"I have been guilty of several monographs. They are all upon technical subjects" (SIGN)

Holmes wrote several monographs - the known subjects of which are listed below. Naturally, he would have kept original copies and notes of these in the Suite. Francois de Villard translated many of the monographs into French (SIGN).

Published Monographs

¤ A monograph on 140 forms of cigar, cigarette, and pipe tobacco, with coloured plates
illustrating the difference in the ash entitled, "Upon the Distinction between the Ashes of the Various Tobaccos." (SIGN)
¤ A monograph "upon the tracing of footsteps, with some remarks upon the uses of plaster of Paris as a preserver of impresses." (SIGN)
¤ A monograph "upon the influence of a trade upon the form of the hand, with lithotypes of the hands of slaters, sailors, corkcutters, compositors, weavers, and diamond-polishers." (SIGN)
¤ A Monograph on Polyphonic Motets of Lassus, which was later printed for private circulation, and is said by experts to be the last word upon the subject. (BRUC) (For more information, see Now It Can Be Told)
¤ A monograph upon the dating of documents using handwriting techniques and other elements (HOUN)
¤ Two short monographs on the ear and its distinctions, both likely published in the "Anthropological Journal" in 1888 (CARD)
¤A monograph on the forms of secret writings which analyzes 163 ciphers (DANC)
¤ A monograph on the study of tattoo marks (which may have included a section on Oriental ink colors and designs) (REDH)
¤ A magazine article entitled, "The Book of Life" which attempted to show how much an observant man might learn by an accurate and systematic examination of all that came in his way. A long quote from the article can be found in STUD.
¤ The "Practical Handbook of Bee Culture, with some Observations upon the Segregation of the Queen" (LAST)

Contemplated Monographs (Certainly he kept notes on these but whether they were written and published is debatable)

¤ A monograph on the typewriter and its relation to crime (IDEN)
¤A monograph on malingering (or feigning illness or incapacity) (DYIN)
¤A monograph upon the uses of dogs in the work of the detective (CREE)
¤A one volume treatise on the whole art of detection (ABBE)