The Merck Index

ImageMany readers will be aware that the Royal Society of Chemistry acquired The Merck Index* from Merck & Co. in 2012. The Merck Index is an incredibly useful resource that has gained legendary status among chemists, and so we were delighted to take on its stewardship and future development.  

We published the 15th print edition in 2013, but our main ambition was to create a modern, user-friendly online home for the same content. The Merck Index Online enables users to search by chemical structure, physical properties and text, or a combination of these. Free from the space restrictions of a single printed volume, we have also reintroduced about 1,500 entries that were previously cut from print editions.

The Merck Index Online team here in Cambridge, UK comprises the Editor, Serin Dabb, who provides editorial oversight, and two Data Content Editors, Michael Townsend and Mark Archibald, who investigate new scientific areas and research and write the content. Our scientific backgrounds are spread across organometallic chemistry and catalysis (Serin), physical organic chemistry (Michael) and synthetic organic chemistry (Mark). We’re always keen to hear comments, suggestions, and corrections from readers, either regarding content or features of the website; you can reach us at

One of the things we love about The Merck Index is the quirky nature of some of the older content. Perhaps the most famous example is caproic acid’s eponymous “goat-like odor.” This gives a flavour, often quite literally, of a former age of chemistry when smell and taste were routine methods of product characterization. When we bring old records up to date, we try to add the relevant modern science without removing this link to the past.

In keeping with The Merck Index’s tradition, our primary focus is on substances of pharmaceutical interest, with the aim of including every newly approved drug. That said, the scope of the existing content spans all of chemistry and we have already created new entries in the fields of materials chemistry, agrochemicals, and synthetic chemistry. We plan to carry on in this vein: if a chemical substance is of significant interest and importance, for medicine or technology or anything else, then it belongs in The Merck Index.

This continued survey of the broad scope of chemistry goes hand-in-hand with continued technical development of the online platform. We recently added a browsing feature to complement the usual search-based approach, which restores the serendipitous discovery that was always possible with the printed book. Further development is planned to present important information as clearly as possible, and to provide clear links to related external content. The combination of modern database technology with expert curation of the overwhelming mass of chemical data offers readers easy access to the relevant, authoritative information they need.

Mark Archibald, Royal Society of Chemistry

*The name THE MERCK INDEX is owned by Merck Sharp & Dohme Corp., a subsidiary of Merck & Co., Inc., Whitehouse Station, N.J., U.S.A., and is licensed to The Royal Society of Chemistry for use in the U.S.A. and Canada.