SKETCH OF JULIUS ADOLPH STOCKHARDT. 263 



course he is approachable, kind, ready for a pleasantry, a laugh, or 

 to impart from the great store of his learning whatever the earnest 

 inquirer may need. In the lecture-room his talk is so simple and 

 familiar that the most abstruse principles seem like every-day facts ; 

 and his illustrations, drawn from the ordinary and homely experi- 

 ences of common life, are so clear, pat, and to the point, that one can 

 neither fail to feel their force nor forget their application. With 

 farmers, be they great landholders or humble peasants, his informa- 

 tion and explanations are always plain, attractive, practical, and suited 

 to the occasion and the men. And everywhere he is the earnest, la- 

 borious, learned, and reverent student, the kindly, faithful instructor, 

 and the worthy man. 



Among the especial services Stockhardt has rendered as teacher 

 and promoter of science is one which, perhaps, is best illustrated in his 

 text-book of chemistry (" Schule der Chemie "), the setting forth of the 

 idea that the right way to teach science is by bringing the student 

 into direct contact with nature, by making him an observer, an inves- 

 tigator, and thus his own best teacher. In the preface to the twelfth 

 edition of this book, he says : 



Experiments must be the foundation of theory. With them the beginner 

 should learn to observe, reflect, and judge ; from them he should himself unfold 

 the general chemical relations and truths; he should himself discover, and in 

 this way by his own efforts, along with manual dexterity, acquire an intellectual 

 possession also. Every experiment and every fact observed therein will thus 

 be to him a conquest, and will incite to new exertion. 



Accordingly the book abounds with simple experiments to be made 

 with apparatus which any student may get and handle, and is yet suf- 

 ficient to illustrate, enforce, and impress the truths that are taught, 

 and, what is better, to enable the learner to find the highest inspira- 

 tion in working out the truths himself. How useful this system of in- 

 struction, as thus set forth by Stockhardt, has proved, may be inferred 

 from the wide circulation of the book as mentioned above, and the 

 facts that sets of apparatus put up to go with it were sent to all parts 

 of Germany, to England, and to Russia, and that a depot for their sale 

 was established in New York. 



Of Stockhardt's greatest work, the promotion of agricultural sci- 

 ence, perhaps the best idea may be got from his " Chemical Field- 

 Sermons," which show his methods of popularizing science, and espe- 

 cially from his journal, " Der chemische Ackersmann," in which both 

 his popular treatises and his scientific investigations have been pub- 

 lished. 



As a discoverer, Stockhardt, though well known, is outranked by 

 other agricultural chemists of his time. Liebig, the father of agricult- 

 ural chemistry, Wolff, Henneberg, Knop, Nobbe, Stohmann, Ktihn, 

 and others in Germany, Boussingault in France, and Lawes and Gil- 



