PEEFACE 



THIS little book has been written as an experimental 

 introduction to Agricultural Chemistry for beginners, 

 and I have therefore not assumed any knowledge of 

 chemistry on the part of the reader. On the other 

 hand, he will have, in the course of carrying out the 

 experiments described in the text, occasionally to 

 perform operations which he cannot fully understand 

 the meaning of without some little knowledge of 

 chemistry. It would, therefore, be advisable to 

 combine the study of the Chemistry Primer with the 

 study of this book. 



I have been long convinced that science can be 

 taught only in the laboratory or in the field, and 

 that it is of educational value only in so far as it 

 presents a logical course of reasoning based on ex- 

 periment to the young student. Accordingly I have 

 tried, as far as possible, to keep this method of 

 instruction in view, though I have been compelled, 

 especially in the last chapter, to give a good deal 

 of general information for which experimental proof 



