Attribution 4.0 International (CC BY 4.0)
You can use this work for any purpose, including commercial uses, without restriction under copyright law. You should also provide attribution to the original work, source and licence. Read more about this licence.
Credit
Pulse glass: one minute. Formerly in the possession of Sir George Buchanan (1869-1936). Acquired circa 1915. Wellcome Collection. Attribution 4.0 International (CC BY 4.0). Source: Wellcome Collection.