AUTHOR'S PREFACE 



A FARMER does not need to be a chemist ; at the same time 

 he needs the training in accuracy, careful observation, and 

 experimental method which a study of chemistry, properly 

 carried out, imparts, and he needs a knowledge of the ele- 

 mentary principles of chemical change and of the properties 

 of certain chemical substances, both inorganic and organic. 

 The customary four years' course of inorganic and organic 

 chemistry goes far beyond the requirements of an agricultural 

 student, and is usually beyond the time at his disposal. 



The following course is designed to enable an agricultural 

 student to acquire the knowledge and training he needs by 

 a short experimental study of the chemical substances with 

 which agriculture is concerned, his attention being directed 

 at the same time to the practical application of each subject 

 dealt with to rural industry. The course upon which the 

 work is founded has been in use during the past three years 

 in some of the grammar schools and evening continuation 

 schools in the rural districts of Essex, and has also been used 

 in the County Technical Laboratories at Chelmsford by the 

 students of the agricultural classes, and as a preparatory 

 course for elementary school teachers who wish to qualify 

 themselves to teach chemistry in the agricultural parts of 

 the county. 



In rural districts the introduction of the study of experi- 

 mental science is often prevented by the costliness of 

 apparatus and laboratory accommodation. With a view, 

 therefore, to economy, the experiments have been designed 

 for simple and inexpensive apparatus and chemicals. The 



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