40O POPULAR SCIENCE MONTHLY. 



aid of tlie microscope. The difficult task was performed to the 

 entire satisfaction of Nagele, who took occasion to express it in a 

 peculiar manner. As Moleschott was returning for the first time 

 from clinical practice in the lying-in hospital, for which he had 

 paid the required fee to the secretary, Nagele accompanied him, 

 and, as they were going downstairs, stuck the amount of the fee 

 into Moleschott's vest pocket with the remark, " Clericus clericum 

 non decimat (Clergy does not take tithes of clergy)." 



In 1844 the Teyler Society of Harlem offered a prize for the 

 best dissertation on Liebig's theory of the nutrition of plants, 

 which formed the basis of his application of chemistry to agricul- 

 ture, and which at that time excited as lively discussion in the 

 scientific world as did Darwin's theory of the origin and evolu- 

 tion of species fifteen years later. Moleschott took a deep interest 

 in the subject and was urged by Delffs to compete for the prize, 

 which was also awarded to him. His dissertation contained a thor- 

 ough examination and keen analysis of Liebig's views, and pointed 

 out some instances of hasty generalizations and unwarranted con- 

 clusions. Moleschott exposed these logical fallacies and showed 

 how largely they entered into the reasoning and vitiated the de- 

 ductions of the distinguished chemist. The copy of the prize 

 essay sent to Liebig was accompanied by a note in which Mole- 

 schott, while venturing to criticise his views, expressed the warm- 

 est admiration and enthusiasm for his personal character and 

 scientific achievement. Liebig replied, thanking him for the es- 

 say, and added : " So far from being offended by opposition, I de- 

 sire it, since it serves to separate the grain from the chaff" ; and I 

 have all the more reason to be satisfied when this is done, as in 

 your case, in a clever and gentlemanly manner.'' 



On January 22, 1845, Moleschott passed his examination, and 

 was promoted to the degree of Doctor of Medicine, receiving the 

 first rank. But in order to practice his profession in Holland it 

 was necessary to have a certificate of proficiency also from a 

 Dutch university. For this purpose he went to Leyden, where 

 he passed the so-called colloquium doctum, which consisted in a 

 pleasant conversation with professors of the medical faculty — 

 Broers, Pruys van der Hoeven, and Suringar — on the endemic 

 diseases of Holland. He then established himself in Utrecht. 



In connection with Donders and a Jewish physician. Van Deen 

 (afterward professor in the University of Groningen), Moleschott 

 founded a scientific journal for the publication of the latest re- 

 searches made by Hollanders in anatomy and physiology, to which 

 Mulder, Harting, Jansen, Van den Broek, Kees Verloren, Eduard 

 von Baumhauer, and others sent valuable contributions. Notwith- 

 standing the congeniality of many of his associations and his inter- 

 est in these investigations, he was not contented with his life and 



