Philippe Thomas (4 May 1843 – 12 February 1910) was a French veterinarian and amateur geologist who discovered large deposits of phosphates in Tunisia.

[3] In 1876, the Société des Sciences physiques, naturelles et climatologiques d'Alger recognized his work between 1868 and 1875 in geology and palaeontology by awarding him a silver medal.

[6] He was assigned to the expedition at the recommendation of the paleontologist Jean Albert Gaudry, and because Jules Ferry knew his ability and perfect knowledge of the Arabic language.

[4] He identified the geology of the Gafsa chain with that of the M'fatah massif in Algeria and on 18 April 1885 found phosphates at Jebel Tselja.

[4] Thomas crossed the Chaîne du Tseldja through the dramatic gorges of the Oued and found identical phosphate deposits on the southern slope of the range extending for at least 80 kilometres (50 mi).

[9] Thomas sent rock samples to the École des Mines de Paris for analysis, and on receiving the results on 18 October 1885, informed Dr. Cosson, head of the mission.

[10] Philippe Thomas published the palaeontology results of the Scientific Exploration Mission in six instalments plus an atlas, giving the work of Victor-Auguste Gauthier (sea urchins), Arnould Locard (Mollusca), Auguste Péron (Brachiopods, Bryozoa, and Pentacrinitess), and Henri Émile Sauvage (fish).

[10] In 1902, the Ministry of Education proposed that Georges Rolland should write up the results of the Scientific Mission, but he refused for health reasons.

[15] The third part of Thomas's Essai d'une description géologique de la Tunisie, which was to have described the Tertiary formations, was completed and published by his friend, Professor Léon Pervinquière (1873–1913), holder of the Chair of Geology at the Faculty of Science in Paris.

[11] Émile Haug published the Essai d'une description géologique de la Tunisie after Pervinquiere had also died and presented it to the Geological Society of France in session on 6 April 1914.

[6] The Vétérinaire Général Léon-Paul-Charles Vivien wrote, When the French protectorate was established, Tunisia was a vast depopulated, barren, and arid country.

New deposits of iron, zinc, copper and manganese were successively discovered and Tunisia appeared as one of the richest mining regions in the world.

[14] A monument with a bust of Thomas by the sculptor André César Vermare was inaugurated in Sfax by Gabriel Alapetite, Resident-General of France in Tunisia on 26 April 1913.

[18] The fragments of the bust were recovered and sent to France, where they are held in the Philippe Thomas room in the Compiègne school of the Army Biological and Veterinary Service.