332 ANNOTATED LIST OF PERSONS 



Duclaux, Pierre Justin (1798-1860). Father of Emile Duclaux. 



Dujardin, Felix (1801-1860). French zoologist, student of Vermes, 

 Rhizopods, etc. He left unfinished a "Natural History of 

 Echinodermes." 



Dumas, Jean Baptists Andre (1800-1884). French chemist. Member 

 of the Academy of Sciences. Professor in the Sorbonne, Minister 

 of Agriculture and Commerce. Senator. Succeeded Guizot in 

 the Academic Francaise and was followed by Renan. Determined 

 the atomic weight of many elements. Studied amyl alcohol; 

 discovered the law of substitutions, which upset the ideas of Berzelius. 

 Published a great treatise (in 8 volumes) ' on applied chemistry. 

 For portraits see Harper's Mag., 1898, p. 625, and Pop. Sci. Monthly, 

 1880, p. 145. 



"I attend at the Sorbonne the lectures of M. Dumas, a celebrated 

 chemist. You cannot imagine what a crowd of people come to these 

 lectures. The room is immense, and always quite full * * * 

 there are always six or seven hundred people." (Pasteur in 1842.) 



"Le premier bane 6tait reserve aux el eves de PEcole normale. 

 J'ecoutais, j'applaudissais, je sortais de chacune de ces lemons 

 1'esprit tourne vers de vaste projets." (Pasteur in 1895.) 



Dusch, Theodor Freiherr von (1824 ). German pathologist. 



Student of Henle. Professor in Heidelberg. Wrote on Icterus, 

 brain sinus thrombosis, and diseases of the heart. Collaborated 

 with H. Schroder in the discovery of cotton as a dry (air) filter 

 for bacteria ("Ueber Filtration der Luft in Beziehung auf Faulniss 

 und Gahrung." Ann. der Ch. u. Pharm., Bd. 89, p. 232, Heidelberg, 

 1854). For portrait see Pagel, p. 431. 



Duval, or Duval-Jouve, Joseph (1810-1883). French botanist. Studied 

 Equisetums and anatomy of grasses. Father of the anatomist. 

 For portrait see Wittrock II, Tan. 138. 



Ehrenberg, Christian Gottfried (1795-1876). German medical man, 

 naturalist and traveler. Author of many elaborate and important 

 works on microscopic organisms, partly in Latin, and many of 

 them magnificently illustrated. Ehrenberg discovered fossil in- 

 fusoria and laid the foundations of our knowledge of this group of 

 animals. Traveled with Humboldt in Asia and with Hemprich 

 in Egypt. Opposed to the theory of spontaneous generation. 

 For portraits see Pop. Sci. Monthly, March, 1879, and Werck- 

 meister, 1901, 5, pi. 481. 



Fabroni, J. Valentin (1752-1822). Italian chemist and engineer. 



Farges, Agnes ( ). Mother of Emile Duclaux. 



"Tous les mendiants de la ville connaissaient le chemin de sa porte." 



(Madame Duclaux.) 



