Charles Richet, Professor at the Faculty of Medicine of Paris, and Paul Portier, assistant of physiology at the Sorbonne, were invited to join the expedition in order to isolate this venom and study this phenomenon. The work carried out on board the second Princess-Alice with the physalie, and then on their return to Paris, especially with the anemones Actinia equina and Anemonia cerae, consisted of injecting cnidarian extracts into guinea pigs (dogs and pigeons), with a sufficiently long interval between each injection and using low doses of toxins.