134 THE SPIRIT OF THE SOIL 



appreciated by the statements that the formula for 

 Urea is 



/H 



o=c; 



\H 



and that the amide is an important constituent of the 

 various alkaloids. 



In reading this chapter the caution must be made 

 against too literal an interpretation of many of the 

 above statements. No one, for instance, imagines 

 that an atom is a rounded body with a number of 

 hooks on it. Recent research, in fact, would suggest 

 rather that it would be found to be comparable with 

 a firmament. To derive any value from these more 

 modern conceptions, however, a chemical training 

 is necessary, and I have thought it better to describe 

 the cruder views that very largely obtained in the 

 recent past, as they are rigidly true in so far as they 

 gave and still give a true expression to the majority 

 of the facts with which the working chemist is called 

 upon to deal. 



