VI PREFACE. 



perhaps in whicli the present aspects of the science 

 are at all adequately represented. 



The present little book is primarily intended to 

 supply a demand, which we believe is gradually 

 arising, for the teaching of agricultural science in 

 our schools ; it is intended as a small text-book 

 for the use of teachers, expressing briefly, and we 

 hope clearly, the principal facts which form the 

 basis of agricultiu'al chemistry. Though intended 

 thus in a special manner for teachers, we hope it 

 may prove useful to all who may wish to become 

 students of the subject. When used by a teacher 

 the matter should be taken a little at a time, and 

 enlarged upon in the course of the lesson. Parti- 

 cular opportimity for enlargement is furnished by 

 the tables contained in the book ; the facts they 

 represent, being self-evident on a consideration of 

 the figures, are often very slightly alluded to in 

 the text, but are left to the observation and study 

 of the reader. 



It is assumed that those who use this book will 

 have a general acquaintance with the facts of ele- 

 mentary chemistry ; a knowledge of these must 



