Public Domain Mark
You can use this work for any purpose without restriction under copyright law. Read more about this licence.
Credit
Concerning the action of salts of potash, soda, and ammonia on the frog's heart / by Sydney Ringer. Public Domain Mark. Source: Wellcome Collection.
Provider
This material has been provided by The Royal College of Surgeons of England. The original may be consulted at The Royal College of Surgeons of England.