THE INFLUENCE OF CHEMISTRY. 93 



The name, organic substance, had thus far been reserved 

 for the products of vegetal)le and animal life. \V()hler's suc- 

 cessful artificial production of a prominent constituent of 

 animal secretion — urea — in 1828, was still the only noted 

 instance of a decidedly organic substance having been pro- 

 duced without the assistance of the animal organism. Only 

 a limited numl)er of scientists looked upon that discovery as 

 the first practical demonstration of chemical possibilities re- 

 garding the study of vital activity. The production of 

 organic substances in the organism of plants and of animals 

 was ascribed to a peculiar agency called vital force, and it 

 was not less almost universally accepted, that their chemical 

 relations to each other as well as towards inorganic matter 

 in general were widely differing from observations obtained 

 in the study of inorganic matter. 



Liebig dissented at an early date almost instinctively from 

 that view. To him there was but one science of chemistry, 

 equally applicable to organic and inorganic substances. Al- 

 though recognizing at any period of his life the peculiar influ- 

 ence of the living organisms on the production of organic 

 compounds, he did not hesitate to assume that the vital 

 energy in its construction of organic substances would follow 

 the general laws which govern chemical transformations. 



1"he first systematic and concise statement of his advanced 

 views Avas published at the special request of the British As- 

 sociation for the Advancement of Science at their Liverpool 

 meeting in 1837, namely : " To report on the condition of 

 organic chemistry." His reply to this flattering invitation 

 is contained in a publication which appeared in 1840 : 

 " Chemistry in its application to Agriculture and to Physiol- 

 ogy." 'Jhis masterly presentation of the experimental obser- 

 vations of precedmg times as Avell as of his own extensive 

 investigations regarding organic compounds, not less than 

 the bold enunciations of his personal views concerning their 

 bearing on vital ])oints in the life of plants and of animals, 

 created an unusual sensation among scientists and intelligent 

 agriculturists everywhere. The great influence of this publi- 

 cation, and its six revised editions, on the development of a 

 rational agricultural practice, as well as on the science of 

 physiology, is a recognized fact. 



