Two published versions of a letter in which Oliver Wendell Holmes, MD, recommended the name anaesthesia were identified from publications supportive of the claims of W. T. G. Morton. The earliest known publication of Holmes' letter is in a pamphlet published by Edward Warren in May-June 1847. Another version of the letter was published 12 years later in Nathan P. Rice's biography of Morton. Holmes' letter to Morton was probably lost when a substantial part of a collection of Morton's papers was damaged during storage. There are no reported copies of Holmes's letter. The currently available information does not provide any assistance in determining the correct form of Holmes's letter.
Keywords: Edward Warren; James Y Simpson; Letheon; Nathan P Rice; Oliver W Holmes; William TG Morton; anaesthesia; etherization; insensibility.