6 PREFACE 



be forced through the long process of laboratory method to re- 

 discover what scientists have fully established. There can be 

 no real substitute for the farm or the garden as a practical 

 laboratory. On this account we have given very few ex- 

 periments to be performed by the students. 



The order of the main topics as given in the text is logical, 

 but it may be varied to suit special conditions. A very ele- 

 mentary agricultural chemistry is given first, because the names 

 of the elements directly concerned in plant life, and somewhat 

 of a familiarity with them, serve as a basis for all agricultural 

 teaching. It also renders possible the use for reference of a 

 larger number of more advanced textbooks and articles by sci- 

 entists than would otherwise be available. Familiarity with the 

 elements and with selected compounds is the purpose rather 

 than adherence to applications that are directly related to agri- 

 culture. If chemical laboratories are accessible for use, some 

 of the experiments given and others to be dictated by the 

 teacher may well be performed by the student, but excellent 

 results for the purpose here intended may be secured if the 

 experiments are performed by the teacher before the class. 



It is not expected that this textbook will meet all the con- 

 ditions in all schools, and it is hoped that in no school will it 

 be pursued as a complete treatise on the general subject of 

 agriculture. Certain parts should be amplified and others 

 eliminated from class consideration according to local demands 

 and the interest and ability of the class. 



If a real interest in the theory and practice of agriculture is 

 stimulated and a basis for the understanding of the literature 

 of the subject is furnished, we feel that the utmost that can 

 be expected from a course in a secondary school has been 

 achieved. 



