[1] Lefevre wrote about their ride the following day : "Everything that I had hitherto beheld appeared insignificant compared with the scenery which now presented itself...under our feet extended a long plain of meadowland, through which the Gave serpentined in a quick and bubbling stream.
The foreground was bounded by a long ridge of hills covered with the vines festooning from their summits to their feet; backed by forest and bounded by the Pyrenees stretching along the horizon, resembled, by their rugged summits, the back bone of the globe...The sight of all this grandeur determined the party upon making Pau their winter quarters.
"After Lord Selkirk's death in April 1820, Lefevre visited the mineral springs of Eaux-Bonnes and Eaux-Chaudes, returned to Pau and then climbed what he believed to be Mont Perdu in Haute-Pyrenees and finally to Saint-Sauveur.
He finally left the post at Odessa and went to Saint Petersburg, where he began in private practice, and became physician to the British Embassy.
He suffered from depression, and on 12 February 1846 committed suicide by swallowing prussic acid, at the house of his friend Dr. Nathaniel Grant in Thayer Street, Manchester Square.
Experience led him to oppose the indiscriminate use of calomel and opium in the treatment of cholera, to favour the use of purgatives, and to avoid that of astringents.
In 1844 he published An Apology for the Nerves, or their Influence and Importance in Health and Disease, a collection of medical notes including one on plica polonica.