40 NUTRITION DEPENDS ON THE 



ceeded in converting fibrine into albumen, that is, in 

 giving it the solubility, and coagulability by heat, which 

 characterize the white of egg.* 



* This remarkable experiment was first performed by M. Prosper 

 Denis; but as it confirms, in an unexpected and very interesting 

 manner, the conclusion drawn by Professor Liebig from the researches 

 of Mulder, and from those jnade at Giessen : namely, the identity of 

 the organic part of vegetable fibrine, albumen, and caseine with that 

 of animal fibrine, albumen, and caseine; and as M. Dumas has 

 made a claim to this discovery, as being previously well known to 

 the French chemists, it appears advisable to mention a few circum- 

 stances connected with the history of these researches. 



The opinions of Liebig on this subject were not only detailed in 

 his lectures in the winter session of 1840-41, but communicated to 

 Mailer, Wagner, and Tiedemann, and also among others to M. Ma- 

 rignac of Geneva, a friend of M. Dumas, who shortly after returned 

 from Giessen to Paris, viz., in February, 1841. 



In the mean time, M. Denis, having made his curious researches, 

 found, that they were not received as they ought to have been by 

 the Parisian chemists. On the contrary, he was laughed at for his 

 facts! He then applied to Liebig, who, at once, caused his experi- 

 ments to be repeated, and confirmed his conclusions. To those who 

 know the care with which every new observation is protected in 

 Paris, there can be no stronger proof that no other French chemist 

 had any idea of the truth as it now appears, otherwise it would have 

 been announced and the date taken. 



In a work published by Dumas and Boussingault, on the composi- 

 tion of the air, in the spring of 1841, the ideas in regard to the cause 

 of the uniform amount of oxygen in the atmosphere, are those pre- 

 viously published in Liebig's Organic Chemistry applied to Agricul- 

 ture, published in 1840. 



Further, M. Dumas, in a lecture published by him in the end of 

 August, 1841, consequently long after the views of Liebig were 

 known in Paris, put forth views, coinciding with those of Liebig in 

 regard to the nutrition of animals, and the composition of the azotized 

 vegetable nutritious compounds, without the slightest acknowledg- 

 ment. 



The researches which led to these views were not Parisian ; for 

 M. Dumas had never made researches on vegetable fibrine, albumen, 

 and caseine ; while the researches of Boussingault led to the conclu- 

 sion, that these substances differed in composition from the constitu- 

 ents of blood. Now, during the two preceding years, Mulder had 



