In 1755 the most comprehensive listing of alchemical symbols was published at Ulm in Germany, the 'Medicinisch-chymisch- und alchemistisches Oraculum'. The book consists of a series of thirty four full page engravings of 1829 symbols with the names in Latin and German overprinted in letterpress. There are 359 entries with multiple graphic images associated with each entry. Some ten years ago Adam McLean placed these images onto his alchemy web site. A number of people then asked him to provide explanations for the obscure terms, but he was not immediately able to find the time to do this. At the end of 2013 he had the idea of issuing this in book form, and after a few months editorial work and research this has resulted in the present volume in the Hermetic Studies series.