vi PREFACE 



the teacher of Agricultural Chemistry should insist on 

 his students using quantitative work largely as a 

 means of interpreting principles or expressing ideas, 

 and not regarding it as an end in itself. It must be 

 borne in mind that those taking such a course of study 

 are primarily agriculturists and not chemists. 



Nevertheless, with students of a higher standard, 

 and with those intending to specialise, quantitative 

 Agricultural Chemistry has its place, and the methods 

 given in this book have consequently been carefully 

 chosen, and may be relied upon, as standard or 

 approved processes. 



Throughout the book a fair knowledge is assumed 

 on the part of the student of the commoner qualitative 

 and quantitative processes of general chemistry, while 

 in cases of estimations which are not generally included 

 in a course of pure chemistry, such as, for example, 

 the determination of the Iodine Value, Reichert-Meissl 

 number, etc., full practical directions are given. It may 

 be also mentioned that all the experiments described 

 in the text have been personally worked through by 

 one or both of the authors. 



The authors are indebted to the standard text-books 

 on the different subjects included under the head of 

 Agricultural Chemistry, especially Hall's Soil, Hall and 

 Russell's Practical Exercises in Agricultural Chemistry^ 

 and Droop Richmond's Dairy Chemistry ; they also 

 wish to thank Mrs Auld and Mr L. S. Charleton for 

 the line drawings given throughout the book, Mr 

 H. Wormald, B.Sc, for the photomicrographs of starch 

 granules, Messrs R. H. Carter and J. Amos for the 



