XXXIV 



and Berzelius at first expressed himself as very doubtful about them/ and 

 after some years got into actual hostility with Liebig about this applica- 

 tion of chemistry, which he called " Probabilitats-Theorien." In his 

 Jahresbericht of 1841, Berzelius said that Liebig's book was executed 

 with all the talent which one would expect of so distinguished an author, 

 but he does not conceal his opinion that Liebig had erected an edifice 

 which was but too insecure. He said that Boussingault was working in 

 the same field as Liebig, but was taking the long and difficult road, 

 answering every inquiry by one or more experiments, that he did not 

 give his answers so quickly, but they might be relied on. 



This partly cautious, partly dissentient, and partly actually hostile 

 attitude of the agriculturists, physiologists, and chemists seemed only to 

 tune to a louder key the enthusiasm and applause of the general public ; 

 but this was probably no satisfaction to Liebig, for of all the applauding 

 crowd who besides his own pupils surrounded him, not one was able to 

 bring Berzelius over to different views, to weaken the experiments of 

 Braconnot, and the objections of Boussingault, or to convince the scep- 

 tical agriculturists and controversial physiologists. 



Then, perhaps for the first time in his life, Liebig may have oft felt 

 right lonely, despite the homage of the masses ; for even his best friends 

 and scholars saw too well that Liebig in this high flight (this book) had 

 often maintained more than he had proved, that the proof was in many 

 points still wanting. 



At no time did Liebig profess to be the first who had made chemical 

 experiments in agriculture. In fact, in the dedication of his book to 

 Alexander von Humboldt, he says, " I hardly know whether even a part 

 of the little work which I make bold to dedicate to you is my own." 



What, then, was it which caused so much excitement ? It was the idea 

 which Liebig brought so prominently forward, that plants alone are 

 capable of assimilating inorganic materials, such as carbonic acid, water, 

 and ammonia, and of building up complex substances such as albumen, 

 starch, and fat, &c. ; while animals live upon these complex products 

 and reduce them to simpler ones. 



Liebig undertook the determination of the ashes in several parts of 

 many varieties of plants and from different localities. He cared little 

 for analyses of soils hitherto considered so important, especially how 

 much humus an earth contained, but he wanted specially to know what 

 each plant did with the earth on which it grew. 



It soon appeared that all plants leave qualitatively the same mineral 

 constituents in their ashes, but that every kind of plant, so to say, yields 

 its own peculiar ash, inasmuch as different kinds, even when growing on 

 the same soil, take up its mineral constituents in very different propor- 

 tions. It was soon found that wheat, rye, barley, &c. have their 

 distinct ashes, also the grains of a corn compared to the corresponding 

 straws. 



