in London appointed as his First Physician, an offer which Denys declined in order to return to Paris in November 1673. This was probably the last mention of the ‘essence’ ever since. The first fully documented experiment using Denys’ blood staunching liquor was carried out on May 30, 1673 in London by English physician Walter Needham and surgeon Richard Wiseman. In an attempt to demonstrate the effectiveness of the ‘essence’, Needham cut open a dog's neck exposing the jugular vein and carotid artery, he then applied Denys’ hemostatic liquor to the bleeding vessels and applied pressure using a pledget for 30 minutes. Upon removal of the pledge, free-flowing bleeding was no longer observed - the artery had been staunched. Under the order of King Charles II, the two proceeded to test the liquor on patients at the St. Thomas Hospital in London's Southwark, the same extraordinary results were obtained. Further reading References External links Red Gold - Innovators & Pioneers: Jean-Baptiste Denis 1643 births 1704 deaths 17th-century French physicians 18th-century French physicians