The development of 

 ogriculturol chemistry 



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When we attempt to study the factors that have played important 

 roles in the development of scientific agriculture, we find that chemis- 

 try has occupied a most prominent place. The part that chemistry 

 has played in this development has been of such far-reaching impor- 

 tance that a special branch of this science, known as agricultural 

 chemistry, has been a natural outgrowth. It is to this particular phase 

 of chemistry that we wish to direct the reader's attention, for agricul- 

 tural chemistry, probably more than any other single factor, has been 

 responsible for the development of the quantitative aspects of modern 

 agricultural practice and for the elimination of the old "rule-of- 

 thumb" methods which had been followed for centuries. 



BEGINNINGS OF AGRICULTURAL SCIENCE 



Nearly all the early workers who were interested in solving nature's 

 secrets as they relate to agriculture were trying to discover "the prin- 

 ciple of vegetation." They were seeking to answer the question, "Why 

 and by what method do plants grow and develop?" One of the first 

 theories which aimed to explain the secret of plant growth was that 

 advanced by a Belgian physician and alchemist by the name of van 

 Helmont. Working in the latter part of the sixteenth and the early 

 part of the seventeenth centuries, he was among the first to introduce 

 the use of the balance and to interpret data from the quantitative 



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