The fictional detective Sherlock Holmes was an expert in the study of cigar ash and wrote a monograph, Upon the Distinction Between the Ashes of the Various Tobaccos, about it. This expertise was used in his cases such as A Study in Scarlet, The Boscombe Valley Mystery and The Hound of the Baskervilles. This is repeatedly used as an example of deduction or the Baconian method in philosophical accounts of science and reasoning.
- Sonia Weiss (1997), The cigar enthusiast: the definitive guide to selecting, storing, and smoking cigars, p. 68, ISBN 978-0-425-15981-1
- "The uses of cigar ash", Tobacco talk and smokers' gossip, 1886, p. 138
- Tamar Gendler, John Hawthorne, "Holmesian inference", Oxford studies in epistemology, p. 11
- Robert L. Ellis, Marcia J. Lipetz, Essential sociology, p. 26
- Matthew Bunson, Encyclopedia Sherlockiana, p. 50
- Jonathan Smith (1994), Fact and feeling: Baconian science and the nineteenth-Century literary imagination, p. 214