6 PREFACE. 



cured to improve a hard clay soil, the vicinity of saw- 

 mills will often supply a substitute in saw dust, but as 

 some is rather acid, it should be corrected by composting 

 with the aid of lime, or by not using it until it has been 

 exposed some time to the weather. 



A reference to the abstract of the Contents will give 

 the reader a better idea of the scope of this Treatise, 

 than any account which can be given within the limits 

 of a preface. 



