[Early contributions from Erlangen to the theory and practice of general anesthesia with ether and chloroform. 2. The animal experiments of Ernst von Bibra and Emil Harless].

Just three months after the first application of sulphuric ether to a patient in german-speaking countries the monography Die Wirkung des Schwefeläthers in chemischer und physiologischer Beziehung was published. In this book Ernst von Bibra and Emil Harless presented their experimental research on the effects of ether on humans and compared it to those on animals. The contents of the book are described. The authors "Theory on the action of ether" will be discussed in the context of contemporary criticism. Their hypothesis affected the discussion on the mechanisms of anaesthetic action up to the twentieth century.