Inscribed Visiting Card, explaining that he is not well enough to visit Madame Fuchs, suggesting a time for her to visit him. In French. 2 x 4 inches, in good condition. c.1870-1880. Jean-Baptiste Dumas (1800-1884), French chemist, prominent teacher and investigator, one of the first men in France to realise the importance of experimental laboratory teaching. In the Essai Statique Chimique (1841), he treated the chemistry of life, both plant and animal.