Norris, and led to their practice and teaching of ophthalmic surgery.
Dr. Thomson, thus led by his mastery of photography to a close study of optics, began soon to display that facility of resource in ophthalmic medicine which characterized all he did.
Early in his career, his attention was directed to the subjective methods of de- termining the static refraction of the eye, and in 1870 he described a test for ametro- pia based on the experiment of Scheiner, and later in the same year brought his method to the notice of the members of the American Ophthalmological society.
In 1902 he brought before this society a new apparatus for the correction of ametropia, and upon its constant im- provement he spent much time during the last years of his life, working at it almost until the day of his death. In 1896 he wrote his important article on "The Detection of Color Blindness."
Two institutions in Philadelphia are es- pecially indebted to one work of William
Thomson, namely, the Wills Eye Hos- pital, with which he became connected in 1868, and the Jefferson Medical College, with which he was identified from 1873 until 1897, first as lecturer on diseases of the eye, later as honorary professor of ophthalmology, and finally, in 1895, as full professor of ophthalmol- ogy, with a seat in the faculty.
He was a member of the Philosophical Society, the Academy of Natural Sciences, honorary member of the New York Neurological Society, sometime physi- cian to the Episcopal Hospital.
A list of his ophthalmic papers is given in the " Transactions of the College of Physicians," of Philadelphia, 3 s., 1909, vol. xxxi. They include: Chapter on Diseases of the Eye in Gross' "Surgery" (fifth edition); "Test for Diagnosis of Ametropia, with Instru- ment;" "Ophthalmoscope in Diagnosis of Intracranial Lesions;" "History of First Case of Tumor of Brain Diagnosti- cated with the Ophthalmoscope in Philadelphia;" "Astigmatism as a Cause of Persistent Headache" (-n-ith Mitchell); "Connection between Posterior Staphy- loma and Astigmatism;" "Correction of Conical Cornea by Sphero-cylindrical Glasses;" "Rapid Diagnosis of Refrac- tion with a New Instrument;" "System Adopted by the Pennsylvania Railroad in 1880 for Examination of Employees for Color-blindness, Vision and Hearing, with Instruments, Color-stick, etc.;" "Supplement to Nettleship on Diseases of the Eye;" "Edition of Ophthalmo- logical Part of Annual of Medical Sciences" (1SS9); "New Wool Test for Detecting Color-bhndness;" "Normal Color Sense and Detection of Color- blindness in Norris and OUver's System;" Chapter on Diseases of Eye in "Ameri- can Text-book of Surgery;" "Relation of Ophthalmology to Practical Medicine;" " Use of Circles of Diffusion for Correcting Ametropia, with an Instrument."
S. W. M.
Tr. Coll. of Phya. of Phila., 1909, vol. x.xxi
(S. W. Mitchell).
Tr. Am. Ophth. Soc, Phila., 1909, vol. xii.