The faith that heals.

Perhaps Osler's most significant discussion of "faith" and faith healing. Digital facsimile from PubMedCentral at this link.
The same journal issue also contains Clifford Albutt's "Reflections on faith healing," pp. 1453-1457; Henry Morris's " 'Suggestion' in the treatment of disease," pp. 1457-1466; H. T. Butlin's "Remarks on spiritual healing," pp. 1466-1470; T. Claye Shaw's "Considerations on the occult," pp. 1472-1477, and Jame Rorie's "Abstract of a lecture on psycho-pneumatology; or, the interactions of mind, body and soul," pp. 1477-1478.