Chemicals of St. Louis was clear to differentiate the inclusion of true unicorn rather than false unicorn in its preparation. The earliest versions did contain drugs that are still in use today for the same purposes, for example digitalis for heart failure;, salicylates for headache rheumatism and fever, nitroglycerin for cardiac angina pectoris;, and bismuth salicylate for diarrhea Merck also began publishing Merck’s Archives of the Materia Medica, a monthly journal consisting of papers related to drugs and uses, which was available for an annual subscription of US $1.00. The second edition of The Merck Manual was published in 1901, was expanded to 282 pages and included new sections on poisons and antidotes, tables and conversion charts, and a detailed explanation of the metric system. The 5th edition, published in 1923 was delayed due to paper shortages caused by World War I, and the release of the 6th edition was delayed until 1934 due to the Stock Market Crash. The editor of that edition, Dr. M. R. Dinkelspiel had overseen the growth and reorganization of the Manual to discuss specific diseases, diagnosis and treatment options, and external specialists reviewed each section. The 8th edition of the Manual was delayed by World War II until 1950. The 13th edition, released in 1977 was the first time the textbook was produced using magnetic tape and IBM punch cards, the previous version having been typed on a manual typewriter. The Centennial (17th) Edition published in 1999 included a separate facsimile version of the 1899 1st edition. It is reported that both Admiral Richard E. Byrd took the book with him on his expedition to the South Pole in 1929 and Albert Schweitzer had a copy of The Merck Manual with him at his hospital mission in Africa in 1913. The recommended doses given in Part 1 of 1901 edition of The Manual were for adults when given by mouth. It included the following dose adjustment recommendations: Print editions of The Merck Manual 1899 1901 1905 1911 1923 1934 1940 1950 1956 1961 (There were two printings in 1961, June and Nov; a third in Aug 1962 and a fourth in June 1963) 1966 1972 1977 1982 1984 1992 (2 million copies sold) 1999 (Centennial Edition) 2006 2011 2018 (current print edition) Content The Merck Manual is organized, like many internal medicine textbooks, into organ systems (see List of Medical Topics below) which discuss